Sclerophylly and Plant Water Relations in Three Mediterranean Quercus Species - Salleo, S; GULLO, M A L O (Annals of Botany, 1990)
The possible role in drought resistance played by sclerophylly was studied in the Mediterranean oaks Quercus ilex, Q. suber and Q. pubescens. Studies were conducted on leaves at 30, 50 and 80% of their final surface area, as well as on mature leaves of the current year's growth in June and September and on 1-year-old leaves.Leaves of different ages of the three species showed quite different degrees of sclerophylly (DS). Q. ilex leaves reached the definitive DS of 1.75 g dm−2 during leaf expansion; Q. pubescens leaves hardened at the end of their expansion, with a final DS of 0.93 g dm−2; Q. suber showed the lowest DS of 0.76 g dm−2.Leaf conductance to water vapour (g1) of 1-year-old leaves of Q. ilex, measured in the field, showed a duration of the g1 peak values about twice that of the other two species. The minimum leaf relative water content (RWC), however, was near the same in the three species, indicating that water loss was recovered partly by Q. ilex leaves. This was apparently due to the higher bulk modulus of elasticity (max) as resulting from leaf water potential isotherms.High correlation coefficients were noted between DS and max but large changes in DS were needed to display minor changes in max. When both DS and max were correlated to the minimum RWC, an increase in DS of 133 % (corresponding to an increase in max of only 12 %) was needed to cause an increase in RWC of 2%. Therefore, sclerophylly cannot be considered as significantly related to a drought-avoiding strategy.
Keywords: Drought resistance; leaf conductance; Quercus ilex; Quercus pubescens (PG); Quercus suber L.; Relative water content; sclerophylly

Stomatal and non stomatal limitation of photosynthesis by leaf water deficits in three oak species: a comparison of gas exchange and chlorophyll a fluorescence data - Epron, D; Dreyer, E (Ann. For. Sci., 1990)
Net CO2 assimilation (A), stomatal conductance for CO2 (g), intercellular mole fraction of CO2 (Ci), kinetics of chlorophyll a fluorescence, and their half decay time (t1/2), their ratio of fluorescence decrease (Rfd), and their adaptive index (Ap) have been monitored on potted trees from 3 oak species (Quercus petraea, Q pubescens and Q ilex) grown in a climate chamber and submitted to drought. Use of A vs Ci representations for photosynthesis data revealed an apparent impairment of mesophyll photosynthesis, together with reduced CO2 supply to mesophyll due to stomatal closure. But in all species chlorophyll a fluorescence kinetics displayed very similar shapes, constant t1/2 and stable Rfd and Ap values until predawn leaf water potential dropped below -4.0 MPa. These observations led to the conclusion that photochemical energy conversion and photosynthetic carbon reduction cycle could be very resistant to leaf water deficits, and that observed decreases in mesophyll photosynthesis had to be attributed to a possible artefact in Ci calculation. On the other hand, the susceptibility of leaves to photoinhibition increased as a consequence of water shortage, especially in Q petraea and Q pubescens. Differences in drought adaptation between the studied species could probably be related to susceptibility to photoinhibition rather than to a direct sensitivity of photosynthesis to leaf water deficits, at least in the range of stress intensities of ecophysiological significance.
Keywords: Chlorophyll a fluorescence; Drought; oak; photoinhibition; photosynthesis; Stomatal conductance; water stress

Synthesis of mycorrhizas on Quercus suber using Hebeloma sinapizans and Paxillus involutus - Branzanti, Barbara; Zambonelli, Alessandra (Agriculture, Ecosystems & Environment, 1990)
Hebeloma sinapizans and Paxillus involutus formed ectomycorrhizae with cork oak (Quercus subedotr) in axenic conditions and glasshouse trials. Inoculation with H. sinapizans, but not P. involutus, prevented the contamination of seedlings by Sphaerosporella brunnea. Whereas H. sinapizans formed mycorrhizas with a majority of feeder roots, P. involutus formed mycorrhizas with a minority.
Keywords: contamination prevention (PG); ectomycorrhiza; Quercus suber

THE TIMING OF BREEDING AND CLUTCH SIZE OF BLUE TITS (PARUS-CAERULEUS) IN AN EVERGREEN HOLM OAK HABITAT IN SOUTHERN SPAIN - ISENMANN, P; ALES, E; MORENO, O (REVUE D ECOLOGIE-LA TERRE ET LA VIE, 1990)
APS
Keywords: blur tits; clutch size; Holm oak; Parus cearuleus; Spain

Use of pressure volume curves in water relation analysis on woody shoots: influence of rehydration and comparison of four European oak species - Dreyer, E; Bousquet, F; Ducrey, M (Ann. For. Sci., 1990)
Pressure volume analyses were undertaken on leafy shoots of 4 European oak species (Quercus robur, Q petraea, Q pubescens and Q ilex) in order to determine the relationship between leaf water potential, average osmotic potential and volume averaged turgor. Some technical limitations of pressure volume analysis, as shown by the influence of the resaturation method on computed turgor, were overcome by accounting for losses of intercellular water during the first stages of dehydration. Variations in leaf to stem ratio, which are very important between large leaved oaks and small leaved evergreens, surprisingly did not influence the relative symplasmic volume of our samples. Differences in mean osmotic potential at full turgor (&Pi0) were related to species, with higher values in drought adapted species, and to leaf age and growing conditions. Values of volumetric modulus of elasticity (ε o) did not significantly influence the relations between leaf water potential (Ψw) and turgor (P) in different species. This relationship was mostly related to &Pi0. Finally, tolerance to drought appeared to be related more to the ability to osmotically adjust in response to changes in environment rather than to the absolute values of &Pi0.
Keywords: pressure-volume curve; Quercus sp; turgor; water potential; water relations

Use of pressure volume curves in water relation analysis on woody shoots: influence of rehydration and comparison of four European oak species - Dreyer, E.; Bousquet, F.; Ducrey, M. (Ann. For. Sci., 1990)
Pressure volume analyses were undertaken on leafy shoots of 4 European oak species (Quercus robur, Q petraea, Q pubescens and Q ilex) in order to determine the relationship between leaf water potential, average osmotic potential and volume averaged turgor. Some technical limitations of pressure volume analysis, as shown by the influence of the resaturation method on computed turgor, were overcome by accounting for losses of intercellular water during the first stages of dehydration. Variations in leaf to stem ratio, which are very important between large leaved oaks and small leaved evergreens, surprisingly did not influence the relative symplasmic volume of our samples. Differences in mean osmotic potential at full turgor (&Pi0) were related to species, with higher values in drought adapted species, and to leaf age and growing conditions. Values of volumetric modulus of elasticity (ε o) did not significantly influence the relations between leaf water potential (Ψw) and turgor (P) in different species. This relationship was mostly related to &Pi0. Finally, tolerance to drought appeared to be related more to the ability to osmotically adjust in response to changes in environment rather than to the absolute values of &Pi0.
Keywords: pressure-volume curve; Quercus sp; turgor; water potential; water relations

Water balance of Eucalyptus globulus and Quercus suber forest stands in south Portugal - PEREIRA DE ALMEIDA, A; RIEKERK, H (Forest ecology and management, 1990)
The study utilized two watersheds near the town of Odemira in Alentejo, a southern province of Portugal. The region has a relatively humid climate because of its proximity to the sea. One 6-ha watershed contained scattered native cork oak (Quercus suber) with a newly developing understory of shrubs. An adjacent 19-ha watershed contained a mature Eucalyptus globulus stand, which was harvested for the study. The study included measurements of precipitation, runoff and soil water storage. Measurements of the tree stands and canopies were included for the characterization of throughfall and stemflow
Keywords: Angiospermae; Anthropogenic factor; Arbol forestal frondoso; Arbre forestier feuillu; Artificial forest stand; Balance agua; Bilan eau; Bosque; Dicotyledones; Eucalyptus globulus; Europa; EUROPE; Facteur anthropique; Factor antrópico; Fagaceae; Forests; forêt; Hardwood forest tree; Mediterranean vegetation; Myrtaceae; Peuplement forestier artificiel; Poblamiento forestal artificial; Portugal; Quercus suber; Spermatophyta; Vegetación mediterránea; Végétation méditerranéenne; Water balance (citation)

Water Relations of Evergreen Sclerophylls. I. Seasonal Changes in the Water Relations of Eleven Species from the Same Environment - RHIZOPOULOU, S; MITRAKOS, K (Annals of Botany, 1990)
Leaf water relationships were studied in eleven evergreen sclerophyll species from a macchia near Athens, Greece. Water (ψ), solute (ψs) and turgor (ψp) potentials as well as relative water content (RWC) and stomatal conductance were measured during the course of a year. Relatively high values of water potential were measured initially in the young expanding leaves during the 60–90 d of the growth period. After this period a soil moisture deficit developed and leaves increased to full size. During the drought period leaf water potential and solute potential values, as well as stomatal conductance were low. The results show that during the dry season (Jun.–Aug.) all species are at or near zero turgor and this occurs in Arbutus, Myrtus and Nerium at around −1.5 MPa, in Ceratonia, Pistacia and Quercus at around −2.0 MPa, in Laurus, Olea and Phillyrea below −3·5 MPa. These values largely reflect differences in ψs at this time. Also, the seasonal variations in the water relations components reflect the responses of the different species to variation in water availability.
Keywords: Arbutus andrachne L.; Arbutus unedo L.; Ceratonia siliqua L.; Laurus nobilis L.; Mediterranean Region; Myrtus communis L.; Nerium oleander L.; Olea europaea L.; Phillyrea Iatifolia L.; Pistacia lentiscus L.; Quercus coccifera L.; Quercus ilex L.; Stomatal conductance; water relations

Wood anatomy of some trees with diffuse- and ring-porous wood: Some functional and ecological interpretations - LO GULLO, M A; Salleo, S (Giornale botanico italiano, 1990)
Abstract The xylem conduit dimensions (i.e. their width and length) have been measured in 1-year-old internodes, nodes and node-to-petiole (N-P) junctions of three species with diffuse-porous wood, namely Ceratonia siliqua L., Laurus nobilis L. and Olea europaea L. as well as of three species with ring-porous wood, namely Quercus ilex L., Q. suber L. and Q. pubescens Willd? The xylem conduit diameter and length distributions have been related to the drought resistance strategies adopted by the six species. C. siliqua and Q. ilex (drought avoiding water spenders) showed the widest xylem conduits (each species within its characteristic pattern of wood anatomy). This is consistent with their high demand of efficient water transport to leaves. L. nobilis (drought avoiding water saver) showed relatively narrow xylem conduits, efficient enough, however, to assure water supply to leaves at the reduced transpiration rate exhibited by the species. O. europaea, Q. suber and Q. pubescens (drought tolerants) showed the narrowest xylem conduits but also the longest ones. The xylem system of C. siliqua and Q. ilex represented a good compromise between efficiency and safety of the water transport, the former as due to wide xylem conduits, the latter to the reduced xylem conduit length as well as to the strong «hydraulic constrictions» at their nodes and N-P junctions. The ecological interpretation of such hydraulic architecture is discussed.
doi: 10.1080/11263509009430260

Wood cell morphology characteristics of some oak species and mediterranean shrubs - Voulgaridis, E (European Journal of Wood and Wood Products, 1990)
Some characteristics of wood cell morphology of three oak species (Quercus conferta, Q. flex, Q, coccifera) and five Mediterranean shrubs (Arbutus andrachne, A. unedo, Erica arborea. Phillyrea me- dia, Pistacia lerebinthus) were investigated at height 30 cm above ground. The mean fiber length of oak species ranged between 1.10 and 1.35 mm and that of Mediterranean shrubs between 0.56 and 0.82 ram. The mean wtlues of vessel dimensions ranged as follows: 0.22q).31 mm (vessel length) and 0.080-0.087 mm (vessel diameter) for oaks and 0.19-0.40 mm (vessel length) and 0.033-0.043 mm (ves- sel diameter) for Mediterranean shrubs. The pith to bark variation of fiber length appeared to follow the general patterns of length var- iation but differences were observed between the species tested with regard to the rate of fiber length increase and to the number of years necessary to reach a typical length. The horizontal variation of vessel length and diameter was not consistent between the species: from pith to bark, vessel length and diameter increased in a few species and decreased or remained more or less unchanged in the others. For each species, a similar horizontal variation pattern of fiber length and, to a lesser extent, of vessel length was observed between the trees. The greatest pith to bark variation of three-ring mean values relative to the first three growth rings occurred in Quercus conferta for fiber and vessel length and in Quercus coccifera and Q. ilex for vessel diameter.
Keywords: fiber length; Mediterranean shrubs; Pith to bark variation; Quercus (voyant); vessel length

ASPECTS OF CROWN RECONSTRUCTION AND LEAF MORPHOLOGY IN QUERCUS-ILEX L AND QUERCUS-SUBER L AFTER DEFOLIATION BY LYMANTRIA-DISPAR L - PICOLO, R; Terradas, J (ACTA OECOLOGICA-OECOLOGIA PLANTARUM, 1989)
The effect of a complete defoliation of the evergreen Quercus ilex L. ssp ilex and Quercus suber L. by Lymantria dispar on some variables of sprout development and leaf morphology was studied. Samples were collected at different locations within the crown and along the branches. The effects of species defoliation and location factors on the variables have been tested using multivariate and univariate analysis of variance have been applied. All factors show significant effects on the variables considered jointly, and the responses to defoliation differ between species and between lower and upper crown parts. Differences are discussed and this gives useful information to the understanding of crown reconstruction patterns in both species.
APS
Keywords: defoliation; herbivory; leaf damage; Quercus ilex; Quercus suber

Colonisation d'un nouvel habitat par Culex pipiens (Diptera, Culicidae) : le creux d'arbre des subéraies en pays Zaer, Maroc - Metge, G; Belakoul, N (Annales de Limnologie - International Journal of Limnology, 1989)
The dry conditions which occurred in Morocco from 1981 to 1983 have resulted in the selection of a new habitat by Culex pipiens, which is a very adaptable species, in hollows of trees. Morphological descriptions of the fourth larval instar, the pupae and the male and female adults have shown that these populations living in iree holes (phytotelmata) belong to the form C. pipiens autogenicus.
Keywords: Culex pipiens; Culicidae; Diptera; ecology; habitat; Morocco; taxonomy

Conditions d'apparition d'une embryogénèse somatique sur des cals issus de la culture de tissus foliaires du chêne vert (Quercus ilex) - Féraud-Keller, C.; ESPAGNAC, H. (Canadian Journal of Botany, 1989)
The proliferation of parenchymatous foliar tissue of Quercus ilex was obtained from current year leaves taken from old trees and cultivated in vitro on modified Murashige and Skoog's medium supplemented with benzylaminopurine (4 mg ∙ L−1) and naphthyl acetic acid (0.5 mg ∙ L−1). Only the fragments cultured in October reacted. The neoformations only appeared on calluses that had not been subcultured for 7 months. Primary nodules arising on these calluses were removed and subcultured on the same medium either in the dark or in the light. In the dark only, they produced secondary nodules, which were the source of somatic embryos both in light and dark. Presently, they seem to regulate their structure in the dark but they do not develop in a way that leads to germination.
doi: 10.1139/b89-139doi: 10.1139/b89-139The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: Callus; Quercus ilex; tissue culture

CONTRIBUCIÓN DE PRATENSES ANUALES EN LA EXPLOTACIÓN DE PASTOS NATURALES DE LA DEHESA EXTREMEÑA - Granda Losada, M; Prieto Macias, P M (II Reunión Ibérica de Pastos y Forrajes Badajoz, 1989)
Mediterranean semiarid pastures show a better maintenance capacity due to several management practices (stocking rate, fertilization). The dominance of some annual pasture species produce food for drought periods.
Keywords: management; phosphorus fertilization; Stocking rate

COSTE DE PRODUCCIÓN DEL TERNERO DESTETADO CHAROLÁIS x RETINTA EN UN SISTEMA DE EXPLOTACIÓN CON PARIDERA CONTINUA EN LA DEHESA - Daza, Argimiro; Ovejero, Ismael; Blanco, Pedro J; Callejo, Antonio; Buxade, Carlos (II Reunión Ibérica de Pastos y Forrajes Badajoz, 1989)
According to technics results obtained during three consecu tive years in an extensive cattle farm with 79 Retinta cows, which is sited in the province of Cáceres (Spain), the cost of feed suplementation of the standard cow depending of the month of parturition and the net yield per calf produced depending of the month of birth, have been calculated and compared by means of index. Calculations were made either in an own farm or in a rent one. The best economic results are obtained with parturitions in Octo ber, November, December and January. That is why we recommend to concéntrate the parturitions in autumn and beginning'of winter, in extensive cattle farms in Spanish dehesa (pasture). Key words: extensive cattle, pasture, continual parturition, economic efficiency
Keywords: Dehesa; paridera continua; rendimiento económico; Vacuno extensivo

Cultivo in vitro del alcornoque - TORIBIO, M; CELESTINO, C (Scientia gerundensis, 1989)
Vegetative plant propagation is mainly used in the operational line of Forest Tree Improvement Programs to capture all the genetic potential, including the non-additive component of the genetic variance. In the case of genus Quercus, it could be also used to avoid the problems derived from installation and yielding of seed orchards. The tissue culture based micropropagation arises as an alternative technique to solve the problems of space and time associated with the classical techniques of asexual propagation. This article reviews the work done with cork-oak in this field. Up to date there are few papers dealing with in vitro culture of Quercus suher L. Embryo culture has been tryed to determine the minimum requeriments of the species and its morphogenic potential. Plantlet regeneration has been obtained following axillary budding on nodal segments from juvenile and rejuvenated tissues, elongation and rooting of microcuttings. Main problems arise on transplanting soil the neoformed plants. Callus culture has been achieved from cotyledons and epicotyl segments from young seedlings. In booth cases also somatic embryogenesis has been reported. This fact opens a new way for micropropagating cork-oak, which is discussed.
Keywords: cork-oak; micropropagation; plant regeneration; Quercus suber L.; Somatic embryogenesis; tissue culture

Dieback of cork oak (Quercus suber) in Catalonia (NE Spain) caused by Botryosphaeria stevensii - LUQUE, J; Girbal, J (European Journal of Forest Pathology, 1989)
Botryosphaeria stevensii Shoemaker (anamorph: Diplodia mutila Fr. apud Mont.) is reported as the cause of canker and dieback of cork oak (Quercus suber L.) in Catalonia (NE Spain). It also causes wilting of trees after cork is removed for industrial purposes. Symptomatology and details of morphology for both anamorph and teleomorph are given.
Keywords: Botryosphaeria stevensii; canker; Cork oak; dieback; diplodia mutila; morphology (PG); Symptoms

Dispersion active et passive de Lymantria dispar (L.) (Lép., Lymantriidae), cas de la subéraie marocaine atlantique - Fraval, A; Yousfi, M El (Journal of Applied Entomology, 1989)
Abstract Active und passive dispersal of Lymantria dispar (L.) (Lep., Lymantriidae) in cork-oak stands in MoroccoGypsy moth, Lymantria dispar, a serious insect pest of cork-oak in Morocco, exhibits several dispersal modes. Sessile forms, especially eggs, are transported by man; neonate larva may be dropped by wind; older caterpillars move by crowling, in search of better food- or resting places; the male butterflies fly in search of a female; female imago is unable to fly.Authors review the modalities and conditions of these dispersal movements, by examining their possible effects on population dynamics. Attempts to control the insect by perturbating its movements were not successful. Many important questions concerning dispersal behaviour of the Gypsy moth remain to be answered. Résumé Des types divers de dispersion s'observent chez Lymantria dispar, ravageur du Chêne-liège. Les formes immobiles, les oeufs notamment, sont transportés par l'Homme; les chenilles nouveau-nées peuvent se laisser emorter par le vent; les chenilles plus âgées se déplacent surtout en rampant, à la recherche de meilleures conditions: les papillons mâles volent en quête d'une femelle; cette dernière est incapable de voler.Les auteurs passent en revue les modalités et les conditions de ces divers déplacements, en examinant leurs conséquences possibles sur le devenir des populations. Les tentatives faites pour lutter contre le ravageur en perturbant certains de ses déplacements n'ont pas été couronnées de succès. De graves lacunes subsistent dans notre connaissance de ces aspects de la bioécologie du ravageur. Zusammenfassung Über die aktive und passive Verbreitung des Schwammspinners Lymantria dispar (L.) (Lep., Lymantriidae) in den Korkeichenwäldern des atlantischen MarokkoDie Verbreitung des Korkeneichenschädlings Lymantria dispar erfolgt auf verschiedene Weise. Immobile Stadien, vor allem die Eier, werden von Menschen verschleppt. Junglarven lassen sich vom Wind transportieren, ältere Raupen verbreiten sich kriechend selbst. Männliche Falter fliegen auf der Suche nach Weibchen, während letztere nicht flugfähig sind.Die Autoren beschreiben die verschiedenen Modalitäten und Bedeutungen der Verbreitung und die möglichen Konsequenzen daraus für die Bildung einer Population. Versuche, durch Störung der Entwicklung eine Bekämpfung zu erreichen, schlugen bisher fehl. Große Lücken bestehen in unserer Kenntnis dieses Aspektes der Bioökologie des Schädlings.
Keywords: Cork Oak Forest; dispersal behaviour; Lymantria dispar; Population Dynamics (PG)

Ecología y potencialidades del subtrebol - Montserrat Recoder, P (II Reunión Ibérica de Pastos y Forrajes Badajoz, 1989)
Opportuníties for pasture improvement are important and will be decisives en the next future. Money coming from foreign aids should be destructive if arríving directly to farmers; it will be essentíal to improve the husbandry and grassland productivity, mainly by the best subclover strains and making also a good use of the local ones. The productivity coming from plant to animáis and farmers, will improve the country life and the culturalised science
Keywords: "dehesas"; cultural shepherding; harmonious development; research; training; Trifolium subterraneum

Efectos en el rendimiento de la produccion de corcho al modificar el calibre de las planchas taponables - González Fernández, T; Al, D E Corcho; El, Modificar; Fernández, T González (Scientia gerundensis, 1989)
The main purpose of this paper is to analise the posible effects of a diminution on the caliber of the bottle-cork on the economic profitability of the Extremadura cork-oak forest. A reduction from 22 mm to 17 mm in the wine-bottle neck will supose an increment of 27% in the raw production of bottle-cork.
Keywords: Cork; Cork Production; cork-oak; wine bottle neck

Effects of acid fog and detergents on foliar leaching of cations - Paoletti, E; GELLINI, R; Barbolani, E (Water, Air, & Soil Pollution, 1989)
Relative rates of nutrient leaching from the epygeous apparatus of Quercus ilex L., Fagus sylvatica L., Acer opalus Mill., Euonymus japonicus L. and Phaseolus vulgaris L. were examined after exposure to simulated acid fog. Copper, A1, Fe, Mn, Ca, Mg, and Pb were preferentially leached at low pH, whereas leaching rates of Na, K, and Cd did not appear to be pH-influenced. Addition of surfactant to the spray solutions showed a slight reduction of leaching for all elements investigated. Except for Mg, foliar nutrient levels were not influenced during our experiments.
Keywords: acid deposition; detergent (voyant); nutrient leaching

EL RAY-GRASS ITALIANO DE SECANO EN LA DEHESA EXTREMEÑA - Molina Perez, M R; Cabeza De Vaca Munilla, Francisco (II Reunión Ibérica de Pastos y Forrajes Badajoz, 1989)
Rain fed Italian Ray-Grass considerably increases stocking rate. It permits ten times the stocking rate of non-fertilized pasture and five times that of fertilized pastures. It is a crop equally suitable for grazingsheep or cattle. The cost per feed unit can be estimated in 8 Pts (1.987). Stocking rate is 22,62 mediterranean sheep units. It is a very interesting crop as it improves productivity- of extremeñan "dehesa" with low man-power needs
Keywords: lolium multiflorum; ray-grass italiano

Elemental leaching from Quercus ilex L. in response to simulated acidic fog - Paoletti, E; Udisti, R; Pantani, F; Barbolani, E (Water, Air, & Soil Pollution, 1989)
Quercus ilex L. seedlings were intermittently exposed to simulated acidic and non-acidic fogs in 6-hr events for 16 times. After a 1-mo break, treatments were carried out again for a 5 day period. Strong acidity neutralization, weak acidity release and cation leaching from foliage and stem were determined. Leaching of AI, Cu, Mn, Fe, Cd, Pb, Ca, Mg, and K increased in response to acid treatment. This effect was less marked for Na. A positive correlation between H ÷ uptake and cation leaching was found. Cationic release and neutralization of strong acidity increased after breaks in acid treatment, but this faculty and the a m o u n t of leached cations and neutralized acidity decreased with time. The stem showed a higher cation loss and higher buffer capacity than the leaves.
Keywords: acidity; Cations (voyant); foliar leaching

Estudio preliminar del crecimiento del alcornoque en la fase juvenil. - Oliva, M; Molinas, A Caritat M; Caritat, A; Molinas, M (SCIENTIA gerundensis, 1989)
Shoot elongation has been measured in two different groups of juvenil cork-oaks (Quercus suber) by means of their budding segments. One group has got 14 seedlings three years old, proceeding from a forest nursery. The other group consistes in 17 sprouts of three and one years old from a bumed cork-oak forest. Buddings segments of the three- years old seedlings show an average elongation of 4,l cm. Sprouts are more vigorous; the three years old ones have an average value of segment elongation of 6,05 cm, and the one year old ones an average value of 15,3 cm. A decrease in elongation appears along the succesive buddings
Keywords: buds; cork-oak; Quercus suber; shoot elongation; sprouts

Estudio silvopastoral de la dehesa boyal de Alia (Caceres) - Bravo Oviedo, F. (Ecologia, 1989)
Se analizan los diferentes factores que intervienem en el agroecosistema dehesa. Se hace una crítica concreta del índice de productividad animal empleado en la Ley de la Dehesa en Extremadura
Keywords: arbolado; Dehesa; ganado (voyant); pasto

Etude de la productivité des parcours de la zone d'Ain-Leuh (Moyen Atlas, plateau central). I. Effets de la fréquence d'exploitation et du taux de couvert arboré sur la productivité herbacée - Qarro, M; de Montard, F X (Agronomie, 1989)
Rough pastures in Middle Atlas spread over four bioclimatic levels: 1, Quercus ilex and Juniperus oxycedrus forest; 2, pure Quercus ilex forest; 3, Cedrus atlantica and Quercus ilex forest; 4, unsylvatic low grass, from 900 to 2 200 m above sea level. Dry matter production of grass was measured from and underneath the tree canopy in 1983 and 1984 in order to compare the effect of a variety of intervals between cuts and to measure shadow influence. Grass growth mainly occured from late January to early July; it began later at Cedrus-Quercus and low grass sites and stopped earlier at pure Quercus and Quercus-Juniperus sites, depending on longer frost persistence at highest levels, on earlier arrival of drought at lowest levels. Mean dry matter production was 2.5 kg h 1a d-! on light 30 cm deep soils at Quercus-Juniperus level and dolomitic soils at Cedrus-Quercus level. It was 5.5 kg ha-! d i- on colluvial soils at pure Quercus level and basaltic soil at lowgrass level Water balance and legume species abundance explained a great part of D.M. variance. Four cuts per year were more productive than three or five. Missing the earliest cuts resulted in much lower D.M. yields: a half with two cuts; three of five with an only cut per year. Shadow poorly reduced the yield up to a forest canopy cover of about 60%: from 35 to 65% cover, the canopy resulted in 30% fall in seasonal yield as water supply was not limiting, but had no effect as relative water deficit occurred. A pasture and forestry mixed system, aiming a canopy of 60 to 70% cover, would result in better conditions for cattle breeding and timber as a whole.
Keywords: clipping; dry matter; rythm; silvopastoral; water deficit

Evolution of the tree cover (Quercuspyrenaica Willd and Quercus ilex subspecies ballota (Desf. Samp)) in a dehesa over the last 100 years - Pérez-Fernández, M A; Gómez-Gutidrrez, J M (ressources.ciheam.org, 1989)
1. During the first 60 years, the decrease in the numbers of both the holm oak and the oak was due to tree felling. The first 6 years were devoted to tree felling and cut clearing in order to clear dense forest with a view to transforming it into pasture and farmland; during the next 54 years the cut trees were used as a source of heat for the home and of wood for construction and the making of farming tools and diverse utensils. 2. Tree felling has gradually declined over the last 40 years (ít has almost disappeared) as the use of wood has been replaced by gas and gas-oil for fuel and iron and cement for construction. However, the mortality rate has increased. The deaths are mainly the result of the effects of the xylophagous insects (its effects are not usually lethal to trees under 100 yrs. old) ando ther as yet undetermined causes, perhapso f drought. 3. In stands 2 and 3 (N orientation) agriculture benefitted the old oak, which deveioped on the fringes and rocky outcrops and immediately invaded the territory as soon as the cultivation of cereals was stopped. A similar phenomenon occurs int he SW orientation witht he holm oak. 4. Autochthonous livestock (mainly cattle) on an extensive free range basis impedes the recovery of oak density, eliminating almost all oft he youngest ones in the underbrush and shrub phases, whent heir diameter in the first meter of height is less than 9 cm. It does not eliminate the holm oaks, but greatly retards their growth. When young holm oaks are taller than Zm, they can aiso be broken by domestic livestock if they do not reach a diameter of 6 cm in the first meter. 5. The end result is a rapid and dramatic decrease in tree-cover.
Keywords: Dehesa; livestock; Quercus iiex subsp ballota; Quercus pyrenaica

A kinetic study of holm oak wood pyrolysis from dynamic and isothermal TG experiments - Cordero, T; Garcia, F; Rodriguez, J J (Thermochimica acta, 1989)
The kinetics of holm oak wood thermal decomposition in a nitrogen atmosphere have been studied using dynamic and isothermal TG experiments. A number of different kinetic models are examined. Discrimination between the first order, second order and spherical symmetry boundary surface reaction models is difficult with the dynamic TG experiments. The isothermal weight loss curves obtained are best described by a first order rate equation.
Keywords: heating rates; Holm oak; isothermal experiment; Kinetic model; pyrolysis (voyant); Wood

Los alcornocales de la provincia de Girona. - Vilar, L; Polo, L; Planella, D (Scientia gerundensis, 1989)
A first attempt to typify the ecology of cork oak in Girona country (NE part of Iberian Peninsula) is done. The evolution of forest cork oak grove's areas in recent decades is given. We found that it is in regression and it would be necessary urgent actions to recuperate it.
Keywords: Cork oak; cork oak grove; ecological typification; forest evolution; Girona country

Metal contamination in leaves and fruits of holm-oak (Quercus rotundifolia Lam.) trees growing in a pyrites mining area at Aljustrel, Portugal - Fernandes, J C; Henriques, F S (Water, Air, & Soil Pollution, 1989)
Pyrites extraction at Aljustrel mines, south Portugal, is causing severe metal pollution of soil, water and air, leading to a growing concern with environmental degradation in the mining area and its surroundings. In this work we measured levels of Fe, Mn, Zn, Cu, and Pb in leaves and fruits of holm-oak (Quercus rotundifolia Lain.) trees growing at the outskirts of the mining area. The trees showed pronounced stunting, reduced leaf size and extensive necrotic and chlorotic spotting. The leaves from trees growing in the area under study had much higher concentrations of metals than the controls - ca. 50 times higher for Cu, 20 times for Pb and Zn, 10 times for Fe, and 2 times for Mn - but is is possible that part of the metals associated with the leaves are actually retained in the dense hair cover present on their lower surface. The acorns from the contaminated areas were also metal polluted, particularly with Fe, Zn, and Cu, and this finding raises the threat of animal and human health hazards, since these fruits are commonly used for feeding livestock and are occasionally consumed directly by man. 1.
Keywords: acorns; holm oak (voyant); leaves; Metal pollution

Metal contamination in leaves and fruits of holm-oak (Quercus rotundifolia Lam.) trees growing in a pyrites mining area at Aljustrel, Portugal - Fernandes, J. C.; Henriques, F. S. (Water, Air, & Soil Pollution, 1989)
Pyrites extraction at Aljustrel mines, south Portugal, is causing severe metal pollution of soil, water and air, leading to a growing concern with environmental degradation in the mining area and its surroundings. In this work we measured levels of Fe, Mn, Zn, Cu, and Pb in leaves and fruits of holm-oak (Quercus rotundifolia Lain.) trees growing at the outskirts of the mining area. The trees showed pronounced stunting, reduced leaf size and extensive necrotic and chlorotic spotting. The leaves from trees growing in the area under study had much higher concentrations of metals than the controls - ca. 50 times higher for Cu, 20 times for Pb and Zn, 10 times for Fe, and 2 times for Mn - but is is possible that part of the metals associated with the leaves are actually retained in the dense hair cover present on their lower surface. The acorns from the contaminated areas were also metal polluted, particularly with Fe, Zn, and Cu, and this finding raises the threat of animal and human health hazards, since these fruits are commonly used for feeding livestock and are occasionally consumed directly by man. 1.
Keywords: acorns; holm oak (voyant); leaves; Metal pollution

Metals in Leaves as Indicators of Atmospheric Pollution in Urban Areas - Valerio, F; Brescianini, C; Lastraioli, S; Coccia, S (International Journal of Environmental Analytical Chemistry, 1989)
Abstract The use of biological indicators to monitor atmospheric pollution is widely distributed. The analysis of heavy metals in leaves is suggested as a method for a rapid identification of polluted areas. Reproducibility and representativity of this method must be assessed. We have verified if the concentration of lead, chromium, copper, nickel and manganese in ?Quercus Ilex? leaves may be used to classify urban areas according to the level of their atmospheric pollution. Particular emphasis was placed on reproducibility of sampling and the analytical method. Preliminary results show a linear correlation between concentration of metals in atmosphere (particularly lead) and in leaves collected in the same sampling areas.
doi: 10.1080/03067318908026901
Keywords: atmospheric pollution; Heavy metals (PG); Quercus ilex leaves

Metals in Leaves as Indicators of Atmospheric Pollution in Urban Areas - Valerio, F.; Brescianini, C.; Lastraioli, S.; Coccia, S. (International Journal of Environmental Analytical Chemistry, 1989)
Abstract The use of biological indicators to monitor atmospheric pollution is widely distributed. The analysis of heavy metals in leaves is suggested as a method for a rapid identification of polluted areas. Reproducibility and representativity of this method must be assessed. We have verified if the concentration of lead, chromium, copper, nickel and manganese in ?Quercus Ilex? leaves may be used to classify urban areas according to the level of their atmospheric pollution. Particular emphasis was placed on reproducibility of sampling and the analytical method. Preliminary results show a linear correlation between concentration of metals in atmosphere (particularly lead) and in leaves collected in the same sampling areas.
doi: 10.1080/03067318908026901doi: 10.1080/03067318908026901The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: atmospheric pollution; Heavy metals (PG); Quercus ilex leaves

Modelling Mediterranean pasture dynamies - Peco, B (Plant Ecology, 1989)
Pasture vegetation in an open woodland of Quercus rotundifolia subjected to periodic ploughing was sampled in spring during 8 consecutive years. The frequency of herbaceous species was recorded in a total of 69 permanent plots located on 5 adjacent sites with similar lithology, slope and orientation but differing in age since previous ploughing. Vegetation dynamics expressed as trajectories of permanent plots in a non-metric multidimensional scaling space has been modelled in terms of evironmental variables. By fitting a generalized linear model, the dynamics are shown to be related to years since last ploughing, geographical location of plots, total annual rainfall and November rainfall. Meteorological patterns of the sampling period are also described
Keywords: annual vegetation; generalized linear model; non-metric multidimensional scaling; Ploughing; rainfall pattern; succession

New types of damage to forest trees typical of the Mediterranean region - Clauser, F; GELLINI, R; Bussotti, F; Cenni, E; Bottacci, A (European Journal of Forest Pathology, 1989)
Since 1984 a new type of damage to the typical tree species growing in the mediterranean area has been observed. The pathological picture includes the typical features of “Waldsterben”. The new symptoms occurring in Pinus pinea, P. pinaster, P. halepensis and Quercus ilex are described.
Keywords: crown damage; damage; decline (voyant); foliage reduction

New types of damage to forest trees typical of the Mediterranean region - Clauser, F.; GELLINI, R.; Bussotti, F.; Cenni, E.; Bottacci, A. (European Journal of Forest Pathology, 1989)
Since 1984 a new type of damage to the typical tree species growing in the mediterranean area has been observed. The pathological picture includes the typical features of “Waldsterben”. The new symptoms occurring in Pinus pinea, P. pinaster, P. halepensis and Quercus ilex are described.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: crown damage; damage; decline (voyant); foliage reduction

ORGANIZACION Y VARIACIONES ESTACIONALES DEL ÁPICE VEGETATIVO DEL ALCORNOQUE - Molinas, M; Oliva, P; Vázquez, M Oliva P (Scientia gerundensis, 1989)
This paper is directed to the basic understand of organization and seasonal changes in the vegetative buds of the cork-oak through the study of the phenology and the histology of a branch during to annual cycles. During the period under study, two sprouting seasons succeded each year; one sprouting was allways in the middle of the spring and the other one either in the summer or in the fall. The elongation of the branch segments was characteristic of a cork-oak in juvenil phase. The hight value of the whole growth should be noticed. The cork oak produces both short and long shoots. Long shoots occur at the apex and distal portions of branches. The long and short shoots differ in number of leaves but not in internode elongation. Elongation depend on the shoot vigor and position. There is a good correlation between elongation and number of leaves per segment. Buds show seasonal changes. A rest phase, a bud expansion phase and a new bud formation phase partially omerlaping the bud expansion phase can be distinguished. Cork-oak vegetative buds show a tunica and corpus type of cellular zonation which corresponds to the Type I of the Gifford and Carson (1971) classification. Only lowermost leaves ovenvinter in the bud. This may explain the maked heteroblastia of the leaves in the shoots. The seasonal study shows that maximum cytohistological zonation occurs near the end of rapid shoot elongation.
Keywords: bud morphology; cork-oak; Phenology; Quercus suber; shoot elongation

Planta of resurrection plants to desiccation and rehydration - Schwab, K. B.; Schreiber, U.; Heber, U. (1989)
Using non-invasive techniques (CO2 gas exchange, light scattering, light absorption, chloro- phyll fluorescence, chlorophyll luminescence), we have analysed the response of respiration and pho- tosynthesis to dehydration and rehydration of leaves of the resurrection plants Craterostigma plantagineum Hochst., Ramonda mykoni Reichb. and Ceterach officinarum Lam. et DC. and of the drought-sensitive mesophyte spinach (Spinacia oleracea L.). The following observations were made: (i) The rate of water loss during wilting of detached leaves of drought-tolerant resurrection plants was similar to that for leaves of the sensitive mesophyte, spinach. Leaves of Mediterranean xerophytes lost water much more slowly. (ii) Below a residual water content of about 20%, leaves of spinach did not recover turgor on rewatering, whereas leaves of the resurrection plants did. (iii) Respiration was less sensitive to the loss of water during wilting in the resurrection plants than in spinach. (iv) The sensitivity of photosynthesis to dehydration was similar in spinach and the resur- rection plants. Up to a water loss of 50% from the leaves, photosynthesis was limited by stomatal closure, not by inhibition of reactions of the photo- synthetic apparatus. Photosynthesis was inhibited and stomates reopened when loss of water became excessive. (v) After the leaves had lost 80% of their water or more, the light-dependent reactions of photosynthetic membranes were further inhibited by rewatering in spinach; they recovered in the resurrection plants. (vi) In desiccated leaves of the resurrection plants, slow rehydration reactivated mitochondrial gas exchange faster than photosyn- thetic membrane reactions. Photosynthetic carbon assimilation recovered only slowly.
Keywords: Carbon dioxide (gas exchange); Chlorophyll (fluorescence - luminescence); Drought tolerance; Light scattering (thylakoids); Resurrection plants; water stress

PRODUCCIÓN ANIMAL EN EL SUROESTE ESPAÑOL - Martin Bellido, M (II Reunión Ibérica de Pastos y Forrajes Badajoz, 1989)
En el S.O. peninsular se desarrolla un ecosistema, la "dehesa" en España y los "montados" en Portugal, carac terizado por la presencia conjunta de especies vegetales (herbáceas y arbustivas) y animales (domésticas y salva- jes). Se extiende en España por las provincias de Zamora, Salamanca, Avila, Toledo, Ciudad Real, Cáceres, Badajoz, Córdoba, Sevilla, Huelva y Cádiz abarcando más de 5 millo nes de hectáreas. En Portugal tiene 1 millón de hectáreas y se extiende por el Alentejo. Es una zona eminentemente ganadera donde se crian una serie de razas autóctonas dependiendo fundamentalmen- te de los recursos naturales para su alimentación. Es ca- racterístico de la zona la utilización de suplementación en épocas de escasez de pastos. Las razas más importantes son: Retinto, Morucha y Avileño-Negro Ibérico con más de 134, 109 y 76 mil cabezas en la zona respectivamente. En cuanto a ganado ovino, éste se cría principalmente para producción de carne y las razas de más efectivos son la Merina, Castellana, Manchega y Talaverana con más de 2.165, 759, 610 y 288 mil cabezas en la región respectiva- mente. El ganado caprino en dehesa representa el 46,22% del censo existente en España, siendo las razas Serrana, Verata, Malagueña y Retinta las más extendidas en la zona. Por último, el cerdo Ibérico con alrededor de 70 mil reproductoras en la dehesa se encuentra en un momento de expectativas ante una nueva normativa de la CEE y su repercusión en la zona. Resumiendo, la dehesa es una zona de amplios recur- sos naturales para la cría extensiva de ganado que poste- riormente en muchos casos es engordado y sacrificado fue- ra de la zona. La utilización integral de los recursos pro pios puede generar un valor añadido a estas producciones
Keywords: cerdo Ibérico; Dehesa; ganado caprino; ganado ovino; Ganado vacuno; montado

PRODUCCION DE PLANTA DE ALCORNOQUE Y OTRAS QUERCINEAS PARA REPOBLACION FORESTAL EN LA ALMORAIMA (CADIZ) - Álvarez De la Puente, J M (Scientia gerundensis, 1989)
Después de justificar brevemente la necesidad de recurrir a veces a la plantación en las re- poblaciones con alcomoque y otras quercíneas mediterráneas, y tras comentar 10s proble- mas que plantea la producción de plantas a raiz desnuda, en bolsas de polietileno y en paper pot, se exponen 10s resultados obtenidos en la finca <<La Almoraima~ (Cádiz) en la producción de planta de alcomoque (Q. suber), quejigo andaluz (Q canariensis) y encina (Q. rotztndifolia) en envases del tipo superleach (S.L.) para repoblación forestal. Las experiencias se realizaron a escala real: unas 250.000 plantas durante el tercer año. El trabajo expone brevemente las experiencias y 10s resultados obtenidos en diversos aspectos de la producción de plantas: tip0 de envase, estructuras portaenvases, sustratos, recolección, conservación y siembra de bellotas, germinación, riegos, crecimiento, trans- plante al monte, costos de producción, calendario, etc. y en el arraigo y supervivencia de las plantas tras unos primeros ensayos de repoblación en la misma finca. Como conclusiones, se destaca la posibilidad de producir plantas de quercíneas medite- rráneas aptas para la repoblación forestal y con una aceptable garantia de arraigo y super- vivencia, y se analizan 10s aspectos todavia pendientes de experimentación en este tema.
Keywords: Alcornoque; bellota (voyant); envase; germinación; repoblaciones; sustratos

PYROLYSIS OF HOLM OAK AND OLIVE WOOD - Figueiredo, J L (International Conference on Biomass for Energy and Industry, 1989)
The pyrolysis of olive and holm-oak wood to produce charcoal and fuel gas was studied in the temperature range from 3 00 to 9 00°C. The charcoals were characterized by proximate and ultimate analyses, and the gases were analyzed chromatographycally The fised carbon content of the charcoal increased with temperature up to 600-700°C and then remained essentially constant. The gases produced were mainly CO, CO , H and CH . The composition of the pyrolysis gas produced at each temperature was determined, and its heating value was calculated. Taking into consideration the quality of the charcoal and the heating value of the gases produced, it can be concluded that the optimal pyrolysis temperature is 600'C.
APS
Keywords: charcoal production; fuel gas; Holm oak; olive; pyrolysis

Pyrolysis of holm-oak wood: influence of temperature and particle size - Figueiredo, J. L.; Valenzuela, C.; Bernalte, A.; Encinar, J. M. (Fuel, 1989)
The pyrolysis of holm-oak wood sawdust was studied to determine the characteristics of the charcoal and the nature and amounts of gases produced. The temperature was varied from 300 to 900 °C and the wood particle size from 0.40 to 2 mm diameter. The fixed carbon content of the charcoal increased with temperature up to 700 °C, and then remained essentially constant. The gases produced were mainly CO, CO2, H2 and CH4. The rate constants and activation energies for the production of each gas were calculated assuming first order kinetics. The composition of the pyrolysis gas produced at each temperature was determined, and its heating value was calculated. Taking into consideration the quality of the charcoal and the heating value of the gases produced, it can be concluded that the optimal pyrolysis temperature is ≈ 600 °C.
Keywords: charcoal; Particle Size; pyrolysis

Pyrolysis of holm-oak wood: influence of temperature and particle size - Figueiredo, J L; Valenzuela, C; Bernalte, A; Encinar, J M (Fuel, 1989)
The pyrolysis of holm-oak wood sawdust was studied to determine the characteristics of the charcoal and the nature and amounts of gases produced. The temperature was varied from 300 to 900 °C and the wood particle size from 0.40 to 2 mm diameter. The fixed carbon content of the charcoal increased with temperature up to 700 °C, and then remained essentially constant. The gases produced were mainly CO, CO2, H2 and CH4. The rate constants and activation energies for the production of each gas were calculated assuming first order kinetics. The composition of the pyrolysis gas produced at each temperature was determined, and its heating value was calculated. Taking into consideration the quality of the charcoal and the heating value of the gases produced, it can be concluded that the optimal pyrolysis temperature is ≈ 600 °C.
Keywords: charcoal; Particle Size; pyrolysis

Scanning electron microscopy observations of insulation cork agglomerates - Pereira, H; Ferreira, E (Materials Science and Engineering: A, 1989)
Observations by scanning electron microscopy were made of insulation cork agglomerates and of cork raw material. The insulation cork agglomerates are agglomerates of granules of cork from the cork-oak tree (Quercus suber), self-bonded and expanded by autoclave steaming at approximately 300°C and 40 kPa. In this process, the cork cells expand by unfolding the cell wall corrugations and by stretching the cell walls (concurrently decreasing the cell wall thickness). In the junctions between granules, the cells are compressed against each other and collapsed; the region of cell collapse is restricted to a limited number of cell layers at the boyndary between the granules. The cell wall material is thermochemically degraded and a weight loss of approximately 30% of the cork material is observed in the production of these insulation agglomerates.

SELECCION DE HABITAT Y DISTRIBUCION TERRITORIAL DE UN GRUPO DE VACAS EN AMBIENTE DE DEHESA - Miguel, J M D E; Rodriguez, M A; Sal, A Gdmez; Ecologia, Departamento De; Biologia, Facultad De (Options Méditerranéennes, 1989)
From a sampling based on'.systematic routes, the territorial distributioofn a herd of about 400 cows ona 3000 Ha "dehesa" is analysed. The animals' preference and aggregationd egree as regardsh omogeneous territorial areas, detected according to vegetation, geomorphology and land use, are studied.The presence of cows was discovered in only 51% of thes ampled units and clear asymmetries were found between them (80% for environments with large isolated trees and 18% in shrubby and rockrose thickets areas). Animal dispersion is analysed in the different seasons and according to the influence of forage supply.
Keywords: "dehesa" pastureland; Cattle; habitat preferences; territorial behaviour

Sorptive substance for recovering oil on water - produced by rendering comminuted cork oleophobic and hydrophobic by heating with steam under pressure - A, JONES J (1989)
Improved substance for the recovery of oil and similar compounds from the surface of water, and other substrates is produced from a naturally occurring arborial material, typically the cork of the cork tree (Quercus Suber.), which is subjected to a process to improve the sorptive character of the raw material, by heating under pressure for a time. Specifically, the substance is heated at 150-350 deg.C for a period of time with the application of steam at a pressure of 0-1.5 megapascals in an autoclave or similar apparatus, comminuted in size below 5 mm mesh to give a sorptive capacity for oil and related compounds of 5-10 times its own weight. ADVANTAGE-The improved material exhibits ease of collecting sorbed oil from water using a strainer of nominal mesh size to effect 100% recovery with little uptake of water. The oil and related compounds can be separated from the sorbate by the application of pressure, centrifugal force, or by solvent extraction and/or distillation.
APS
Keywords: arborial material; Cork; oil compounds; Quercus suber; sorptive capacity

TIPIFICACIÓN DE LAS EXPLOTACIONES EXTREMEÑAS DE DEHESA MEDIANTE ANÁLISIS FACTORIAL Y CLUSTER - Escribano, M; Gaspar, P; Rodríguez de Ledesma Vega, Antonio; Mesías Díaz, Francisco Javier; Pulido, F (Gestión ambiental y económica del ecosistema dehesa en la Península Ibérica, 1989)
El trabajo analiza las explotaciones de dehesa en Extremadura a partir de indicadores técnicos y económicos. Los datos utilizados proceden de encuestas realizadas durante 2004 y 2005 a propietarios o gestores de 69 explotaciones. A partir de técnicas de análisis de datos multivariantes se establecen cinco grupos de explotaciones en función de sus niveles de rentabilidad, intensificación y orientación productiva. Hecho que permite adecuar los niveles óptimos de dimensionamiento de las explotaciones, la presión ganadera y, en definitiva, racionalizar los niveles de actuación en grupos homogéneos de explotaciones. Las explotaciones estudiadas han sido fincas colaboradoras del proyecto "Desarrollo de un sistema de información para la gestión ambiental y económica del ecosistema dehesa/montado en Extremadura y Alentejo':

Betulin-3-Caffeate from Quercus suber, 13C-nmr Spectra of Some Lupenes - Patra, Amarendra; Chaudhuri, Swapan K; Panda, Samir K (Journal of Natural Products, 1988)
A new a-lupene ester, Iup-20(29)-en-28-01-3P-y1 caffeate (betulin-3-caf- feate) El], has been isolated from cork waste along with betulin, betulonic acid, and betulinic acid. "C-nrnr signal assignments of 1 and its derivatives are reported
doi: 10.1021/np50056a004
Keywords: a-lupene derivatives; Chemical characterization (voyant); Cork waste; NMR; Structural characterization

Biomass Equations for Quercus ilex L. in the Montseny Massif, Northeastern Spain - CANADELL, J; Riba, M; Andres, P (Forestry, 1988)
Biomass estimation equations for individual holm oak (Quercus ilex spp. ilex) were developed using data from 71 sample trees. Diameter alone was a strong predictor of biomass, but better biomass estimates were obtained when height and crown projection radius were added to the model. In addition to total above-ground dry weight, different biomass components were calculated: stem (greater than 5 cm in diameter), branches 1 to 5 cm in diameter, branches less than 1 cm in diameter, and foliage. Grouping the trees according to height (taller or shorter than 7 m) and aspect (north-and south-facing slopes) resulted in significantly different allometric equations for most of the components considered. Improved estimates were achieved in many cases when D50 (diameter at 0.5 m) was used instead of DBH. Comparison of the results with other published equations developed for Q.ilex and other oaks showed differences, probably due to morphological diversity of trees and different DBH class distribution of samples used.
10.1093/forestry/61.2.137
Keywords: Allometric equations (voyant); biomass; Northeastern Spain; Quercus ilex

Chemical composition and variability of cork from Quercus suber L. - Pereira, H (Wood Science and Technology, 1988)
The chemical composition of cork from Quercus suber L. was determined for virgin cork and for reproduction cork. Average chemical composition of virgin cork is: ash 0.7%, total extractives 15.3%, suberin 38.6%, lignin 21.7% and polysaccharides 18.2%. The carbo- hydrate composition shows that glucose represents 50.6% of all monosaccharides, xylose 35.0%~ arabinose 7.0% and galactose and mannose, respectively, 3.6% and 3.4%. Reproduction cork has a composition similar to virgin cork. For the cases studied, reproduction cork had however less extractives and a higher amount of suberin. Significant differences were found for the chemical composition of virgin cork in relation to location of extractives and polysaccharide content. The between-tree variability was large and a variation within the tree was also recorded.
Keywords: chemical composition; Cork; reproduction cork (voyant); virgin cork

The convergent trajectories of bird communities along ecological successions in european forests - Blondel, Jacques; Farré, H. (Oecologia, 1988)
There is much more variation in the composition of bird communities in the earlier open and semi-open seral stages of ecological successions in forested landscapes of Europe than later on in preforested and forested climactic stages. The demonstration of this trend is achieved from the study of four habitat gradients, two in the mediterra- nean region (Provence and Corsica) and two in central Eu- rope (Burgundy, France and Poland). A multivariate analy- sis has been used to illustrate the dynamics of communities along these successions. Displays of the results in bivariate space as well as an illustration of the distributional profiles of some of the most characteristic species show that: i) there is a discrimination between the two mediterranean gradients and the two medioeuropean ones and ii) each succession starts with a very distinct set of species and then the four gradients regularly converge in the last climactic stage where there is almost no discrimination between com- munities. These results are discussed in the light of the histo- ry of European biotas during the Pleistocene. The reason why there is more variation in species composition in the earlier seral stages than in the later forested stages are dis- cussed according to current theories on the role of habitat selection on speciation processes.
Keywords: Community dynamics; Ecological succession; historical biogeography; Mediterranean; speciation

Crecimiento longitudinal del alcornoque: segmentos y hojas - Caritat, A; Molinas, M; Oliva, M (SCIENTIA gerundensis, 1988)
This paper is directed to the basic understand of longitudinal growth of the cork-tree Quercus suber L. Branch constitution is analized through the relation of segments and leaves. To duly recognize segments in branches, an apropiate nomenclature is used. Segments length changes from 0,2 to 11,6 cm, with an average of 2,3 cm. Two kind of shoots, long and short shoots, can be distinguished. Segment elongation tend to decrease as succesive periods accumulate. No differences in segments can be related to the period of the year in which they were developed. Leaves show heteroblastic distribution. Leave lamina has an average length of 3,3 cm and is 2,O cm wide. Petiol is very constant with an average of 0,6 cm.
Keywords: branch growth; cork-tree; leaves; Quercus-suber; shoots

The dehesa: an agrosilvopastoral system of the Mediterranean region with special reference to the Sierra Morena area of Spain - Joffre, R; Vacher, J; Llanos, C; Long, G (Agroforestry Systems, 1988)
A multidisciplinary team undertook a six-year investigation on the agro-ecological and socio-economic aspects of the dehesa system in the Sierra Norte area, a part of the Sierra Morena of the Sevilla Province, Western Andalusia, Spain. This paper summarizes its findings on the various agro-ecological features of the system and evaluates the system's functional aspects vis-a-vis the trends and developments in land use in the region over the past few centuries. The synergistic effects of tree cover on understorey grassland vegetation is discussed in terms of soil fertility build-up and favourable micro-climatic and hydrological features, and the potential use of this information in future research and development programmes to improve the dehesa system in the Mediterranean region is outlined.
Keywords: agrosilvopastoral system; Dehesa; effect of trees on soils; Mediterranean Region; oak trees (Quercus spp.); sierra morena

Digestibilité du feuillage de chêne vert (Quercus ilex) distribué frais à des caprins entraînés au pâturage sur parcours - MEURET, M (Reprod. Nutr. Dévelop., 1988)
A high and steady intake of fresh branches of holm oak, distributed to local goats (28 days in April) led to a 100 g/day gain and a positive nitrogen balance despite low fiber digestibility. Our foraging conditions gave reliable results with very little variation between animals.
Keywords: caprins (voyant); chêne vert; Digestibilité; feuillage; rameaux

Distribution spatiale des génotypes dans une population de chêne vert (Quercus ilex L.), flux génique et régime de reproduction - Yacine, Assia; Lumaret, R (Genetics Selection Evolution, 1988)
Spatial distribution of genotypes in holm oak (Quercus ilex L.) was analyzed within a site using three allozyme systems (PGI-I, IDH-1, ADH-1) as markers. No aggregation effect of the genotypic classes could be pointed out at any locus. Wright’s fixation index calculated over all the individuals of the site was not significantly different from zero (Fis = 0.02), indicating a situation close to the Hardy-Weinberg equilibrium expectation. Allele frequencies in the effective pollen responsible for the observed progenies of nine open-pollinated individual trees of the site were significantly different (P < 0.05) even when the parents were very close. Finally, the results clearly show that the trees are not necessarily pollinated by their neighbours, but rather by those individuals that are both synchronous phenologically and that invest primarily in the male function.
Keywords: allozyme.; genetic structure; mating system; Quercus ilex L.

Estructura básica generada por el arbolado en pastos semiáridos (ecosistemas de dehesa) - Rico, M; Puerto, A (Pastos, 1988)
A study was made of the effect on spatial distribution of species from semiarid grasslands. The basic structural aspects considered were: num- ber of species, exclusive species, and dominant species. Comparisons were made among the sites: under crown, canopy edge, and open grassland; in all three cases the N-S orientation was taken into account. The reduced number of species below the crown contrasts with the much higher number found at the canopy edge. However, in the latter case there were almost no exclusive or dominant species present since, owing to its intermedíate position, the most contrasted ecological charac- teristics correspond to the location receiving the most direct influence of the tree canopy and to the open spaces. Additionally, the similarity between the locations under the crown and the N exposure of the edge, and between the open spaces and S exposure of the edge leads to different results, according to whether orientation is considered or not
Keywords: Canopy effect; Dominance; exclusivity; floristic richness

Etude de l'appareil radical de jeunes plants de Chênes verts dont le pivot se développe sans amputation, ni déviation - BEISSALAH, Y; AMIN, T; EL HAJZEIN, B; NEVILLE, P; BERNARD, Janine (Ann. For. Sci., 1988)
The experimental study of the root system of woody plants is far behind that of the aerial system. To make up for this difference, a study was begun on a Mediterranean sclerophyllous oak (Quercus ilex L.). The present study defines the developmental characteristics of the root system in young seedling whose tap root has neither been diverted nor amputated and which grows in different ecological conditions (substrates, temperatures). The results obtained can be used as an interpretative guide for the root system’s reactions to both diverting and amputating. These reactions will be described elsewhere. The study was made in R IEDACKER type minirhirotrons (1974) and L AMOND type fog chambers (1975). The root system of holly oak seedlings (fig. 1) consists of one main root (tap root) with positive geotropism and rapid and theoretically unlimited growth, from which thin, usually short, branch roots, either subhorizontal or oblique with slow, limited growth, spread out (fig. 5). The tap root is not rectilinear, but ondulates more or less regulary (fig. 1), both in loosely-packed substrates (peat ou loam) and in the absence of any substrate (fog chamber). The substrate’s resistance to root penetration, therefore, does not cause these ondulations. The largest branch roots generally begin growth on the convex part of the ondulation (fig. 1, B and C). The tap root grows better in peat than in loam or fog chambers (fig. 2). Its growth is subject to different types of fluctuations (fig. 4). It is highly sensitive to thermic variations (fig. 2 and 3). A 5 °C temperature drop (from 25 °C to 20 °C) decreases its growth rate by a quarter in peat and by half in loam (fig. 2). This decrease is lower in fog chambers because of their neutralizing effect. The tap root’s growth rate also fluctuates regardless of temperature, substrate (peat or loam), or lack of substrate (fig. 4). The fluctuation period varies from 2 to 7 days and is probably the expression of an irregular endogenetic rythm. Systematic ablation of branch roots as they appear has not effect on the variations in the tap root’s growth rate. Anatomy also differentiates the tap root from branch roots. The tap root usually has 6 major xylem fascicles (more rarely 4 to 8) directly underneath the cotyledons and connected to them in groups of three per cotyledon (fig. 6). Between these are often extra xylem fascicles which are smaller, connected to the epicotyle and disappear rapidly lower down (fig. 7, A and A’). The major xylem fascicles divide between the 3‘d and T&dquo; centimeter from the cotyledon by enlarging and isolating their wings (fig. 7, A and B) which can result at most in a tripling of the number of xylcm fascicles. These additional fascicles vanish progressively either by fusion and/or reduction up to the 20’&dquo; centimeter from the cotyledon (fig. 7, C). Beyond this, we find the same number of xylem fascicles as at the start, i.e. only major fascicles remain (fig. 7, D). The number of phloem fascicles, at first twice that of the major xylem fascicles in the area of the tap root near the cotyledons (fig. 7, A and B), decreases progressively, generally by fusion, until it equals the latter beyond the 20’&dquo; centimeter from the cotyledon (fig. 7, D). This remarkable fluctuation in fascicle number is probably related to the period of cotyledon influence. It is not present in the branch roots, which have between 3 and 5 xylem fascicles alternating with an equal number of phloem fascicles.
Keywords: development; Quercus ilex; rool; Seedling; Temperature; vascular bundles

Evergreen oak leaves as natural monitor in environmental pollution - Capannesi, G; Caroli, S; Rosada, A (Journal of radioanalytical and nuclear chemistry, 1988)
Evergreen oak was chosen as a possible biological monitor of environmental pollution. It was shown that there is a direct relationship between the concentration of elements in leaves and the presence of pollution sources, i.e. the density of vehicular traffic.
Keywords: Elemental analysis; leaves (voyant); pollution

Fitomasa subterránea en pastizales semiáridos de dehesa. Estudio comparativo de cuatro transecciones - Gomez Gutiérrez, J M; BARRERA MELLADO, I; FERNÁNDEZ SANTOS, B; Guti, M E Z; Mellado, Barrera; Santos, Ndez (Pastos, 1988)
A comparative study of the underground phytomass (roots) valúes obtained along four transverse sections of four water courses was made in some semiarid grasslands, that are representative of the Central- Western área of Spain (Provinces of Avila and Salamanca). In order to perform this study, the following item's were studied: a) the total phyto- mass valúes for each profile (30 cm depth, 9 cm diameter), b) the hori- zons or 5 cm horizontal transect, in each section, c) the samples in each profile. Very similar sequences were observed in all the transects, high- lighting the effect of relief on underground phytomass, wich is considered a synthesis and an expression of the edaphicclimatic and anthropozoogenic action that governs its development. Key
Keywords: fitomasa subterránea; Grasslands; pastizales; raíces; roots; vaguada; water course

GASEOUS EXCHANGES AND THEIR REGULATION IN 2 SPECIES OF EVERGREEN OAK (QUERCUS ILEX AND QUERCUS SUBER) - VIGNES, D (BULLETIN DE LA SOCIETE BOTANIQUE DE FRANCE-ACTUALITES BOTANIQUES, 1988)
This article presents a comparison on the physiology (hyrdic potential, stomatal resistances, transpiration, net photosynthesis) of young plants of Quercus ilex and Quercus suber submitted to different temperatures, light environment and water supply. Relative to temperature and light, the two species present similar reactions, although gaseous exchanges are more important on Quercus ilex. On the contrary, they present distinctive differences on water absorption. Quercus ilex have an important transpiration when water supply is not limited, but presents also a good tolerance to low hydric potentials and sufficient stomatal conductance according to photosynthetic production. On Quercus suber, survival seems more important than production : water consumption is relatively reduced at high water potential as good as at low water potential.
APS
Keywords: hydric potential; photosynthetic production; Plant physiology; Quercus ilex; Quercus suber; Stomatal conductance

The holocene- and upper pleistocene pollen record from Padul (Granada, Spain): A new study - Pons, A; REILLE, M (Palaeogeography, Palaeoclimatology, Palaeoecology, 1988)
Two borings were made at the site of Padul (Granada). Pollen analysis of 200 spectra from two successive sequences, 14.8 and 8 m deep, enables a description of the vegetational and climatic history of this region, the most southern one in Europe, from Early Würmian times. The chronology is supported by twenty-one 14C dates. Original equivalents are found for the great European Prewürm interstadials. A markedly arid though thermically not extreme episode, exactly equivalent to stage 4 of the marine isotopic stratigraphy, closes this relatively temperate period. The middle part of the Last Glacial shows climatic fluctuations that are poorly characterized, as is often the case in Europe for this period. A long section, very probably corresponding to the complete Last Pleniglacial, does not show any climatic amelioration. Towards 15,000 yr B.P. a change in the diagram is noted that can only be interpreted as reflecting a larger expansion of a regional steppe cover. This event, also reported on three occasions in southeast France, marks the beginning of the Oldest Dryas. The climatic amelioration of ca. 13,000 yr B.P. is far more pronounced here than anywhere else in Europe, whereas that at 10,000 yr B.P. is not so clearly marked. This unexpected result may be accounted for by the fact that Padul is the first continental site so far south and so near Pleniglacial refuges to be known: on the other hand, this result is consistent with what is known from oceanic isotopic stratigraphy. A quite new late-glacial and Holocene vegetational history is revealed, characterized by the early appearance and dominance of Quercus ilex oak forests of a southern type and the early occurrence of Quercus suber and Olea: it is the first account of a complete history of the postglacial reafforestation in a region with a modern semi-arid mediterranean climate. From the palaeoclimatic point of view, it shows that the hot and humid Holocene optimum was attained slightly before 8000 yr B.P. and that the Holocene climatic fluctuations were of but small amplitude.
Keywords: climatic fluctuations; Holocene; Padul; Pollen analysis; vegetation history (PG)

Structural studies of a hemicellulose B fraction (B-2) from the cork of Quercus suber - Asensio, A (Canadian journal of chemistry, 1988)
Polysaccharide B-2 contains xylose, arabinose, glucose, galactose, 4-0-methylglucuronic acid, and rhamnose in the molar ratio of 17: 12: 12:6:4: 1. The polysaccharide has a backbone of P(1-4)- and P( 1-3)-linked glucopyranosyl, P(lk4)-linked xylopyranosyl, and (1-4)- and (1-6)-linked galactopyranosyl residues. Arabinofuranosyl, rhamnopyranosyl, and some xylopyranosyl and galactopyranosyl groups are present as nonreducing end units. Glucopyranosyluronic acid side chains are attached at 0 - 2 of some xylose residues. The anomeric configurations of the different glycosyl groups were determined by a study of the chromium trioxide oxidation of the acetylatcd polysaccharide and by nuclear magnetic reasonance spectra of the methylated polysaccharide.
Keywords: Configuration; GLC-MS (voyant); Polysaccharides

Successional pathways of Mediterranean evergreen vegetation on Sicily - Marchese, E P; Benedetto, L; Maugeri, Giuseppe (Plant Ecology, 1988)
The Mediterranean evergreen vegetation of Sicily, comprised in the belt of the Quercetea ilicis, occupies a large part of the island. Human intervention (cutting, fire, pasture) has brought about a degradation of the natural vegetation. This study is based on our phytosociological research of the Quercetea ilicis belt on Sicily. With the 'habitat comparison' method, the dynamical relations between the different vegetation units have been defined. We distinguish the following stages, with reference to their vegetation structure: - a herbaceous stage formed by steppic vegetation, preceded by various types of nitrophilous-ruderal vegeta- tion on abandoned fields; - a garrigue stage dominated by half-shrubs; - a macquis stage with various distinct plant communities, four communities being important in regressive successions, and three in progressive ones; - a woodland and shrub-woodland stage with three different substages: pre-existent forests, present wood- lands, and woodlands which tend towards the final, stable stage of vegetation (potential natural vegetation). The dynamic relationships both in progressive and regressive successions have been synthesized in a scheme. In this scheme we have shown the main stages of the vegetation in their dynamics and we have constructed different series of vegetation types in two altitudinal belts, which are determined by varying environmental conditions of today. The results also show that in some cases the progressive series follow different pathways than the regressive series, and the final stage of the progressive series is different from the original vegetation.
Keywords: development stage; dynamic series; progressive succession; regressive succession

6. Plant growth regulator effects in the invitro propagation of three hardwood tree genera: Castanea, Juglans, and Quercus - Schwarz, O. J. (Plant growth regulation, 1987)
Castanea, Juglans, and Quercus are genera containing hardwood forest species that are difficult to propagate asexually by conventional means. Their in vitro clonal propagation would assist forest tree improvement and silvacultural research. The research efforts in clonal propagation of these three genera are reviewed with respect to plant growth regulator effects as they are related to primary explant source, multiple shoot formation, somatic embryogenesis, rooting, and transfer to soil.
Keywords: growth regulators; in vitro culture (voyant); shoot proliferation

Caractérisation de formations végétales mediterranéennes à partir de données ‘Thematic Mapper’ Une étude de cas en Andalousie (Espagne) - LACAZE, BERNARD; Joffre, Richard (International Journal of Remote Sensing, 1987)
Abstract The study is focused on the characterization of vegetation formations in a Mediterranean area (943 km2) located in southern Spain: herbaceous canopies (rangelands), shrubby vegetation (?matorral?) and complex woody/herbaceous formations (?dehesa?). Vegetation formations (physiognomical units) have been characterized by their spectral responses in the six reflective TM channels and by vegetation indices. From the ratio index TM4/TM3 there has been derived a map displaying seven classes (water, bare soil and five biomass levels reflecting the hierarchy of vegetation formations). Channels TM3, TM4 and TM5 have been considered for a supervised classification into nine land-cover categories (seven vegetation formations, bare soil and water). The proportion of correct classification of vegetation formations is about 78 per cent when considering test areas. Classification made from three principal components gives similar results.
doi: 10.1080/01431168708954777
Keywords: Automatic classification; biomass; characterization; Europe (citation); Image interpretation; land use; Mediterranean vegetation; Multispectral remote sensing; rangeland; Regional study; Satellite observation; Shrubbery; Spain; Survey; Thematic map; Vegetation type

THE CELLULAR STRUCTURE OF CORK FROM QUERCUS SUBER L - Pereira, Helena; Rosa, M Emília; FORTES, M A (IAWA Bulletin, 1987)
The main characteristics of the cellular struc- ture of cork from Quercus suber L. are review- ed and comph;mented with new observations of virgin and reproduction cork by scanning electron microscopy. Particular emphasis is given to cell geometry and topology and to the corrugations that are observed in the cell walls. The effect of the growth season in these fea- tures is described. Large variations in cell size, wall thickness ajld corrugations are reported. Key words: Quercus SIlber, cork, cell gcometry, topology, cell wall corrugations.
Keywords: cell gcometry; cell wall corrugations; Cork; Quercus suber; topology

Contribution à l'étude de la production des taillis de Chêne vert en forêt de la Gardiole de Rians (Var) - MIGLIORETTI, Françoise (Ann. For. Sci., 1987)
Cet article traite de la méthodologie mise au point pour l’étude de la production en volume et biomasse des taillis sclérophylles dans le massif forestier de la Gardiole de Rians (Var), ainsi que de la croissance en diamètre et hauteur des brins de Chêne vert en vue de dégager un certain nombre de classes de fertilité. La prise en compte de tous les brins d’une cépée y compris ceux de faible diamètre, permet de mieux exprimer la production du taillis au regard de celle définie en dendrométrie classique pour les futaies, et de parvenir ainsi à une meilleure compréhension du fonctionnement des cépées de Chêne vert qui émettent des brins à des périodicités successives, et d’aborder les problèmes de concurrence intraspécifique pour l’utilisation des ressources du milieu. Cette étude rend compte aussi des modèles mathématiques retenus pour les diverses évaluations de production ainsi que pour la croissance en diamètre et hauteur des tiges de chêne vert.
Keywords: chêne vert; Croissance; phytomasse; production; taillis sclérophylle

Determination of amino acids from the leaves of evergreen oak (Quercus ilex L.) at four different stages of decomposition - SADAKA, N; Poinsot-Balaguer, N (Biology and fertility of soils, 1987)
It was established by weak ion exchange resin chromatography that 17 amino acids in proteins and 15 free amino acids account for almost all of the amino acids present in the leaves of evergreen oak (Quercus ilex L.) in four different stages of decompo- sition. No significant change in the amounts of these amino acids was observed in the course of decomposi- tion. The amino acid content of evergreen oak leaves is comparable to that in pine needles and beech leaves.
Keywords: amino acids; Evergreen oak leaves; Quercus ilex L.; Stages of decomposition

Effects of fire on soil carbon and nitrogen in a Mediterranean oak forest of Algeria - Rashid, G H (Plant and Soil, 1987)
The effects of wildfire on the dynamics of pH, organic C, total and mineral N and in vitro C and N mineralization were investigated in the soil under oak (Quercus suber L.) trees. Soil samples were taken from 5 to 21 months subsequent to the fire. The pH increased sharply in the burned surface soil (0-5 cm) taken 5 months after the fire and dropped only by half a unit over 14 to 21 months. However, at greater depth (5-15 cm), the burned soil was more acidic than the adjacent unburned soil up to 9 months following the fire, and thereafter its pH rose only slightly above that of the unburned soil. There were sharp rises in the concentration of organic C, total and mineral N in addition to in vitro mineralization activities in the burned surface soil collected 5 months after the fire; these dropped off in the subsequent samples approaching or falling below the values obtained in the unburned surface soil after 21 months. At a depth of 5-15 cm only slight or no increases over unburned soil were evident.
Keywords: Carbon; forest soil; mineralization; nitrogen; pH; Wildfire

An evaluation of the differences in the composition of humic acids in soils under oak and pine forest by GC-MS after mild degradation - González-Vila, F L; Almendros, G; Martin, F (Plant and soil, 1987)
Significant differences were found in the products released after eight samples of humic acids (HA's) isolated from soils under mediterranean pine and oak forests underwent mild degradation. A number of compounds, including typical degradation products of lignins, were found exclusively in the HA's from the soils under pine forests. The aliphatic constituents were more firmly retained in the HA's under oak, which presented mean values for aromatic acids lower than the humic samples from pine forests. Different types of diterpene resin acids were also found amongst the mild degradation products of HA's from the studied areas.
Keywords: Forest soils; humic acids; Lipids; mild degradation; Pinus; Quercus; resin acids

Evolución de la producción de pastos mejorados en la dehesa extremeña en año seco - Espejo, Diaz; Martin Bellido, M (Pastos, 1987)
It is studied the influence of the type of pastures (pasture implemented with subterranean clover and natural pasture), variability, frequency of cuts starting date, cuts high on the annual and monthly production of DM/ha under environmental "dehesa" conditions in Extremadura, Spain, during a climatological adverse year. The first two factors have not significant differences. The subterranean clo- ver pasture produced more than doubled than natural pasture being significant the differences between locations within this type of pastures. The monthly cut produced 40% less when the distance between cuts was longer, this drop was mainly produced in March. The figures of distribution of the production are shown. They present a má- ximum in March, falling in April because of the cold weather and lack of rain. Natural pasture production is restricted to the months of February to April whe- reas the subterranean clover pasture began production in November. Key
Keywords: Climatology; Dehesa; Grass production figures; Subterranean clover

THE IMPORTANCE OF TERRITORIAL BEHAVIOR AMONG BLUE TITS (PARUS-CAERULEUS) BREEDING IN A HOLM OAK FOREST - Clamens, A. (Revue D Ecologie-La Terre Et La Vie, 1987)
In a ringed population of Blue Tits (Parus caeruleus) living in a Holm Oak (Quercus ilex) forest of Languedoc, Southern France, and provided with artificial nest-boxes, territorial behaviour plays a major role in limiting the number of breeding pairs. The experimental removal, or the spontaneous disappearance, of a breeding pair is followed by an increase in size of the territories of the neigbouring pairs, or by the arrival of non-ringed juvenile individuals settling in the vacant territory. In a Holm Oak forest without artificial nest-boxes, territorial behaviour does not play such a role, as the major limiting factor in that case is the number of available tree-holes. Pairs of Blue Tits settled on territories where Downy Oaks (Quercus pubescens) are mixed with Holm Oaks, lay their eggs four days earlier on the average, than Blue Tits breeding in pure Holm Oak forest. However, the number of fledglings per brood, and their body weight at 15 days of age, tend to be smaller. The benefit of a later laying date in pure Holm Oak forest quite likely lies in a better synchronization of the maximum nutritional requirements of the young, and of the period of maximum food availability in the environment.
APSAPSThe following values have no corresponding Zotero field: label: Biodiversidade
Keywords: Biodiversidade; breeding pairs; France; holm oak forests; nest-boxes; Parus caeruleus; Quercus ilex

Influence of particle size and pyrolysis conditions on yield, density and some textural parameters of chars prepared from holm-oak wood - Valenzuela-Calahorro, C; Bernalte-Garcia, A; Gómez-Serrano, V; Bernalte-García, Ma.J. (Journal of Analytical and Applied Pyrolysis, 1987)
Chars were prepared from holm-oak wood (Quercus ilex) using sawdust, cubes (20 × 20 × 20 mm) and octagonal prisms (20 × 20 × 80 mm) by heating in nitrogen under dynamic (sawdust and cubes) and isothermal (sawdust and prisms) conditions to different final temperatures. The yield of char production depends on the wood particle size, heating rate and final temperature. The density of the chars as measured by helium displacement, ϱHe (g/cm3), is influenced by the wood particle size and heating conditions. Chars prepared from holm-oak wood are essentially microporous solids. The apparent surface area and the micropore volume increase only slightly up to the treatment temperature of 500°C, increase greatly up to 800°C and decrease at higher temperatures.
Keywords: biomass; chars; holm-oak; pyrolysis; wood.

Local characterization of vegetation through growth forms: Mediterranean Quercus ilex coppice as an example - Floret, C; Galan, N J; Floc'h, E; Orshan, G; Romane, F (Plant Ecology, 1987)
Growth forms are considered from two viewpoints: a descriptive and a functional one. Mono-character growth forms and their biological spectra were used to test whether they can characterize certain underlying processes in Quercus ilex coppice in southern France. Correspondence analysis of 35 mono-character growth forms of 203 described taxa shows that location of renewal buds is a good integrating indicator of plant adaptations to the environment. Two of these characters (renewal bud location, Le. Raunkiaer's main life forms, and leaf consistency) appear to vary significantly along a gradient of increasing environmental constraints, especially climatic ones.
Keywords: coppice; growth form; Life form; Mediterranean climate; Quercus ilex L; Southern France

NEOFORMATION OF SOMATIC EMBRYOS-LIKE STRUCTURES FROM CORK-OAK (QUERCUS-SUBER L) TISSUE-CULTURES - ELMAATAOUI, M; Espagnac, H (COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES, 1987)
Embryoid-like formations were induced on cork-oak (Quercus suber L.) calluses grown in vitro on Murashige and Skoog's médium, supplemented with IBA and BAP. Thèse formations rapidly differenciated an apical meristem, flanked with two cotylédons, and a radicular meristem on the opposite end. In most cases embryoids' development stopped there, as if meristems became dormant immediately after their organization. But under certain culture conditions these somatic embryos can produce a great number of secondary embryoids. This multiplication capacity seems to be maintained over generations

NEOFORMATION OF SOMATIC EMBRYOS-LIKE STRUCTURES FROM CORK-OAK (QUERCUS-SUBER L) TISSUE-CULTURES - ELMAATAOUI, M.; ESPAGNAC, H. (COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES, 1987)
Embryoid-like formations were induced on cork-oak (Quercus suber L.) calluses grown in vitro on Murashige and Skoog's médium, supplemented with IBA and BAP. Thèse formations rapidly differenciated an apical meristem, flanked with two cotylédons, and a radicular meristem on the opposite end. In most cases embryoids' development stopped there, as if meristems became dormant immediately after their organization. But under certain culture conditions these somatic embryos can produce a great number of secondary embryoids. This multiplication capacity seems to be maintained over generations
The following values have no corresponding Zotero field: pub-location: 127 AVE DE LA REPUBLIQUE, 92120 MONTROUGE, FRANCE publisher: JOHN LIBBEY EUROTEXT LTD

Palynology of the 112.8–197.8 m interval of the core Tenaghi Philippon III, Middle Pleistocene of Macedonia - Van Der Wiel, A M; Wijmstra, T A (Review of Palaeobotany and Palynology, 1987)
In this article the palynological record of the Tenaghi Philippon III core (112.8–197.8 m) from the Philippi Plain in Greece is discussed. The arboreal pollen diagrams show an alteration of steppe phases (representing glacial periods) and oak forest phases (coinciding with interglacial periods). A proposal for a local biostratigraphy is given and a preliminary correlation is suggested with the Northwest European subdivision of the Middle Pleistocene. From the AP diagrams it appears that the flora is gradually impoverished in Arcto-Tertiary elements and obtains a more mediterranean character. In this section, however, the real mediterranean forest, rich in Quercus ilex/coccifera type is not yet present, which implies that a warm humid climate dominated with rainfall throughout the year. The presence of a great number of Tertiary pollen, two sterile intervals and clastic sediment in the lower part of the core, while from 181.6 m upwards organic sediment is found, indicates a change in sedimentation regime around a depth of 182 m. The sedimentation regime changed from fluvatile to lacustrine as a result of the aftermath of tectonic events. Chronostratigraphy of the diagrams is based on radiocarbon dates from the TF2 core, paleomagnetic polarity determinations in the TF3 core as well as interpolations between the two. In this way the core was dated at 900,000-approx. 600,000 yr B.P. A correlation with deep-sea Core V28–239 is proposed. From this correlation it appears that both in the diagrams and in the oxygen isotope curve the glacial and interglacial periods of the Middle Pleistocene are of a different wavelength and amplitude as compared to the ones of the Upper Pleistocene.
Keywords: Biostratigraphy; Chronostratigraphy; palynology; vegetation history (PG)

Some autecological data on the Urodeles of Sardinia - Voesenek, L.A.C.J.; van Rooy, P.T.J.C.; Strijbosch, H (Amphibia-Reptilia, 1987)
In the spring of 1984 an ecological investigation on the endemic salamanders Hydromantes genei flavus and Euproctus platycefihalus was carried out in eastern Sardinia. The investigation was focussed on natural population sizes and densities. The Sardinian cave salamander was found to occur in two clearly distinct habitats, viz. humid holm oak forests and limestone caves. The density found in the forests was 300/ha and 98 ± 7 individuals were found in one cave. The Sardinian brook salamander was found in a habitat not reported before, viz. a stagnant mountain lake. There the animals were rather robust, and a neotenic specimen was captured.
Keywords: Euproctus platycefihalus; Hydromantes genei flavus; Sardinia (PG)

Structural studies of a hemicellulose B fraction from the cork of Quercus suber - Asensio, Amparo (Carbohydrate Research, 1987)
Polysaccharide B-2 contains xylose, arabinose, glucose, galactose, 4-0-methylglucuronic acid, and rhamnose in the molar ratio of 17: 12: 12:6:4: 1. The polysaccharide has a backbone of P(1-4)- and P( 1-3)-linked glucopyranosyl, P(lk4)-linked xylopyranosyl, and (1-4)- and (1-6)-linked galactopyranosyl residues. Arabinofuranosyl, rhamnopyranosyl, and some xylopyranosyl and galactopyranosyl groups are present as nonreducing end units. Glucopyranosyluronic acid side chains are attached at 0-2 of some xylose residues. The anomeric configurations of the different glycosyl groups were determined by a study of the chromium trioxide oxidation of the acetylatcd polysaccharide and by nuclear magnetic reasonance spectra of the methylated polysaccharide.
PGPG
Keywords: acid hydrolysis; chromium trioxide oxidation; methylation analysis; NMR; Polysaccharide B-2; Structural analysis

Substance for recovering oil from water, etc. - esp. comprising pretreated cork - A, JONES J (1987)
A substance for recovering oil and similar cpds. from the surface of water and other substrates is claimed. The substance is cork from the cork oak (Quercus suber) which has been heated under pressure and then comminuted to less than 5mm to give a prod. with an oil sorption capacity of 5-10 times its own lot. Sorbed oil can be recovered from the cork by pressing, centrifuging, solvent extraction and/or distn., or it can be incinerated in situ or after removal from the substrate. The cork may be packaged in an oil-permeable pillow, sock or blanket. It may be used to recover oil from sand and/or shale by intimate mixing and subsequent sepn.

Comportement alimentaire d'un troupeau caprin dans un taillis de chêne vert - MEURET, M; LECRIVAIN, Elisabeth; LECLERC, Bernadette (Reprod. Nutr. Dévelop., 1986)
By studying the grazing behaviour of a flock of goats in an holm-oak copse, data were obtained on the intake rate and the botanical composition of the diet.
Keywords: caprins; chêne vert (voyant); comportement alimentaire

La régulation des populations de Lymantria dispar (L.) (Lép., Lymantriidae) en suberaie marocaine atlantique: effets du climat, des entomophages et des facteurs anthropiques - Fraval, A (Journal of Applied Entomology, 1986)
Abstract Lymantria dispar (L.) (Lep., Lymantriidae), the Gypsy Moth, is a major pest in several forest areas from Japan to U.S.A. On the atlantic coastal plains of Morocco host-plant is cork oak, Quercus suber (L.). Depending upon the forests, its populations are latent or cyclic. In this later case, population dynamics are governed by quantitative and qualitative variations of the food provided by the tree (Fraval 1984).This paper deals with other factors acting as population regulators. Climate may have mainly indirect effects, modifying nutritional substrate. There are few natural enemies and we never observed any epizootic; gypsy moth population are affected by sudden and heavy mortalities triggered by trophic factors. Entomophagous insects rarely are efficient. Human activities have multiple effects upon cork oaks forests: trees are weakened and become more favourable to the insect pest; controlling measures are seldom. The mode gypsy moth population regulation that is described here seems to be specific. Résumé Lymantria dispar (L.) (Lép.; Lymantriidae) est un ravageur redoutable de diverses forêts, depuis le Japon jusqu'aux U.S.A. Dans les plaines de la bordure atlantique du Maroc, il vit sur Chêne-liège, Quercus suber (L.); selon les forêts, ses populations demeurent très peu denses (mode latent) ou bien passent par des phases de pullulation entrecoupées de périodes de latence (mode cyclique). Dans ce dernier cas, les variations quantitatives et qualitatives de l'alimentation, dues aux particularités de Q. suber, gouvernent la dynamique de ses populations (Fraval 1984). Les rôles d'autres facteurs sont examinés ici. Le climat semble agir surtout de façon indirecte, en modifiant le substrat alimentaire. Les ennemis naturels sont peu diversifiés et aucune épizootie n'a été remarquée; leurs populations sont sous la dépendance des mortalités brutales et massives engen-drées par le jeu des facteurs trophiques. L'impact des entomophages est le plus souvent négligea-ble. Les actions de l'Homme sont multiples dans les suberaies; la plupart affaiblissent les arbres, en les rendant plus favorables au ravageur; les interventions de lutte sont exceptionnelles. La façon dont les populations de L. dispar sont régulées apparaît originale. Zusammenfassung Zur Populationsregulation bei Lymantria dispar (L.) (Lep., Lymantriidae) in Korkeichenwäldern West-Marokkos: Einwirkungen des Klimas, der Entomophagen und des MenschenDer Schwammspinner, der von Japan bis zu den USA verbreitet ist, findet in Marokko in der Korkeiche, Quercus suber, seine Wirtspflanze. In Abhängigkeit von den Baumbeständen sind seine Populationen latent oder sich zyklisch vermehrend. Im letzteren Fall wird seine Populationsdynamik von den quantitativen und qualitativen Veränderungen des Nahrungswerts der Blätter bestimmt.Die vorliegende Arbeit behandelt die anderen Regulationsfaktoren. Das Klima hat vor allem indirekte, die Nahrung beeinflussende Wirkung. Es gibt wenige natürliche Feinde, und es werden niemals Epizootien beobachtet. Die Populationsdynamik des Schwammspinners wird durch plötzliche und starke Schwankungen unter dem Einflußtrophischer Faktoren bestimmt. Entomo-phage Insekten sind selten wirksam. Die Aktivitäten des Menschen resultieren in einer Schwächung und Schädlingsdisponierung der Bäume. Bekämpfungsmaßnahmen werden selten durchgeführt. Der hier beschriebene populationsdynamische Modus scheint artspezifisch zu sein.
Keywords: Cork oak forests; human activities (PG); Lymantria dispar; Population Dynamics; trophic factors

Model for a new sylvo-pastoral system in the Mamora cork-oak forest - Montoya Oliver, Jose Miguel (Landscape and Urban Planning, 1986)
The Mamora cork forest (central Morocco), located on sandy soils in the Moroccan coastal plain where the climate is semiarid (annual rainfall, depending on the zone, in the range 400–600 mm) with very dry summers and temperate-warm winters, covers 60 000 ha and is the largest cork forest in the world. The trees in this forest are vital in that they protect and improve the pasture growing beneath them, as well as producing abundant fruit that can be eaten by livestock, and foliage which can serve as emergency feed. This, combined with its special geographic/regional location, makes Mamora an important pasturing area. It also produces some 40% of Moroccan cork and is therefore of great sylvicultural and industrial significance also, making it a sylvo-pastoral area of major economic and social importance at both regional and national levels.
Keywords: activité forestière; écologie; élevage; emploi; forêt; prairie; PVD (citation); utilisation du sol

Multi-species pattern analysis of Mediterranean pastures in three stages of ecological succession - Castro, Isabel; Sterling, Agustina; Galiano, E F (Plant Ecology, 1986)
Multi-species patterns were analyzed in three stages of ecological succession in oligotrophic pastures in Central Spain using a new method of analysis. The method is based on plotting the species coordinates of principal components analysis undertaken at different block sizes. It allows the detection of any heterogenei- ty present and reveals both microtopographical and macrotopographical trends in species patterns.
Keywords: grassland; mediterranean pasture; pattern analysis; principal components analysis; succession

Orígenes y expansión de la dehesa en el término de Cáceres - García Oliva, M. Dolores (Studia historica. Historia medieval, 1986)

PARTICIPACION DE Diplopia sp. EN EL ESCALDADO DEL ALCORNOQUE - Oliva i Estanyol, M; Molinas de Ferrer, M L (Scientia gerundensis, 1986)
This paper describes the association of Diplodia sp., a Sphaeropsidal fungus, with a new form of (<escaldat)) (dieback associated with trunk lessions) that we call <xancre secu (dry canker) in the cork-oak, Quercus suber L. The dry canker is a complex syndrome consisting of wilting and trunk canker lessions. The disease occurs in an acute form and then the tree dies quickly after cork removal; or it can follow an insidious form and the tree can react and form several layers of cork before dying. A description of the simptomatology is given. The fungus Diplodia sp. is isolated from diseased trees and it has infectious capatity on the living tissues. The isolate has conidial characteristics that slightly differ from other Diplodia parasitic in Quercus. Because the taxonomic revision of the genus is lacking we have not given an species name. The relation between ecological stress and disease is emphasized and some possible preventive measures are given.
Keywords: canker; cork-oak; forest pathology; Quercus suber L.; wilt

Production and spatial structure of Mediterranean pastures in different stages of ecological succession - Casado, M A; Miguel, J M; Sterling, A; Peco, B (Plant Ecology, 1986)
The aim of this paper is to describe the changes of Mediterranean pasture phytomass and their dependence on succession, slope geomorphology and herbivore consumption. Four neighbouring slopes of similar aspect and steepness, located in a pasture area of Central Spain, were chosen for sampling. The slopes had not been cultivated for 1, 3, 8 and 40 years respectively. On each slope both the upper, erosion zone and the lower, accumulation zone were sampled during the months of plant growth (April to July), phytomass being record- ed in plots where herbivore consumption was avoided with protection cages and in unprotected plots. Results from the protected plots show that the upper and lower parts of slopes undergo a different develop- ment during succession. The highest values of phytomass reached, tended to decrease during succession in the upper zones, the same being true for production. However in the lower zones both parameters tended to increase in time. The ratio P/B, widely known in ecology to decrease with time, did not seem to behave as a usual index of succession in the studied ecosystem. In the upper zone this ratio tended to decrease but in the lower zone it increased with succession after the first years. Phytomass consumption by herbivores was progressively concentrated during succession in the slope sec- tors of greater production, mainly in the lower zone, which increased its productivity as the slope-talweg sys- tem became functional. The evolution of the ecological structure of a slope should be interpreted not only as a result of the tolerance of species to phsysico-chemical factors. It may also reveal the existence of an im- portant interaction between the pasture and the grazing behaviour of exploiting animals. Multivariate analy- sis of phytomass records revealed a trend of temporal variation which should be identified with the progress
Keywords: herbivore consumption; mediterranean pasture; primary production; slope geomorphology; spatial structure of phytomass; succession

Successional changes in the morphology and ecological responses of a grazed pasture ecosystem in Central Spain - Sal, A Gomez; Miguel, J M; Casado, M A; Pineda, F D (Plant Ecology, 1986)
Morphological characteristics related to spatial occupation, reproduction and adaptations to grazing were used to characterize the most frequent species in a therophytic pastureland of Central Spain. Periodic ploughing is a traditional practice in these pastures and allows observation of successional change. In the present study, four neighbouring slopes of differing time since last ploughing were chosen. Species biomass was measured at different times during the annual growing season for two different slope positions. Grazing pressure is an important environmental factor affecting ecosystem organization, the most palata- ble plants tending to show increasing biomass with succession. In the most mature stages, there is a predomi- nance of species characterized by horizontal occupation of space and sprouting after mowing or grazing. During succession segregation of the different morphological characteristics occurs in slope sectors related to geomorphological dynamics. Similarly, phenological development tends to be later in pastures in the lowest slope zones, due probably to their greater summer soil moisture content.
Keywords: ecosystem exploitation; Grazing; herbivore; mediterranean pasture; Phenology; phytomass; Plant morphology; succession

Ultrastructural Changes in Chloroplasts of Quercus rotundifolia Lam. in Response to Evernic Acid - ASCASO, C; RAPSCH, S (Annals of Botany, 1986)
The amount of total chlorophyll, chlorophylls a and b as well as the ratio of a to b decreased in chloroplasts isolated from Quercus rotundifolia leaves, kept for 17 d in a solution of 35.5 μM evernic acid in 1 mM Na HCO3, when compared with the chloroplasts of control leaves (kept in NaHCO3). The chloroplasts in the spongy parenchyma were smaller and the amount of starch and plastoglobuli lower. The number of grana per chloroplast section, the number of thylakoids per grana and the height of grana stacks were also less in the chloroplasts of leaves treated with evernic acid. Quantitative ultrastructural differences were determined by means of electron microscopy and image analysis techniques.
Keywords: chloroplasts; evernic acid; lichens; Quercus rotundifolia Lam.; ultrastructure

Chioroplast-ultrastructure and chlorophyll contení in leaves from Quercus branches with and without epiphytic lichen thalli - ASCASO, C (Plañí, Cell and Environment (1985), 1985)
The effect that the massive presence of lichen thalli growing on the branches of Quercus pyrenaica and Q. rotundifolia leaves has on their chloroplasts been studied. In both species there were significant decreases in the amount of chlorophylls in the leaves of twigs with a dense cover of lichens in comparison with the leaves from thallus-free twigs. The áreas and perimeter of chloroplasts in leaves from twigs with epiphytes did not differ significantly from those in leaves without epiphytes. However, in leaves with epiphytes the percentage of chloroplast área occupied by starch was higher. In Q. pyrenaica the number of grana per chloroplast section and per //in2, the percentage of chloroplast stroma occupied by grana, the average number of thylakoids forming grana and the grana width was significantly smaller in leaves near lichen populations. These results are discussed and related to the great chelating capacity of the lichen's substances.
Keywords: chlorophyll content; chloroplast-ultrastructure of Quercus

Effects of temperature at constant air dew point on leaf carboxylation efficiency and CO 2 compensation point of different leaf types - Weber, J. A.; Tenhunen, J. D.; Lange, O. L. (Planta, 1985)
The effect of temperature on photosyn- thesis at constant water-vapor pressure in the air was investigated using two sclerophyll species, Ar- butus unedo and Quercus suber, and one meso- phytic species, Spinacia oleracea. Photosynthesis and transpiration were measured over a range of temperatures, 20-39 ~ C. The external concentra- tion of CO 2 was varied from 340 ~tbar to near CO 2 compensation. The initial slope (carboxylation effi- ciency, CE) of the photosynthetic response to inter- cellular CO 2 concentration, the CO 2 compensation point (/-), and the extrapolated rate of CO 2 re- leased into COa-free air (Ri) were calculated. At an external CO 2 concentration of 320-340 labar CO2, photosynthesis decreased with temperature in all species. The effect of temperature on F was similar in all species. While CE in S. oleracea changed little with temperature, CE decreased by 50% in Q. suber as temperature increased from 25 to 34 ~ C. Arbutus unedo also exhibited a de- crease in CE at higher temperatures but not as marked as Q. suber. The absolute value of Ri in- creased with temperature in S. oleracea, while changing little or decreasing in the sclerophylls. Variations in F and Ri of the sclerophyll species are not consistent with greater increase of respira- tion with temperature in the light in these species compared with S. oleracea.
Keywords: Carboxylation efficiency; Compensation point (CO2); Photosynthesis (temperature-humidity); Sclerophyll; Transpiration

H-1 AND C-13 NMR SPECTROSCOPIC STUDY OF EXTRACTS FROM CORKS OF RUBUS-IDAEUS, SOLANUM-TUBEROSUM, AND QUERCUS-SUBER - ZIMMERMANN, W; NIMZ, H; SEEMULLER, E (HOLZFORSCHUNG, 1985)
Pre-extracted corks from Rubus-ideaus L., Solanum-tuberosum L., and Quercus-suber L., were milled in a vibrational ball mill. The material released was extracted with aqueous dioxane and DMF, Gel permeation chromatography of the extracts resulted in high and low molecular weight fractions. 3H and 13C NMR spectroscopic examination revealed that these fractions consisted mainly of saturated and unsaturated aliphatic compounds, alcohols, acids and esters. Aromatic substances could early be detected in very small amounts. Signals correspinding to guaiacyl, syringyl, and dilignol units were not found indicating that lignin is not prevent in the examined cork extracts.
Keywords: 1H and 13C NMR; aromatic substances; Cork; Quercus suber; Rubus idaues; Solanum tuberosum; suberin

Changes in photosynthetic capacity, carboxylation efficiency, and CO 2 compensation point associated with midday stomatal closure and midday depression of net - Tenhunen, J D; Lange, O L; Gebel, J (Planta, 1984)
The carbon-dioxide response of photo- synthesis of leaves of Quercus suber, a sclerophyl- lous species of the European Mediterranean re- gion, was studied as a function of time of day at the end of the summer dry season in the natural habitat. To examine the response experimentally, a "standard" time course for temperature and hu- midity, which resembled natural conditions, was imposed on the leaves, and the CO 2 pressure exter- nal to the leaves on subsequent days was varied. The particular temperature and humidity condi- tions chosen were those which elicited a strong sto- matal closure at midday and the simultaneous de- pression of net CO 2 uptake. Midday depression of CO 2 uptake is the result of i) a decrease in CO2- saturated photosynthetic capacity after light satu- ration is reached in the early morning, ii) a de- crease in the initial slope of the CO 2 response curve (carboxylation efficiency), and iii) a substantial in- crease in the CO 2 compensation point caused by an increase in leaf temperature and a decrease in humidity. As a consequence of the changes in pho- tosynthesis, the internal leaf CO 2 pressure re- mained essentially constant despite stomatal clo- sure. The effects on capacity, slope, and compensa- tion point were reversed by lowering the tempera- ture and increasing the humidity in the afternoon. Constant internal CO 2 may aid in minimizing photoinhibition during stomatal closure at midday. The results are discussed in terms of possible tem- perature, humidity, and hormonal effects on pho- tosynthesis.
Keywords: Carboxylation efficiency; Compensation point (CO2); Photosynthesis (temperature- humidity); Quercus; Sclerophyll

Flora briologica della lecceta di Monte S. Angelo (Foggia) - Pedrotti, Carmela Cortini; Troiano, Raffaella (Giornale botanico italiano, 1984)
Abstract The bryological flora of the Mt. S. Angelo (Foggia) Quercus ilex wood. - The authors have carried out a study on the bryological flora of the Mt. S. Angelo Quercus ilex wood, on the Gargano peninsula (Italy). After a brief survey of climate and vegetation, a list of 69 bryophytes is given: 6 species of liverworts and 63 species of mosses. 27 species belong to the circumboreal element, 26 are mediterranean, 13 cosmopolitan and 3 atlantic. Some comparisons with other zones of the mediterranean area are given.
doi: 10.1080/11263508409426672
Keywords: Bryophyte flora; Foggia (PG); Quercus ilex woods

Free and bound hydroxyl and carboxyl groups in the cutin of Quercus suber leaves - Agulló, C; Collar, C; Seoane, E (Phytochemistry, 1984)
The number of free and bound hydroxyl and carboxyl groups of the cutin of Quercus suber leaves was investigated by the lithium borohydride hydrogenolysis of mesyl-cutin compared with the lithium borohydride hydrogenolysis of untreated cutin. Fifty per cent of the vic-diol groups of the trihydroxy C18 acid component and twenty five per cent of the secondary hydroxyl groups of the dihydroxy C16 acid component are free. The rest of the secondary and all of the primary hydroxyl groups are esterified; all carboxyl groups are esterified.
Keywords: cutin; Fagaceae; free hydroxyl groups; hydrogenolysis; leaves; mesyl-cutin; Quercus suber

Influence de la qualité et de la quantité de l'alimentation sur les fluctuations des populations de Lymantria dispar L. (Lep. Lymantriidae) en forêt de la Mamora (Maroc) - FRAVAL, Alain (Agronomie, 1984)
Lymantria dispar L. est un ravageur cyclique des suberaies de la bordure atlantique du Maroc. L’abondance du feuillage qualitativement satisfaisant offert par l’arbre-hôte, Quercus suber L., varie largement en fonction de l’année et de l’intensité du débourrement. Différentes situations trophiques ont été observées depuis 1976 sur un transect fixe de 7 km de long installé en forêt de la Mamora. Leurs répercussions sur les populations du ravageur sont décrites et examinées à la lumière des résultats d’élevages au laboratoire conduits par HÉ RARD (1984). Il est apparu en outre que Q. suber ne débourre pas ou bien débourre très tardivement l’année suivant sa défo- liation par L. dispar. La régulation des populations est assurée, dans un premier temps, par la famine consécutive à la défoliation complète puis, à la génération suivante, par le défaut qualitatif de nourriture dû à la réaction de Q. suber. Ce mécanisme n’explique pas seul les fluctuations de populations du ravageur enregistrées à l’échelle de la forêt.
Keywords: alimentation; discordance phénologique; Quercus suber L.; relations plante-insecte

Inhaltsstoffe von Cupuliferae, 8. Ein neues, hoch acyliertes Astragalin aus Quercus ilex L. - Romussi, Giovanni; Sancassan, Fernando; Parodi, Brunella; Bignardi, Gaetano (Liebigs Annalen der Chemie, 1984)
Constituents of Cupuliferae, 8. — A Novel, Highly Acylated Astragalin from Quercus ilex L. From leaves of Quercus ilex L. a new, highly acylated astragalin has been isolated and identified as 3-O-kaempferol 3,6-di-O-acetyl-2,4-di-O-(p-coumaroyl)-β-D-glucopyranoside (1).

Inhaltsstoffe von Cupuliferae, 9. Ein ungewöhnlicher Diester des Astragalins mit cis- und trans-p-Cumarsäure aus Quercus ilex L. - Romussi, Giovanni; Parodi, Brunella; Sancassan, Fernando (Liebigs Annalen der ChemieLiebigs Annalen der Chemie, 1984)
Constituents of Cupuliferae, 9. — An Unusual Diester of Astragalin with cis- and trans-p-Coumaric Acid from Quercus ilex L. From leaves of Quercus ilex L. a new acylated astragalin has been isolated and identified as 3-O-kaempferol 2,6-di-O-(trans/cis-p-coumaroyl)-β-D-glucopyranoside (1).

Leaf fall as a source of leaf miner mortality - Pritchard, I M; James, R (Oecologia, 1984)
Leaf miner deaths resulting from the death of their leaves were assessed by collecting falling leaves of holm oak and beech. The PhylIonorycter mines thus cap- tured were examined to ascertain the cause of death. For both mining species the mortality from leaf shedding ac- counted for less than 2.8% of the mining cohorts. It is argued that the level of mortality is insufficient for popula- tion regulation, as has been previously suggested.
Keywords: leaf miners; leaf shedding; Mortality (voyant)

Melophia ophiospora Lev. Sacc., mutatis characteribus, a phellophagic fungus on cork-oak - Speer, E O (Mycotaxon, 1984)
APS
Keywords: Fungus; Holm oak; Pragas e doencas - Melophia ophiospora

Métodos rápidos para evaluar la capacidad germinativa de las semillas de QUERCUS SUBER L. - Sobrino, E; Soriano, J M; Viviani, A B; González, a (III Congreso Forestal Español Congreso, 1984)
The cork oak ( Q. Suber L. ) has recalcitrant seeds, therefore without proper conservation methods, the seeds quickly loose the germinating capacity. The germination analysis methodology proposed by ISTA takes a long time in order that the germinating capacity may be reduced substantially. With the object of estimating in real or nearly real time, the germinating capacity of seed lots, different methods which are quick and easy are studied and compared. Regression curves and correlation coefficients are established between the proposed methods and germinating capacity, obtained experimentally with ISTA methodology. The methods use seeds between 0 and 12 days old at 30ºC and 33% of relative humidity. The proposed methods which present higher levels, ( in experimental conditions and with the Regression adjusted methods obtained ) are: the acorns’ humidity content with a linear function ( r= 0,98 ), the cotyledons’ pH with a lineal function ( r= -0,98 ), the acorns’ apparent respiration with a parabolic function ( r= 0,97 ) and the acorns’ density with a parabolic function ( r= 0,97 ).
Keywords: germination; Quercus suber; quick germination-test; recalcitrant seed

Coenological research on macrofungi in evergreen oak woods in the hills near Siena (Italy) - Dominicis, V; Barluzzi, Carla (Plant Ecology, 1983)
For a mycocoenological study of macromycetes in Mediterranean evergreen forests in the Sienese pro- vince, five stands belonging to the Quercion ilicis have been observed during more than two years. The phytosociological analysis of these evergreen oak woods, situated at the limit of the geographical distribution of the alliance, reveals them as intermediate between the typical Mediterranean vegetation and the sub-Mediterranean deciduous broad-leaved forests. 181 fungal species were recognized and assigned to seven ecological groups on the basis of substratum, habitat, forest management and/or particular mycorrhizal relationship. Our results have been compared with those obtained in some European deciduous forests. Such a comparison shows the occurrence of 16 thermophilous fungal species in the Siena woods which are missing or very rare in the European deciduous forests. On the basis of our present knowledge, five of these species ( Boletus lepidus, Hygrophorus dichrous, Hygrocybe nigrescens, lnocybe similis, Phellinus torulosus) may be considered as strictly tied to the evergreen oak woods. Five others, which have been reported for several European phytocoenoses, seem to be 'preferential taxa' of our evergreen oak woods, namely: Cortinarius calochrous, C. sodagnitus, Hygrophorus arbustivus, H. russula, Lyophyllum immundum. On the whole the highest similarities have been found with the more xerothermophilous European forests (Querco-Lithos- permetum and Sorbo-Quercetum). The presence in the Quercus ilex woods of numerous more mesophilous fungi, some of which are widespread in beech forests, underlines the transitional nature of the phytocoenoses studied.
Keywords: fungi; macromycetes; mycocoenology; phytosociology; quercus ilex coppices; toscana

Crecimiento de terneros lactantes y producción lechera de un rebaño de vacas Retinto en la Dehesa - Martin Bellido, M (Pastos, 1983)
Calves growth and milk production of Retinto beef cows were studied in Southwest of Spain. Data were taken in 1979-80 and 1980-81 at «El Gaitán» ranch located at the San Pedro mountain (Cáceres). Calves were weighed at birth and later from 20 days of age until weaning (~ 7 months) each 35 days, also was estimated milk production by the calf nursing method. Environmental factors considered in the study were: calving season, sex, year, and two-way interactions among these factors, and the linear and quadratic effeets of age of cow, gestation number and age of calf. In the study of calves growth were also considered the linear and quadratic effeets of milk production. Using the stepwise regression technique, the variables which have more influence on calf growth and milk production accumulated at wean- ing have been selected. The nine variables selected for calf growth explain- ed 94.6 % of the variability, being calf age and milk production the most important (R2 = 91.9%); when calf age is excluded from the model, milk production itself explains 77.6 % of the variation on calf growth. Consi- dering milk production as a dependent variable, a group of seven varia- bles explained 72.6 % of the variability of this characteristic, being the suckling days the variable that affects more to this response (R2 = 66.7 %). 174
Keywords: crecimiento de terneros; Dehesa; edad del ternero; producción lechera; sistema extensivo (voyant)

Determination of hemicellulose, cellulose and lignin contents of dietary fibre and crude fibre of several seed hulls. Data Comparison - Saura-Calixto, F; Cañellas, J; Garcia-Raso, J (Z Lebensm Unters Forsch, 1983)
The contents of hemicellulose, cellulose and lignin in neutral-detergent fibre, and acid-detergent fibre in hulls of hazelnuts, peanuts, coconuts, sun- flower seeds, p u m p k i n seeds, acorns and chestnuts were determined. Similar cell-wall characteristics for sunflower-acorn, peanut-pumpkin and hazelnut-chest- nut pairs can be deduced from their similar composi- tion. High amounts of hemicellulose and lower ones of cellulose and lignin are dissolved in the process of de- termining crude fibre. The results are discussed.
Keywords: Cellulose; hemicellulose; hulls (PG); Lignin

Ein neues acyliertes flavonoidglycosid aus Quercus ilex L. - Romussi, Giovanni; Cafaggi, Sergio; Ciarallo, Giovanni (Liebigs Annalen der Chemie, 1983)
From leaves of Quercus ilex L. a new acylated flavonoid glycoside has been isolated and identified as kaempferol-3-O-[2,4-(di-p-coumaroyl)-β-D-glucopyranoside]
APS
Keywords: acyclated flavonoid glycoside

Estudio comparativo de la movilización de bioelementos por los subsistemas arbóreo y herbáceo del ecosistema de Dehesa - Escudero Berian, A; Montalvo Hernândez, M I; GARCÍA CRIADO, B; Gomez Gutiérrez, J M (Pastos, 1983)
The quantity of various elements such as N, P, K, Ca, Mg, Na, Fe, Cu, Mn and Zn, mobilized annually by the two phytocoenotic components of the «dehesa» ecosystem has been evaluated from the data collected over two consecutive years. For this purpose, zones dominated by Oaks (Quer- cus rotundifolia Lam. and Q. pyrenaica Willd.) were selected, and, based on the annual nutrient input of the soil throug leaf litter and other re- sidues, the quantity of minerals removed was estimated. In the same lo< cations, nutrients removed from pastures were also estimated in áreas with and without tree cover. From the results obtained, comparisons have been made between the two phytocoenotic components of the «dehesa». Conclusions have been formulated regarding the recycling tendencie exhibited by each nutrient element, based on the results obtained from internutrient comparisons. The role of tree cover in regulating the rate of nutrient cycling and conservation of nutrient reserves in the ecosystem, has also been eva- luated. 20

Evolution après incendie de la structure de quelques phytocénoses méditerranéennes du Bas-Languedoc (Sud de la France) - Trabaud, L (Ann. For. Sci., 1983)
L’évolution de la structure de la végétation des garrigues après incendie a été étudiée sur 47 placettes réparties dans le Bas-Languedoc. C’est la méthode directe (ou diachronique) qui a été utilisée pendant la douzaine d’années qu’ont été suivies les placettes incendiées. Huit types de communautés végétales représentatives de la région ont été étudiés, allant des taillis de chêne vert aux pelouses de brachypodes. Après le feu, l’accroissement quantitatif de la végétation tend à retourner vers une structure comparable à celle qui existait avant l’incendie. Assez rapidement, la végétation réapparaît et recouvre la surface du sol. L’accroissement vertical a été aussi considéré : au fur et à mesure que les communautés vieillissent, l’importance des strates basses ([ 25 cm) diminue, tandis que celle des strates hautes augmente.
Keywords: accroissement vertical; communautés végétales; feu; recouvrement (voyant); végétaux herbacés; végétaux ligneux

Influencia de la suplementación proteica en las producciones del cerdo Ibérico en la Dehesa - LÓPEZ DE TORRE, GUILLERMO; BENITO HERNÁNDEZ, JOSÉ; FERRERA CLARAMONT, JOSÉ LUIS (Pastos, 1983)
The effect of adding 15 percent soybean meal to the summer cereal ration has been studied. Also the addition of 15 percent vs 5 percent soy- bean meal to a cereal mixture has been compared during the fattening period in the autumn when they were giving oak acorns under grazing conditions. Those effects were measured on weights at the end of sum- mer and fall, gains, feed effeciency and carcass characteristics. Four groups of 20 castrated pigs (10 males and 10 females) chosen at random were made. Average rate of gain was higher (460 vs 395 gr./day, p <^ 0,01) and food conversión was better (3,98 vs 4,64) for pigs receiving 15 percent soybean meal during summer. Protein contení of ration during fall while grazing on the oak fields did not affect gains. Carcass characteristics were not influenced by summer protein percent and, only some of them as carcass yield and back fat thickness were affected by fall protein percent. Sex affected all weights and gains considered. These results suggest that high protein rations during summer may result in improved productions at the end of the following acorn crop period. PASTOS
Keywords: aumento de peso; cerdo Ibérico (voyant); Montanera; suplementación de proteína

Inhaltsstoffe von Cupuliferae, 6. Ein neues Triterpensaponin aus Quercus ilex L. - Romussi, Giovanni; Bignardi, Gaetano; Sancassan, Fernando; Falsone, Gioacchino (Liebigs Annalen der Chemie, 1983)
Constituents of Cupuliferae, 6. - A Novel Triterpene Saponin from Quercus ilex L. From leaves of Quercus ilex L. a new triterpene saponin has been isolated and identified as the α-D-glucopyranosyl ester 3 of the 2α,3β,19α,23-tetrahydroxy-12-ursen-28-oic acid (1).

Mise en évidence de la dynamique de quelques écosystèmes forestiers et préforestiers provençaux aux étages méditerranéens SL à l'aide des taxons indicateurs - Bonin, G; Aubert, G; Barbero, M; Gamisans, J (Plant Ecology, 1983)
Evidence is presented for dynamic successions in the Provence on the basis of a multivariate analysis, of a very large sample. Different phases in the Quercus suber series on silicious substrate are shown. Also the evolution of the vegetation groupings on Ventoux and Sainte-Baume mountains on calcareous substrate and at different levels in the zonation is specified. The succession of the grasslands is as follows: Isoetes and Nasturtium groupings, Serapias, Lotus and Trifolium, then Vulpia and Aira groupings, and finally Helianthemum guttatum grasslands, preceding the shrub groupings: Cistus ladaniferus, then Cistus albidus and Cistus monspeliensis. Then follow either Erica and Calluna maquis or Quercus suber formations. On Mont Ventoux, the stages of degradation of the Quercus pubescens forests are Aphyllantes and Thymus vulgaris grasslands, and Buxus sempervirens and Genista scorpius scrubs. On the oromediterranean level, the transition from Avena setacea and Galium villarsii grasslands, then Ononis caenisia grasslands to Pinus uncinata forests is demonstrated. The development of reforestation is predicted on the basis of the floristic composition of the previous stages. On Sainte-Baume Mountain, the Quercuspubescens supramediterranean series is formed by the following stages: low scrubs of the Lavandulo-Astragaletum, and Prunus mahaleb and Phillyrea media, Acer monspes- sulanum groves, and forests with prevailing Quercuspubescens. The succession on rocky traverses and crests is slightly different. The first stages are Sesleria grasslands and the later ones are woodland groupings of Tilia platyphyllos, Acer opalus and llex aquifolium.
Keywords: Analyse des correspondances; Ecosyst~mes forestiers; France; Provence; Successions dynamiques

Pollen grain morphology supports the taxonomical discrimination of Mediterranean oaks (Quercus, Fagaceae) - Colombo, P M; Lorenzoni, F C; Grigoletto, F (Plant Systematics and Evolution, 1983)
The exine architecture and some quantitative parameters (polar and equatorial axes and their ratio) of pollen grains allow a clear discrimination between groups of Mediterranean oak species. For the differentiation of species within groups only the quoted parameters prove useful.
Keywords: Angiosperms; Fagaceae; Pollen exine architecture; pollen grain size and form; Quercus

Comportement hydrique estival de Cedrus atlantica Manetti, Quercus ilex L. et Quercus pubescens Willd. et de divers pins dans le Mont Ventoux - AUSSENAC, G; VALETTE C., J (Ann. For. Sci., 1982)
La mesure du potentiel de sève au cours des étés 1977 et 1979 a permis de caractériser les potentialités hydriques de quatre stations forestières du versant sud du Mont Ventoux (Vaucluse, France) et les réponses de dix espèces forestières aux facteurs clima- tiques. La mesure du potentiel de sève ( yf ,) au cours des étés 1977 et 1979 a satisfaisantes dans toutes les stations. Des différences systématiques de potentiel de base (Pu) ont été observées et s’expliquent par des évapotranspirations potentielles (E’TI’) plus élevées sur les stations de basse altitude. profondes d’eau, alors que dans les stations climatiquement plus favorables les arbres ont, en année sèche, des dilficultés à s’alimenter en eau, probablement à cause d’un enracine- ment plus superficiel. Associées aux mesures ont permis la détermination des potentiels de base critique (P.,,,). Cedrus atlantica, Quercus ilex, Quercus pubescens, et Acer opulifolium maintient leurs activités transpiratoires et photosynthétiques jusqu’à des niveaux de grande sécheresse (P!%. entre - 30 et - 35 bars). Par contre, les pins bloquent leur activité transpiratoire vers / l - 15 ou - 17 bars. rieures aux limites actuelles de la cédraie. Mais, en relation avec les conditions édaphiques. il pourra s’agir de peuplements clairs et le reboisement économique de ces zones difficiles Sur le plan sylvicole, il apparaît que le cèdre peut être installé à des altitudes infé- passe par la constitution cl’îlots de semenciers susceptibles d’étendre les peuplements n la faveur de séquences climatiques favorables.
Keywords: cèdre; Chêne pubescent; chêne vert; ombre; pin; Potentiel hydrique; rameaux (voyant); réserves en eau

El estudio de los sistemas de producción animal en el sudoeste español. Planteamiento general y diagrama del agrosistema productivo - López Carrión, Tomás; Martín Bellido, Manuel; Espejo Díaz, Manuel; Mora Seco de Herrera, Mariano; González Crespo, José (Anales del Instituto Nacional de Investigaciones Agrarias: Serie Ganadera., 1982)
Se han examinado algunos factores que afectan a los Sistemas de Producción Animal en condiciones extensivas del Suroeste español. Se destacan la fertilización e implantación de es- pecies mejoradas en los pastos naturales de ciertas áreas de la explotación que por sus condi- ciones edáficas o microclimáticas lo permitan; el empleo racional de la suplementación del ganado y cargas ganaderas, con el objetivo de conseguir un óptimo de producción animal y producción por hectárea que no comprometa la capacidad productiva del rebaño ni lleve a una degeneración de los pastos. Habrá que plantear experimentos que sean representativos de un gran número de situacio- nes posibles y para ello habrá que tener en cuenta además de los factores ya citados, a las va- riables biológicas, edáficas y climáticas así como su influencia en el sistema. La medición del consumo, selectividad animal, comportamiento alimenticio y otras, aunque difíciles de estimar en pastoreo, su conocimiento junto con los otros factores llevará consigo el planteamiento de modelos o esquemas que representen el agrosistema de la dehesa y permita simular situaciones y predecir tendencias. Se incluye un diagrama esquemático del agrosistema productivo, y se resalta la importancia del conocimiento de los factores limitantes de la producción, su cuantificación y el uso de diseños especiales que sin pérdida de información minimicen el costo de la experimentación. INTRODUCCION

Les peuplements de fourmis dans la Sierra Morena centrale (Espagne) rapports avec l'exposition et la vegetation - Haeger, J F; González, A R (Insectes Sociaux, 1982)
Le but de ce travail est d'étudier l'influence d'un facteur biotique (la végétation) et d'un facteur abiotique (l'exposition) sur la distribution des especes de fourmis dans une zone de la Sierra Morena Centrale (Sud de l'Espagne). Pour cela, on a r6alis6 des 6chantil- lonnages stratifi6s dans chaque unit6 de v6g6tation, en soulane et en ombrée. L'analyse des correspondances a permis d'abord de s6parer les espèces trouvées dans les principaux types de v6gdtation de la zone d'étude (pâturage, reboisement de pins et zone inondée le long d'une rivière). Quand on supprime les relevés des endroits inondables, on peut distinguer les espèces indicatrices des zones oú prédominent soit le maquis ("matorral") soit le pâtturage ("dehesa"), ainsi que celles des zones exposées en soulane ou en ombrée. Dans la zone reboisée, il est impossible de distinguer des espèces indicatrices des associations végétales caractéristiques du milieu, ce qui peut s'interpréter comme une conséquence de l'homogénéisation due aux pratiques culturales.
Keywords: Espagne; espèces indicatrices; exposition solaire (voyant); fourmis; Maquis; pâturage; sierra morena

Methods of studing canopy cover of Quercus-ilex coppices - Houssard, C; Escarré, J; Romane, F (ACTA OECOLOGICA-OECOLOGIA APPLICATA, 1982)
APS
Keywords: canopy cover; Quercus ilex

Modifications expérimentales de la morphogénèse et des géotropismes dans le système racinaire de jeunes chênes - Riedacker, Arthur; Dexheimer, Jean; Tavakol, Rahmat; Alaoui, Hachimi (Canadian Journal of Botany, 1982)
Seedlings of English oak (Quercus robur L.) and cork oak (Quercus suber L.) grown in minirhizotrons have (i) semiplagiogeotropic lateral roots which reorient their tip when placed in certain positions; their growth is very brief; (ii) taproots which are strongly orthogeotropic when they are short and weakly orthogeotropic when they are 2 m long; (iii) replacement taproots, appearing after a decapitation of the taproot, which are either orthogeotropic or slightly oblique. The orthogeotropic caracteristics of taproots and replacement taproots seem difficult to alter.Deviating, slowing the growth, blocking, or drying the tip of the taproot induces various transformations of lateral roots. Axial growth, radial growth, growth of the ramifications, and geotropism of the lateral roots can be changed separately, but in a certain order. Growth correlations within the root system of young oaks are compared with those already studied in the root system of Theobroma cacao L. The nature of the correlations is discussed.
doi: 10.1139/b82-100

Pattern detection in plant populations through the analysis of plant-to-all-plants distances - Galiano, E F (Plant Ecology, 1982)
A method of sampling and analysis is proposed to detect pattern parameters in plant populations from two-dimensional data. The use of aerial photographs to find the coordinates of trees and the measurements of plant-to-all-plants distances yields conditioned probability spectra which can be interpreted in terms of pattern parameters. Two artificial populations and a set of real data have been analysed to test the accuracy of the method.
Keywords: nearest neighbour; pattern detection; Quercus rotundifolia

Space-time variability in mediterranean pastures analyzed with diversity parameters - Pablo, C L; Peec, B; Galiano, E F; Nicolas, J P; Pineda, F D (Plant Ecology, 1982)
Different parameters of diversity and spatial niche amplitude (Pielou, 1975, Pineda et aL, 1981 b) have been used to describe the spatial organization of mediterranean grasslands in Central Spain. A slope sampled by 480 contiguous 8 X 8 cm quadrats proved to have a homogeneous floristic distribution when it was divided into 160 parts and maximum heterogeneity when divided into 4 sectors. These sectors corresponded to different geomorphological zones of the slope. The complexity of vegetation distribution on the slope was reflected by differences in organization - measured by diversity parameter A = H ( P / E ) / l o g a N (number of plots) between the parts obtained by division. The presence of low-entropy species - specialists - and high entropy species - generalists - was related to the different scales of slope organization. The spatial distribu- tion of plants was compared for different successional stages. Multivariate analysis of sampling plots confirmed previously identified organizational characteristics and clarified the nature of transitions between communities of different floristic composition or structure.
Keywords: diversity; geomorphology; grassland; spatial organization; succession

Análisis de los sistemas de explotación de ganado ovino en la dehesa extremeña - LÓPEZ CARRIÓN, T.; JIMÉNEZ MOZO, J.; ESPEJO DÍAZ, M.; GARCÍA BARRETO, L. J. (Pastos, 1981)
Sheep flock in EXTREMADURA, Spain, accounts for 1.300.000 heads beying the firts province in the national ranking and with 2.300 Tm. of sheep meat, mainly lamb, in 1978. Wool production in Spain was 21.962.517 Kg. with 4.200.000 Kg. in this region for the same year. Response to phosphorus fertilizar of natural pasture, subterranean clover introduction, use of forage for supplementation, management of stocking rate and reproductive systems are the most important tools for increasing outputs in sheep producers. Merino breed, very well adapted to our environment, has a mean to good lamb performance under good management conditions. Wool produc- tion, with no entity in relation to total output, is high and of good quality.
Keywords: manejo de cargas animales (voyant); manejo de pastos; producción de carne; producción de pasto; production de lana

CHARACTERIZATION OF WETCORK IN QUERCUS-SUBER L - PARAMESWARAN, N; LIESE, W; GUNZERODT, H (HOLZFORSCHUNG, 1981)
The wetcork containing more than 400% moisture is developed as islets in the otherwise dry cork tissue of Quercus suber. A characterization using electron moscroscopy yielded no marked differences in the wall structure, except for formation of gaps due to lack of substances in the middle lamella of some wetcork cells. The chemical constitution of the two tissues types equally showed no obvious differences. During drying the wetcork shrinks to a great extent, thus influencing the utilization of such a cork in certain fields of application.
Keywords: chemical constitutions; Fine structure; Moisture content; Quercus suber; shrinkage; utilization; wetcork

Ecological succession in oligotrophic pastures of central Spain - Pineda, F D; Nicolas, J P; Rou, A; Galiano, E F (Plant Ecology, 1981)
The dynamics of oligotrophic pastures were analyzed in the area of El Pardo (Central Spain), and related with geomorphological features and time elapsed since the last ploughing. A sampling of the area was carried out regarding these two factors. The data were subjected to correspondence analysis, which showed the progressive replacement of species related to succession, variation along slopes, with a tight interaction between both phenomena. The correspondence between vegetation change and slope geomorphology is closer as succession progresses.
Keywords: Central Spain; correspondence analysis; geomorphology; grassland; slope; succession

Le pouvoir calorifique supérieur d'espèces forestières méditerranéennes - DOAT, Jacqueline; VALETTE Ch., J; ASKRI, D; CAUMARTIN, L; BETTACHINI, M; MORO, M (Ann. For. Sci., 1981)
Le pouvoir calorifique supérieur (P.C.S.) est le maximum d’énergie que peut dégager une combustion. Il conduit au bilan énergétique d’un incendie de forêt. Rapporté au poids de matière sèche ou au poids de la seule matière organique, le P.C.S. permet de hiérarchiser les végétaux selon leur caractère énergétique. Bien que les P.C.S. croissent avec la lignification des tissus, ils conduisent au classement par ordre décrois5ant : - feuilles de bruyère arborescente, - feuilles de pin d’Alep, - feuilles d’arbousier et pousses terminales d’ajonc épineux, - feuilles de chêne vert et de chêne kermès. Les P.C.S. de ces espèces méditerranéennes sont supérieurs ou au moins égaux à ceux d’espèces de régions plus tempérées.
Keywords: combustion (voyant); espèces mediterranéenes; pouvoir calorifique supérieur

Manganese depletion in chloroplasts of Quercus rotundifolia during chemical simulation of lichen epiphytic states - Orús, M Isabel; Estévez, M Filar; Vicente, Carlos (Physiologia Plantarum, 1981)
Incubation of Quercus rotundifolia branches in culture media containing lichen substances isolated from Evernia prunastri thallus produces inhibition of Hill reaction in chloroptasts isolated from the leaves of the branches. Incubation with lichen substances diminishes the amount of chloroplastic manganese through a chelation process. This decrease causes the loss of photosynthetic activity because the Hill reaction is restored upon addition of exogenous manganese to the chloropiasts.
Keywords: Evernla prunaslri; lichen acids; manganese chelation; Quercus roiundifolia

Midday Stomatal Closure in Mediterranean Type Sclerophylls Under Simulated Habitat Conditions in an Environmental Chamber II. Effect of the Complex of Leaf Temperature and Air Humidity on Gas Exchange of Arbutus unedo and Quercus ilex - Tenhunen, J D; Lange, O L; Braun, M (Oecologia, 1981)
Shrubs of the Mediterranean sclerophyllous species Arbutus unedo and Quercus ilex were studied under simulated habitat conditions in an environmental chamber. Temperature, humidity, and light intensity were altered stepwise to simulate diurnal changes in conditions similar to those measured in an evergreen macchia in Sobreda, Portugal. Leaves were enclosed in cuvettes which reproduced the growth chamber climate and which allowed measurement of gas exchange. Increasing atmo- spheric stress in the form of higher temperature and lower humid- ity on successive days gradually results in midday depression of transpiration rate and net photosynthesis rate of leaves due to midday stomatal closure.
Keywords: midday stomatal closure; net photosynthetic rate (voyant); transpiration rate

Processus dynamiques de reconstitution dans la série du Quercus ilex en Corse - Allier, C; Lacoste, A (Plant Ecology, 1981)
The use of permanent plots in representative sites of various phytosociologically defined stages of the Quercus ilex series in N W Corsica allows us to analyse the natural dynamical process occurring in the development sequence. The regular floristic analysis of stands and transects (mainly using a linear cover measure) during 5 yr not only shows variations of composition and structure but also results in a diachronic understanding of the temporal relations between the stages. The study of forest plots (structure, n u m b e r and development of seedlings) enables us to generalize the principle of ponctual and cyclic self-transformation of climatic and subclimatic stages.
Keywords: Diachronic study; Permanent plots; Quercus ilex series; Transects

The Sines industrial complex monitoring programme: a preliminary report - Jones, M P; Catarino, F M (Environmental Monitoring …, 1981)
It is anticipated that the establishment of the industrial complex at Sines, Alentejo, Portugal, will have some impact on the environment. Details of the methods used in the monitoring programme are provided. Records of the epiphytic lichen vegetation in permanent quadrats have been made and changes shown in selected sites over a three year period are discussed. Material has been collected for analysis for heavy metals and the results discussed. There is considerable variation in replicates and in interspecies values. The problem of age and bio-accumulation is mentioned. Scanning electron microscopy has shown the accumulation of particulates, as yet unidentified, the quantity varying with increase in age and surface texture. A broadly based study of the local epiphytic flora is being carried out to record the present day diversity. There appears, as yet, to be no detectable influence of the industrial complex on the epiphytic flora of the permanent quadrats.
Keywords: bio-accumulation; epiphytic lichens; Monitoring programmes (voyant); Sines industrial complex

Variación estacional de la composición mineral en pastizales de dehesa - GARCÍA CIUDAD, A.; MORENO DOMÍNGUEZ, A.; GARCÍA CRIADO, B. (Pastos, 1981)
The seasonal variations in the concentrations of sahes, N, P, K, Ca, Mg, Na, Fe, Mn, Cu and Zn in the pasture lands of a dehesas in the Pro- vince of Salamanca are studied. The sampling was monthly and took place during the period from September 1978 to October 1979. In general, the contení of ashes, N, P and K evolves in a similar ma- nner, reaching highest valúes in spring and lowest valúes in summer. Ho- wever, the concentrations of Ca, Mg and Mn show sharp oscilations at zone or fasture-type level. Those of Na, Cu and Zn are totally different from eteach other, but while in the Na concentration there are scarce fluc- tuations throughout the seasons, there are marked variations in the other tvvo. The elements Mg and Na are outstanding due to their relatively low concentrations which lie between 0 03 and 0.15% and 0.02 and 0.14% for the former and the latter, respectively. In the pasture land of the dehesa studied, it is usual to find deficien- cies in the elements Na, Cu and Zn throughout the year, while it is only in spring that the concentrations of N, P, Ca and Mg rise above the cri- tical levéis of an adequate nutrition for rumiants.
Keywords: composición mineral; Dehesa; pastizales; variación estacional (voyant)

Algunas consideraciones sobre la explotación de la dehesa extremeña, su problemática y posibles soluciones - de Muslera Pardo, E; Cruz Guzmán, E (Pastos, 1980)
The dehesa is the most characteristic type of extensive livestock farm in the S.W. of Spain. The past and present productive situation of these farms are described in this paper. New demand trends in the last years require a great change in the structure of their different activities of animal production. For their development an ordenated plan of invest- ments is necessary, requiring also a long term financing. Methods of clearing and pasture improvement are emphasised as the better way to increase carrying capacity. Is concluded about the need of farm improvement as a whole, and the possible solutions to develop the dehesa área, through livestock development programs.
Keywords: Dehesa; ganado; manejo (voyant); pastoreo; pastos

Análisis fenológico en pastizales de dehesa - Calabuig, E L; Navascués, I; GÓMEZ, J M (Pastos, 1980)
One oí the features of the dynamics of the grazing-lands is represented by its evolution during primary growth, when all phenological sings of the plants are seen. In the «dehesa» área in Salamanca, the prevernal, vernal and aestival periods are the most significant, and show the highest quantity of differentiatingpoints between one typegrazing-land and another. It was during these periods that regular observadons were made in 21 allotments, which belong to the most representative communities in the área, showing for each of the species its phenological state at any given moment. The information gathered has been simplified so as to offer a more general view of the phenological aspects of each type of grazing-land, summarizing the observations made per species for the group of pastures of similar taxonomic category. Likewise, the species which showed phisionomical character were selected, i.e.: those which contribute in highest proportion to the biomass of the community; in a word, those species which are dominant due to their hi^her absolute frecuency or their greater covering. To-complement this, the characteristic species are also considered. This study, descriptive in its essence, enables us on the one hand, to correlate the specific phenological observations with the general characteristics of the grazing-land to which they belong, and, in the other, to analyse the evolution of the same species in different pastures. The results obtained are given graphically, showing the differences between the definable types of pasture using the oligotrophy-eutrophy gradient
Keywords: Dehesa; especies caracteristicas (voyant); fenología; gradiente de oligotrofia; pastizales; Trifolium

Bases para la tipificación integrada de los pastizales de dehesa - González Bernáldez, F; Díaz Pineda, F (Pastos, 1980)
Rational use of seminatural rangeland requires integrated surveys and tipification. These rely upon a synthesis of characteristics of the geosystems underlying such natural complexes. Although there are different possible procedures, it is important that integrated typolo- gies reflect the most important geosystemic features, according to funcional, structural and genetic criteria. Homologies should clearly appear even when floristically unrelated áreas are considered (Mediterranean, California, Australia, etc.). Integration criteria specified by four dimensions or aspects are described. These have been rried by the authors in rangeland áreas of Center and the Southwest of the Iberian Península and are: Equipotenciality (zonality): related to position in gradients, altitudinal zones, northern and southern slopes, radiation patterns. Vectoriality: related to position in the dynamical system of interfluve and channel and slope dynamics. Mosaicity (azonality, cellularity): appartenence to roughly isodiametric patterns superposed to the forms and uncorrelated with them. Successional dinamicity: related to succesional changes normally conditioned by range management. Most of the differentiated features tend to recur within the landscape thus facüitating survey and mapping
Keywords: geosistema (voyant); ladera; pastizales; Sistema Central; tipificación integrada

Characterization of mineral content in Quercus ilex leaves by photon and neutron activation analysis - Bruno, Franco; Capannesi, Geraldo; Gratani, Loretta; Manes, Fausto (Giornale botanico italiano, 1980)
Abstract As part of a research on the holm oak stand and the Mediterranean « macchia » of Castelporziano, this study has provided the mineral characterization of Quercus ilex leaves by means of photon and neutron activation analysis. Although there is no evidence to indicate a selective distribution of the elements in the trees' crowns, some correlations are of considerable interest. Highly significant correlation coefficients are observed for the following pairs of elements: Fe-Sc, Fe-Cr, Fe-Th, Fe-Eu.
doi: 10.1080/11263508009427960
Keywords: Castelporziano (voyant); leaves and twigs; nuclear analysis; Quercus ilex; Trace Elements

La vegetation du bassin de l'aude, entre pyrenees et massif central, au tardiglaciaire et au postglaciaire d'apres l'analyse anthracologique - Vernet, Jean-Louis (Review of Palaeobotany and Palynology, 1980)
This study presents the first synthesis of the Late and Postglacial vegetation between the Pyrénées and the Massif Central, in the Aude Basin at lower elevation. The results are based upon the identification of more than 2,000 charcoal pieces from prehistoric settlements. Firs and pines (Pinus sylvestris) persist in the Pyrenean area as far as the Neolithic, contrary to the south of the Massif Central where a Mediterranean influence is recorded. Refuges of vegetation give the best explanation for Late Glacial phytogeography; evidence for these refuges has been found at Belvis. In the Mediterranean area we can describe three vegetation successions during Postglacial time. The early vegetation was dominated by pines and deciduous oaks (Preboreal, Boreal). Later deciduous oak forests with thermophilous plants were growing (Atlantic period). Finally, in the Subboreal and Subatlantic period evergreen oak forests (Quercus ilex) are extended. The late extension of Quercus ilex (Subatlantic or earlier) is of anthropic origin.
Keywords: CHARCOAL ANALYSIS; human influence (PG); Pyrenees; vegetation succession

Influence of Temperature on the Effects of Water Stress on Quercus Species - SPYROPOULOS, C G; LAMBIRIS, M P (Annals of Botany, 1979)
Quercus coccifera L. and Q. ilex L. leaves, collected in winter, when the plants were in full turgor, were treated with polyethylene glycol (PEG) with a water potential of −48 and −65 bar, at 15 °C and at 30 °C, for 2 days. The response of each species differs with temperature as far as the plastid pigment, anthocyanin and soluble sugar content is concerned. Thus Q. ilex is affected more at 15 °C rather than at 30 °C, while in Q. coccifera, apart from a small increase in anthocyanins, no significant change was observed at 15 °C. On the contrary, at 30 °C significant changes were observed in all studied parameters. Chloroplast pigments decreased generally on the first day and their content either dropped further or increased to reach the control values on the second day. All treatments resulted in an increase in anthocyanin content. Soluble sugar content raised in Q. ilex at 15 °C and decreased in both species at 30 °C.
Keywords: anthocyanin; carotenoids; chlorophyll; oak; Quercus coccifera; Quercus ilex; Temperature; water stress

CORK OAK HAS STRENGTH AND CHARACTER - NEUBAUER, L W (FOREST PRODUCTS JOURNAL, 1978)
Cork oak (Quercus suber) has been grown to some extent in several areas of the United States, but the bark is inferior for corks and is in small demand. Some trees have diameters as large as 5 feet, containing a considerable volume of wood. Sample beams and columns have recently been tested, with MOR averaging 13,000 pounds per square inch, MOE of 2,200,000 pounds per square inch, and fc of 9,730 pounds per square inch. With these excellent strength characteristics and a unique interwoven grain pattern, it is suggested that this wood might be useful for construction lumber, decorative panels, and furniture. - See more at: http://www.forestprod.org/knowledge_base/demo2.0/Main/ind/?id=68856#sthash.6Kr1nwGM.dpuf

Effect of Water Stress on Pigment Formation in Quercus Species - SPYROPOULOS, CAROLINE G; MAVROMMATIS, MARIA (Journal of Experimental Botany, 1978)
The effect of water stress in three Quercus species belonging to different habitats is investigated. Chlorophyll concentration decreased in all Quercus species with the greatest decrease occurring in Quercus robur. An increase of total carotenoid content was observed in Quercus coccifera and Quercus ilex, while in Q. robur water stress effected a carotenoid content reduction. Anthocyanins increased with decreasing relative water content in the three Quercus species, the largest increase occurring in Q. coccifera. A correlation between xerophytic character and pigment concentration is discussed.
10.1093/jxb/29.2.473

MEDITERRANEAN SHRUBBY VEGETATION AND ITS VALORATION .6. EVOLUTION OF CHEMICAL COMPOSITION OF QUERCUS-ILEX L - PEINADOLUCENA, E; GOMEZCASTRO, A G; RODRIGUEZBERROCAL, J; MEDINACARNICER, Y M (ARCHIVOS DE ZOOTECNIA, 1978)
APS
Keywords: chemical composition; Mediterranean; Quercus ilex; shrubby vegetation

A Comparison of Methods for the Determination of Water Status in Quercus ilex L. - Kyriakopoulos, Elfrieda; Richter, Hanno (Zeitschrift für Pflanzenphysiologie, 1977)
Summary Water saturation deficit (WSD), osmotic potential of the cell sap (Ψo) and total water potential (Ψt) were determined in drying shoots and saplings of the Mediterranean evergreen oak, Quercus ilex L. Reliability as well as time and material requirements were assessed. Thermocouple psychrometry and the pressure chamber technique offer great advantages over refractometry of exchange solutions for the determination of Ψt. The relationship between WSD, Ψo and Ψt was evaluated by means of the «pressure-volume curve« technique in the modification of Talbot et al. (1975). While the direct comparison of the cryoscopically determined osmotic potential and the psychrometrically determined total water potential suggests the occurrence of negative turgor, this evidence appears doubtful after a scrutiny of the pressure-volume curves. Some advantages of this evaluation technique are emphasized: osmotic relations may be analyzed in organs where the cryoscopic technique cannot be applied, e.g. in stem disks; linear regressions may be calculated for data from cryoscopy and vapour pressure osmometry as well as from different Ψt-techniques; and curves may be extrapolated to high WSDs, whereas direct determinations are not feasible with most of methods due to technical limitations.
Keywords: comparison of methods; Quercus ilex; water status

Estudio ecológico de los pastizales de dehesa en la provincia de Badajoz. Tipificación preliminar de la vegetación empleando el análisis de correspondencias - MARAÑÓN, T; Figueroa, E; Cota, H; Doncel, J L; García Novo, Francisco (Pastos, 1977)
42 grasslands of Badajoz and Huelva provinces (Western Spain) were studied recording plant species frequencies with 10 quadrats (20 X 20 cm.) randomly distributed over 2 X 2 m. plots taken under the crown of Quercus rotundifolia trees. Soil samples collected on every plot were analysed for pH, orgainic matter, P, Ca, K and Na. Frequency matrix (80 plant species X 42 plots) was analysed by the method know as "Analyse des Correspondences" (BENZECRI, 1973). The two main components (accounting for about 20 % of the overall variation) sepárate plots into six recognizable groups (grassland types). A preliminary attempc to interpret those groups is made in terms of biotope (soil and substrate) differencies. The two main directions of variation found correspond to an eutrophization gradient (poor acidic versus rich basic soils) and to an erosión gradient (soil erosión versus pedogenesis). Secondary causes of variation are interpreted as due to lithology, climate and management. Further analysis of present data is currently under way.
Keywords: Dehesa; pastizales; suelo; vegetación (voyant)

LIMITACIONES A LA REGENERACIÓN NATURAL DE LOS ALCORNOCALES EN EL PARQUE NACIONAL DE DOÑANA (HUELVA, ESPAÑA) P.M. - VÁZQUEZ, P M; Suárez, M A; TORRES, E (II Congreso Forestal Español, 1977)
The possible limitations to the in several experiences natural regeneration of the Quercus suber L. in a guarded area (Doñana) are undertaken in this study. The outputs offer a global vision of the natural regeneration in the Doñana's National Park. The production of seeds the sanitary state of the hoisted and their plagues, the attack of the spineless on the fruits and the climate don't harm the process of the natural regeneration in the -forest of Q. suber L. However the animal pressure (mammals), and the load cattle are the two factor s that impede the natural regeneration of the cork oak in Doñana. Finally, different strategies are contributed in order to recuperate the cork oak: fence, sowing, plantation and descent of the pressure animal in the zone.
Keywords: cork-oak; Doñana; natural regeneration; Quercus suber L.; silviculture

Notas sobre el comportamiento de Cistus salviaefolius tras desbroces, laboreos, fertilizaciones y aplicación de fitocidas - Montoya Oliver, J M; Montero González, G (Pastos, 1977)
The Cistus salviaefolius L. is an invading and competitive species in the pastures of Quercus súber covered mounts. In order to control it we carried out some triáis of (1) rotary cutting, (2) rotary cutting -+- ploughing and (3) rotary cutting + ploughing -+- fer- tilizing, under Q. súber trees that covered 40 % aind (4) rota'ry cutting in 25 % shade: The inventory of the number of plants shows according to the comparative plots which did not undertake any treatment at all, that the reinvasion is fast and very intense. In triáis with phytocides before emergence (atrazine, simazine, bromacil and diuron) the results of control of Cistus were not as good as the ones we got in the comparative plots that were just ploughed; and besides that they produced a lack of pasture for nearly two years. The phytocides did not damage the Q. súber when using those dosis. Those results have improved the knowledge of how meteorological factors could affect the germination abi'lity of Cistus salviaefolius, that could be useful for the coming studies directed to its control. 246
Keywords: Cistus salviaefolius; desbroce; fertilización; fitocidas (voyant); laboreo

Resultado de los estudios regionales de introducción y adaptación de especies y variedades pascícolas en zonas semiáridas del SW español - Olea, Leopoldo; Gallardo, D; Paredes, J; Martínez, a (Pastos, 1977)
Results from a series of triáis conducced in S.W. Spain between 1972-1976 using different species and varieties of grasses and legumes indicated the advantages from fertilizer applications in all the áreas studied with the exceptions of "La Serena" and "Palomas-Hornachos". Soil deph was also a major factor determining the success of pasture establishment and subsequently persistence and production. The Australian subclover cultivare used in these triáis did not generally persist adequately. It is tberefore concluded that there is a need to select "local" ecotypes of this species and of others species that are more adapted to the environmental conditions of the zone. More information is also required on the environmental factors, managerial practicas and agro- nomic characteristics that contribute to persistence of annual legumes. It is believed that persistence is the major determinant of success in pasture improvement involving the use of annual legumes; with perennial grasses in S.W. Spain, establishment appears to be major determinant. 222
Keywords: fertilización; pastos; persistencia; suelo (voyant); variedades recomendadas

Variación de la composición mineral de la hierba de una pradera semiagostante con su estado de madurez - Montalvo, I; García, B; GÓMEZ, J M (Pastos, 1977)
In this paper seasonal advance and maturity effects on the contents of ten bioeiements (N, P, Na, K, Ca, Mg, Fe, Mn, Cu and Zn) in a grass community from a Salamanca área pasture, are studied. N, P, K, Fe, and Mn levéis show a high decreasing tendency with maturity while those of Na and Ca tend to increase. Influence by the plamt stage is very little: Cu, Mg, and Zn show no effect at all. Seasonal advance largely affects to K, Mn, Fe, Ca, and Na: causing a decrease in the contents of the first three and showing a tendency to increase in those of the 'last two. This influence slightly appeared in P and Mg, while N and Cu are not affected. Data of dried sustance production and each element productions along the chosen period for this study are included. June reaches the highest yieids with the exception of Cu and Mg whose máximum productions are found during the first fortnight of July. PASTOS
Keywords: contenido mineral; crecimiento primario; estado de madurez; hierba (voyant); variación estacional

Distribución de la vegetación en una ladera sometida a riego temporal - Gomez Gutiérrez, J M; Puerto Martín, A; Calabuig, E L (Pastos, 1976)
A quantitative analysis of the vegetation on a slope of a "dehesa" of Salamanca pro- vince has been made for the purposes of observing the effects of temporal irrigation. The 17 samples takings that were made included the presence of a total of 102 species whose abundance was studied by means of the analysis of correspondances. The first 3 components, which cover 47,21 % of the variance, are deduced and are interpreted from the analysis; the first as reflecting the access to water, the second as representative of the retention of water. The third seems to be related to the similarity between samplings. In the plañe defined by the first and second components, three zones became apparent; these were identified as swamping, aridity and an intermediate zone between these two. This intermediate zone is formed in the vértex of the directions of the other two which may be schematically represented as two linear trajectories which have the form of lines regres- sion and of which the coefficient of correlation are significantly different of zero. PASTOS
Keywords: aridez (voyant); disponibilidad hídrica; encharcamiento; ladera

Vegetazione e ambiente delle Marche e relativi problemi di salvaguardia - Pedrotti, Franco (Giornale botanico italiano, 1976)
Abstract Vegetation and environment in the Marche and related problems of protection. ? The « Marche » region is situated in central Italy and corresponds with the natural region east of the Appennine ridge and spreading as far as the coast which is washed by the Adriatic Sea. As to the climate, we may distinguish a coastal strip with Mesomediterranean climate with dry season, corresponding to the distribution area of Quercus ilex; a hilly strip with Submediterranean climate, corresponding to the distribution area of Quercus pubescens; a mountain strip with temperate axeric climate with sub-dry period, corresponding to the distribution area of Fagus silvatica and finally a high mountain strip with cold axeric climate, corresponding to altitude pastures. The Marche vegetation is shown in the vegetation map of Fabriano sheet (scale 1:50,000) plotted according Ozenda's vegetational series. The following vegetation series have been plotted: submediterranean series of Quercus ilex; series of thermophilic oak wood with priority of Quercus pubescens or Quercus cerris; series of Ostrya carpinifolia; series of Quercus petraea and series of Fagus silvatica. As far as the problems to safegard environment are concerned, a plan is given providing for the institution of 4 complete nature reserves, 34 nature reserves, and 9 regional nature parks among which those of Monte Conero, of Monti Sibillini and Monti della Laga.
doi: 10.1080/11263507609426403
Keywords: Marche (PG); vegetation series

Feeding behaviour of autumn passage migrants in north east Portugal - Ferns, Peter N. (Ringing & Migration, 1975)
IN THE SUMMER and autumn of 1973, a mist netting site in the sparsely wooded hill country of north east Portugal was continuously manned by members of the Iberian Ringing Group. The main objective was to study the increases in weight of trans-Saharan passerine migrants which use this particular area as a staging post on their southward journey (Mead 1968). These migrants arrive on the central Iberian plateau towards the end of a long, dry summer, at a time when conditions appear relatively inhospitable. Yet Willow Warblers* and Pied Flycatchers gain over 0.2 g/day in weight, while Whitethroats increase by over 0.4 g/day (C. J. Mead and B. R. Watmough in prep.). Though this is somewhat less than, for example, the 0.6 g/day gained by Whitethroats at Lake Chad, Nigeria, in preparation for the return journey to the Palaearctic in spring (Fry. Ash and FergusonLees 1970), it still suggests that reasonable food supplies are available. In order to determine the nature of the foods being taken by these migrants, a series of observations were made during late August and early September 1973 in association with mist-netting activities.
doi: 10.1080/03078698.1975.9673692doi: 10.1080/03078698.1975.9673692The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Feeding activity; Feeding habits (PG); migration; passerines

Inquadramento fitosociologico delle leccete dei dintorni di Siena - de Dominicis, Vincenzo (Giornale botanico italiano, 1973)
Abstract A phytosociological study of the Quercus ilex woods in the surroundings of Siena (Italy). Numerous stands of Quercus ilex woods around Siena have been studied phytosociologically and compared to the better known similar forests of Southern France. As a rule the Siennese Quercus ilex woods (Table 1) can not be considered to belong to the association Quercetum mediterraneo-montanum Br.-Bl. 1936 because of the absence of various significant central European and montane species, nor to Quercetum galloprovinciale because of the presence of too great a number of Quercetalia pubescenti-petraeae and Querco-Fagetea species. Only rarely communities similar to the first mentioned association have been found: i.e. on Mount Cetona at 1.800 feet and in two particularly cool and humid localities at a lower height (Table 2). Taking into account the way these woods have been managed for centuries it can be concluded that they are mixed formations of Quercetum galloprovinciale and an oakwood association belonging to the order Quercetalia pubescenti-petraeae; the exploitation techniques have caused the evergreen oak to become dominant therefore creating conditions favourable to the more thermophilous and shade loving plants characterics of Q. ilex woods and at the same time bringing about a sharp decrease in the number of the light demanding species typical of deciduous oakwoods.
Keywords: phytosociological study; Quercus ilex; Southern France

The composition of suberin from the corks of Quercus suber L. and Betula pendula roth - Holloway, P J (Chemistry and Physics of Lipids, 1972)
The suberin constituents of Quercus suber and Betula pendula have been isolated after alkaline hydrolysis of the corks and over 80% by weight identified using thin-layer chromatography, preparative thin-layer chromatography, gas-liquid chromatography and combined gas chromatography — mass spectrometry. Long-chain aliphatic acids ranging from C16–C26 comprise about 90% of both suberin fractions; monobasic, α,ω-dibasic, ω-hydroxymonobasic, dihydroxymonobasic, dihydroxydibasic and trihydroxymonobasic acid classes are present. The principal suberin acids of Q. suber are 18-hydroxyoctadecenoic (12%), 22-hydroxydocosanoic (25%), 9,10-dihydroxyoctadecane-1,18-dioic (15%) and 9,10,18-trihydroxyoctadecanoic (8%), and those of B. pendula 9,10,18-trihydroxyoctadecanoic (43%) and 22-hydroxydocosanoic (16%). The remainder of the suberin fractions are non-acidic and comprise mainly unidentified cyclic alcohols in B. pendula. Similar compounds and alkan-1-ols occur in Q. suber.

ensayos preliminares de métodos de siembra de Iriíolium subterraneum en zonas de implantación difícil de las dehesas extremeñas - DE ZULUETA Y ARTALOYTIA, JULIÁN (Pastos, 1972)
At a preliminary trial for subclover establishment on unfavorable soil and climate in «dehesas» (ground under Quercus ilex cover) four sowing sistems were comparated: sowing broadcast (Vi) 10 Kg/Ha. of seeds, and (V2) 15 Kg/Ha.; sowing in rows (L^) 10 Kg/Ha. and (¿2) 15 Kg/Ha. At all sistems the cover seeds is made by means of passing a broom picking sledge over ground. The issues showed was more important the sowing method than the amount of seed for the number of plants obtained and its distribution over ground. In this trial, with 10 Kg/Ha. of seeds sowed in rows. 1,5 cm. deep (Li) 85 % more plants than 15 Kg/Ha. broadcast (V2) were obtained. PASTO
Keywords: dehesa (voyant); dosis de semilla; métodos de siembra; trébol subterráneo

La présence du chêne–liège à Minorque - Montserrat, P (Rapport Communication Internationale Mer Mediterraneen, 1972)
Le Quercus suber est un arbre typique de la Méditerranée occidentale, comme on peut le voir dans l'aire cartographiée par ZELLER [1958 : 168-169, fig. 18] dans laquelle on n'exclut pas les Baléares et les Pythiuses espagnoles. Le même auteur [1958 : 154, s] signale sa présence dans les îles d'Hyères, en Corse, en Sardaigne, en Sicile et les îles proches de la péninsule italienne. La récente Flore européenne exclue Quercus suber de l'archipel Baléares-Pythiuses. Les archéologues de Minorque, spécialement G. FLüRIT, trouvent souvent des morceaux de liège dans les nécropoles de l'île. S'agissant d'un matériel qui flotte, il est très possible que les natifs aient déjà connu ses applications, sans être contraints de l'obtenir à Minorque. Il pourrait éventuellement s'agir de l'introduction très ancienne de ses glands; on ne doit pas exclure cette possibilité, mais elle semble peu probable. On veut maintenant donner notice seulement du bosquet rélicte que l'on a pu étudier à Minorque, ainsi que d'un inventaire des principales plantes ligneuses et quelques herbacées qui les accompagnent. La discussion d'après laquelle l'homme aurait introduit les glands et cultivé le chêne-liège, reste ouverts aux intéressés sur ce thème. Ce qui est indubitable est que, outre quelques exemplaires détachés et cultivée, déjà signalés par RODRiGUEZ-FEMENiAS (1904, 125) à Binisequi et Binimoti, on trouve un bosquet dans le centre de l'île, avec une végétation qui l'accompagne propre au Maroc et au SW. de l'Espagne.
Keywords: chêne-liège; Minorque; spontanéité (voyant)

The place of the Tenagi Philippon in the Pleistocene stratigraphical sequence - Wijmstra, T A (Zeitschrift der Deutschen Geologischen Gesellschaft, 1972)
From an analysis of a 120 m section in Eastern Macedonia a sequence steppe and forest phases became evident. By C14 analysis it could be proved that during the stadial phases within the Weichselian an open Artemisia-Chenopodiaceae steppe existed in the area. On the other hand during the interstadials, shrub steppe phases in which pine and oak were present, existed in the area. During the interglacials forest was found. In these forests a Carpinus-Ulmus belt was succeeded by a Pinus nigra-Abies zone. In this zone the presence of Ericaceae is of importance (WIJMSTRA 1969). It became also clear from the analysis of this section that the glacial phases were equally long, but in each glacial the development of the Vegetation sequence and consequently of the climate was different. It was possible to establish the position of the Holstein interglacial either at a depth between 78 and 70 m or between 62 and 62.5 m. In this interglacial the presence of Pterocorya is worth mentioning, also Buxus and Myrtus were found in this interval. In the first phase between 87 and 105 m a series of three humid zones existed. In these zones Carpinus and Ulmus were important constituents of the Vegetation. These zones were found separated by long dry periods when the forest was dominated by Pinus nigra, Pinus heldreichii and evergreen oaks from the group Quercus ilex/coccifera. In this dry type of forest frequently naturally buming lead to open places. On these open places at first an Artemisia-Chenopodiaceae Vegetation was present.
Keywords: climatology Greece (Macedonia); Flora; Pleistocene; prairie-zone

STUDY OF OUTER BARK OF BIRCH (BETULA-VERRUCOSA) AND CORK OAK (QUERCUS-SUBER) BY SCANNING ELECTRON-MICROSCOPY - JENSEN, W (ANALES DE QUIMICA-INTERNATIONAL EDITION, 1972)
The outer bark of corkoak and birch constitutes a particularly suitable starting material for the study of suberin, the cell wall substance that imparts specific properties to the cork cell. In investigations of birch and oak suberin made by the author in the fifties, great interest was attached to the publications of Ribas on the chemistry of cork. The present article contains a brief survey of the differences between, and the similarities in, the outer bark of these two wood species, demonstrable on the basis of the investigations mentioned. This comparison, concerned with the chemical properties, is supplemented by a number of scanning electron micrographs of the cork tissue of the two species.
APS
Keywords: chemical properties; cork cells; scanning electron micrographs; suberin

Notes: Effects of Artificial Defoliation on the Growth of Cork Oak - Magnoler, Aldo; Cambini, Anna (Forest Science, 1970)
In Sardinia a single artificial removal of 50 percent or 100 percent of the foliage from Quercus suber L. trees in June caused serious growth losses. The weight of new leaves diminished significantly. Shoot growth and cambial growth were seriously reduced both in the year of treatment and in the following year. Ring width of the cork was greatly reduced in the year of treatment, but recovery was almost complete the following year. The decrease in xylem ring width reduced the generating area of the cork. The reduction in ring width of the cork and generating area resulted in a decline in cork production.
Keywords: Bark; Porthetria dispar; Quercus suber

INCREASE IN ABILITY TO BECOME FROST-RESISTANT DURING AGEING IN QUERCUS ILEX - LARCHER, W (PLANTA, 1969)
Shoots of Quercus ilex gain more efficient ability to become frost- hardened in winter during the course of ageing. The greatest increase in frost- hardiness occurs within the first five winters. Full capacity for frost-resistance is not reached until the plant enters its reproductive phase. Roots do not change their resistance pattern with age.
APS
Keywords: frost hardiness; Quercus ilex; resistance pattern

LITTER PRODUCTION AND MINERAL ELEMENT SUPPLY TO SOIL IN 2 MEDITERRANEAN ECOSYSTEMS - QUERCUS-ILEX FOREST AND QUERCUS-COCCIFERA GARRIGUE - Rapp, M (OECOLOGIA PLANTARUM, 1969)
APS
Keywords: LITTER PRODUCTION; Mediterranean ecosystems; minerals; Quercus coccifera; Quercus ilex

Remarques sur les chênaies d'Yeuse de l'Apennin méridional et de la Sicile - Gentile, S (Plant Ecology, 1969)
On the basis of the observations and the records presented, it is remarked that in the Southern Apennines and in Sicily the forests of Quercus ilex are prevalently localised in the altimetrical band included between 65oP7oo and 9oo--95 o m. But the greater exten- sion is rejoined in the band from 8o0 and 95 ° m. This limitation above and especially below those levels is to be considered actual and caused only by man. The examination of the flowering records permits the arrange- ment of the forests of Quercus ilex of the Southern Apennines and Sicily in a new association: the Querco-Teucrietum siculi, that here seems the only representative also of the Quercion ilicis. It borders upon the associations of the Oleo-Ceratonion in the lower part and upon those of the Quercion pubescenti- petraeae in the higher part and often immediately with those of the F a gi o n. The elements of the physical environment of the present and potential surfaces of the association are distinguished in geologi- cal-pedologicals and climatics. The substratum pedogenetic is very variable therefore it doesn't seem determinant for the normal development of the Qu e r c o- T e u c r ie t u m sicu li. The factors of the climate result instead determinant. At the lowest levels the limit is formed by the temperatures too high and the excessive drought. At the highest levels the limitant element is especially formed by the high atmospherical dampness, especially in the form of fogs. It is said that the association finds favourable conditions where the index of DE MARTONNE is included between 25 and 35, or little more. The geographical area of the association for the moment is not sufficiently delineated. The dynamic series also connected with it are yet little determined. The outline of the soil can be considered of type A/C. The charac- teristics of the horizons lead to think that they are types of "brown Mediterranean soil of the xerophitic forest". The Querco-Teucrietum siculi, on the basis of ecological characteristics of the environment, can be considered intermediate between the Quercetum ilicis galloprovinciale (replaced from the associations of the Oleo-Ceratonion) and the Querce- turn mediterraneo-montanum, that, much probably, are lacking in the Southern Apennines.
Keywords: Chênaies; Querco-Teucrietum siculi (voyant); Quercus ilex

RETURN OF MINERAL ELEMENTS TO SOIL BY RAINWATER LEACHING CANOPIES OF QUERCUS ILEX L QUERCUS LANUGINOSA LAMK AND PINUS HALEPENSIS MILL WOODS - Rapp, M (OECOLOGIA PLANTARUM, 1969)
APS
Keywords: Pinus halepensis; Quercus ilex L.; Quercus lanuginosa; rainwater leaching

TEMPERATURE RESISTANCE AS AN ECO-PHYSIOLOGICAL CHARACTERISTIC OF PLANTS .1. QUERCUS-ILEX AND OTHER MEDITERRANEAN OAKS - LARCHER, W; MAIR, B (OECOLOGIA PLANTARUM, 1969)
APS
Keywords: eco-physiology; mediterranean oaks; Quercus ilex; temperature resistance

Vue d'ensemble de la végétation des îles Baléares - de Bolòs, O; Molinier, R (Vegetatio, 1969)
The vegetation of the Balearic Islands is pure mediterranean. The climax forests belong to the northern mediterranean alliance of the Quercion ilicis (rainy regions in Majorca and Menorca) and to the southern mediterranean community of the Oleo-Ceratonion (Querco-Lentiscetum with Iberic affinity in Ibiza; community with Ceratonia siliqua and Cneorum tricoccum in the dry region in Majorca, community with Otea europaea and Prasium majus in the driest region in Menorca). Communities rich in endemic plants characterize the karst of the high summits in Majorca, and coastrocks of the windy shores in Majorca and Menorca. The tyrrhenic influence, important in the Gymnesies (Majorca and Menorca), is more feeble in the group of the Pithyuses (Ibiza and Formentera), nearer to the Iberic Peninsula.
Keywords: groupements vegetaux; Iles Baleares; Maquis (voyant)

Fire tests on thermal insulation systems for pipes - Way, D H; Hilado, C J (Fire Technology, 1968)
Thermal insulation systems used to conserve heat and refrigeration in industrial plants should be evaluated in the same manner as construction materials insofar as fire performance is concerned.
Keywords: fire damage; fire hazard; fire protection; fire tests; thermal insulation systems (voyant)

Forme di Quercus suber L. della Sardegna centro-meridionale - Chiappini, M (Tip. Gallizzi, 1968)
Keywords: Cork oak Varieties; Geral; Trees Italy Sardinia

On the forest history of the Dalmatian coast - Beug, Hans-Jürgen (Review of Palaeobotany and Palynology, 1967)
The Postglacial history of the vegetation of southern Dalmatia is studied by means of pollen analysis of the lake deposits of the Malo Jezero on the island Mljet. The pollen diagrams reflect four forest periods: 1. (1) Period A: period of deciduous oak forest. About 7,000 (beginning of sedimentation)-5,600 B.C. 2. (2) Period B: Juniperus-Phillyrea period. Beginning of eu-mediterranean climate conditions. 5,600-4,300 B.C. 3. (3) Period C: Quercus ilex period. 4,300-about 200 B.C. 4. (4) Period D: Pinus-Quercus ilex period. Sediments of the last 1,900−2,000 years are lacking.
Keywords: Pollen analysis; Postglacial; vegetation history (PG)

Régénération artificielle du chêne-liege et équilibre climacique de la subéraie en forêt de la Mamora - Lepoutre, B (Annales de la Recherche Forestiere au Maroc, 1967)
In order to determine the edaphical conditions, which warrant a successful artificial regeneration of the cork-oak in the Mamora forest, the author passes in review previous inquiries and to begin points out material already learned on this problem. After giving a quick glance at the nature of soils constituted by a sandy cover of variable depth (0,40 to 6 ni) on an antique argillaceous- sandy deep formation, the author firstly puts forward the obviousness of the harmful influence of the considerable sand depths on the artificial regeneration of the cork-oak in the western Mamora. Inversely, he shows that a successful regeneration is as surely secured when the deep argilla- ceous-sandy formation called (( Mamora red clay D is closer to the surface. At this juncture, he manages to specify that the depth of sand over two meters is incompatible with the growth of cork-oak seedlings, but that the latter is subject to variations in cases where clay is close to the surface. The analysis of these variations enables the detection of a new factor of a favourable issue, which can be defined by the intensity of the side draining, the best outcome being under the conditions of a medium side-draining. Leaving the western Mamora with its more humid climate, the author continues his investigations in the semi-arid central Mamora. Generally, the soils are here less deep and the side-draining appears as a determinant factor in a favourable outcome or a failure of artificial cork-oak sowings. On flat or slighty sloping grounds the zones of failures fall in with localizations of perched winter phreatic sheets. The mechanical action of these sheets is studied parallelly with the nature of the cultural profile and the cork-oak rooting. Then, it becomes evident that the young cork-oak is unable to hold its ground during summer unless its radicular system succeeded to settle in the deep clay during the winter. On a sloping ground, the author comes to consider the depth of the sand as a vertical component of the draining and couples it with the horizoiztal component represented by the slope. Every sowing inventory site can be defined in this way through its draining characteristics and be graphically shown in relation to two axis of rectangular co-ordinates, bearing respectively, the slope on the absciss and the depth on the ordinate. Then, in applying to each inventory site a criterion for the growth of a sowing, the author comes to set up a diagram showing on one hand, the relationship between the good issue or the failure, and on the other hand, the draining. The study of the said diagram provides esential laws of repartition of successful issues and failures in the artificial regeneration. This method of study being applied to the even more arid oriental Mamora brings forward new results, while it warrants replacing the results of western Mamora into the same ecological scope. Comparing the three climatic sectors, it becomes possible to introduce climate as a factor in the interpreting of the results and, finally, to determine the edaphical climatic conditions of cork-oak regeneration in Mamora forest. This successful method, which seems to supply essential ecological elements to determine the installation and the growing of young cork-oaks leads the author to follow up his investigations, this time in the adult cork-oak forest, making evident the laws of the repartition of the forest dependent on draining, but, where he also shows the link between the density and the age of the stump range on one hand, and the edapho- climatic conditions on the other hand. Finally this study ends at the equilibrium of the climax in the cork-oak The synthesis warrants, in fact, comparing the previous conditions of the installation of the cork-oak, the more recent and the present one, by means of studies, respectively of old trees, young pole stage, and artificial regeneration. forest. Thereupon conclusions can be obtained in two fields. On the practical plan, the author lays down a correlation between the conditions of cork-oak artificial sowing and the density or the state of an adult forest. This correlation is the key to interpret the air photogra- phic covering in view of artificial regeneration and enables to ground a new management, based on extremely precise rules. On the ecological plan, the author is able to determine accurately the evolution of the forest, an evolution expressed by three natural states related to edapho-climatic conditions. The first state, where the regressive dynamism of the afforestation is observed by the presence of very old trees and where sowing is ineffective ; it is the old thin forest on deep sands or steep slopes. The second, where, on the contrary, exists a progressive dynamism of afforestation ; there are no trees, but empty spaces are conquered by young seedlings or by successful artificial regenerations. The third, where the equilibrium of the forest is secured by a strong density and a younger age of individuals, combined with the possibility of artificial or natural sowing. The author suggests for these three states the following denominations : postclimax, preclimax and euclimax, which would subdivide the general notion of climax as commonly used, and in which the existence of ecological equivalents forbids in any case the dissociation of edaphical factors and climatic conditions. He notes the interest of this notion of climax equilibrium in the scope of forestry management and, finally, underlines the parallelism of these conclusions with the one of his previous works, asserting a present seasonal climatic evolution in Morocco.
Keywords: chêne-liège; conditions édaphiques; drainage (voyant); épaisseur des sables; Mamora; Regeneration; réussite des semis; semis; semis artificiels

Une flore d'âge ougartien (seconde partie du quaternaire moyen) dans les monts d'ougarta (Sahara Nordoccidental) - Beucher, Françoise (Review of Palaeobotany and Palynology, 1967)
The analysis of a series of samples carried out in the versicoloured conglomerates of the “Oued Farès” (Ougarta Mountains, western Sahara) gives the first conception of what the vegetation was like in this region throughout the Ougartian (second phase of the Middle Quaternary). Superimposing on the herbaceous layer which widely represents the desert-like xerophyte element, the arborescent flora bears the imprint of diverse influences: a typical Mediterranean influence (Quercus ilex, Quercus coccifera, Pinus halepensis, Cedrus cf. atlantica, Oleaceae, Anacardiaceae, Vitis, Argania); an influence undoubtedly of the mountainous zones of the eastern Mediterranean (Alnus, Ulmus, Carpinus betulus, Salicaceae), and finally a tropical influence (Acacia, cf. Sapindaceae). If one should attempt to characterize the three main episodes which the stratigraphy permits one to distinguish in these formations studied on the spot (Lower Ougartian, Middle Ougartian, Upper Ougartian), one can recognize from the Lower Ougartian a relatively dry period both preceded and followed by a more humid phase; during the Middle Ougartian the climatic conditions favourize the simultaneous blooming of Mediterranean species and those of the outer Sahel; the Upper Ougartians remains poorly characterized by a very limited number of pollen grains.
Keywords: Climatic conditions; Middle Quartenary; Ougarta Mountains; vegetation history (PG)

Sapogenin triterpene intermediates - PHARM, CENTRE D'ETUDES POUR L'IND (1966)
Process for extracting sapogenin triterpene complexes from plants, incl. Hedera helix. The complexes are used as intermediates for pharmaceuticals. Plants other than Hedera helix are e.g. Platanus orientales L., Betula alba, Quercus Suber L, Myrica ale L, Papaver somniferum L. etc. The plant material (pref. a wood) is ground to a fine powder and extracted by refluxing with water-alcohol (50-70% alcohol) in amt. of 4-8 lt. solvent/kg. wood powder. Supernatant is centrifuged off, and absolute alcohol added to ppte. water solubles, which are removed, and supernatant evap. to dryness, and residue extracted with acetone. The extract is then evap. to dryness to obtain the desired complex.
Keywords: extraction technique; plant material; Wood

The Twig Wasp of Cork Oak - Its Biology and Control - BAILEY, STANLEY F.; STANGE, LIONEL A. (Journal of Economic Entomology, 1966)
Cork oak (Quercus suber L.), the principal source of commercial cork, was introduced to this country in 1858 from acorns sent from Spain. For Many years no pests were noted. In 191R the twig wasp Plagiotrochus suberi Weld, not described until 1926, was observed injuring the tree in California. It has since become a pest, particularly when the cork oak is planted as an ornamental or shade tree. The larvae feed within a jellylike matrix in the small twigs. The resulting dead twigs on the infested trees pn,- sent an unsightly, brushy appearance. The wasp has 1 generation a year. The agamic females emerge from the twigs via a small round hole in May. They are very weak fliers and remain close to the twigs on which they originated. Oviposition is in the twig growth of the previous year. The eggs hatch in late summer and the larvae develop slowly, pupating the following April. The insect has been found in Switzerland and Portugal (where it probably originated) only in the past few years. The time and manner of introduction into California are not known. In North America the wasp is found only in California. Only moderate control has been obtained with sprays of lindane and carbaryl directed against the adult stage. A European aphid, Myzocallis borneri Stroyan, is now a pest of the cork oak in California. This record is new. Other insect pests of the tree in this country are of very minor importance.
The following values have no corresponding Zotero field: label: California;Plagiotrochus suberi;cork oak;twig wasp (PG)
Keywords: California; Cork oak; Plagiotrochus suberi; twig wasp (PG)

TOWARDS STATISTICAL DEFINITION OF ECOLOGICAL RANGE - CASE OF QUERCUS SUBER - HAGGETT, P (ECOLOGY, 1964)
The general problem of constructing gross climatic limits from analysis of a map of species distribution is raised. A study of the distribution of Q. suber suggests that the use of measures of central tendency rather than an attempt to define limits may provide a more fruitful approach to such problems. Use of the standard deviation, together with the mean, provides a probabilistic measure of plant ranges which may provide a useful tool in locating climatically analogous areas for plant introduction.
APS
Keywords: climatic limits; plant ranges; Species distribution

EINIGE BEOBACHTUNGEN UBER DIE HOHENSTUFEN-DIFFERENZIERUNG DER MAHWIESEN IN DER MEDITERRANEN QUERCUS ILEX-STUFE VON MONTPELLIER - HUNDT, R (VEGETATIO, 1961)
Während eines Studienaufenthaltes in der Station Internationale de G6obotanique M6diterran6enne et Alpine in Montpellier hatte ich auf mehreren Exkursionen in die Umgebung von Montpellier und in die Stid-Sevennen Gelegenheit, u.a. einige Beobachtungen tiber die H6hen- stufen-Differenzierung der M~ihwiesen in der Mediterran-Region dieses Gebietes anzustellen. Herin Prof. Dr. BRAuN-BLA~QUET m6chte ich an dieser Stelle ftir die Einftihrung in die Mediterranvegetation der Provence und ftir die zahlreichen vegetationskundlichen Anregungen recht herzlich danken. Mein Dank gilt auch Herrn Prof. Dr. MeusEL, der durch seine Fiirsprache den Studienaufenthalt ermörglichte.
APS
Keywords: Mediterranean; Montpellier; Quercus ilex

Contributo Allo Studio della Vegetazione Dei Calcari Dolomitico-Giurassici della Sardegna: Vegetazione Del “Texile” di Aritzo E- “Toneri” di Belvì (Sardegna Centrale) - Martinoli, Giuseppe (Giornale botanico italiano, 1956)
Summary The vegetation of dolomitic and jurassic calcareous rocks has been studied and, particularly, the flora of Aritzo's and Belvi's ?Toneri? both located in the middle east of Sardinia. The flora of Aritzo's Toneri is very scanty because the calcareous tower-like blocks lie on a schistic ground and are very narrow. The predominant species are those with a short annual cycle: the only exception being the Quercus Ilex, growing on the walls of the calcareous rocks. The flora of Belvi's ?Toneri?, on the contrary, is more copious because this is larger than Aritzo's Toneri and here the erosions are less evident. As a matter of fact, here, besides the Quercus Ilex, there are some commun species of the ?macchia?. The flora of neighbouring schistic mountains is very different. The difference in the chemical characteristics of ground, as the Author claims, does not justify the great difference observed between the flora of calcareous and schistic ground. The last is typicaly mesophylic, Quercus Robur var. lanuginosa, Castanea sativa, Juglans regia, Ilex Aquifolium have been chiefly found. In the same region at a higher altitude xerothermic species, like Quercus Ilex, have been observed. The Author points out that the typical characteristic of Toneri's flora depends upon geological factors more than chemical or climatic one. In agreement with this point of view the Author found the same vegetation in Oliena, Tuttavista, Albo and Other dolomitic-jurassic calcareous Mountains of Sardinia.
doi: 10.1080/11263505609431614
Keywords: calcareous and schistic grounds; macchia species; Sardinia

Sui Limiti Altimetrici Dei Consorzi Rupestri Di Leccio in Garfagnana - Arrigoni, Pier Virgilio (Giornale botanico italiano, 1956)
Summary One of the most characteristic species of the present Mediterranean vegetation, the holm-oak, still presents in the Appennines, after the alternate glacial periods, relict stations, separated and disjointed, strictly bound to the rocky places. The Author takes the examination of the altimetrical limits of the holm-oak in Garfagnana (Tuscany), in the valleys of Turrite Secca and Fegana, as a starting point to take into consideration the value and the floristic-oecological aspects of these rocky relicts. After a climatic and geomorphologic classification of the examined places, the distribution of the holm-oak in the aforesaid valleys is minutely described. The historical examination shows a derivation of the present plant-communities, rocky and relict, from the dispersion of a presumable anathermic mountain forest, referable to the period of the Quercetum mixtum, rather than to the ancient tertiary, thermophilous and orophilous, Mediterranean forest. The permanence of the holm-oak in the submontane and mountain stations is strictly bound to their peculiar oecology and its specific temperament. The rocky stations, at least those examined in Garfagnana, are remarkably arid and thermically continental, especially those exposed to the south and south-west. Their aridity, however, helps to lessen the dangers of the frost. The holm-oak can live there in virtue of its tolerance and biological plasticity. To the south it reaches the most elevated heights owing to the protection from cold winds and owing to its greater thermic availability. A peculiar attention is given to the dynamics, in time and space, of the floral-physiognomical groups: dynamics which has its impulse in the unceasing instability of the rocky micro-places. Some botanic observation, made in different floral districts, in different conditions of positions, altitude and nature of the substratum, aim at representing the floral aspects of the examined Quercus Ilex-stations. The flora is constituted with entities fit (preadapted) for the rocky places and with species supplied with remarkable qualities of adaptation. Through the comparisons of the biological spectra, it appears the great fitness of the Chamephytes to the harsh rocky places. Among the few Mediterranean species able to follow the holm-oak in the rocky localization it is worth mentioning, above all, the Juniperus phoenicea L., species typically of the littoral, never noticed in Tuscany at such elevated heights as those which have been noticed, as it appears in this work, in the Apuane Alps (till 1200 metres).
doi: 10.1080/11263505609431629
Keywords: Holm oak; Plasticity (PG); Quercetum mixtum; rocky relicts; tuscany

Forest-tree genetics research: Quercus L. - Irgens-Moller, H (Economic Botany, 1955)
Oaks are the sources, not only of the most valuable timber among broad-leaved trees of the northern hemisphere, but also of cork, tannin, a dye, and food for man and beast. Their prolonged pre- flowering periods and other factors have discouraged genetic in- vestigation of them, but what little is known in that direction is here summarized.
Keywords: Hybridization; oak products; oak trees (Quercus spp.); propagation

La Vegetazione del Parco del Conte (Ruvo di Puglia) - Scaramuzzi, Franca; Lorito, Fernanda (Giornale botanico italiano, 1953)
Summary The flora of a Quercus pubescens wood, near Ruvo di Puglia, has been studied. The presence of Pirus amygdaliformis, and of various weeds, together with the disappearence of some species like Bivonaea albiflora, indicate a certain amount of degradation due to grazing and cutting. The biological spectrum shows a noticeable abundance of therophytes (45%). The mixture of typical mediterranean «maquis» plants and of more mesophilous species suggests that at Ruvo the basal Quercus Ilex horizon finds its ecological boundary, Q. pubescens substituting green oak and decidous plants outbalancing evergreens.
doi: 10.1080/11263505309432122
Keywords: degradation; ecological boundary; floral composition; Mediterranean maquis; Ruvo di Puglia (PG)

Erborlzzazioni in Una Lecceta Sulla Scarpata Orientale Delle Murge Tra Fasano E Locorotondo - Corti, Roberto (Giornale botanico italiano, 1952)
Abstract The author describes a portion of Quercus Ilex wood, placed between Fasano and Locorotondo (Bari), at the cross-road to Selva di Fasano, 300 m. about on the sea level. This woodland, partly destroied, situated at the limits with Q. Troiana woodland, is one of the many remains which are present in the marginal zone of Murge. These remains testify that the Q. Ilex wood was probably in the past, more widly extended, in comparison with Q. Troiana wood, preeminently present today in the low Murgia. Its flora is mostly characteristic of the «Q. Ilex Gürtel» of the Medit. series (after Schmidt) but in the meantime it shows infiltrations of species belonging to the «Q. pubescens Gürtel» and to the «Quercus-Tilia-Acer Gürtel» of the Eurosib. Boreoam. series. This floristic arrangement is in accordance with the climatic-phytogeographic characters of this zone, which is to be referred to the «middle sub-zone of Lauretum» (Pavari) and to the contact zone between the semi-arid and the sub-humid levels (Emberger), where the «pluviofactor» (P/T of Lang) is still below 50. We are here near the upper margin of the Q. Ilex level, where haevy infiltrations of the upper zones are to be found.
doi: 10.1080/11263505209436484

Note floristiche e fenologiche nel territorio di Arneo (Fra Taranto e Gallipoli) - Ferente, Adriana (Giornale botanico italiano, 1952)
Summary The author describes the vegetation and phenology of a Quercus Ilex wood in the Comprensorio dell'Arneo, betwen Taranto and Gallipoli along the eastern shore of the Ionian Sea (Golfo di Taranto). The wood consists partly of a degraded bushy vegetation. The wood was visited eleven times during the year and each time species found flowering were noted (Table at pp 296?301): the greatest number of them, many being therothytes, was found on April 21rst (fig. 2) with about a month's delay in comparison with Palestine (Gindel). In May there is a considerable i decrease in number of species flowering. In summer and winter, because of drought and low temperature very few species, mostly geophytes, were found flowering, and only slightly but markedly more in Autum.
The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Phenology; Quercus ilex; Taranto Golf

Residui di Leccete pure e miste sulla Murgia di Putignano - Delfine, Antonia (Giornale botanico italiano, 1952)
Purpose of this paper is to point out the residues of Quercus Ilex woods in the hilly region of Murgia di Putignano (Puglia) which lies inside the distribution area of Q. trojana, now the main wood-forming tree-species of this territory. Fourteen different small Q. Ilex stands are mentioned, as marked on alleged map. One of them (n° 1 on the map) has been more carefully studied through a whole year, and all plants growing in it have been collected.
doi: 10.1080/11263505209431543
Keywords: Puglia; Quercus ilex; residues

Evoluzione della Cerchia Legnosa in Quercus Suber L. - Ciampi, Clara (Giornale botanico italiano, 1951)
Summary The evolution of the wood ring in Quercus Suber L. (from October 1946 to September 1947). ? The Author has studied the wood ring evolution in Quercus Suber L. during one year, by means of sampling monthly the main stem and young branches of a specimen growing as S. Giust near Florence (m. ca. 500 ov. s. l.). In Quercus Suber L. cambial activity starts off probably first in the stem and secondly in the branch; it comes to an end sooner in the latter and in a clear cut manner, ending later in the stem and in a dragged out manner. There are two separate stages in wood ring development: cell walls undergo a thickening process during the first one, and lignification during the second one. This last stage is drawn out for a long time ending, both in stem and branch, only shortly before the cambium becomes active again in the following' spring. Cambial activity in the branch begins before the buds open. Wood growth cycle in Quercus Suber is in perfect harmony with prevailing climatic conditions. The cambial tissue starts dividing at the end of March, during a period of remarkable rainfall and of increase of temperature, continues its activity in May and June, ending completely in Summer, when temperature and dryness reach their highest values.
doi: 10.1080/11263505109431516

The resistance of cork to decay by wood-destroying molds - DeBaun, Robert M; Nord, F F (Archives of Biochemistry and Biophysics, 1951)
A new method for the determination of the lignin in cork has been reported. This procedure gives values ca. 25–30%. It is based on the colorimetric estimation of the lignin released by autoclaving with alkali. Using this method it was shown that cork is highly resistant to decay by brown-rot wood-destroying molds. This is attributed to the protective action of the suberin or to the presence in the cork of substances toxic to the molds.
APS
Keywords: Cork; Lignin; molds; resistance

Buxus Balearica Willd., Elemento Mediterraneo-Occidentale della Sardegna - Martinoli, Giuseppe (Giornale botanico italiano, 1950)
Summary The occurance of Buxus balearica Willd. in Sardinia, already reported by Gennari (1864), and its indigenous state are confirmed by the present study. Its station and geographic distribution as well as the biocenosis in which this species takes part (Barbusi near Sulcis in S. Sardinia) are considered. The study of the Barbusi station, in comparison with others hitherto known, brings a general confirmation to Chiarugi's view concerning the mountainous origin of the mediterranea elements. Besides, it emphasizes the differences between the stations of B. balearica, an element of the mediterranea ?macchia?, and those of B. sempervirens, an undergrowth element of mesophilous formations (deciduous woods), which only rarely belonges to more termophilous bioceneses. The author notes that both species belong to the same stage of Q. Ilex and that the altitude range in which the Q. Ilex stage is comprised is very wide in the different mediterranean regions. In addition, the author emphasizes that Buxus sempervirens occurs in Corsica and Atlas up to the upper limit of Quercetum Ilicis, together with species belonging to higher stages, whilst Buxus balearica belongs to the lower limit of Quercetum Ilicis in the underzone ?Olea-Ceratonia?. The altimetric separation of these species is, therefore, obvious. Due to the compenetration of floras of mountainous origin during the phases of the Ice-period, the knowledge of the segregation epoch of these species from each other is made impossible. Buxus balearica occupies actually as eocene substratum and, therefore, shows edaphic exigences for soils of a certain age: a condition not occurring for Buxus sempervirens. Both Buxus species, together with other horeal-tertiary ones (all constituting actually, in the mediterranea countries, a special relict flora) belong to the Lauretum, in a historic sense (Chiarugi).
doi: 10.1080/11263505009431487doi: 10.1080/11263505009431487The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Buxus balearica; geographic distribution; origin (PG); Sardinia

L'evoluzione della cerchia legnosa in Quercus Pubescens W. Ein Quercus Ilex L. nel clima di Firenze - Maugini, Elena (Giornale botanico italiano, 1950)
Summary The evolution of the wood ring in Quercus pubescens W. and in Quercus Ilex L. in Florence (from June 1946 to June 1947). The present study deals with the anatomical characters of the wood ring of Q. pubescens and of Q. Ilex. In both the specimens the wood of the stem and of the young branch has been investigated. In both plants studied the cambial tissue of the stem starts dividing at the end of April, reaching its maximum activity from May to June. On the contrary the cambium of the branch differentiates in Q. pubescens a month earlier (18 March-18 April) than in Q. Ilex (18 April-18 May). While in the branch of Q. Ilex a false ring can be seen corresponding to the autumn months, nothing of the kind is found in the branch of Q. pubescens; though it presents a false ring in the stem. It is difficult to date clearly the period when the cambium stops its activity, but probably it happens at the end of August in the samples of the stem. The leaf buds of Q. pubescens and of Q. Ilex open during April-May and the young branch is completely developed at the end of June. In both oaks some buds open in autumn, but the small branches are prevented to develop because of the cold. No comparison can be made between the opening of the buds and the beginning of the cambial activity in the stem and in the branch. Considering the evolution of these woods and their relationship to climatic factors, we can see that the cambial activity starts during a period of remarkable rainfall and of regular increase of temperature, and stops almost completely at the end of July, when temperature and dryness reach their highest values. The autumn rainfall would favour again a cambial activity, but the values of the temperature, regularly decreasing, do not allow it.
doi: 10.1080/11263505009431489
Keywords: Quercus ilex; Quercus pubescens (PG); wood anatomy; wood rings

The cork oak tree in California - Metcalf, Woodbridge (Economic Botany, 1947)
Cork oaks have been planted in Cali- fornia since about 1855, and there are some outstandingly fine specimen trees growing from San Diego to Eureka at elevations below 2,700 feet. There are about 5,000 trees more than ten years old in the state. Cork oak acorns produced in Cali- fornia average 70 per pound, have a high germinative capacity which can be main- tained for twelve months or more by moist cold storage at 38° F., and during most years it should be possible to obtain from five to ten tons of cork oak acorns from California trees. During the past six years about 200,- 000 seedling trees of cork oak have been grown and distributed to land owners under the cooperative cork oak project. Where carefully planted, protected from animal damage and given adequate irri- gation, shade and care, many of these plantations have shown excellent sur- vival and growth. Because of the kind interest and co- operation on the part of owners of cork oak trees, it has been possible to carry on experimental stripping of about 500 cork oaks during the past six years. The stripping season has been found to be from about July 1 to early in October. Most vigorous and full-crowned trees can be stripped easily with the special tools developed and with virtually no damage to the inner bark. It is not advisable to strip trees which are thin crowned or suffering from drought, insects or dis- ease. Removal of cork from ornamental cork oaks changes their appearance but does not seriously check their growth or lessen their ornamental character. The 15 tons of cork has been quite thoroughly tested and found to be well suited for the making of composition cork articles, insulation blocks and other been rapid and satisfactory with trees, usually regaining the diameter before stripping in five years. Indications are that the reproduction cork is of excellent quality. Trees 25 to 30 years of age when stripped have put on a growth of 100 pounds of reproduction cork in five years. The most serious insect enemy of the cork oak in California is the gall wasp which kills many twigs, particularly on trees in dry locations. There is no known control for this pest. If the cooperative distribution of trees can be continued until there are one mil- lion cork oaks growing in California, they will when 30 years old contain an emergency supply of 50,000 tons of cork. This amount may be increased and the quality improved by successive stripping of the trees after they become 20 years of age.
Keywords: acorns; California; Cork; cork oak trees; diameter; growth (voyant); stripping

Some colonies of eurasian relict species at the Quercus ilex L stage - Roi, J (COMPTES RENDUS HEBDOMADAIRES DES SEANCES DE L ACADEMIE DES SCIENCES, 1938)
APS
Keywords: Quercus ilex L.

Cork and its uses - Cooke, Giles B. (Journal of Chemical Education, 1931)
Cork is the bark of the cork oak which i s found along the shores of the West- ern Mediterranean. When the tree is twenty years old the cork i s stripped from the trunk and at nine-year intewals thereafter. Cork i s composed of tiny air-filled cells held together by a natural resinous binder. Because of this structure cork i s light, compressible, resilient, and waterproof. Cork has a low thermal conductivity and a high coefficient of friction. Cork has b e a shown to contain tannins, phlobaphaes, lignin, and cerin. Glycerin and several acids h o e been obtained by saponification. Natural cork is used to manufacture stoppers, life presewers, and many other articles. Scraps of cork are ground and used i n the manufacture of cork composition from which gaskets, polishing wheels, crown seels, and numerous other articles are made. Corkboard for insulation and cork tile, cork carpet, and linoleum for floors, are manufactured from cork.
doi: 10.1021/ed008p1462doi: 10.1021/ed008p1462The following values have no corresponding Zotero field: publisher: American Chemical Society
Keywords: Cork; cork cells; Cork composition; natural cork; uses (voyant)

Cork and Corks - Glasspoole, H G (Scientific American, 1879)
NA

O passado, o presente eo futuro dos montados. Estudo económico agrícola no Distrito de Beja - Carvalho, E. F. N. (1870)
NA
Keywords: Beja; montado; Quercus rotundifolia; Quercus suber

Os montados em Portugal - Luz, C S (1866)
NA
Keywords: montado; Quercus rotundifolia; Quercus suber