<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Heredia-Guerrero, Norberto</style></author><author><style face="normal" font="default" size="100%">Oliet, Juan a</style></author><author><style face="normal" font="default" size="100%">Villar-Salvador, Pedro</style></author><author><style face="normal" font="default" size="100%">Benito, Luis F</style></author><author><style face="normal" font="default" size="100%">Peñuelas, Juan L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Fertilization regime interacts with fall temperature in the nursery to determine the frost and drought tolerance of the Mediterranean oak Quercus ilex subsp. ballota</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cold acclimation</style></keyword><keyword><style  face="normal" font="default" size="100%">Hardening</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Nutrient loading</style></keyword><keyword><style  face="normal" font="default" size="100%">Osmotic potential</style></keyword><keyword><style  face="normal" font="default" size="100%">Soluble carbohydrate</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><volume><style face="normal" font="default" size="100%">331</style></volume><pages><style face="normal" font="default" size="100%">50-59</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Nitrogen fertilization in the nursery usually improves the transplanting performance of Mediterranean oaks. However, high N fertilization can reduce seedling stress tolerance, probably depending on the environmental conditions under which plants grow. We hypothesize that high N fertilization under mild fall conditions reduces cold and drought acclimation. To assess this hypothesis, we studied if fall temperature differences among cultivation locations influence the effect of N fertilization regime on cold and drought tolerance, N status and growth in the evergreen Mediterranean oak Quercus ilex subsp. ballota (Desf.) Samp. Plants were cultivated in two nurseries of distinct fall temperature conditions (mild and cold fall nurseries) under four fertilization regimes: Low and high N at constant rate (total N, 33 and 175mgseedling−1), high N at exponential rate (175mgNseedling−1) and fall N loading (89mgNseedling−1). Seedling water relations, survival to a −12°C frost and leaf soluble carbohydrates concentration were assessed three times in the fall, and shoot elongation was measured weekly through the fall. Moreover, seedling mass and N concentration were measured at the end of the fall. Fall loaded seedlings had the highest tissue N concentration, while seedling mass was highest in the high N constant and exponential fertilization regimes. Seedlings at the cold fall nursery concentrated more N but were smaller than seedlings at the mild fall nursery. Cessation of shoot elongation in the mild fall nursery occurred 1month later than in the cold location and high N exponentially-fertilized plants ceased shoot elongation later than the rest of fertilization treatments. Seedlings at the mild fall location had lower drought and cold tolerance than plants at the cold fall site. At mid fall, exponential fertilization at the mild nursery reduced seedling frost and drought tolerance, but treatment differences vanished at the end of the fall. In contrast, fertilization regime did not affect either cold or drought tolerance of seedlings at the cold fall nursery. Across dates and nurseries, frost survival was positively related to leaf soluble carbohydrates concentration and dry weight fraction. Beside, degree of cold acclimation decreased with shoot elongation cessation date and increased with leaf soluble carbohydrates concentration, suggesting a link between shoot growth activity, soluble carbohydrates, and frost tolerance. We conclude that Q. ilex subsp. ballota hardening is reduced by high N exponential fertilization mainly under mild fall conditions, while fall loading and constant low N fertilization did not affect hardening.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sala, Anna</style></author><author><style face="normal" font="default" size="100%">Tenhunen, John D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Site-specific water relations and stomatal response of Quercus ilex in a Mediterranean watershed</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Mediterranean sclerophylls</style></keyword><keyword><style  face="normal" font="default" size="100%">oak forest</style></keyword><keyword><style  face="normal" font="default" size="100%">oak watershed</style></keyword><keyword><style  face="normal" font="default" size="100%">Osmotic potential</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water potential</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1994</style></year></dates><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">601-617</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Intraspecific variations in the water relations and stomatal response of Quercus ilex L. were analyzed under field conditions by comparing trees at two locations within a Mediterranean watershed (l'Avic, Catalonia, NE Spain). Distinct environmental gradients exist between the two sites (referred to as ridge top at 975 m and valley bottom at 700 m) with greater soil depth for water storage, reduced radiation, reduced wind and higher water vapor pressure deficits at the valley bottom than at the ridge top. Osmotic adjustment and changes in tissue elasticiity did not significantly increase drought resistance in the trees studied. The leaf-to-air vapor pressure difference (Δw) threshold for inducing stomatal closure was higher at the ridge top (15.6 kPa MPa−1 ± 0.5 SE) than at the valley bottom (9.8 kPa MPa−1 ± 1.0 SE). However, increases in Δw beyond the threshold were followed by greater reductions in leaf conductance of trees at the ridge top than at the valley bottom. At both sites, maximum leaf conductance was related to predawn shoot water potential which, in turn, was related to watershed stream flow. The effects of water deficits during the dry summer of 1989 were more severe in trees at the valley bottom than at the ridge top. During periods of high evaporative demand, site-specific differences in the control of water loss led to more conservative water use by trees at the ridge top and, thus, to even greater drought avoidance (higher predawn water potentials) in late summer.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/treephys/14.6.601</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/treephys/14.6.601</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Duhme, F.</style></author><author><style face="normal" font="default" size="100%">Hinckley, T. M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Daily and seasonal variation in water relations of macchia shrubs and trees in France (Montpellier) and Turkey (Antalya)</style></title><secondary-title><style face="normal" font="default" size="100%">Vegetatio</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought resistance</style></keyword><keyword><style  face="normal" font="default" size="100%">Malacophyllous shrubs</style></keyword><keyword><style  face="normal" font="default" size="100%">Osmotic potential</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomata control types</style></keyword><keyword><style  face="normal" font="default" size="100%">Turgor loss point</style></keyword><keyword><style  face="normal" font="default" size="100%">Xylem water potential</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1992///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/BF00118225</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">99-100</style></volume><pages><style face="normal" font="default" size="100%">185 - 198</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Based upon two different research studies in the mediterranean regions of France and Turkey, drought resistance strategies were investigated in a broad group of species. The diurnal and seasonal patterns of the water relations of different lifeforms from the thermo-mediterranean to submediterranean lifezones were compared. Three sites near Montpellier, in Southern France, and five sites near Antalya, Turkey were used for this comparison. Xylem pressure potential and relative stomatal aperture were the key water relations parameters collected in France while these parameters as well as osmotic potential and leaf conductance were studied in Turkey. From the 26 different study species investigated in France, 7 distinct types of stomatal control were observed, with the deciduous lifeforms showing the least control, the sclerophyllous and coniferous evergreens the greatest control and the malacophyllous shrublets intermediate levels of control. Predawn water potential values provided a means of classifying species according to their temporal and spatial utilization of site water reserves. The comparison of turgor potentials (difference between water and osmotic potentials) gave an insight into leaf adaptations to site moisture. Species with high predawn water potentials generally maintain positive turgor even at midday during the summer, whereas species with low predawn values were frequently at zero turgor even at predawn. Phlomis grandiJtora was the most extreme species with mid-summer predawns and midday water potentials of -6 MPa and osmotic potentials never more negative than -2.4 MPa.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record></records></xml>