<?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%">Gea-Izquierdo, G</style></author><author><style face="normal" font="default" size="100%">Cañellas, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Analysis of holm oak intraspecific competition using Gamma regression</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">diameter increment growth</style></keyword><keyword><style  face="normal" font="default" size="100%">generalized linear model</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">55</style></volume><pages><style face="normal" font="default" size="100%">310-322</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Analysis of plant competition is a major issue in ecology and forestry, as it influences plant growth and plant-environment interactions. Competition is expected to be lower in the sparse tree stratum of open woodlands and agroforestry systems than in closed forests. We have analyzed competition in open woodlands of Quercus ilex in the Iberian Peninsula by studying a 10-year diameter growth increment from collected samples and from consecutive National Forest Inventories. Density was the competition index selected in all models, outperforming more complex distance-dependent indices. The models showed that competition is playing a role in growth but that the covariate most correlated with growth is age or dbh as a surrogate of age. Therefore, below-ground competition is likely to be limiting tree growth, but below-ground competition is lower in open woodlands compared with that in denser forests and thus potential growth (which is strongly linked to age) is almost expressed. Model behavior was improved when data were fitted directly using generalized linear models, which do not require transforming of the dependent variable. Our results showed that modeling growth with the gamma probability distribution resulted in better models compared with Gaussian linear models. Gamma regression offers a great potential for many forestry applications.</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%">Gea-Izquierdo, G</style></author><author><style face="normal" font="default" size="100%">Montero, G</style></author><author><style face="normal" font="default" size="100%">Cañellas, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Changes in limiting resources determine spatio-temporal variability in tree–grass interactions</style></title><secondary-title><style face="normal" font="default" size="100%">Agroforestry Systems</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Abiotic stress</style></keyword><keyword><style  face="normal" font="default" size="100%">competition</style></keyword><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">Facilitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Grass production</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">76</style></volume><pages><style face="normal" font="default" size="100%">375-387</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Changing biotic and abiotic stress mediate in plant–plant interactions resulting in positive to neutral or negative effects, and these effects can change with gradients of stress or through plant dynamics. Here we studied the variability in annual grass production and composition induced by gradients of intercepted light by trees in years of contrasting precipitation in Mediterranean holm oak open woodlands. Although trees reduce the light radiance received by the pasture community, the presence of trees generally had a positive effect on pasture production in average climatic years where soil fertility was low. However, the interaction changed with increasing abiotic water stress. In a dry year, the increase in fertility could not be utilized and the effect of the crown was neutral. The effect of shade turned out to be beneﬁcial for growth, contrary to the situation in an average climatic year. Light insolation was positive for legume biomass. There was high variability in functional components over the course of the growing period and from 1 year to another. Under low levels of other biotic stresses such as livestock grazing or root competition, the limiting factor among light, soil moisture or soil nutrients may determine whether facilitation or competition occurs.</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%">Gea-Izquierdo, G</style></author><author><style face="normal" font="default" size="100%">Cañellas, I</style></author><author><style face="normal" font="default" size="100%">Montero, G</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Acorn production in Spanish holm oak woodlands</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Systems</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acorn</style></keyword><keyword><style  face="normal" font="default" size="100%">agrosilvopastoral systems</style></keyword><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">fruit production</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">339-354</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We present a review on the state-of-the-art of fruit prodution in Western Iberia woodlands («dehesas»), and particularly in Q. ilex (holm oak) «dehesas». This threatened ecosystem is of very high ecological and economical importance. Quercus sp. fruits (acorns) are essential for wildlife, and for pig fattening in «dehesas». In the first part of this review we briefly describe the phenology of the holm oak and the factors affecting acorn morphology and chemical composition. In the second half we analyze the main known factors reported in the literature that determine acorn production: pruning, stand characteristics, and site (weather and soil). We make several suggestions to improve future research and detect the existing gaps in the undertanding of acorn production. Fruit production is highly variable, both between and within years and individuals. The mean production in «dehesas» (mean density circa 50 trees/ha) is around 250-600 kg/ha (≈100 g/canopy-m2 , CV&gt; 100%). Acorn morphology is also very variable, with mean sound acorn size around 3.5 × 1.6 cm, CV ≈ 10% (3.5 g/acorn, CV &gt; 50%). Silviculture plays an essential role in acorn production. Acorn production per tree seems to be negatively related to density. The effect of pruning is less clear: production seems to be reduced in the first and second years after pruning. After the third year it is not possible to discern from the literature whether there is any response to pruning or not. Weather and soil (site) also impact production and their effects should be explored in future management. The influence of genetics is unknown and should also be addressed. Longer data series are necessary. The dasometric features of the stands need to be characterized, in order to better understand production and compare results from different locations. Much research is still required to understand the functioning of fruiting in these woodlands.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>7</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cañellas, I</style></author><author><style face="normal" font="default" size="100%">Sanchez-Gonzalez, M</style></author><author><style face="normal" font="default" size="100%">Bogino, S M</style></author><author><style face="normal" font="default" size="100%">Adame, P</style></author><author><style face="normal" font="default" size="100%">Herrero, C</style></author><author><style face="normal" font="default" size="100%">Roig, S</style></author><author><style face="normal" font="default" size="100%">Paulo, J A</style></author><author><style face="normal" font="default" size="100%">Bravo, F</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Bravo, F</style></author><author><style face="normal" font="default" size="100%">Jandl, R</style></author><author><style face="normal" font="default" size="100%">LeMay, V</style></author><author><style face="normal" font="default" size="100%">Gadow, K V</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Silviculture and Carbon Sequestration in Mediterranean Oak Forests</style></title><secondary-title><style face="normal" font="default" size="100%">Managing Forest Ecosystems: The Challenge of Climate Change,</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon stock</style></keyword><keyword><style  face="normal" font="default" size="100%">Kyoto protocol</style></keyword><keyword><style  face="normal" font="default" size="100%">Portugal</style></keyword><keyword><style  face="normal" font="default" size="100%">Spain</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer Netherlands</style></publisher><pages><style face="normal" font="default" size="100%">317-318</style></pages><isbn><style face="normal" font="default" size="100%">978-1-4020-8342-6</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The Kyoto Protocol requires every industrialized country to have a transparent and verifiable method for estimating the size and evolution of the carbon stored in forest ecosystems. The intergovernmental panel on climate change (IPCC, 2007) predicts the evolution of the stock over the first commitment period (2008–2012) using the “bottom-up approach”. This approach is based on the use of data from national or regional forest inventories. The biomass of living trees including their dead parts comprises the main carbon pool in forest ecosystems along with the biomass of understorey plants, litter, woody debris and soil organic matter (Pignard et al., 2004). The objective of this chapter is to present some of the studies currently being carried out in Spain and Portugal which are concerned with the possibility of estimating the amount of carbon fixed by two of the main oak species in the Iberian Peninsula; rebollo oak (Quercus pyrenaica Willd.) and cork oak (Quercus suber L.). Three different methodological approaches have been used. The first approach is to use growth models to evaluate the carbon sequestration in both cork and wood over the life of a cork oak plantation. This approach has been applied both for Spain and Portugal. The second approach involves using a yield table as a tool to estimate the carbon sequestration in Quercus pyrenaica forests based on Spanish National Forest Inventories. In a third approach, data from a network of plots is used to estimate the carbon sequestration in pure and mixed Quercus pyrenaica forests. The application of these different methodologies would allow us to forecast and improve the carbon sequestration in oak forests as well as increasing our understanding of their dynamics.</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%">Sanchez-Gonzalez, M</style></author><author><style face="normal" font="default" size="100%">Cañellas, I</style></author><author><style face="normal" font="default" size="100%">Montero, G</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Generalized height-diameter and crown diameter prediction models for cork oak forests in Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Investigación Agraria: Sistemas y Recursos Forestales</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">crown width</style></keyword><keyword><style  face="normal" font="default" size="100%">forest growth modelling</style></keyword><keyword><style  face="normal" font="default" size="100%">height-diameter relationship</style></keyword><keyword><style  face="normal" font="default" size="100%">mixed effects models</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">76-88</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A generalized height-diameter equation, along with a crown diameter prediction equation for cork oak forests in Spain were developed based on data from the Second Spanish Forest Inventory. Nine generalised height-diameter equations were selected as candidate functions to model the height-diameter under cork relationship, while for the crown diameter prediction model five linear and non-linear equations were tested. The equations were fitted using the mixedeffects model approach. The Stoffels &amp; Van Soest power equation, constrained to pass through the point of dominant diameter and dominant height, was selected as the generalised height-diameter model. Regarding the crown diameter prediction model, the parable function without the intercept and with quadratic mean diameter incorporated as a fixed effect into the b parameter, proved to be the model with best prediction capabilities. The models were validated by characterising the model error using the PRESS (Prediction Sum of Squares) statistic. Both equations will be submodels of the ALCORNOQUE v1.0, a management oriented growth and yield model for cork oak forests in Spain.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pardos Mínguez, M</style></author><author><style face="normal" font="default" size="100%">Cañellas, I</style></author><author><style face="normal" font="default" size="100%">Bachiller, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Influencia del tamaño de bellota y del régimen de riego en la calidad de planta de alcornoque cultivada en vivero</style></title><secondary-title><style face="normal" font="default" size="100%">II Congreso Forestal Español</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acorn size</style></keyword><keyword><style  face="normal" font="default" size="100%">irrigation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">seedling quality</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><pages><style face="normal" font="default" size="100%">491-496</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effect of three acorn sizes (small, medium and large, 2.5, 5 and 8.8 g mean fresh weight, respectively) and two irrigation regimes (Rl=2R2) in the growth of cork oak containerized (Forest Pot 300) seedlings was studied. The seedlings were grown in the nursery for one year.The results showed the influence of the acorn size on caliper, root volume, shoot, root and acorn dry weights, leaf area, leaf weight ratio (L WR), leaf area ratio (LAR), midday water potential and transpiration. Irrigation was statistically significant for height and totalleaf area. Water potential reached less than -2 MPa in July. This fact reveals the adaptation of the species to drought.</style></abstract></record></records></xml>