<?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%">Poorter, Lourens</style></author><author><style face="normal" font="default" size="100%">Lianes, Elena</style></author><author><style face="normal" font="default" size="100%">Moreno-de las Heras, Mariano</style></author><author><style face="normal" font="default" size="100%">Zavala, Miguel A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Architecture of Iberian canopy tree species in relation to wood density, shade tolerance and climate</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Architecture</style></keyword><keyword><style  face="normal" font="default" size="100%">Crown traits</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">shade tolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">Tree height</style></keyword><keyword><style  face="normal" font="default" size="100%">Wood density</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">213</style></volume><pages><style face="normal" font="default" size="100%">707-722</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Tree architecture has important consequences for tree performance as it determines resource capture, mechanical stability and dominance over competitors. We analyzed architectural relationships between stem and crown dimensions for 13 dominant Iberian canopy tree species belonging to the Pinaceae (six Pinus species) and Fagaceae (six Quercus species and Fagus sylvatica) and related these architectural traits to wood density, shade tolerance and climatic factors. Fagaceae had, compared with Pinaceae, denser wood, saplings with wider crowns and adults with larger maximal crown size but smaller maximal height. In combination, these traits enhance light acquisition and persistence in shaded environments; thus, contributing to their shade tolerance. Pinaceae species, in contrast, had low-density wood, allocate more resources to the formation of the central trunk rather than to branches and attained taller maximal heights, allowing them to grow rapidly in height and compete for light following disturbances; thus, contributing to their high light requirements. Wood density had a strong relationship with tree architecture, with dense-wooded species having smaller maximum height and wider crowns, probably because of cheaper expansion costs for producing biomechanically stable branches. Species from arid environments had shorter stems and shallower crowns for a given stem diameter, probably to reduce hydraulic path length and assure water transport. Wood density is an important correlate of variation in tree architecture between species and the two dominant families, with potentially large implications for their resource foraging strategies and successional 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%">Leal, Sofia</style></author><author><style face="normal" font="default" size="100%">Sousa, Vicelina B</style></author><author><style face="normal" font="default" size="100%">Knapic, Sofia</style></author><author><style face="normal" font="default" size="100%">Louzada, José Luís</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Vessel size and number are contributors to define wood density in cork oak</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">vessels</style></keyword><keyword><style  face="normal" font="default" size="100%">wood anatomy</style></keyword><keyword><style  face="normal" font="default" size="100%">Wood density</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><volume><style face="normal" font="default" size="100%">130</style></volume><pages><style face="normal" font="default" size="100%">1023-1029</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Cork oak (Quercus suber L.) has a dense wood that allows high-quality uses. In the present work, we study the inﬂuence of vessel characteristics, measured through image analysis and optical microscopy, on wood density, measured using X-ray microdensitometry, on 40-year-old trees. Vessel area increases with cambial age (5403–33064 lm 2 ), while wood density decreases (1.229–0.836 g/cm 3 ). The number of vessels is relatively constant at 6 vessels/mm 2 , while vessel proportion in cross-section increases from 3.3% near the pith to 20.5% near the bark. In growth rings closest to the pith, with high wood density and low vessel area, the relationship between the two variables is linear (R 2 = -32.1%, P\0.01) but with increasing tree age and vessel size, the wood density remains rather constant, suggesting that decreases in density might compromise mechanical support of the tree at a stage when the increase in crosssectional area alone might not provide mechanical stability. Other anatomical characteristics not considered in this study, like large xylem rays that increase with cambial age, may be responsible for the constant density</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%">Knapic, Sofia</style></author><author><style face="normal" font="default" size="100%">Louzada, José L</style></author><author><style face="normal" font="default" size="100%">Leal, Sofia</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Within-tree and between-tree variation of wood density components in cork oak trees in two sites in Portugal</style></title><secondary-title><style face="normal" font="default" size="100%">Forestry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">axial variation (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">cork oak trees</style></keyword><keyword><style  face="normal" font="default" size="100%">radial variation</style></keyword><keyword><style  face="normal" font="default" size="100%">Wood density</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">81</style></volume><pages><style face="normal" font="default" size="100%">465-473</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The axial and radial variation of wood density was studied using microdensitometry in cork oaks (Quercus suber) in two sites in Portugal. The observations were made in mature trees under cork production and in juvenile trees before the first cork extraction, at three height levels (stem base, 1.3 m and before stem bifurcation). The cork oak wood revealed a very high mean density (0.884–1.068 g cm−3). Differences between earlywood and latewood were small (0.866 and 1.061 g cm−3, respectively). Latewood corresponded on average to 61 per cent of the total. The variation of density between trees was statistically highly significant, but no differences were found between the two sites. The within-tree axial variation was negligible but the radial direction within a cross-section was one of the main origins of variation of the density components (18 per cent of the total variation). The density decreased from pith to cambium and this radial variation corresponded to 19–24 per cent of the total variation of wood density. Overall, the magnitude of density variations between and within cork oaks was small and an advantageous factor for their use for quality wood products.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/forestry/cpn012</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/forestry/cpn012</style></research-notes></record></records></xml>