<?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></contributors><titles><title><style face="normal" font="default" size="100%">How resilient is Quercus suber L. to cork harvesting? A review and identification of knowledge gaps</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0378112712000357</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">270</style></volume><pages><style face="normal" font="default" size="100%">257 - 272</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.) woodlands are ecologically sensitive and human-supported areas which strongly rely on the high market value of cork for their sustainability. Cork harvesting is a forestry practice speciﬁc to this Mediterranean evergreen oak, whereby the bark (cork) is periodically removed from stems and branches over the whole tree lifetime. This practice is a strain factor for the tree, particularly because it is performed during the most stressful time of the year, and also because stripped oaks become more vulnerable to pathogens and environmental hazards such as wildﬁres. This review gathers and analyzes information about tree responses to cork harvesting. Cork removal leads to phellogen destruction and subsequent regeneration. Upon each harvesting, the tree faces important losses of water, released from the suddenly exposed living cells, and of cork. Immediate responses relate to stem healing mechanisms, leaf stomatal closure and prompt production of new cork layers by the restored phellogen, the latter actually representing the most evident response of Q. suber to cork harvesting. Further strategies to compensate for water and cork losses are insufﬁciently understood, but possibly include prolonged reduction of leaf transpiration (and consequent reduction of photoassimilation), increased water uptake from the soil, use of reserves and changes in whole-tree energy allocation to support cork regeneration. Cork stripping by unskilled workers may leave wounds on the tree, which eventually hinder cork regeneration and lead to premature tree death. The relationship between current cork harvesting practices (e.g. harvesting intensities or periodicity) and tree resilience is not quite established. Higher stripping pressures seem to trigger more pronounced or drastic tree responses and/or to enhance their decline. A major conclusion is that the available information is still too scarce to allow for a consistent evaluation of the effects of cork harvesting on cork oak and on its associated woodlands. So far, few studies have addressed how tree resilience relates to harvesting intensities, a crucial issue to enable improved tree and stand management strategies and to ensure adequate conservation of these sensitive forest systems.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">How resilient is Quercus suber L. to cork harvesting? A review and identification of knowledge gaps</style></title><short-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012/4/15/</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0378112712000357</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">270</style></volume><pages><style face="normal" font="default" size="100%">257 - 272</style></pages><isbn><style face="normal" font="default" size="100%">0378-1127</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Cork oak (Quercus suber L.) woodlands are ecologically sensitive and human-supported areas which strongly rely on the high market value of cork for their sustainability. Cork harvesting is a forestry practice specific to this Mediterranean evergreen oak, whereby the bark (cork) is periodically removed from stems and branches over the whole tree lifetime. This practice is a strain factor for the tree, particularly because it is performed during the most stressful time of the year, and also because stripped oaks become more vulnerable to pathogens and environmental hazards such as wildfires.This review gathers and analyzes information about tree responses to cork harvesting. Cork removal leads to phellogen destruction and subsequent regeneration. Upon each harvesting, the tree faces important losses of water, released from the suddenly exposed living cells, and of cork. Immediate responses relate to stem healing mechanisms, leaf stomatal closure and prompt production of new cork layers by the restored phellogen, the latter actually representing the most evident response of Q. suber to cork harvesting. Further strategies to compensate for water and cork losses are insufficiently understood, but possibly include prolonged reduction of leaf transpiration (and consequent reduction of photoassimilation), increased water uptake from the soil, use of reserves and changes in whole-tree energy allocation to support cork regeneration.
Cork stripping by unskilled workers may leave wounds on the tree, which eventually hinder cork regeneration and lead to premature tree death.
The relationship between current cork harvesting practices (e.g. harvesting intensities or periodicity) and tree resilience is not quite established. Higher stripping pressures seem to trigger more pronounced or drastic tree responses and/or to enhance their decline.
A major conclusion is that the available information is still too scarce to allow for a consistent evaluation of the effects of cork harvesting on cork oak and on its associated woodlands. So far, few studies have addressed how tree resilience relates to harvesting intensities, a crucial issue to enable improved tree and stand management strategies and to ensure adequate conservation of these sensitive forest systems.
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Respostas morfológicas e fisiológicas das folhas de duas espécies mediterrânicas a factores ambientais durante o Inverno</style></title><secondary-title><style face="normal" font="default" size="100%">Revista de Biologia</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">22</style></volume><pages><style face="normal" font="default" size="100%">53-63</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">The relative importance of cork harvesting and climate for stem radial growth of Quercus suber L.</style></title><short-title><style face="normal" font="default" size="100%">Annals of forest science</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">EDP Sciences</style></publisher><volume><style face="normal" font="default" size="100%">59</style></volume><pages><style face="normal" font="default" size="100%">439 - 443</style></pages><isbn><style face="normal" font="default" size="100%">1286-4560</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">4</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Respostas fotoquímicas e fenológicas de uma espécie perenifólia e de uma espécie semi-decídua durante o Inverno mediterrânico.</style></title><secondary-title><style face="normal" font="default" size="100%">Revista de Biologia</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">249-259</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></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%">Oliveira, Graca</style></author><author><style face="normal" font="default" size="100%">Correia, Otflia</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Phenological and growth patterns of the Mediterranean oak Quercus suber L.</style></title><secondary-title><style face="normal" font="default" size="100%">Trees-Structure and …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Growth</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">specific leaf weight</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1994</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1994///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/r14387032226767q.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">41 - 46</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The phenology of Quercus suber L., a dominant species of the montados in the Iberian Peninsula, was studied for 2 years in southwest Portugal. The seasonal progression of phenological events was analyzed in seven trees. Selected branches were examined monthly for shoot elongation, leaf number, branching, flowering, and fruiting. Radial stem growth and specific leaf weight were also studied. Active growth was observed from early spring to early summer. Reserves accumulated during winter and high photosynthetic activity in early spring apparently supported this strong development. The growth flush started with stem radial increment, which seemed to be impaired by spring rainfall. Male inflorescence production was the next phenological event. Old leaves were shed during new twig and leaf emergence. Shoot elongation and the number of new leaves produced were well correlated with the previous-year shoot's length, and were not clearly related to climatic factors. Radial growth resumed in au- tumn at a lower rate than in the previous spring, a possible consequence of a reserve depletion due to lower photo- synthetic production in summer and investment on fruit maturation, which was complete by late autumn. Premature and excessive new leaf production were apparently sub- jected to self-pruning strategies related to the development of each tree's crown. Younger cork-oaks produced shorter and fewer shoots per module, and more sclerophyllous leaves than the older ones. A high intra-specific variability was observed in all the results.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Phenological and growth patterns of the Mediterranean oak Quercus suber L.</style></title><short-title><style face="normal" font="default" size="100%">Trees</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">1994</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1994</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">41 - 46</style></pages><isbn><style face="normal" font="default" size="100%">0931-1890</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Phenological and growth patterns of the Mediterranean oak Quercus suber L.</style></title><secondary-title><style face="normal" font="default" size="100%">Trees-Structure and …</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1994</style></year></dates><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">41-46</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The phenology of Quercus suber L., a dominant species of the montados in the Iberian Peninsula, was studied for 2 years in southwest Portugal. The seasonal progression of phenological events was analyzed in seven trees. Selected branches were examined monthly for shoot elongation, leaf number, branching, flowering, and fruiting. Radial stem growth and specific leaf weight were also studied. Active growth was observed from early spring to early summer. Reserves accumulated during winter and high photosynthetic activity in early spring apparently supported this strong development. The growth flush started with stem radial increment, which seemed to be impaired by spring rainfall. Male inflorescence production was the next phenological event. Old leaves were shed during new twig and leaf emergence. Shoot elongation and the number of new leaves produced were well correlated with the previous-year shoot's length, and were not clearly related to climatic factors. Radial growth resumed in au- tumn at a lower rate than in the previous spring, a possible consequence of a reserve depletion due to lower photo- synthetic production in summer and investment on fruit maturation, which was complete by late autumn. Premature and excessive new leaf production were apparently sub- jected to self-pruning strategies related to the development of each tree's crown. Younger cork-oaks produced shorter and fewer shoots per module, and more sclerophyllous leaves than the older ones. A high intra-specific variability was observed in all the results.</style></abstract></record></records></xml>