<?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%">Cierjacks, a.</style></author><author><style face="normal" font="default" size="100%">Hensen, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variation of stand structure and regeneration of Mediterranean holm oak along a grazing intensity gradient</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology (formerly Vegetatio)</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acorn predation</style></keyword><keyword><style  face="normal" font="default" size="100%">acorn quality</style></keyword><keyword><style  face="normal" font="default" size="100%">forest conservation</style></keyword><keyword><style  face="normal" font="default" size="100%">grazing intensity</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">south-eastern spain</style></keyword><keyword><style  face="normal" font="default" size="100%">sustainable land-use</style></keyword><keyword><style  face="normal" font="default" size="100%">vegetative reproduction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">173</style></volume><pages><style face="normal" font="default" size="100%">215-223</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean ecosystems are traditionally inﬂuenced by human disturbance. In the mountain chains of southeastern Spain, holm oak forests representing the potential natural vegetation are currently highly fragmented and subjected to extensive grazing by goats and sheep. This grazing activity by large herbivores has important impacts on community structure and dynamics of the remaining remnants because several processes associated with reproduction are affected. The present research analyses the variation of stand structure and regeneration of six forests dominated by Quercus ilex along a gradient of increasing grazing intensity. Stands of higher grazing intensity are characterized by a lower trunk number. Particularly, trees 1.3 m height and diameter classes 20 cm are clearly less represented. In addition, more intensively grazed forests show a highly aggregated dispersion of trees, which might be explained by an increase of clonally produced ramets by silvipastoral use. On the other hand, no Quercus ilex seedlings were found in any of the stands examined, although acorn production was high and did not correlate with grazing intensity. However, grazing clearly inﬂuences the quality of acorn harvest. We found a signiﬁcant negative correlation between acorn length, acorn mass and grazing intensity and a positive correlation between the percentage of aborted acorns, acorn predation and herbivore activity. Thus, management of grazing in holm oak forests must take the high inﬂuence that livestock exerts on the regeneration of Quercus ilex into account, and maximum sustainable grazing intensity should be signiﬁcantly lower than 0.8 animals per ha.</style></abstract></record></records></xml>