<?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%">Zavala, M. A.</style></author><author><style face="normal" font="default" size="100%">Espelta, J. M.</style></author><author><style face="normal" font="default" size="100%">Retana, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Constraints and trade-offs in Mediterranean plant communities: The case of holm oak-Aleppo pine forests</style></title><secondary-title><style face="normal" font="default" size="100%">The Botanical Review</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Aleppo pine</style></keyword><keyword><style  face="normal" font="default" size="100%">disturbance regimes</style></keyword><keyword><style  face="normal" font="default" size="100%">forest dynamics</style></keyword><keyword><style  face="normal" font="default" size="100%">holm oak (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">light intensity</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean plant-communities</style></keyword><keyword><style  face="normal" font="default" size="100%">Water availability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/3u77576376314080.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">119 - 149</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In this paper we review those aspects that are relevant to the development of a mechanistic ecological theory to account for the structure and dynamics of Mediterranean forests, focus- ing our attention on mixed forests of holm oak (Quercus ilex L.), a shade-tolerant, slow- growing species that resprouts vigorously after disturbance, and Aleppo pine (Pinus halepen- sis M.), a fast-growing, nonresprouting, shade-intolerant species. The main objectives of this report are: to introduce some of the primary features of these forests, showing their structural complexity and historical peculiarities; to show that much of this complexity can be concep- tually reduced to two main factors of variation, soil-moisture gradients and a complex inter- action of historical management and disturbance regimes; and to contrast the unique features of Mediterranean systems with other communities that have inspired generalization in ecol- ogy. Plants in Mediterranean-climate regions must face several environmental constraints dur- ing their life cycle: water limitation, competition for light, and a complex set of disturbance regimes, mainly fire, herbivory, and human exploitation. The response of co-occurring spe- cies to a given set of environmental constraints depends on a combination of physiological and morphological traits. In holm oak-Aleppo pine forests, the lower limit of distribution along a soil-moisture gradient appears to be controlled by dry-season water stress on seedling performance, and the upper limit seems to be controlled by shade tolerance relative to com- petitors. The processes that generate and maintain these patterns are related to the responses of the two species to the water and light environments that result from interacting gradients of disturbance and resource availability. The dynamics of mixed holm oak-Aleppo pine forests may be represented along two major environmental axes: water availability and light intensity; namely, time since last disturbance. At the regional scale, the presence of holm oak and Aleppo pine is expected to be driven mainly by the precipitation regime, with the proportion of Aleppo pine in- creasing toward the driest border and with holm oak being the dominant species in areas with higher precipitation. Changes of dominance of holm oak and Aleppo pine also re- spond to water availability at the local scale. In this case, variations between species de- pend on different factors in a complex way, because reduced soil-moisture levels may re- sult either from low precipitation or from topography and edaphic features. The dynamics of holm oak-Aleppo pine forests are also determined by temporal changes in canopy clo- sure; that is, forest recovery after disturbance. In this case, the proportion of Aleppo pine would increase in recently disturbed stands (i.e., with high light intensity reaching the for- est floor), whereas regeneration of holm oak would be dominant under partially closed canopies. Theories of forest dynamics developed in humid regions may apply only poorly to Medi- terranean plant communities, where vegetation change is qualitatively or quantitatively dif- ferent. Thus, succession in temperate forests appears to be driven by differences in light availability and shade tolerance; but in Mediterranean plant communities, water limitation is of greater importance for the distribution of forest species. In Mediterranean landscapes the interaction of life-history strategies with changing environments is difficult to infer from observational and experimental studies. A mechanistic approach, in which competi- tion or plant performance is measured as a function of resource availability, seems more feasible. The idea should be to develop multispeeies models calibrated specifically for Mediterranean forests in a combined program of modeling, field research, and experimenta- tion.</style></abstract><issue><style face="normal" font="default" size="100%">March</style></issue></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%">ARISTA, M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">THE STRUCTURE AND DYNAMICS OF AN ABIES PINSAPO FOREST IN SOUTHERN SPAIN</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%">ABIES PINSAPO</style></keyword><keyword><style  face="normal" font="default" size="100%">forest dynamics</style></keyword><keyword><style  face="normal" font="default" size="100%">MEDITERRANEAN FIR</style></keyword><keyword><style  face="normal" font="default" size="100%">Regeneration</style></keyword><keyword><style  face="normal" font="default" size="100%">SIZE STRUCTURE</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1995///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">81 - 89</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The forest composition and age-diameter relationships of Abies pinsapo were studied in a natural forest in the Nature Reserve of the Sierra de Grazalema (southern Spain). The composition and structure of the forest was very different with respect to gaps and closed forest. Altitudinal differences in forest composition were also found. Abies pinsapo was the dominant species, Quercus rotundifolia and Quercus faginea were the other important overstorey species. The diameter distributions of A. pinsapo were skewed toward the larger size classes, with a large seedling proportion of about 70%. Abies pinsapo establishment rates were higher in the gaps. Seedlings of Abies pinsapo established under the closed canopy forest had suppressed growth, as indicated by their relatively advanced ages. Seedlings and saplings with suppressed growth can survive for a mean of 40 years, constituting a pool from which canopy trees may be recruited. Results show that the pinsapo forest of the Sierra de Grazalema is in equilibrium and that its dynamics are conditioned by a small-sapling bank and canopy gap formation.</style></abstract><issue><style face="normal" font="default" size="100%">1-3</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS&lt;br/&gt;publisher: ELSEVIER SCIENCE BV</style></notes></record></records></xml>