首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Phylogenetic alpha and beta diversity in tropical tree assemblages along regional-scale environmental gradients in northwest South America
Authors:Sebasti  n Gonz  lez-Caro  Marí  a Natalia Uma  a  Esteban   lvarez  Pablo R Stevenson  Nathan G Swenson
Institution:1. Ecosystem Services & Climate Change Lab, Botanical Garden of Medellín, Medellín, Antioquia 050001, Colombia;2. Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA;3. Department of Ecology, Universidad de Alcalá, Alcalá, Madrid 28801, Spain;4. Department of Biological Sciences, Universidad de Los Andes, Bogotá 7495, Colombia
Abstract:Aims Environmental gradients are drivers of species diversity; however, we know relatively little about the evolutionary processes underlying these relationships. A potentially powerful approach to studying diversity gradients is to quantify the phylogenetic structure within and between assemblages arrayed along broad spatial and environmental gradients. Here, we evaluate the phylogenetic structure of plant assemblages along an environmental gradient with the expectation that the habitat specialization of entire lineages is an important evolutionary pattern influencing the structure of tree communities along environmental gradients.Methods We evaluated the effect of several environmental variables on the phylogenetic structure of plant assemblages in 145 plots distributed in northwestern South America that cover a broad environmental gradient. The phylogenetic alpha diversity was quantified for each plot and the phylogenetic beta diversity between each pair of plots was also quantified. Both the alpha and beta diversity measures were then related to spatial and environmental gradients in the study system.Important findings We found that gradients in temperature and potential evapotranspiration have a strong relationship with the phylogenetic alpha diversity in our study system, with phylogenetic overdispersion in low temperatures and phylogenetic clustering at higher temperatures. Further, the phylogenetic beta diversity between two plots increases with an increasing difference in temperature, whereas annual precipitation was not a significant predictor of community phylogenetic turnover. We also found that the phylogenetic structure of the plots in our study system was related to the degree of seasonal flooding and seasonality in precipitation. In particular, more stressful environments such as dry forests and flooded forests showed phylogenetic clustering. Finally, in contrast with previous studies, we find that phylogenetic beta diversity was not strongly related to the spatial distance separating two forest plots, which may be the result of the importance of the three independent mountain ranges in our study system, which generate a high degree of environmental variation over very short distances. In conclusion, we found that environmental gradients are important drivers of both phylogenetic alpha and phylogenetic beta diversities in these forests over spatial distance.
Keywords:phylogenetic conservatism  habitat filtering  immigration  environmental gradient  
点击此处可从《Journal of Plant Ecology》浏览原始摘要信息
点击此处可从《Journal of Plant Ecology》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号