Beta-diversity in temperate and tropical forests reflects dissimilar mechanisms of community assembly

• Published in: Ecology letters Vol. 16; no. 2; pp. 151 - 157
• Main Authors: Myers, Jonathan A., Chase, Jonathan M., Jiménez, Iván, Jørgensen, Peter M., Araujo-Murakami, Alejandro, Paniagua-Zambrana, Narel, Seidel, Renate
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.02.2013; Blackwell
• Subjects: Amazonia; Animal and plant ecology; Animal, plant and microbial ecology; beta-diversity; Biodiversity; Biological and medical sciences; Bolivia; Carya; Climate; community assembly; Community ecology; dispersal limitation; environmental filtering; Forestry; Fundamental and applied biological sciences. Psychology; General aspects; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; intraspecific aggregation; metacommunity; Missouri; Models, Biological; Ozarks; Plant populations; Quercus; Rainforests; Species composition; Species diversity; species pool; species sorting; Temperate forests; Terrestrial ecosystems; Trees; Tropical Climate; Tropical environments; Tropical forests; Woody plants; South America; America; Amazon Basin; Bolivia; Missouri; Filtering; intraspecific aggregation; beta-diversity; Beta diversity; Tropical forest; Dispersion; Sorting; Aggregation; species pool; dispersal limitation; Ozarks; environmental filtering; Amazonia; species sorting; Temperate forests; Community; community assembly; metacommunity
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/ele.12021

Site‐to‐site variation in species composition (β‐diversity) generally increases from low‐ to high‐diversity regions. Although biogeographical differences in community assembly mechanisms may explain this pattern, random sampling effects can create this pattern through differences in regional species pools. Here, we compared assembly mechanisms between spatially extensive networks of temperate and tropical forest plots with highly divergent species pools (46 vs. 607 species). After controlling for sampling effects, β‐diversity of woody plants was similar and higher than expected by chance in both forests, reflecting strong intraspecific aggregation. However, different mechanisms appeared to explain aggregation in the two forests. In the temperate forest, aggregation reflected stronger environmental correlations, suggesting an important role for species‐sorting (e.g. environmental filtering) processes, whereas in the tropics, aggregation reflected stronger spatial correlations, more likely reflecting dispersal limitation. We suggest that biogeographical differences in the relative importance of different community assembly mechanisms contribute to these striking gradients in global biodiversity.