The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity |
| |
Authors: | Frans Bongers Lourens Poorter William D Hawthorne Douglas Sheil |
| |
Institution: | Forest Ecology and Forest Management Group, Centre for Ecosystem Studies, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands; Resource Ecology Group, Centre for Ecosystem Studies, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands; Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, United Kingdom; Institute of Tropical Forest Conservation (Mbarara University of Science and Technology), PO Box 44, Kabale, Uganda |
| |
Abstract: | The intermediate disturbance hypothesis (IDH) predicts local species diversity to be maximal at an intermediate level of disturbance. Developed to explain species maintenance and diversity patterns in species-rich ecosystems such as tropical forests, tests of IDH in tropical forest remain scarce, small-scale and contentious. We use an unprecedented large-scale dataset (2504 one-hectare plots and 331 567 trees) to examine whether IDH explains tree diversity variation within wet, moist and dry tropical forests, and we analyse the underlying mechanism by determining responses within functional species groups. We find that disturbance explains more variation in diversity of dry than wet tropical forests. Pioneer species numbers increase with disturbance, shade-tolerant species decrease and intermediate species are indifferent. While diversity indeed peaks at intermediate disturbance levels little variation is explained outside dry forests, and disturbance is less important for species richness patterns in wet tropical rain forests than previously thought. |
| |
Keywords: | Disturbance Ghana guild intermediate disturbance hypothesis shade tolerance species density species richness tropical forest |
|
|