Abstract
Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.
Original language | English |
---|---|
Article number | 20130502 |
Number of pages | 8 |
Journal | Proceedings of the Royal Society of London. B, Biological Sciences |
Volume | 280 |
Issue number | 1764 |
Early online date | 19 Jun 2013 |
DOIs | |
Publication status | Published - 7 Aug 2013 |
Bibliographical note
Funding statement
The CTFS plots were individually supported from a number of sources, details of which are given in the electronic supplementary material, text S2. C.B. was financially supported by a Microsoft PhD Scholarship.
Acknowledgements
We are grateful for the assistance of Yu-Wen Pan, Sandeep Pulla, Hugo Romero-Saltos and anonymous referees who provided helpful comments on the manuscript. The census and topographic data used here may be accessed directly via individual plot Principal Investigators.
© 2013 The Author(s) Published by the Royal Society. All rights reserved.
Keywords
- species coexistence
- tropical forest
- niche differentiation
- neutral theory
- spatial pattern
- cross-pair overlap distribution
- Lankan dipterocarp forest
- habitaty associations
- beta-diversity
- patterns
- communities
- abundance
- distributions
- availability
- mechanisms