Does phylogenetic distance aid in detecting environmental gradients related to species composition?
Version of Record online: 11 JUL 2011
© 2011 International Association for Vegetation Science
Journal of Vegetation Science
Volume 22, Issue 6, pages 1143–1148, December 2011
How to Cite
Root, H. T. and Nelson, P. R. (2011), Does phylogenetic distance aid in detecting environmental gradients related to species composition?. Journal of Vegetation Science, 22: 1143–1148. doi: 10.1111/j.1654-1103.2011.01320.x
Co-ordinating Editor: Michael Palmer
- Issue online: 5 OCT 2011
- Version of Record online: 11 JUL 2011
- Received 7 March 2011, Accepted 6 June 2011
- Community analysis;
- Niche conservation;
- NMS ordination;
- Oregon trees;
- Phylogenetic distance;
- Synthetic data
Questions: How should we evaluate the success of new distance measures combining community abundance and phylogenetic information? How do we interpret ordinations using these metrics?
Methods: We generated synthetic data along a known environmental gradient with two hypothetical underlying phylogenetic structures: niche phylogenetically conserved or dispersed along a gradient. We also examined tree species composition associated with gradients in elevation and longitude in Oregon, USA. NMS ordinations of plots in species space from phylogenetic (PD) and Sørensen distance (SD) matrices allowed comparison of the use of PD in different scenarios.
Results: PD caused plots to cluster based on the clades that they contained, reducing stress with the synthetic data but not with the real example. Phylogenetic distance highlighted clades related to gradients when these were associated. When phylogeny was not conserved along a gradient, that gradient was less strong. Regardless of phylogenetic conservation, NMS using SD consistently extracted the strongest gradients in species composition.
Conclusions: The success of PD should be evaluated on how well it extracts gradients in species composition and allows community ecologists to determine which gradients are partially explained by phylogeny and not based on its ability to reduce ordination stress. PD ordinations can help community ecologists interpret niche conservation but may obscure gradients related to species composition when niches are not conserved along the gradient of interest at the scale of the study.