Does climate determine broad-scale patterns of species richness? A test of the causal link by natural experiment
Article first published online: 17 OCT 2003
Global Ecology and Biogeography
Volume 12, Issue 6, pages 461–473, November 2003
How to Cite
H-Acevedo, D. and Currie, D. J. (2003), Does climate determine broad-scale patterns of species richness? A test of the causal link by natural experiment. Global Ecology and Biogeography, 12: 461–473. doi: 10.1046/j.1466-822X.2003.00058.x
- Issue published online: 17 OCT 2003
- Article first published online: 17 OCT 2003
- Bird species richness;
- Central America;
- distribution patterns;
- North America;
- spatial and seasonal variation
Aim Broad-scale spatial patterns of species richness are very strongly correlated with climatic variables. If there is a causal link, i.e. if climate directly or indirectly determines patterns of richness, then when the climatic variables change, richness should change in the manner that spatial correlations between richness and climate would predict. The present study tests this prediction using seasonal changes in climatic variables and bird richness.
Location We used a grid of equal area quadrats (37 000 km2) covering North and Central America as far south as Nicaragua.
Methods Summer and winter bird distribution data were drawn from monographs and field guides. Climatic data came from published sources. We also used remotely sensed NDVI (normalized difference vegetation index — a measure of greenness).
Results Bird species richness changes temporally (between summer and winter) in a manner that is close to, but statistically distinguishable from, the change one would predict from models relating the spatial variation in richness at a single time to climatic variables. If one further takes into account the seasonal changes in NDVI and within-season variability of temperature and precipitation, then winter and summer richness follow congruent, statistically indistinguishable patterns.
Main conclusions Our results are consistent with the hypothesis that climatic variables (temperature and precipitation) and vegetation cover directly or indirectly influence patterns of bird species richness.