Relative roles of ecological and energetic constraints, diversification rates and region history on global species richness gradients

Jonathan Belmaker*, Walter Jetz

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Regions worldwide differ markedly in species richness. Here, for birds and mammals worldwide, we directly compare four sets of hypotheses regarding geographical richness gradients: (1) evolutionary, emphasising heterogeneity in diversification rates, (2) historical, related to differences in region ages and sizes, (3) energetic, associated with variation in productive or ambient energy and (4) ecological, reflecting differences in ecological niche diversity. Among highly independent regions, or 'evolutionary arenas', we find that richness is weakly influenced by richness-standardised ecological niche diversity, questioning the significance of ecological constraints for producing large-scale diversity gradients. In contrast, we find strong evidence for the importance of region area and its changes over time, together with a role for temperature. These predictors affect richness predominately directly without concomitant positive effects on diversification rates. This suggests that regional richness is governed by historical and evolutionary processes, which promote region-specific accumulation of diversity through time or following asymmetrical dispersal.

Original languageEnglish
Pages (from-to)563-571
Number of pages9
JournalEcology Letters
Volume18
Issue number6
DOIs
StatePublished - 1 Jun 2015

Funding

FundersFunder number
National Aeronautics and Space AdministrationNNX11AP72G
National Science FoundationDEB 1026764, DBI-1262600, DBI 0960550
National Science Foundation1026764, 1262600

    Keywords

    • Birds
    • Diversification rate
    • Diversity
    • Functional diversity
    • Mammals
    • Species traits

    Fingerprint

    Dive into the research topics of 'Relative roles of ecological and energetic constraints, diversification rates and region history on global species richness gradients'. Together they form a unique fingerprint.

    Cite this