COS 144-3 - Pervasive effects of warming and cooling on biodiversity change across realms

Background/Question/Methods

Biodiversity change is pervasive and highly heterogeneous, with the composition of some assemblages changing rapidly and others slowly. A major challenge is to understand if and how temperature change contributes to this local heterogeneity. Warming is associated with faster biodiversity change in some ecosystems, but the extent and variation of this effect across realms, regions and taxa has not been clear. Here, we examine rates of composition change from 42,255 globally distributed biodiversity time series across terrestrial, marine, and freshwater realms and eight taxonomic groups. To account for the hetergeneous nature of the dataset, we tested for associations between environmental factors and the rate of composition change with beta generalized linear mixed effects models (beta GLMMs).

Results/Conclusions

We find that temperature change is a major driver of biodiversity change, but that the effects of cooling are just as large as the effects of warming. Marine ecosystems with warm rather than cold baseline temperatures exhibit particularly large responses to temperature change, consistent with predictions from metabolic effects. In contrast, cold rather than warm terrestrial and freshwater ecosystems have larger responses, consistent with a stabilizing effect from strong species interactions. We also detect a strong synergy between temperature change and non-climate human impacts in terrestrial and freshwater ecosystems. This research reveals how a suite of environmental factors mediate community responses to ongoing climate change and provides the basis for anticipating where and when rapid biodiversity change will appear in the decades ahead.