Novel assemblage formation as a consequence of unequal range shifts

Background/Question/Methods

Climate change has produced a global pattern of shifts in the distribution of species.  However, differences in species’ thermal sensitivity and their dispersal ability may lead to different responses to rising temperatures among taxonomic groups.  We examined how different groups are responding to warming by analyzing the rate of range shifts and the change in species co-occurrence. We surveyed published studies that analyzed species distributions between eras to estimate range shifts and the changes in species assemblages

Results/Conclusions

The rate of uphill range shifts is 2-3 times greater in ectothermic animals than in plants or endotherms.  Consequently, ectothermic assemblages have become up to 20% more dissimilar in their patterns of co-occurrence than assemblages of plants or endotherms.  As taxonomic groups shift uphill at different rates, novel assemblages are forming within and across taxonomic groups.  The differential rates of range shifts among major taxonomic groups may be particularly important for plant-pollinator interactions, predator-prey interactions, and the spread of disease.