Consequences of climate-induced range expansions on multiple ecosystem functions

Climate-driven species range shifts are altering community composition, but their functional consequences remain largely unknown. This study combined a 30-year survey of subalpine pond larval caddisfly assemblages with species-specific functional traits to examine how three upslope range expansions affected species' contributions to nutrient supply and detritus processing. A subdominant resident species consistently made large contributions to nitrogen supply, while phosphorus supply and detritus processing were initially regulated by the dominant resident species. The third range expansion led to increased phosphorus supply contribution by the expanding species, displacing the dominant resident's role. Total ecosystem process rates remained unchanged. This suggests that shifts in species' relative functional roles can precede changes in total ecosystem process rates, and these shifts can stabilize processes in changing ecosystems.

Jared A. Balik, Hamish S. Greig, Brad W. Taylor, Scott A. Wissinger