Archive | 2021
Spatial covariance reverses the compound effect of multiple stressors on rocky shore biofilm
Abstract
Understanding how multifactorial fluctuating environments affect species\nand communities remains one of the major challenges in ecology. Here, we\nuse field experiments and simulations to assess the influence of\nnonlinear effects and spatial covariation of two important climate\nvariables – warming and sediment deposition – on the biomass and\nphotosynthetic activity of rocky intertidal biofilm. Simulations\nstemming from an experimentally derived response surface showed how the\ndegree and direction of spatial covariation between warming and sediment\ndeposition ultimately determined the nonlinear response of biofilm\nbiomass (but not photosynthetic activity) to fluctuating levels of the\ntwo climate variables. Experimental results corroborated these\npredictions, probing the buffering effect of negative spatial\ncovariation against extreme levels of warming and sediment deposition.\nTogether, these results indicate that consideration of local-scale\npatterns of covariation between climate drivers can improve our\nunderstanding and ability to predict ecological responses to ongoing and\nfuture changes in Earth’s climate.