Immanent conditions determine imminent collapses: nutrient regimes define the resilience of macroalgal communities.

ABSTRACT: Predicting where state-changing thresholds lie can be inherently complex in ecosystems characterized by nonlinear dynamics. Unpacking the mechanisms underlying these transitions can help considerably reduce this unpredictability. We used empirical observations, field and laboratory experiments, and mathematical models to examine how differences in nutrient regimes mediate the capacity of macrophyte communities to sustain sea urchin grazing. In relatively nutrient-rich conditions, macrophyte systems were more resilient to grazing, shifting to barrens beyond 1 800 g m^-2 (urchin biomass), more than twice the threshold of nutrient-poor conditions. The mechanisms driving these differences are linked to how nutrients mediate urchin foraging and algal growth: controlled experiments sho

SUBMITTER: Boada J 

PROVIDER: S-EPMC5378086 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature