The dependence of heterotrophic consumption and C accumulation on autotrophic nutrient content in ecosystems

Primary producers with high nutrient contents typically exhibit high herbivory rates and fast decomposition rates. These tendencies, however, have not been generalized across ecosystems with contrasting herbivore characteristics and abiotic properties. Here we demonstrate that ecosystem types dominated by richer autotrophs (i.e. higher nutrient contents) are subject to higher rates of herbivory and decomposition in spite of differences in herbivore characteristics and environmental conditions. We further show that, as a result of these tendencies, ecosystems with richer autotrophs accumulate less carbon. These results identify autotrophic nutrient content as a main control of heterotrophic consumption and carbon accumulation in ecosystems. They also provide a basis to evaluate changes in these ecosystem properties following anthropogenic eutrophication.