Trophic cascades in the bryosphere: the impact of global change factors on top-down control of cyanobacterial N2-fixation

摘要: Trophic cascades in which predators regulate densities of organisms at lower trophic levels are important drivers population dynamics, but effects on ecosystem-level fluxes and processes, the conditions under top-down control is important, remain unresolved. We manipulated structure a food web boreal feather mosses found that moss-inhabiting microfauna exerted N2 -fixation by moss-associated cyanobacteria. However, presence higher alleviated this control, likely through feeding bacterivorous microfauna. These food-web cyanobacterial were dependent global change factors strongly suppressed N fertilisation. Our findings illustrate how interactions can cycling ecosystems, where carbon uptake generally N-limited, shifting therefore to impact ecosystem functioning.