FLAMMINGGOS · Functional Links in Avian, Microbial, Macrophyte, and INvertebrate Greenhouse Gas Output Stimulation

Functional Links in Avian, Microbial, Macrophyte, and INvertebrate Greenhouse Gas Output Stimulation

Wetlands are globally important hotspots for atmospheric carbon (C) storage and greenhouse gas (GHG) emissions. Their roles as sinks or sources of GHGs are affected by environmental drivers such as nitrogen (N) and phosphorus (P) availability, which stimulate emission of GHGs such as nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2 ). Biotic communities in wetlands also play an important - but not yet well understood - role in GHG fluxes. Mounting evidence suggests that aquatic invertebrate activity enhances GHG emissions (e.g. burrows of fly larvae emit high concentrations of N2O). Considering that invertebrates can reach high densities in wetlands (>100,000 per square meter), they may be substantial drivers of wetland chemical processes. The roles that larger animals play in modifying GHG emissions have received less attention, and yet their potentially large effects via predation, nutrient subsidies, sediment disturbance, and herbivory may be critical to our understanding of the forces controlling wetland contributions to global GHG emissions. To successfully predict and model GHG fluxes to the atmosphere, a thorough understanding of the factors influencing these processes is crucial. But how do higher trophic levels play a role in these processes? Waterbirds, for instance, have been shown to reduce densities of aquatic invertebrates, which could potentially moderate GHG flux. But on the other hand, C, N, and P subsidies in waterbird guano may stimulate microbial activity. These bottom-up forces could then enhance GHG flux and dampen the top-down effects of predation. Our FLAMMINGGOS (Functional Links in Avian, Microbial, Macrophyte, and INvertebrate Greenhouse Gas Output Stimulation) project was created to test the relative strength of top-down and bottom-up effects of predatory waterbirds on wetland GHG flux by examining these and other interactions through controlled field and laboratory experiments. This represents a new and potentially transformative line of inquiry into the roles of multiple trophic levels in regulating global wetland GHG flux. Our objectives were: 1. To test for top-down control, via a trophic cascade, of waterbirds, benthic invertebrates, and microbes on wetland GHG flux. 2. To test for bottom-up effects on GHG flux, via C, N, P subsidies (guano) and sediment disturbance by waterbirds.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз