Benthic N pathways in illuminated and bioturbated sediments studied with network analysis.

摘要: The regulation of benthic nitrogen (N) cycling by multiple interactions among bacteria, macrofauna, and primary producers is poorly understood. We hypothesized that a biodiverse system should better exploit the N-availability retain N than simpler one. Retention occurs avoiding losses both to water column via increased recycling atmosphere decreased N2 fluxes limiting energy-costly processes as N-fixation. also producer-bacterial competition reduced in presence macrofauna due mobilization refractory pools. To this purpose, effects two bioturbators (the detritivorous Sparganophilus tamesis filter-feeding Corbicula spp.) producer growth forms rooted macrophyte Vallisneria spiralis microphytobenthos) on were studied. An array N-processes measured along complexity gradient (from bare sediments all combinations above mentioned organisms), experimental outcomes analyzed ecological network analysis (ENA). This suite algorithms, applied microscale, revealed differential partitioning (highest denitrification rates), with recycling), plants N-fixation). inputs significantly when components represented, requirements large extent supported activity macrofauna. Ecological systems promoted an efficient exploitation sedimentary pools, coupling between uptake, maximized use efficiency at expenses imports.