Shorebirds Affect Ecosystem Functioning on an Intertidal Mudflat

摘要: Ecosystem functioning and services have provided a rationale for conservation over the past decades. Intertidal muddy sediments perform crucial functions, including erosion protection, nutrient cycling carbon sequestration. Key mediators within this system include microphytobenthic biofilms, which bind sediment influence biogeochemistry, wading birds feed extensively on dwelling infauna, in turn graze biofilms. Some wader species, specifically small sandpipers, recently been found to interact directly with e.g. by grazing, adding complexity food web. It has suggested that infauna grazing waders may lead reduction biofilm pressure infauna. If was case it would likely significant top-down, trophic cascade effects key mudflat ecosystem functions. We carried out an exclusion experiment Colne Estuary, Essex, UK examine whether presence significantly affects erodibility, microphytobenthos fluorescence (Fo) sediment-water fluxes (nitrate, nitrite, ammonia, phosphate dissolved organic (DOC)). Excluding caused changes regulating provisioning erodibility (with exception of DOC). Fo greater, critical shear strength increased, magnitude increased where were absent. did not cause difference density sediment, suggesting measured effects. The dominant species at site, dunlin Calidris alpina, is reported consume considered play role maintenance stability mudflats. After period 23 days, arrival mud snail Peringia ulvae appeared compensate absence waders, consuming causing surface differences between presence/absence plots. This study introduces previously unknown effect foraging bioturbation system, highlights area science could aid joint human action.