Functional diversity across space and time: trends in wader communities on British estuaries

摘要: Aim: British estuarine ecosystems support large populations of protected migratory waders. Understanding how wader communities vary spatially and they may be changing temporally can greatly improve the understanding these dynamic ecosystems. Here, we explore variation in functional diversity (using a range morphological ecological traits) order to identify processes shaping on estuaries changing. Location: England, Wales Scotland. Methods: We use national survey data (Wetland Bird Survey) from 1980/1981 2006/2007 winter calculate (FD) – an index that measures trait dispersion 100 estuaries. test for evidence non-random patterns relative importance two key processes, environmental filtering competition, communities. Results: The observed FD was significantly positively associated with species richness lesser extent estuary area, followed by longitude. An increase since 1980, supported small but significant slope. In majority cases, changes were mirrored richness. Observed average lower than expected chance, as indicated negative value minus FD. However, this difference became less over time, values increasing slightly, significantly, study period. Main conclusions:  Wader varies across estuaries, influence which are structured appears through time. discuss potential drivers underlying identifying such protection communities.