Dispersal Mode and Ability Affect the Spatial Turnover of a Wetland Macroinvertebrate Metacommunity

Abstract

Dispersal limitation is an important element of metacommunity dynamics, but measuring dispersal is complicated because many communities are composed of species that vary in dispersal strategy and ability We explored how macroinvertebrate community structure varied through the growing season and across habitat types in the Muskegon River mouth wetland complex. We then measured the effect of dispersal mode and ability on the structure of these communities. Macroinvertebrates were categorized as having no, poor, or strong ability to either fly or swim. We found that community structure was closely related to micro-habitat type (i.e., sediment, water column, plant stems) and that communities composed of strong flyers had higher cross-site similarity than those composed of poor or non-flyers.Strong swimmers had higher cross-site similarity than poor or non-swimmers. Prior studies have focused on body size or a multivariate measure of dispersal ability to measure the effect of dispersal on metacommunity structure rather than the direct measures that we used. Our results suggest that while micro-habitat strongly influenced community structure in general, both dispersal mode and dispersal ability affected the spatial organization of macroinvertebrate metacommunities in the Muskegon River mouth wetland complex.