Change in biological traits and community structure of macroinvertebrates through primary succession in a man-made Swedish wetland

We investigated the successional development of a benthic macrofaunal community in Kalmar Damme, a man-made wetland in southeastern Sweden, over a 13-y period after construction (1997-2009). We assessed primary succession by monitoring changes in species composition, biological traits, and community structure. Predictable successional changes occurred, and the structure of the community was complex at the advanced phase. Three successional phases were observed, each with typifying species. At the advanced phase, dominant biological traits shifted to favor animals with longer life-cycle durations, aerial dispersal strategies, and certain feeding types (i.e., filter-feeders, fine sediment collectors, predators, and parasites). We selected the Coleoptera assemblage to represent the macroinvertebrate community in an evaluation of the extent to which man-made wetlands in different age classes (<3 y and >= 10 y) were similar to natural wetlands (>50 y). No significant differences in Coleoptera assemblages were found between natural wetlands and man-made wetlands >= 10 y. However, man-made wetlands >= 10 y had significantly higher coleopteran species richness than natural and man-made wetlands <3 y because of the convergence of pioneering species persisting from early successional stages with representative specialized taxa from natural wetlands. Our results suggest that 10 y may be sufficient time for the macrofaunal communities of man-made wetlands to resemble those of natural wetlands.