Detecting restoration impacts in inter-connected habitats: Spring invertebrate communities in a restored wetland

摘要

Habitat restoration that improves the ecological status of a target ecosystem may have undesired effects in adjoining ecosystems. We assessed how restoration of a mire influenced benthic macroinvertebrates in associated freshwater springs. We included springs affected by restoration and compared these to remote control springs. We collected pre-restoration samples in May 2001 and post-restoration samples in May 2003,2005 and 2010. Following restoration, water table rose in the whole mire. Restoration also caused profound changes to groundwater quality but, for the most part, water quality returned close to pre-restoration conditions within two years. Reflecting these chemical and hydrological changes, restoration altered spring invertebrate communities, especially the relative abundances of species, but had only weak effect on species richness. The proportional abundance of spring-dependent macroinvertebrates decreased in the restoration area, whereas their proportion remained stable in the remote control sites. Macroinvertebrate community structure at the remote control sites remained almost unchanged throughout the study, whereas communities in the restoration-area springs showed profound changes after restoration, followed by a slow recovery toward the initial conditions. Our results suggest that restoration planning and monitoring should be extended to adjoining ecosystems, and not only species richness but more complete compositional analysis of communities and species abundances should be used to indicate restoration impacts.