Invertebrate response to moist-soil management of playa wetlands

Moist-soil management is a wetland management technique commonly used to in crease seed production for migratory birds. However the responses of invert ebrates to moist-soil management have seldom been investigated even though their availability may be as important as seeds to foraging waterbirds. We studied the effects of moist-soil management and initial fall flooding date (September vs. November) on invertebrate density, biomass, and diversity i n 12 playa wetlands on the Southern High Plains, USA, during the winters of 1994-1995 and 1995-1996. Invertebrates were sampled using a combination of benthic core, epiphytic, and water-column samplers. Total invertebrate den sity and biomass were higher in playas that were moist-soil managed and tha t had longer hydroperiods (four rather than two months) than in playas that were not managed or that had shorter hydroperiods. Most invertebrate taxa (75%) were more abundant in moist-soil managed wetlands than in unmanaged w etlands. Invertebrate familial richness and diversity were greater in moist -soil managed playas than in unmanaged playas, but initial flooding date ha d little effect on invertebrate diversity. Planorbidae snails were the most abundant invertebrate taxon. A combination of moist-soil management and ea rly fall (September) water application is an effective tool to increase inv ertebrate density, biomass, and diversity in playas for migratory birds.