INVERTEBRATE RESPONSE TO MOIST-SOIL MANAGEMENT OF PLAYA WETLANDS

Abstract

Moist-soil management is a wetland management technique commonly used to increase seed production for migratory birds. However, the responses of invertebrates 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 in 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 density and biomass were higher in playas that were moist-soil managed and that 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 wetlands. Invertebrate familial richness and diversity were greater in moist-soil managed playas than in unmanaged playas, but initial flooding date had little effect on invertebrate diversity. Planorbidae snails were the most abundant invertebrate taxon. A combination of moist-soil management and early fall (September) water application is an effective tool to increase invertebrate density, biomass, and diversity in playas for migratory birds.