Aquatic invertebrate and plant responses following mechanical manipulations of moist-soil habitat

Managers mow, disk, and till moist-soil habitats to set back succession and increase interspersion of emergent vegetation and water for migrant and wi ntering waterbirds. We evaluated effects of autumn applications of these ma nipulations on aquatic invertebrates and moist-soil plants during 2 subsequ ent winters and growing seasons, respectively, at Noxubee National Wildlife Refuge, Mississippi. Greatest seed mass was in tilled and disked plots in 1993 (P less than or equal to 0.008) and in tilled plots in 1994 (P less th an or equal to 0.008). Plant species diversity generally was greatest in ti lled plots in both years (P less than or equal to 0.05). Mowed and control plots produced greatest aquatic invertebrate mass in winter 1992-93 (P less than or equal to 0.025) and diversity in both winters (P less than or equa l to 0.01). invertebrate mass and plant standing crop generally did not dif fer among treatments in winter 1993-94 and both years, respectively. We rec ommend autumn tilling in small moist-soil habitats to increase plant specie s diversity and seed yield. For large-scale management, disking may be more practical than tilling and would likely yield similar plant responses. We recommend autumn mowing if moist-soil habitats exist in early seral stages and contain desirable seed-producing plants that are robust and do not read ily topple following flooding to create open water areas for waterbirds.