Effects of structural marsh management and winter burning on plant and bird communities during summer in the Gulf Coast Chenier Plain

Coastal wetlands in the Gulf Coast Chenier Plain commonly are managed intensively by fall or winter burning and constructing impoundments to improve habitat for wintering waterfowl, reduce wetland loss, and create emergent wetlands. However, little informa- tion is available on effects of these management practices on plant or bird communities during summer. We conducted experimental burns in 4 types of impounded and unim- pounded marshes on Rockefeller State Wildlife Refuge in southwestern Louisiana. We recorded vegetation characteristics and species composition and relative abundance of plants and birds during April-June 1996-1998. We found that vegetation characteristics in burned marshes did not differ from those of unburned marshes by the first summer post-burn and that winter burning did not affect bird species richness or species compo- sition. Birds/survey for all species combined and for sparrows (primarily seaside sparrows (Ammodramus maritimus1) did not differ between burned and unburned marshes during the first or third summers post-burn, but were 2 times greater in burned than in unburned marshes during the second summer post-burn. Our results indicate that winter burning for waterfowl is compatible with management for other marsh birds, provided that meas- ures ensuring sufficient winter cover for passerines are included in management plans. Number of icterids/survey was greatest and sparrows/survey was least in intermediate impounded marshes compared to other marsh-management types. Sparrows generally were most abundant in brackish and saline unimpounded marshes, indicating that con- tinued loss of unimpounded marsh habitat could impact coastal sparrow populations.