Delineation of Coastal Marsh Types Along the Central Texas Coast

作者：Mitchell Michael K; Ballard Bart M^*; Visser Jenneke M; Brasher Michael G; Redeker Eric J

来源：Wetlands, 2014, 34(4): 653-660.

DOI：10.1007/s13157-014-0531-4

• Brackish marsh
• Freshwater marsh
• Intermediate marsh
• Plant community
• Remote sensing
• Saline marsh
• Coastal marsh
• Texas

Tidally influenced wetlands along the Texas coast provide important habitat for wintering waterfowl and myriad other fish and wildlife species. Because habitat values may differ among marsh salinity zones (e.g., waterfowl food resources and use are greatest in fresh and intermediate marsh), the spatial distribution of marsh types is important for understanding the capacity of coastal landscapes to support waterfowl and other wildlife populations and informing coastal restoration priorities. Additionally, documenting spatial patterns of coastal marsh types is necessary for projecting future landscape change and examining impacts of environmental processes (e.g., tropical storms, sea level rise). We used a helicopter-based vegetation survey and remotely sensed imagery to delineate marsh types along the central Texas coast into four categories: fresh, intermediate, brackish, and saline. We recorded vegetation composition at 342 sample points and combined these data with Landsat Thematic Mapper imagery to perform a supervised classification of marsh types throughout our 122,995 ha survey area. Our initial coarse classification delineating coastal marsh from other habitat types was 92 % accurate. Intermediate, brackish, and saline marsh each comprised about 30 % of the coastal marsh in our study area. Freshwater marsh comprised < 1 % and may have been underrepresented within the coastal zone due to placement of the inland boundary of our study area. Our final classification of marsh types was 77.2 % accurate which will provide a framework for further delineation efforts. We offer several considerations for future coastal marsh delineation efforts along the Texas coast.

• 出版日期2014-8