FRESH-WATER WETLAND PLANT-COMMUNITIES OF NORTHERN BELIZE - IMPLICATIONS FOR PALEOECOLOGICAL STUDIES OF MAYA WETLAND AGRICULTURE

Plant species composition and standing crop in relation to soil and wa ter characteristics were studied to determine which environmental vari ables are responsible for structure and distribution of marshes in nor thern Belize. Sampling sites were located in the floodplains of the Ri o Hondo and New River and within karstic depressions in the interfluve s of the two rivers. Relationships among environmental variables and t he occurrence of the individual marsh types, in particular those domin ated by Cladium jamaicense, Eleocharis cellulosa, and Typha domingensi s were investigated using canonical correspondence analysis. Discrimin ant analysis was used to select a reduced set of variables for predict ing the distribution of dominant species. Eleocharis cellulosa marshes dominated areas with soil and water of high conductivity due to high content of gypsum and calcium carbonate. Nutrient concentrations, name ly nitrogen and phosphorus, were very low. Conditions were rather simi lar in sawgrass marshes (Cladium jamaicense), except for higher water depth and lower conductivity. Marshes dominated by Typha domingensis o ccupied areas with higher content of nitrogen and phosphorus. Discrimi nant functions developed for these three marsh communities can be used to help interpret paleoecological data and infer ancient Maya impacts upon marsh development.