Nitrogen and Phosphorus Concentrations within Freshwater Marsh Plant Species

Abstract

Total nitrogen and phosphorus concentrations in twenty-five plant species located in three south Florida marsh sites were studied. Living aerial phytomass was sampled seasonally from summer 1979 through winter 1981 within three distinct communities: upland fringe, transitional ecotone and inundated marsh. Plant species found in the inundated marsh community tended to have more N and P than those found in the other two communities. Forbs generally accumulated more of both nutrients than grasses. Three forb species were identified as having higher concentrations of N and P: Bacopa caroliniana, Hydrocotyle umbellata and Ludwigia repens. Seven plant species were common to all three sites. Nitrogen concentrations among these species were not consistently higher in any site, however every plant species sampled had significantly more P in the marsh located within a tame pasture watershed as compared to the other marshes. Most plants showed a significant seasonal response in N and P concentrations, although no consistent trend was evident.