LTREB: Long Term Studies of Salt Marsh Primary Production

University South Carolina Research Foundation, Columbia SC

Investigators

Abstract

The long-term goal of this research is to understand how salt marsh primary production and soil chemistry will change in response to increasing anthropogenic and natural environmental modifications. Results from this ongoing study show that there are large differences between years in salt marsh production that appear to be caused by salt concentration of marsh soils, and that complex interactions among sea level, flooding frequency, soil chemistry and chemical cycles affect not only salt marshes, but their entire associated estuaries. The established relationship between increasing marsh productivity, high soil salinity and increasing sea level rise suggests that productivity will decline under two conditions: 1) the relative elevation of the salt marsh rises and becomes unfavorable for growth or 2) the current rapid rate of sea level rise decreases. Research is proposed over the next five years that will test the following hypotheses: first, the long-term observed increase in marsh primary production will reverse when the rate of sea level rise slows or reverses; and second, long-term changes in nutrient concentrations in marsh soils will parallel changes in marsh production. This study will provide a scientific basis for predicting how coastal wetlands will respond to changing sea level - a problem of particular importance in coastal areas like Louisiana. It also provides results that will help environmental managers to understand trends in water quality. The study also contributes to several broader initiatives focused on understanding salt marsh ecology, and funded by several federal agencies.