Trends of "Teal Carbon" Stocks including Primary Production, Soil and Decomposition along Forested Swamp Gradients of the Mississippi River Alluvial Valley

Carbon stocks play an important role in carbon dynamics, and may be important in teal carbon storage in inland continental wetlands. Baldcypress (Taxodium distichum) swamps of the MRAV (Mississippi River Alluvial Valley) are an ideal place to explore trends between carbon stocks, decomposition rates, and environmental drivers. The study was conducted in the MRAV in a long-term research network established in 2002. The central part of this region (i.e. Arkansas) has higher precipitation and temperature (climate normal or 30-year averages) than elsewhere in the MRAV. Carbon stocks including primary production (tree, litter and knees) and soil were highest in the middle part of this region. Litter and cloth decomposition rate were also examined in the network. At the same time, the central part of the MRAV had lower rates of leaf and wood litter decomposition. An important aspect of the carbon story in the MRAV is that woody T. distichum detritus decomposes very slowly, with a half-life of up to 300 years. Simultaneous cloth decomposition studies were conducted, but its decomposition bore little resemblance to that of plant litter. As expected, knees contributed substantial carbon to these swamps with higher biomass in environments with longer periods of flooding. Nevertheless, knee biomass responses also were responsive to climate. This analysis of the components of ecosystem carbon shows that "teal carbon" stocks can be substantial in swamps of the southeastern United States, and that climatic variables, environmental drivers, and management regimes can contribute to the maintenance of carbon in this major wetland type.