Above- and Belowground Biomass Allocation in Four Dominant Salt Marsh Species of the Eastern United States

Abstract

Measurements of aboveground and belowground biomass allocations are important for characterization of structure and function in marsh ecosystems as various processes such as carbon sequestration, gas transport, nutrient cycling, and ecosystem resilience are affected by these allocations. We measured aboveground and belowground biomass, root and rhizome characteristics, leaf area index (LAI), and carbon to nitrogen (C/N) ratio of various tissues of four tidal marsh species in New Jersey by harvesting biomass during peak growing season. The aboveground biomasses for Spartina patens, S. alterniflora, Phragmites australis, and Distichlis spicata were 2.3, 2.2, 1.7 and 1.2 kg m−2, respectively. The ratio of belowground to aboveground biomass for S. alterniflora and D. spicata, harvested from a recently restored wetland were lower than in previous studies. LAI for S. alterniflora, D. spicata, P. australis, and S. patens were 8.4, 6.8, 4.8 and 3.7 m2 m−2, respectively. Diameter of rhizome and root, number of primary roots per node, root surface area to volume ratio, and C/N of various tissues varied with species. The measured above- and belowground biometric traits are crucial for a better understanding of carbon dynamics, and modeling greenhouse gas transport in marsh ecosystems.