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Relationships between salinity and short-term soil carbon accumulation rates form marsh types across a landscape in the Mississippi River Delta

March 22, 2017

Salinity alterations will likely change the plant and environmental characteristics in coastal marshes thereby influencing soil carbon accumulation rates. Coastal Louisiana marshes have been historically classified as fresh, intermediate, brackish, or saline based on resident plant community and position along a salinity gradient. Short-term total carbon accumulation rates were assessed by collecting 10-cm deep soil cores at 24 sites located in marshes spanning the salinity gradient. Bulk density, total carbon content, and the short-term accretion rates obtained with feldspar horizon markers were measured to determine total carbon accumulation rates. Despite some significant differences in soil properties among marsh types, the mean total carbon accumulation rates among marsh types were not significantly different (mean ± std. err. of 190 ± 27 g TC m−2 year−1). However, regression analysis indicated that mean annual surface salinity had a significant negative relationship with total carbon accumulation rates. Based on both analyses, the coastal Louisiana total marsh area (1,433,700 ha) accumulates about 2.7 to 3.3 Tg C year−1. Changing salinities due to increasing relative sea level or resulting from restoration activities may alter carbon accumulation rates in the short term and significantly influence the global carbon cycle.

Citation Information

Publication Year 2017
Title Relationships between salinity and short-term soil carbon accumulation rates form marsh types across a landscape in the Mississippi River Delta
DOI 10.1007/s13157-016-0871-3
Authors Melissa M. Baustian, Camille L. Stagg, Carey L. Perry, Leland C Moss, Tim J.B. Carruthers, Mead Allison
Publication Type Article
Publication Subtype Journal Article
Series Title Wetlands
Series Number
Index ID 70185336
Record Source USGS Publications Warehouse
USGS Organization Wetland and Aquatic Research Center