Spartina alterniflora Biomass Allocation and Temperature: Implications for Salt Marsh Persistence with Sea-Level Rise
Crosby SC, Angermeyer A, Adler JM, Bertness MD, Deegan LA, Sibinga N, Leslie HM. 2016. Spartina alterniflora Biomass Allocation and Temperature: Implications for Salt Marsh Persistence with Sea-Level Rise. Journal of the Coastal and Estuarine. 39(5)
To predict the impacts of climate change, a better understanding is needed of the foundation species that build and maintain biogenic ecosystems. Spartina alterniflora Loisel (smooth cordgrass) is the dominant salt marsh-building plant along the US Atlantic coast. It maintains salt marsh elevation relative to sea level by the accumulation of above ground biomass, which promotes sediment deposition and below ground biomass, which accretes as peat. Peat accumulation is particularly important in elevation maintenance at high latitudes where sediment supply tends to be limited. Latitudinal variation in S. alterniflora growth was quantified in eight salt marshes from Massachusetts to South Carolina. The hypothesis that allocation to above ground and below ground biomass is phenotypically plastic was tested with transplant experiments among a subset of salt marshes along this gradient. Reciprocal transplants revealed that northern S. alterniflora decreased allocation to below ground biomass when grown in the south. Some northern plants also died when moved south, suggesting that northern S. alterniflora may be stressed by future warming. Southern plants that were moved north showed phenotypic plasticity in biomass allocation, but no mortality. Below ground biomass also decomposed more quickly in southern marshes. Our results suggest that warming will lead northern S. alterniflora to decrease below ground allocation and that below ground biomass will decompose more quickly, thus decreasing peat accumulation. Gradual temperature increases may allow for adaptation and acclimation, but our results suggest that warming will lower the ability of salt marshes to withstand sea level rise.
- Type
- Journal Article
- Authors
- Crosby, Sarah; Angermeyer, Angus; Adler, Jennifer; Bertness, Mark; Deegan, Linda; Sibinga, Nathaniel; Leslie, Heather
- Units
- FIIS
- Keywords
- Biomass, Climate change, Elevation, Salt marsh, Smooth cordgrass, Spartina alterniflora