Salt Marsh Carbon Pool Distribution in a Mid-Atlantic Lagoon, USA: Sea Level Rise Implications

Abstract

The distribution of carbon (C) within a salt marsh may vary among vegetation zones depending on production and decomposition dynamics and organic and mineral depositional history. We examined spatial and temporal variation of plant and soil C pools within a salt marsh fringing a coastal lagoon along the mid-Atlantic coast of the U.S. The total plant C pool increased from high marsh shrub to low marsh grass dominated areas. Much of the spatial variation in plant C pool was due to fine roots and small organic matter (dlm) that could not be identified by species, which averaged 2398 gC m −2 in Spartina patens-dominated, 2215 gC m −2 in Spartina alternifloradominated, and 676 gC m −2 in Juncus roemerianusdominated areas. Belowground C pool loss was 36% less for S.patens than S.alterniflora and was similar between S. alterniflora and J.roemerianus. Accretion and C accumulation rates were greater in the S.alterniflora-dominated stand than in the J.roemerianus-dominated stand. Our results suggest that landward migration onto terrestrial soils can lead to an estimated 80% increase in belowground plant C composed primarily of fine roots and dlm and 36-70% increase in soil carbon between 15 and 30 cm depths.

Loss of ‘Blue Carbon’ from Coastal Salt Marshes Following Habitat Disturbance

“…This loss was evident in the upper subsurface samples (1-5 cm depth zone), wherein disturbed salt marshes showed significantly lower (~30%) amounts of organic C than undisturbed salt marsh. Additional sampling indicated that this reduction in organic C in disturbed salt marsh was due to loss of belowground plant biomass; an otherwise important component of the C stock [26]. This amount and rate of belowground biomass loss is consistent with litterbag data by Benner et al [27], who reported 55% loss of S .…”

Effects of salinity on soil bacterial and archaeal community in estuarine wetlands and its implications for carbon sequestration: verification in the Yellow River Delta

“…[9] Despite the great attention paid to interior fresh water wetlands, especially boreal peatlands, [10] global warming has resulted in increased studies focusing on carbon sequestration in estuarine and coastal salt marshes. [11,12] Estuarine wetlands are unique ecosystems in which the land connects to the sea and fresh water meets salt water. As a result, the tidal water of estuarine wetlands has widely varying salinity.…”

Nitrogen Pools of Macrophyte Species in a Coastal Lagoon Salt Marsh: Implications for Seasonal Storage and Dispersal

“…Biomass of J. roemerianus represented approximately 82% of the total in areas where it dominated and likewise S. patens represented 77%, and S. alterniflora 85% of the biomass pools in their respective communities (Elsey-Quirk et al 2011). Total plant macro-organic N pools measured to a 30-cm depth ranged seasonally from 46 to 88 g N m −2 in the J. roemerianus-dominated zone, 74 to 136 g N m −2 in the S. patens-dominated zone, and 67 to 150 g N m −2 in the S. alterniflora-dominated zone.…”

“…We collected green leaves, new stems, 3-year old woody stems, and large and fine roots. Five entire shrubs were harvested to develop an allometric equation (e.g., Rittenhouse and Sneva 1977;Thomson et al 1998;Sah et al 2004) based upon the relationship between dry mass, crown area (CA), and the number of secondary stems (SS) originating below a 1-m height (Elsey-Quirk et al 2011). The allometric equation developed was: y=−1,511+1,705 (CA)+585 (SS).…”