Indirect human impacts reverse centuries of carbon sequestration and salt marsh accretion

PLoS One. 2014 Mar 27;9(3):e93296. doi: 10.1371/journal.pone.0093296. eCollection 2014.

Abstract

Direct and indirect human impacts on coastal ecosystems have increased over the last several centuries, leading to unprecedented degradation of coastal habitats and loss of ecological services. Here we document a two-century temporal disparity between salt marsh accretion and subsequent loss to indirect human impacts. Field surveys, manipulative experiments and GIS analyses reveal that crab burrowing weakens the marsh peat base and facilitates further burrowing, leading to bank calving, disruption of marsh accretion, and a loss of over two centuries of sequestered carbon from the marsh edge in only three decades. Analogous temporal disparities exist in other systems and are a largely unrecognized obstacle in attaining sustainable ecosystem services in an increasingly human impacted world. In light of the growing threat of indirect impacts worldwide and despite uncertainties in the fate of lost carbon, we suggest that estimates of carbon emissions based only on direct human impacts may significantly underestimate total anthropogenic carbon emissions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Brachyura / physiology
  • Carbon / chemistry*
  • Carbon Sequestration / physiology*
  • Conservation of Natural Resources*
  • Geographic Information Systems
  • Humans
  • Salinity
  • Salts
  • Soil
  • United States
  • Water Movements
  • Wetlands*

Substances

  • Salts
  • Soil
  • Carbon

Grants and funding

This research was made possible by a grant from the National Science Foundation Biological Oceanography Program and the Brown University Undergraduate Teaching and Research Award Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.