Vegetation Type and Decomposition Priming Mediate Brackish Marsh Carbon Accumulation Under Interacting Facets of Global Change

Authors

Anthony J. Rietl, Virginia Institute of Marine Science
J. Patrick Megonigal
Ellen R. Herbert, Virginia Institute of Marine Science
Matthew L. Kirwan, Virginia Institute of Marine ScienceFollow

Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

4-28-2021

Journal

Geophysical Research Letters

Volume

48

Issue

8

First Page

e2020GL092051

Abstract

Coastal wetland carbon pools are globally important, but their response to interacting facets of global change remain unclear. Numerical models neglect species-specific vegetation responses to sea level rise (SLR) and elevated CO₂ (eCO₂) that are observed in field experiments, while field experiments cannot address the long-term feedbacks between flooding and soil growth that models show are important. Here, we present a novel numerical model of marsh carbon accumulation parameterized with empirical observations from a long-running eCO₂ experiment in an organic rich, brackish marsh. Model results indicate that eCO₂ and SLR interact synergistically to increase soil carbon burial, driven by shifts in plant community composition and soil volume expansion. However, newly parameterized interactions between plant biomass and decomposition (i.e. soil priming) reduce the impact of eCO₂ on marsh survival, and by inference, the impact of eCO₂ on soil carbon accumulation.

DOI

doi: 10.1029/2020GL092051

Publication Statement

© 2021. American Geophysical Union.

Recommended Citation

Rietl, Anthony J.; Megonigal, J. Patrick; Herbert, Ellen R.; and Kirwan, Matthew L., Vegetation Type and Decomposition Priming Mediate Brackish Marsh Carbon Accumulation Under Interacting Facets of Global Change (2021). Geophysical Research Letters, 48(8), e2020GL092051.

doi: 10.1029/2020GL092051