Title | Soil Organic Carbon Development and Turnover in Natural and Disturbed Salt Marsh Environments |
Publication Type | Journal Article |
Year of Publication | 2021 |
Authors | Luk SY, Todd‐Brown K, Eagle M, McNichol AP, Sanderman J, Gosselin K, Spivak AC |
Journal | Geophysical Research Letters |
Volume | 48 |
Issue | 2 |
Date Published | Apr-01-2023 |
ISSN | 0094-8276 |
Abstract | Salt marsh survival with sea-level rise (SLR) increasingly relies on soil organic carbon (SOC) accumulation and preservation. Using a novel combination of geochemical approaches, we characterized fine SOC (≤1 mm) supporting marsh elevation maintenance. Overlaying thermal reactivity, source (δ13C), and age (F14C) information demonstrates several processes contributing to soil development: marsh grass production, redeposition of eroded material, and microbial reworking. Redeposition of old carbon, likely from creekbanks, represented ∼9%–17% of shallow SOC (≤26 cm). Soils stored marsh grass-derived compounds with a range of reactivities that were reworked over centuries-to-millennia. Decomposition decreases SOC thermal reactivity throughout the soil column while the decades-long disturbance of ponding accelerated this shift in surface horizons. Empirically derived estimates of SOC turnover based on geochemical composition spanned a wide range (640–9,951 years) and have the potential to inform predictions of marsh ecosystem evolution. |
URL | https://onlinelibrary.wiley.com/doi/10.1029/2020GL090287 |
DOI | 10.1029/2020GL090287 |