Coastal Marsh Degradation Into Ponds Induces Irreversible Elevation Loss Relative to Sea Level in a Microtidal System
| Autor: | Glenn R. Guntenspergen, Matthew L. Kirwan, Stijn Temmerman, Lennert Schepers, Patrick Brennand |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
geography Marsh geography.geographical_feature_category 010504 meteorology & atmospheric sciences Physics 010604 marine biology & hydrobiology Elevation 15. Life on land 01 natural sciences 6. Clean water Geophysics Oceanography Sea level rise 13. Climate action General Earth and Planetary Sciences Environmental science Degradation (geology) 14. Life underwater Sea level 0105 earth and related environmental sciences |
| Zdroj: | Geophysical research letters |
| ISSN: | 1944-8007 0094-8276 |
| DOI: | 10.1029/2020gl089121 |
| Popis: | Coastal marshes and their valuable ecosystem services are feared to be lost by sea level rise, yet the mechanisms of marsh degradation into ponds and potential recovery are poorly understood. We quantified and analyzed elevations of marsh surfaces and pond bottoms along a marsh loss gradient (Blackwater River, Maryland, USA). Our analyses show that ponds deepen with increasing tidal channel width connecting the ponds to the river, indicating a new feedback mechanism where channels lead to enhanced tidal export of pond bottom material. Pond elevations also decrease with increasing pond size, consistent with previous work identifying a positive feedback between wind wave erosion and pond size. These two positive feedbacks, combined with bimodal elevation distributions and sharp topographic boundaries between interior ponds and the marsh platform, indicate alternative elevation states and imply that marsh loss by pond formation is nearly irreversible once pond deepening exceeds a critical level. |
| Databáze: | OpenAIRE |
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