Are elevation and open-water conversion of salt marshes connected?

Geophysical Research Letters
By: , and 



Salt marsh assessments focus on vertical metrics such as accretion or lateral metrics such as open-water conversion, without exploration of how the dimensions are related. We exploited a novel geospatial dataset to explore how elevation is related to the unvegetated-vegetated marsh ratio (UVVR), a lateral metric, across individual marsh “units” within four estuarine-marsh systems. We find that elevation scales consistently with the UVVR across systems, with lower elevation units demonstrating more open-water conversion and higher UVVRs. A normalized elevation-UVVR relationship converges across systems near the system-mean elevation and a UVVR of 0.1, a critical threshold identified by prior studies. This indicates that open-water conversion becomes a dominant lateral instability process at a relatively conservative elevation threshold. We then integrate the UVVR and elevation to yield lifespan estimates, which demonstrate that higher elevation marshes are more resilient to internal deterioration, with an order-of-magnitude longer lifespan than predicted for lower elevation marshes.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Are elevation and open-water conversion of salt marshes connected?
Series title Geophysical Research Letters
DOI 10.1029/2019GL086703
Volume 47
Issue 3
Year Published 2020
Language English
Publisher Wiley
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description e2019GL086703, 10 p.
Country United States
State Massachusetts, New York, Maryland, Virginia
Other Geospatial Plum Island Estuary, Cape Cod National Seashore, Great South Bay, Chincoteague Bay
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