Constraining Natural and Anthropogenic Disturbances in the Delivery of Coastal Ecosystem Services

Sheron Luk, Ph.D., 2022
Amanda Spivak, Co-Advisor
Matthew Charette, Co-Advisor

This thesis seeks to understand how disturbances impact salt marsh and estuarine ecosystem functioning in order to refine their role in coastal ecosystem service delivery and predict future resilience. I characterized SOC development and turnover in a New England salt marsh and found that salt marsh soils typically store marsh grass-derived compounds that are reworked over centuries-to-millennia. I assessed how two common marsh disturbances – ponding and mosquito ditching – affect salt marsh carbon cycling and storage. Salt marsh ponds deepen through soil erosion and decomposition of long-buried marsh peat. The SOC lost during pond development is not recouped once drained ponds are revegetated and indistinguishable from the surrounding marsh. Mosquito ditches, installed in ~ 90% of New England salt marshes, did not significantly alter marsh carbon storage. In Buzzards Bay, Massachusetts, we tested relationships among measures of estuarine water quality, recreational activity, and local socioeconomic conditions to understand how the benefits of cultural ecosystem services are affected by shifts in water quality associated with global change and anthropogenic activity. In combination, incorporation of both anthropogenic and natural disturbances to coastal ecosystem functioning and service delivery can produce improved estimates of ecosystem service valuation for effective resource decision-making under future climate scenarios.