Date of Award

Spring 2011

Project Type


Program or Major

Natural Resources: Water Resources

Degree Name

Master of Science

First Advisor

David M Burdick


Berms, defined as historic earthen barriers, represent one type of hydrological modification introduced by humans in the tidal marshes of northern New England. Three different research approaches were applied to study the impact of berms on various tidal marsh dynamics. The descriptive study shows that restricted flooding from berm interference can result in significantly altered physical gradients in addition to landward subsidence and pool development. The results from the transplant experiment indicate that the altered landward structure affects the relative importance of biological interactions, namely herbivory, in controlling plant species distribution. The predictive GIS analyses illustrate the location of 34 berm sites within the Great Bay Estuary and highlight the bermed marshes most at risk of invasion by the non-native variety of Phragmites australis and submergence during sea level rise. Based on the combined findings, berms have the potential to reduce the overall biodiversity and integrity of tidal marshes.