Plant Biomass Allocation and Competitive Interactions in Coastal Wetlands of the Chesapeake Bay: Experimental and Observational Studies

Title of Thesis: PLANT BIOMASS ALLOCATION AND COMPETITIVE INTERACTIONS IN COASTAL WETLANDS OF THE CHESAPEAKE BAY: EXPERIMENTAL AND OBSERVATIONAL STUDIES Jenna Marie Clark, Master of Science, 2011 Thesis directed by: Dr. Andrew H. Baldwin, Department of Environmental Science and Technology Wetlands are diverse environments whose vegetation provides numerous natural services including flood and erosion control and excess nutrient absorption; however conditions created by sea level rise and nutrient pollution could lead to possible wetland loss. To assess the responses of vegetation in these conditions in the Chesapeake Bay tidal wetlands, an observational study and a competition greenhouse study were conducted. An aboveground to belowground biomass relationship assessment was done along a salinity gradient within a subestuary of the Chesapeake Bay. The competition study focused on the relationship between a native and a non-native species in the aforementioned conditions. These studies revealed Phragmites australis had more biomass and lower rooting depths than the native Spartina cynosuroides under varying conditions of salinity, competition, and fertilization. Growth of S. cynosuroides may facilitate the growth of P. australis through salinity uptake and root aeration, which could have important impacts on wetland management practices. PLANT BIOMASS ALLOCATION AND COMPETITIVE INTERACTIONS IN COASTAL WETLANDS OF THE CHESAPEAKE BAY: EXPERIMENTAL AND OBSERVATIONAL STUDIES by Jenna Marie Clark Thesis submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Master of Science 2011 Advisory Committee: Dr. Andrew Baldwin Dr. Joseph Sullivan Dr. Dennis Whigham © Copyright by Jenna Marie Clark 2011