Assessing spatial and temporal vegetative dynamics at Mentor Marsh, 1796 to 2000 A.D

The spatial and temporal vegetative dynamics at Mentor Marsh between 1796 and 2000 A.D. are assessed in a landscape history of the region, an ecological synthesis detailing the effect of change in environmental stress within the marsh basin, and a preliminary model using fuzzy logic. A conceptual model or methodology is developed to guide the application of the Gleasonian individualistic concept of vegetative dynamics in the analyses of vegetative-landscape systems. The ecological synthesis links the individualistic concept of vegetative change to ecological system dynamics over time and space by using information identified in the landscape history of the site. The model utilizes fuzzy rule-based modeling to further distill the results of the landscape history and ecological synthesis to produce a more concise and predictive means of addressing vegetative change at Mentor Marsh and to suggest future site research and conservation and restoration strategies.; The landscape history of the Mentor Marsh area provides information on changing land use paradigms between 1796 and 2000 A.D. Land use paradigms shifted from “movement between hunt and harvest” during Native American use of the area to individual property ownership and control established during the beginning of European American settlement. A more recent shift in land use paradigms in the area is characterized by ecosystem management, which emphasizes conservation of natural areas and sustainable land use practices. Population density between 1796 and 2000 A.D is estimated to have increased from 0.25 to 980 persons per square mile in Lake County, where Mentor Marsh is located. The landscape history shows the linkage between agricultural, commercial, and industrial development in the area and changes in the spatial and temporal distribution of vegetative communities at Mentor Marsh. Four environmental stresses were identified in the research of the landscape history: flood stress, salt stress, fire disturbance, and shade stress.; The ecological synthesis shows the influence of both long-term climate change and anthropogenic modifications to hydrologic control points on flood stress, which has affected the vegetative dynamics of the site. Analysis of the long-term record of average annual Lake Erie water levels and annual precipitation for the region, including 5-year running averages, shows a pattern of climate change characterized by extended periods of high flood stress and low flood stress affecting the spatial and temporal distribution of wetland plant community types within the marsh basin. (Abstract shortened by UMI.)...