This proposal will use grid-based statistical data to develop a model that explores the integration of local plant interactions, community development, and ecosystem processes. Analyses will involve data from a gridded plot on Mt. St. Helens during recovery from the eruption, 1983-1993. Growth, survival, and reproduction of individual plants of various species will be used to construct a computer simulation model on a cellular grid that represents local plant interactions. Manipulation of significant influencing factors will indicate the degree to which these factors affect community development and ecosystem processes, such as nitrogen fixation. These simulations will be compared to observations of plants in the field during this award period as a means of model evaluation. %%% Understanding the relative contributions of various environmental factors to local plant population dynamics and interactions, community development and ecosystem processes during recovery from disturbances is major goal of ecological study. The linkage between population, community and ecosystem processes has become a particularly important topic as the functional importance of biodiversity, population interactions, and community development to ecosystem function and recovery from disturbance has been recognized. This research will link field observations and simulation modeling to develop an ecological framework for integrating these processes and levels of organization.
