Applying a complex, general ecosystem model (EDYS) in large-scale land management

Abstract

A critical need in the management of public and non-urban private lands in the United States and elsewhere is assessing the efficacy of different management alternatives under different environmental and land use scenarios. One type of tool that would be extremely valuable is large-scale ecological simulation models designed to project effects of alternative climatic, usage, and management scenarios on ecological resources. A modeling challenge in this type of application is to link mechanistic simulations of small-scale ‘ecosystem’ processes to large-scale ‘landscape’ processes to provide more realistic and exhaustive projections of effects and ramifications of management alternatives. The Ecological DYnamics Simulation model (EDYS) is a general ecosystem simulation model that mechanistically implements relevant processes in ecosystem dynamics, including: climatic inputs, soil water and nutrient dynamics, plant uptake and growth by species, herbivory, fire, contaminants, physical disturbance, and management activities. In the EDYS model, ecological processes simulated in plot-level ecosystem cells are scaled up to the landscape level using a grid-based representation of the spatial extent of that ecosystem across the landscape. A significant practical challenge in applying complex ecological models is compilation of appropriate input data from a wide-variety of print and on-line media. A semi-automated database is currently under development, which will compile, organize, and format data sets to facilitate future EDYS applications. Another challenge is linking different types of models, each of which is specialized to simulate particular aspects of ecosystem and landscape dynamics. As so many different types of organizations are presently involved in model development and resource management, ownership of models and datasets will increasingly become an issue in their distribution and use among different types of land managers.