Simulation of Vegetation Response to Modified Hydrologic Regimes: A Probabilistic Model Based on Niche Differentiation in a Floodplain Forest

Abstract

This study was initiated to develop a model for predicting the relative impacts of alternative reservoir designs on vegetation in the backwater zone. The result is a probabilistic model based on niche differentiation in the floodplain forest. Existing methodologies provided estimates of the flooding regime modifications produced by variable backwater conditions during reservoir operation. The model is exercised, with hydrolic modifications as input, to simulate shifts in species distribution. The model has been applied to evaluate the impact of a proposed reservoir on the vegetation of Robert Allerton Part, a 607 km² natural area in east—central Illinois. Comparison of simulations for three alternative plans for the reservoir provides a basis for distinguishing among them, and suggests that the impact of one would be substantially less than the other two.