Rangeland Drought: Effects and Adaptation Strategies
Drought can have severe impacts on rangeland ecosystems in North America. Drought impacts vary depending on the severity, frequency, duration, and aerial extent of the droughts; how the land is managed; and, whether plans are in place and implemented to respond to drought. Drought can be simply defined as "a lack of water" characteristic of time, not of place; or, it can be defined in a climatic context, as "precipitation levels that are much lower than the annual average water, forage, habitat, recreation, and pollination of native and agricultural plants.” A general lack of quantitative information regarding the effects of varied management strategies on these spatially heterogeneous landscapes complicates our understanding of the processes within them. Influences and managerial strategies, such as grazing intensity and seasonality or fire frequency and behavior presents unique challenges to managers seeking to understand, explain, and justify desired management strategies. In response to this need, Forest Service scientists have developed a decision support system based on ecological models for predicting the impact of climate on fuelbed properties on Great Plains grasslands.
This system utilizes two distinct tools, which act in concert to produce state-of-the-art ecosystem modelling capabilities. The Rangeland Vegetation Simulator deterministically estimates growth, succession, and fuels; and, the State-and-Transition Simulation Model enables stochastic modelling of ecological processes such as plant community development and response to climate.
Forest Service Partners