There is a critical need to understand how drought affects rangelands because drought severity and drought-associated disturbances are expected to increase with climatic change.
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 drought(s); 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.
Drought in rangelands reduces forage and water available for livestock grazing.
Management actions can either mitigate or exacerbate the effects of drought. A first principal for increasing resilience and adaptation would be to avoid management actions that exacerbate the effects of current or future drought.
Trends over the last three decades point to reduced precipitation and increased temperatures in the High Plains Ecoregion, with more and larger fires in High Plains states. Our results will be used to improve predictive forecasts of Great Plains wildfires, which are prone to uncertainties related to current climate projections and a paucity of information on grassland fire climate relationships.
The RVS/ST-SIM decision support system prototyped on the Loamy Plains Ecological Site indicates significant potential to improve management outcomes. The grazing strategies examined provide a range of outcomes influencing annual production, fuelbed properties and species assemblages.