Drought is complex. Temporal accumulation, spatial heterogeneity and precipitation intensity are all extremely important and distinguish hydrological, environmental, agricultural and other types of drought throughout the arid Southwest. The suite of drought indices available is also numerous and it is often difficult to discern which index is most useful for tracking potential impacts on different vegetation communities. Multiscale Drought Index plots show all windows of temporal accumulation of precipitation expressed in standard deviations units which may aid in finding optimal timescales for investigating climate/vegetation relationships. MDI plots were used in conjunction with long-term vegetation monitoring data and stocking rate over a nearly 35-year period to determine whether climate or grazing contributed more to a shift in�B. gracilis�dominated grassland to an�E. Lehmanniana�dominated grassland, or an annual grass dominated landscape on the Crossed J Ranch in Southeastern AZ. It was determined that drought, at different temporal and intensity resolutions directly contributed to the change in the vegetation community. As more long-term vegetation data sets become available, MDI plots may aid in refining the vegetation/climate relationship. Further recommendations may be made by pointing to specific subsets of indices and how to use them.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.