Informing the elk debate: applying NASA Earth Observing System (EOS) data to natural resource management conflicts in the western states

This study was designed to provide information that might help resource managers understand the distribution of elk in Arizona as a consequence of seasonal variation and in response to extreme climatic events (i.e. El Nino and La Nina). The first task involved modeling elk populations over time. A technique for modeling the elk population has been developed that is based on harvest data, gender ratios, and estimates of male mortality. This provided estimates of elk populations for individual game management units (areas for which harvest is reported and within which elk are managed by the Arizona Game and Fish Department). The second task involved the use of satellite data to characterize vegetation responses to seasonal and interannual climate variation among vegetation associations within game management units. This involved the use of NOAA-AVHRR time series data to describe temporal vegetation behavior, Landsat data to describe spatial vegetation distribution in conjunction with U.S. Forest Service vegetation maps. Elk population estimates were correlated with satellite-derived vegetation measures by vegetation association through time. The patterns of elk distribution that this revealed were complex. Not surprisingly, animals appear to respond to differences in vegetation availability-both seasonally and interannually-as portrayed by satellite data.