Projected suitable habitat models were constructed in Maxent (version 3.3; Phillips et al. 2004, 2006) using a set of presence points for the species derived from element occurrence and herbarium records, together with temperature, precipitation, and soil variables. The current distribution used modeled historic period (1970-2000) climate variables from the appropriate matching GCM model run. These model parameters were then used with projected climate data to get future (2020-2050) modeled suitable habitat for each scenario. Modeled past suitable habitat and modeled future suitable habitat are combined to show areas of change, using various thresholds to distinguish change categories, as well as current mapped sagebrush-occupied habitats from SWReGAP landcover (USGS 2004). Current occupied habitat is represented as areas with probability greater than the all-scenario average model-reported threshold (sensitivity = specificity) AND currently mapped as the appropriate sagebrush type. These probability threshold levels were also applied to projected future habitat (since we have no “future” mapping), with the final model was classified as: Value Habt Class Current 2035 1 Lost >= 0.56 < 0.34 2 Threatened >= 0.56 >= 0.34 and < 0.56 3 Persistent >= 0.56 >= 0.56 4 Emergent < 0.56 >= 0.56 0 none of the above where: 0.56 is the average probability of occurrence value from the 3 scenarios, current timeframe, where vaseyana is known to occur (using SWReGAP landcover). 0.34 is the average probability of occurrence value from the 3 scenarios, current timeframe, where the model specificity = the model sensitivity.
Projected suitable habitat models were constructed in Maxent (version 3.3; Phillips et al. 2004, 2006) using a set of presence points for the species derived from element occurrence and herbarium records, together with temperature, precipitation, and soil ...