Ecological Archives E094-141-A9

Erik A. Beever, S. Z. Dobrowski, J. Long, A. R. Mynsberge, N. B. Piekielek. 2013. Understanding relationships among abundance, extirpation, and climate at ecoregional scales. Ecology 94:1563–1571. http://dx.doi.org/10.1890/12-2174.1

Appendix I. Comparison of variable weights, average Akaike weight per model, number of models in which the variable had positive and negative coefficients, and coefficient of variation across the fitted coefficients of the variable for each predictor of pika persistence at sites across the hydrographic Great Basin, for each of two periods.

Table I1. Comparison of variable weights (wi), average Akaike weight per model, number of models in which the variable had positive and negative coefficients (#Coeffs>0 or <0), and coefficient of variation (CV) across the fitted coefficients of the variable for each predictor of pika persistence at sites across the hydrographic Great Basin, for each of two periods (from Beever et al. 2011). Within each period, variables are listed in order of decreasing weight per model.  The left columns include the variables used in Beever et al. (2003), whereas the right columns replace the maximum elevation variable with a novel variable that indexes the latitude-adjusted maximum elevation of habitat available at each site (MaxElevR). The climate-related predictors appear in bold font, and the two versions of maximum elevation appear in bold italics. Note consistency of the sign of regression coefficients for all predictors except distance to road. The null model was plausible for analysis of Recent data that used the original variable describing maximum upslope refuge (MaxElev; see **). The ‘20th-Century’ results reflect patterns observed at the end of 1990s surveys, and ‘Recent’ results reflect patterns observed at the end of 2000s surveys.

TableI1

Literature Cited

Beever, E. A., P. F. Brussard, and J. Berger. 2003. Patterns of extirpation among isolated populations of pikas (Ochotona princeps) in the Great Basin. Journal of Mammalogy 84:37–54.

Beever, E. A., C. Ray, J. L. Wilkening, P. F. Brussard, and P. W. Mote. 2011. Contemporary climate change alters the pace and drivers of extinction. Global Change Biology 17:2054–2070.


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