Predicted probability of fisher occurrence in summer (May – November), 1986-2005, 4 km resolution

Predicted probability of fisher summer occurrence created with Maxent (Phillips et al. 2006) using fisher detections (N = 83, May – November, spanning 1993 – 2009) and eight predictor variables: mean annual precipitation, mean summer (July – September) precipitation, mean summer temperature amplitude, mean understory index (fraction of grass vegetation carbon in forest), mean fraction of total forest carbon in coarse wood carbon, mean forest carbon (g C m2), mean fraction of vegetation carbon in forest, and modal vegetation class. Predictor variables had a grid cell size of 4 km by 4 km, vegetation variables were simulated by the MC1 dynamic global vegetation model (Bachelet et al. 2001) and historical climate variables were provided by the PRISM GROUP (Daly et al. 1994). This fisher distribution model has a 10-fold cross-validated AUC of 0.891 +/- 0.040 and was generated as part of a pilot project to apply and evaluate the Yale Framework (Yale Science Panel for Integrating Climate Adaptation and Landscape Conservation Planning).

Grid Value                          Predicted Probability of Occurrence
1                                                                     0 – 0.2
2                                                                     0.2 – 0.4
3                                                                     0.4 – 0.6
4                                                                     0.6 – 0.8
5                                                                     0.8 – 1.0

References:

Bachelet D., R.P. Neilson, J. M. Lenihan, and R.J. Drapek. 2001. Climate change effects on vegetation distribution and carbon budget in the U.S. Ecosystems 4:164-185.

Daly, C., R.P. Neilson, and D.L. Phillips. 1994. A statistical topographic model for mapping climatological precipitation over mountainous terrain. Journal of Applied Meteorology 33:140–158.

Phillips, S.J., R.P. Anderson, and R.E. Schapire. 2006. Maximum entropy modeling of species geographic distributions.  Ecological Modelling 190: 231-259.

Note: The MC1 model is described in data basin (http://databasin.org/climate-center/features/mc1-dynamic-global-vegetation-model).