(Please note, this is an abstract only) We examined attributes associated with the probability of infestation by pinon ips (Ips confusus), in pinon pine (Pinus edulis), in an outbreak in the Coconino National Forest, Arizona. We used data collected from 87 plots, 59 infested and 28 uninfested, and a logistic regression approach to estimate the probability of infestation based on plot- and tree-level attributes. Pinon pine stand density index was a good predictor of the likelihood of infestation by pinon ips at the plot level and a cross-validation analysis indicated that the model correctly classified 82% of the cases. Diameter at root collar and pinon dwarf mistletoe infestation level were good predictors of individual tree infestation and a cross-validation analysis indicated that the model correctly classified 72% of the cases. Results suggest that the occurrence of pinon ips infestations may be related to stress factors associated with increased stocking and pinon dwarf mistletoe infestations.
Pinon-juniper and juniper woodlands
ponderosa pine forests
southwestern United States
Negron, Jose F.; Wilson, Jill L. 2008. Attributes associated with probability of infestation by the pinon Ips, Ips confusus, (Coleoptera: Scolytidae) in pinon pine, Pinus edulis. In: Gottfried, Gerald J.; Shaw, John D.; Ford, Paulette L., compilers. 2008. Ecology, management, and restoration of pinon-juniper and ponderosa pine ecosystems: combined proceedings of the 2005 St. George, Utah and 2006 Albuquerque, New Mexico workshops. Proceedings RMRS-P-51. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 53