PARENT SESSION
Thursday, August 10, 5:00-6:30 pm
Poster Session 24 - Modeling, statistics, and spatial analysis
Exhibit Hall, Ballroom Level, Cook Convention Center

Modeling bark beetle pressure for pine forests of Mexico.

Salinas-Moreno, Yolanda^*,1, Vargas, Carlos¹, Zuniga, Gerardo¹, Ager, Alan², Hayes, Jane ², ¹ Instituto Politecnico Nacional, Mexico City, Mexico DF, Mexico² Pacific Northwest Research Station, La Grande, OR, USA

ABSTRACT- Bark beetles in the genus Dendroctnus are significant causes of mortality for over half of the 42 species of pines (Pinus) that occur in Mexico and there is a growing need for bark beetle risk predictive capabilities to help forest managers mitigate beetle impacts. In general, the host relationship between beetles and these pines is weak; most of the 12 species of bark beetles attack a number of pine species and considerable overlap of these hosts occurs. The geographic distribution of bark beetle populations is highly influenced by environmental factors such as temperature and elevation, rather than strictly by the distribution of potential hosts, and thus many beetle species are more prevalent in certain portions of their host range. Given these considerations, and a data set consisting of point observations of pine - beetle species throughout Mexico, we devised a measure of beetle pressure by considering the cumulative pine - beetle exposure at each site. Local density of beetles and geographic range maps for pine species were generated from point maps using kernal density functions. The beetle pressure index was calculated by summing the beetle density over all pine-beetle combinations present in that pixel. While other variables like stand density and tree size are most likely important determinants of potential beetle risk, the beetle pressure index may provide an informative broad scale indicator of potential for bark beetle impacts on pine forests in Mexico.

Key words: bark beetle pressure index, pine forests, Dendroctonus