Whitebark pine (Pinus albicaulis Engelm.) tree-ring chronologies of 700 to greater than 1000 years in length were developed for four sites in the Sawtooth - Salmon River region, central Idaho. These ring-width chronologies were used to (i) assess the dendrochronological characteristics of this species, (ii) detect annual mortality dates of whitebark pine attributed to a widespread mountain pine beetle (Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae)) epidemic during the 1909-1940 period, and (iii) establish the response of whitebark pine ring-width growth to climate variables. Cross-dating of whitebark pine tree-ring patterns was verified. Ring-width indices had low mean sensitivity (0.123-0.174), typical of high-elevation conifers in western North America, and variable first-order autocorrelation (0.206-0.551). Mountain pine beetle caused mortality of dominant whitebark pine peaked in 1930 on all four sites. Response functions and correlation analyses with state divisional weather records indicate that above-average radial growth is positively correlated with winter and spring precipitation and inversely correlated with May temperature. These correlations appear to be a response to seasonal snowpack. Whitebark pine is a promising species for dendroclimatic studies.
ASJC Scopus subject areas
- Global and Planetary Change