Mountain pine beetle infestations in second-growth ponderosa pine have been chronic in the Little Belt and Big Snowy Mountains since 1947. In 1976, increasing numbers of attacked trees were observed. Current infestation intensity averages 82 trees per hectare. Losses are expected to continue as long as stands remain stagnates. Commercial...
A mountain pine beetle infestation developed in lodgepole pine stands in the Gold Creek drainage in 1974. From 1974 to 1976 approximately 19,000 trees with an estimated volume of 10,210 cu m were killed. Based on buildup ratios, stand structure, size of trees, and residual green stand, it is predicted...
Mountain pine beetle infestations developed to epidemic level in lodgepole pine stands on the Yaak District in 1972. Approximately 56,282 trees were killed from 1973 to 1975. By 1975, 2,068 ha were infested. This increased to 7,138 ha in 1976, representing a threefold increase. Current infestation occurs on 13 percent...
Mountain pine beetle populations began building in the Kootenai National Forest in 1972. Infestations now encompass an estimated 48,599 acres of lodgepole pine type and 615 acres of ponderosa pine type. Approximately 25 percent of the high-risk stands, 17 percent of the moderate-risk, and less than 1 percent of the...