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Evaluation of multistage sampling techniques to measure lodgepole pine mortality caused by mountain pine beetle in Montana, 1979 Public Deposited
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A pilot survey was conducted to evaluate the effectiveness of using multistage sampling techniques to measure annual and cumulative mortality on a State-wide basis with acceptable statistical reliability, timeliness, and cost. Within the State of Montana, aerial surveys showed about 986,000 acres of lodgepole pine infested with mountain pine beetle. This area was stratified into three intensity classes. Initial stratification, from 1979 aerial sketchmap surveys, was followed by large-scale (1:6000) aerial photography (on a sample basis), photo interpretation, and ground truth measurements. Photo plots were selected by a systematic random process for each stratum. Ground truth plots were chosen by probability proportional to size (pps). Estimates of 1978 attacked lodgepole pine (faders) were 11.6 million trees, representing a volume of 161.4 million cubic feet. Relative sampling errors were 9.8 and 16.5 percent for numbers of faders and volume, respectively. The total number of standing dead was 33.4 million trees, with a volume of 517 million cubic feet. The survey required 257 man-hours at a cost of $43,500.
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