Comparison of Two Roadside Survey Procedures for Dwarf Mistletoes on the Sawtooth National Forest, Idaho

Authors

Robert L. Mathiasen, Idaho Department of Lands, Box 670, Coeur d'Alene, ID 83816
James T. Hoffman, Forest Pest Management, USDA Forest Service, 1750 Front Street, Boise, ID 83702
John C. Guyon, Forest Pest Management, USDA Forest Service, 4746 South 1900 East, Ogden, CT 84401
Linda L. Wadleigh, USDA Forest Service, 524 25th Street, Ogden, UT 84403

Date of this Version

1996

Comments

Published in Great Basin Naturalist 56(2), © 1996, pp. 129-134.

Abstract

Two roadside surveys were conducted for dwarf mistletoes parasitizing lodgepole pine and Douglas-fir on the Sawtooth National Forest, Idaho. One survey used variable-radius plots located less than 150 m from roads. The 2nd survey used variable-radius plots established at 200-m intervals along 1600-m transects run perpendicular to the same roads. Estimates of the incidence (percentage of trees infected and percentage of plots infested) and severity (average dwarf mistletoe rating) for both lodgepole pine and Douglas-fir dwarf mistletoes were not significantly different for the 2 survey methods. These findings are further evidence that roadside-plot surveys and transect-plot surveys conducted away from roads provide similar estimates of the incidence of dwarf mistletoes for large forested areas.