COMPARISON OF 2 ROADSIDE SURVEY PROCEDURES FOR DWARF MISTLETOES ON THE SAWTOOTH-NATIONAL-FOREST, IDAHO

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 ro ads. The 2nd survey used variable-radius plots established at 200-m in tervals along 1600-m transects run perpendicular to the same roads. Es timates of the incidence (percentage of trees infected and percentage of plots infested) and severity (average dwarf mistletoe rating) for b oth lodgepole pine and Douglas-fir dwarf mistletoes were not significa ntly different for the 2 survey methods. These findings are further ev idence that roadside-plot surveys and transect-plot surveys conducted away from roads provide similar estimates of the incidence of dwarf mi stletoes for large forested areas.