Fire Frequency and the Vegetal Mosaic of the Utah State University Experimental Forest
A fire history study conducted for the Utah State University (USU) Experimental Forest using three distinct periods of fire frequency, historic (1700-1855), settlement (1856-1909), and suppression (1910-present), showed a decreased mean fire interval (MFI) during the settlement period and a greatly increased MFI during the suppression era. The difference was attributed to the influx of ignition sources during the settlement of the nearby Cache Valley, located 40 kilometers to the west. The interaction of settlers with the resource during logging and livestock grazing activities encouraged the high MFI and created the vegetal mosaic now observed on the study area. The elevation of the study area, 2377 m to 2651 m, places the site in the Engelmann spruce-subalpine fir zone (Picea engelmannii, Parry ex Engelm.-Abies lasiocarpa (Engelm. ex. Wats)). The suppression era and its corresponding increase in MFI has permitted the advancement of tolerant species in the understory of the intoleran lodgepole pine (Pinus contorts var. latifolia (Engelm. ex. Wats)) and aspen (Populus tremuloides Michx.). Continue suppression of disturbance from wildfire will allow the lodgepole pine cover type, which experienced the lowest MFI during the settlement period, to be further invaded by tolerant species, leading to a decrease in stand diversity and more intense fires when they do occur.
Wadleigh-Anhold, Linda L. (1988). Fire frequency and the vegetal mosaic of the Utah State University Experimental Forest. MS. 54p.