Changes In Cover Types Research Articles

Vegetation, site, and fire relationships within the area of the Little Sioux fire, northeastern Minnesota

The relationships among various landscape features were examined in an area in northeastern Minnesota that burned in a forest fire in May 1971. Maps based on fire intensity, cover types in 1948 and 1970, soils, and topography were randomly sampled. A total of 34 comparisons were made between pairs of classifications based on the mapped characteristics. The closest relationship was between dominant vegetation in 1948 and that in 1970. Relationships between soil mapping units and slope position and between vegetation and soils were also relatively high. The vegetation–soil relationships were influenced by the close associations of lowland vegetation to lowland soils and of upland vegetation to upland soils. However, specific categories of upland vegetation were not well related to specific categories of upland soils. Fire intensity was most closely related to slope position. An 80% decrease in balsam-fir cover types occurred from 1948 to 1970. This decrease was accompanied by a nearly equal increase in aspen cover types. This balsam-fir to aspen cover type change is attributed to the spruce budworm epidemic, which occurred from the mid-1950's to the mid-1960's. Decreases in jack pine, red pine, and white pine cover types are attributed to commercial logging.