Aspen Communities Research Articles

A Comparison of Soil, Climate, and Biota of Conifer and Aspen Communities in the Central Rocky Mountains

That the dominant vegetation in a community influences and even controls to a considerable degree the nature of the soil, the microclimate, and the non-dominant plants and animals is well known (McDougall, 1949), but the exact extent to which different kinds of dominant plants modify the various physical and biological environmental factors within most biotic cornmunities has received little study. The present investigation of aspen communities and coniferous communities in the Central Rocky Mountain Region (fig. 1) was conducted in an attempt to determine the various differences in soil, microclimate, and biota occurring under the influence of coniferous and broadleafed deciduous trees. It is well established in the literature (Oosting, 1948) that the groves of aspen (Populus tremuloides var. aurea (Tides.) Daniels) found in the montane coniferous forests of the Rocky Mountain Region represent subclimax communities of the secondary sere. This ecological position in the sere can readily be established by finding remains of coniferous wood, either

The Ants of Northeastern Minnesota

Whereas over 90 species of ants (including subspecies and varieties) are known from that part of the Upper Austral Zone in the vicinity of Chicago, Illinois (Gregg 1944), as yet only 40 species are represented in our collection of the Lake Superior district and constitute the basis of this paper. The localities where ants were obtained lie entirely within the Canadian Zone, and the specimens illustrate well the typical ant fauna of a northern climate. Some forms characteristic of the more southern area are present in Duluth but seem not to be as conspicuous, and many of their associates in Illinois are completely absent from Duluth, as would be expected. They have been replaced by boreal types not found at all or only rarely south of the coniferous forests. It appears that most of the timber in this portion of Minnesota is of second growth, and while new evergreen forests are developing, many square miles are occupied by aspen communities. The precise nature of the myrmecological changes that have accompanied the floristic ones it is at present impossible to state, but the monotonous aspect of the ant fauna in certain examples of the typical vegetation (spruce-tamarack bogs and stands of upland conifers), as compared with the greater number of varieties in deciduous woodland and the many forest margins, leads one to suspect that the fauna is more mixed than prior to the disturbance of the forest cover. In the following list there are probable omissions which further collecting would fill, but it is felt that such an enumeration is justified in view of the scant literature concerning the ant populations in this section of the country. Wheeler (1908) published an account of ten species taken on Isle Royale, Michigan, and almost all are of a distinctly northern distribution. Burrill and Smith (1918, 1919) provided a guide to the ants of Wisconsin and recognized 46 species from that state. There seem to have been no papers other than these devoted to the ants of the upper lake region. The extensive records in Wheeler's (1913) key to the Formicae contain no references to Minnesota localities though citations from all the surrounding states and Canadian provinces must be admitted. For Minnesota vegetation see Rosendahl and Butters 1928.

The Interrelations of Habitat, Growth Rate, and Associated Vegetation in the Aspen Community of Minnesota and Wisconsin

The Interrelations of Habitat, Growth Rate, and Associated Vegetation in the Aspen Community of Minnesota and Wisconsin