A comparison of Aspen and Pine Communities in the Northern Black Hills

Three study areas, each containing an aspen (Populus tremuloides) community, a pine (Pinus ponderosa) community, and a mixed aspen-pine community, were studied during the summers of 1968, 1969, and 1970. Soil chemistry, plant chemistry, overstory density, understory production, and use by whitetail deer (Odocoileus virginianus) and cattle (Bos taurus) were determined for each community in each study. Pine and aspen communities of one study area were sampled for soil and plant chemistry. Soil phosphate and potassium levels were higher in the aspen community, while soil nitrates were higher in the pine community. Soil pH was similar to the two communities. Plant chemical composition was quite variable from the aspen to the pine community. Vetchling (Lathyrus ochroleucus) had higher levels of phosphorus, potassium, and nitrogen in the aspen community than in the pine community, while bearberry (Arctostaphylos uva-ursi) chemical composition did not change with overstory type. Overstory density, although visually appearing similar, was greatest in the pin communities, intermediate in mixed aspen-pine, and least in the aspen communities, with basal areas (dbh) averaging 180.5, 133.5, and 89.7 square feet per acre, respectively. Understory production was inversely related to overstory density. The greatest production (589 lb./acre air-dried forage) was found under the moderately dense mixed aspen-pine stands, and least production (215 lb.) under the most dense pine stands. Aspen communities appeared to represent better feeding areas for both deer and cattle than mixed aspen-pine or pine communities. However, use by whitetail deer, estimated by pellet group density, was greatest in the mixed aspen-pine communities, intermediate in aspen, and least in the pine communities. Cattle use, estimated by chip density, was greatest in the aspen communities, intermediate in missed aspen-pine, and least in the pine communities.