Nutrient analysis was done for adjacent, 40‐year‐old stands of pure quaking aspen (Populus tremuloides Michx.), white spruce (Picea glauca Moench Voss), red pine (Pinus resinosa Ait.) and jack pine (Pinus banksiana Lamb.) on two soils in Minnesota to determine the effects of tree species on soil properties. On both soils, aspen and spruce stands accumulated more of most nutrients than did pine stands, and these species differences were reflected in the litterfall. The weight of the forest floor did not differ among species, but nutrient accumulation and pH were greatest under aspen and spruce. Calcium content was about twice as high under aspen and spruce as under the pines. In the mineral soil, phosphorus (P) and potassium (K) did not differ among species; organic matter and nitrogen (N) tended to be lowest under aspen, and calcium (Ca) was much lower under aspen and spruce than under the pines. Soil pH and cation exchange capacity were highest under the pines; this was directly related to soil Ca contents. Mineral soil differences related to species were most pronounced in the top 10 cm; few differences occurred below 25 cm.The large species differences in the N, Ca, and Mg contents of vegetation, forest floor, and mineral soil show a redistribution of these nutrients, but their amounts in the entire ecosystem do not differ by species. In contrast, P and K in the ecosystem decrease in the order aspen>spruce>pines, and this is largely a reflection of their accumulation in the vegetation since their differences in the soil are minimal.

Boles of quaking aspen (Populustremuloides Michx.), white spruce (Piceaglauca (Moench) Voss), red pine (Pinusresinosa Ait.), and jack pine (Pinusbanksiana Lamb.) were sampled after decomposing for 11–17 years. Mass loss and changes in chemical composition were determined. Density decreased by 40–73%, and the decomposition constant (k) decreased in the order aspen > spruce > red pine > jack pine. Although the decomposition rate was strongly species dependent, it did not differ between the two sites. The decomposition constant was weakly related to lignin and phosphorus concentration in the original stems (r2 = 0.44 and 0.49, respectively) and not significantly related to original nitrogen concentrations. Nutrient concentration increased during decomposition, particularly for nitrogen and phosphorus. Nitrogen content increased during decomposition, and potassium content decreased. Calcium and magnesium content changed little during decomposition, whereas phosphorus content increased or decreased, depending on species. In general, species with the lowest initial nutrient contents had the greatest nutrient increases during decomposition. Nutrient content of boles of all species became similar during decomposition.

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Vegetation and soils were sampled in adjacent 40-year-old stands of red pine (Pinusresinosa Ait.), jack pine (Pinusbanksiana Lamb.), white spruce (Piceaglauca (Moench.) Voss), and aspen (Populustremuloides Michx., P. grandidentata Michx.) on a very fine sandy loam soil in north-central Minnesota. Total tree biomass was greatest for red pine followed by aspen, spruce, and jack pine. Nutrient weights (N, P, K, Ca, Mg) in the trees were greatest in aspen followed generally by spruce, red pine, and jack pine. Particularly large proportions of biomass and nutrients were found in aspen bark and spruce foliage and branches. Understory biomass contributed less than 1.2% of the total organic matter in the vegetation–soil complex but contributed up to 5.0% of the nutrients. Exchangeable Ca in the surface soil was much lower under aspen and spruce than under the pines. No significant soil differences between species were detected below 36 cm. Harvesting the entire aboveground portion of the tree would remove up to three times more nutrients from the site than would harvesting only the bole.

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