Production and Nutritive Value of Aspen Understory, Black Hills

Abstract

duction of and nutrient concentrationsin understory vegetation was measured in aspen stands representing three different seral stages in the Black Hills. There was little variation in concentrations of nutritive elements in the same plant species among stands. Differences in species composition and shrub, forb, grass, and total production caused some variation in total available nutrients. Production of aspen understory, while variable (676-1226 kg/ha), was one of the higher producing types in the area. Digestible dry matter, fiber, lignin, and calcium were at acceptable levels for white-tailed deer growth. Protein and phosphorus concentrations may be considered marginal, but variation in concentrations among plant species, the large number of pbmt species available, and the selective feeding habits of deer may preclude nutrient deficiencies in their diet. The value each of the seralstages has to livestock and wildlife is discussed and management suggested.Quaking aspen (Populus trernuloides) stands have been recognized as important to many wildlife species and to livestock because of the diversity they create in otherwise homogeneous conifer stands and for the variety and productivity of understory vegetation (Reynolds 1969, Kranz and Linder 1973). Understory production has been studied in several areas of the West, including Utah (Ellison and Houston 1958, Cook and Harris 1968), Colorado (Paulsen 1969), Arizona (Reynolds 1969) South Dakota (Kranz and Linder 1973), and Wyoming (Bartos and Mueggler 198 I). Selected nutritive characteristics have also been reported by Cook and Harris (1968) and Paulsen (1969).Aspen, however, generally is considered a seral stage that will gradually be replaced by conifers (Jones 1974) with fewexceptions (Severson and Thilenius 1976, Mueggler 1976). Studies thus far have not related the seral stage of aspen to understory productivity or nutritive content. This study examines these parameters in aspen stands that represented different successional stages. Study AreaThe study was conducted in the Black Hills of western South Dakota and northeastern Wyoming. Specific study sites were selected from aspen groups as defined and described by Severson and Thilenius (1976), who separated aspen stands of the Black Hills into 9 homogeneous groups by cluster analysis of a similarity matrix based on physical site, soil, and vegetation characteristics. Three groups that contained the largest number of stands and also represented different seral stages were selected for production and nutrient analysis. Group 1 was comprised of 8 stands, and was characterized by a very high average density of small diameter (<lo.2 cm d.b.h.) aspen stems. Average age was 28 years. Most sites in group I had burned 3 1 to 39 years ago. The successional The author is research wildlife biologist, Rocky Mountain Forest and Range Exwriment Station. Arizona State University. Tem~e. Arizona. 85287. Headquarters is i'n Fort Collins, in cooperation with Coldrado state University.

Occupancy modeling of ruffed grouse in the Black Hills National Forest

“…Bur oak (Quercus macrocarpa), hop-hornbeam (Ostrya virginiana), and green ash (Fraxinus pennsylvanica) also occupied the BHNF, comprising < 10% Alexander 1987, Froiland 1990). Common shrubs included western snowberry (Symphoricarpos occidentalis), white coralberry (S. albus), kinnikinnick (Arctostaphylos uvaursi), and common juniper (Juniperus comunis) (Severson andThilenius 1976, Hoffman and.…”

Effects of fire management of southwestern natural resources

“…Reynolds (1969) found that an aspen stand produced 6 times the understory of a mixed conifer stand in Arizona. Severson (1982) noted that only moist, grass-dominated meadows produced more forage than did unmanaged aspen stands in the Black Hills. Aspen stands also contain more species in the understory than do ponderosa pine stands.…”

Occupancy modeling of ruffed grouse in the Black Hills National Forest

“…Our data also implied that dense sapling stands had a slight negative influence on ruffed grouse occupancy. In Minnesota and Wisconsin, investigators found younger age classes (< 25 yr) of forest were preferred over mature stands , Gullion 1989, Severson 1982. However, the young age classes evaluated in those studies consisted primarily of aspen.…”

“…Bur oak (Quercus macrocarpa), hop-hornbeam (Ostrya virginiana), and green ash (Fraxinus pennsylvanica) also occupied the BHNF, comprising < 10% Alexander 1987, Froiland 1990). (Severson andThilenius 1976, Hoffman and.…”

“…Ponderosa pine, quaking aspen, and white spruce were the most abundant forest types in the BHNF; therefore, we included these as covariates in most of these models. In addition to vegetative type and size, the age structure of vegetation might influence ruffed grouse occupancy, colonization, and extinction probabilities , Gullion 1989, Severson 1982. To address age structure influences on these metrics, we developed 10 models incorporating vegetation age.…”