Treesearch

Michigan hardwoods are an important contributor to the Michigan State economy yet the flow of wood and wood products is poorly documented.

In the early 1930s a series of plots were established throughout Connecticut to study the effects of thinning on stand growth.

We are currently investigating patterns of species composition and distribution, ecologically important population processes, and microenvironmental gradients along ten permanent transects (each consisting of a series of. contiguous 10 x 10 m quadrats) established across the typically abrupt and narrow spruce/hardwood ecotone at seven localities in the mountains of central West Virginia and western Virginia Primary emphasis of our research is directed toward testing three basic hypotheses: (1) red spruce communities in the central Appalachians are decreasing in areal extent due to encroachm...

Understanding spatial and temporal variation in the understory light regime of southern Appalachian forests is central to understanding regeneration patterns of overstory species. One of the important contributors to this variability is the distribution of evergreen shrub species, primarily Rhododendron maximum L. We measured photosynthetically active radiation (PAR) in the understory of closed forest canopies in areas with and without R. maximum. Measurements were taken from March through November 1993 with a frequency of approximately 3 weeks. In 1994 measurements resumed from March...

Ingrowth, the number of trees that periodically grow into the smallest inventoried diameter class, has long been recognized as a basic element of multicohort or, uneven-aged, stand development. However, very little information is available to aid forest managers in the estimation of ingrowth. The purpose of this study was to develop a generalized ingrowth model for the northeastern United States. The model was developed in two stages. First, annual ingrowth trees per acre into the 5-inch dbh class was modeled as a function of average stand diameter, overstory trees per acre, and a generaliz...

Herbaceous vegetation was inventoried in 1992 and 1993 in eight Appalachian mixed hardwood stands (< 50% basal area/acre in oak species) and eight oak stands (> 50% basal area/acre in oak species) in north central West Virginia. Vegetation was sampled on 20 6-foot radius plots per stand twice each growing season (once during late spring to sample spring ephemeral species, and later in mid summer). Stand disturbance prior to herbaceous sampling included 1) a silvicultural thinning (8 stands) in the winter/spring of 1990, and/or 2) moderate to heavy gypsy moth defoliation (6 stands) in 1990...

Mixed hardwood forests of the Appalachian region support one of the most diverse communities of woody plants in North America, but the composition and relative dominance of the forest changes substantially with slight changes in physiography, soil type, or microclimate. Composition of oak and other species highly preferred by the gypsy moth determines the susceptibility of forests to defoliation. As composition of these species increases, the susceptibility increases. Silvicultural treatments were developed to minimize the effects of gypsy moth defoliation on forests. A research study was...

Vegetation management with glyphosate and simazine proved to be more effective than preplant subsoiling or irrigation for achieving acceptable walnut biomass growth on an upland old field site (SI = 70 for white oak). In 1980, we direct seeded germinating black walnut seed on an upland, slightly eroded, old field ridge with a 45 to 60 cm deep fragipan. We tested all combinations of with and without preplant subsoiling (75 cm deep); with and without irrigation for 6 years, and with and without chemical weed control for 7 years. The only treatment effect still persisting after 14 years was...

A study was conducted in 1992 to assess the abundance and distribution of viable hayscented fern spores in the forest floor of central Pennsylvania hardwood stands before and after seasonal spore dispersal. Intact soil samples were collected at various distances and directions from established fern communities and placed in a greenhouse to effect spore germination.

Allegheny hardwood stands typically develop vertical canopy layers, or strata, due to differential species-specific growth rates and tolerance to shade. Across the Allegheny Plateau, black cherry dominates the main canopy, while sugar maple, American beech, and red maple are relegated to subcanopy strata.