Treesearch

Since 1985 72 percent of the forest land on the Allegheny National Forest has been subject to at least one moderate to severe defoliation from any of three native or three exotic agents. In addition, droughts affected the forest in 1972, 1988 and 1991. As a result, at least 20 percent of the forest shows tree mortality in from 10 to 80 percent of the overstory trees. Sugar maple is the most seriously affected species. The impacts of this mortality are compounded by the impacts of up to 70 years of overbrowsing by white-tailed deer. Long-term silvicultural research studies were reexamined...

Silvicultural practices used on national forests are changing as a result of the shift to ecosystem management. As a result, the species mix, size, quality, and quantity of woody material that may be removed are changing. In a combined, multidisciplinary effort, Forest Service research units at the Forest Products Laboratory, Pacific Northwest and Southern Research Stations, Northeastern Forest Experiment Station, and national forests in Regions 6, 8, and 9 have been identifying wood utilization options for managing specific ecosystems. Teams have been focusing research on three conditions:...

Silvicultural practices that promote a two-age stand structure provide an opportunity to maintain diversity of woody species and vertical structure for extended periods of time in Appalachian hardwoods. Data from four two-age stands initiated by deferment cutting in West Virginia are summarized for the first 10 to 15 years after treatment. Results indicated that 15 commercial hardwood species regenerated successfully and that height growth of the new cohort provides a predictable change in vertical structure over time. Growth, quality, and vigor of residual trees after treatment varied by...

Overstory species regeneration was examined in 1989, prior to gypsy moth defoliation and thinnings, on 16 stands in the West Virginia University Forest. Three stands were thinned and defoliated while five were thinned only and three were defoliated only. Five stands were neither thinned nor defoliated. Data were collected from these stands for three years subsequent to the disturbances. The general response to defoliation was similar in number of seedlings irrespective of thinning, i.e., there was an initial depression of regeneration, although it was more noticeable in stands that were...

An increased interest in the use of group selection harvesting in the Central Hardwood forests has emphasized the lack of scientific information about species response under this uneven-aged management system. Tree regeneration response following group selection harvesting was studied on thirty-six group selection openings on the Naval Surface Warfare Center, Crane Division in southern Indiana. The objectives were to determine whether aspect, age, species group, size of the opening, or their interactions had any influence on the number of stems or average height of the tree regeneration....

After clearcuting in bottomlands, oak seedlings that naturally regenerate are often overtopped by woody pioneer species, sprouts and herbaceous material. To improve the competitive status of three- to four-year-old oak seedlings in two bottomland stands in South Carolina, several herbicides and methods of application were used to kill and/or stunt the overtopping competition. Oak seedling diameter growth two years after treatment was nearly doubled by four of the late summer herbicide oversprays and by two of the directed applications. Height growth two years after treatment was increased...

Little research has been conducted on the use of mechanical site preparation or fertilization in the Central Hardwood Region. Many hardwood plantings, particularly oak plantings, on old field sites in the region have resulted in high rates of mortality, stem die-back, and slow early-growth rates. The purpose of this study was to investigate the effect of mechanical site preparation techniques and fertilization on the early survival and growth of northern red oak (Quercus rubra L.) seedlings planted on an old field site in southern Indiana. The study was initiated in the Spring of 1993 on a...

In 1982 a black walnut (Juglans nigra) plantation was partly established by planting 200 1-0 seedlings on the first bench adjacent to Copper Creek near its mouth draining into the Clinch River, Scott County, Virginia. In the following years, 50-500 1-0 black walnut seedlings, supplemented by transplanting germinated nuts in failed spots, were planted on the first and second benches until a total of approximately 1600 were established through 1990.

We examined density and reproductive success of passerine species on 7 uncut forest stands and on 12 stands harvested 10-14 years ago on the Monongahela National Forest of West Virginia (6 clearcut stands and 6 stands harvested using 2-age management). In 2-age management, stands resemble a shelterwood cut with 10-30 overstory trees/acre left uncut. Uncut periphery areas adjacent to treatments were used to examine edge effects. All stands and periphery areas were censused 5 times, May-July 1993 and 1994, with the variable-circular plot technique and were thoroughly searched for nests....

Foliage was sampled in June and late August-early September in 1988 and 1989 from the outer crowns of codominant red maple (Acer rubrum L.), northern red oak (Quercus rubra L.), and white oak (Q. alba L.) trees in forest stands along an atmospheric deposition gradient in north-central Pennsylvania. Leaf samples from approximately 480 trees were analyzed for concentration of macroelements N, P, K, Ca, Mg, and S, as well as microelements Al, B, Cu, Fe, Mn, Mo, Na, Pb, Si, Sr, V and Zn. Foliar concentrations of Fe, S, and Sr were generally greater in the high deposition portion of the...