Treesearch

Sulfate deposition and exports from 1988–92 were analyzed for a small headwater catchment in north-centralWest Virginia.Annual sulfate inputs, estimated by applying throughfall-adjusted ratios to bulk deposition values, and outputs were approximately equal for the five years. Annual mean throughfall-adjusted deposition and export loads were 55.78 and 55.48 kg ha−1, respectively. While these results indicate the watershed has reached sulfate equilibrium relative to current deposition levels, seasonal sulfate accumulations and deficits were evident. Deposition and exports averaged 5.61 and...

Using the ROMI-RIP simulator we examined the implications of preprocessing for gang-rip-first rough mills. Rip-first rough mills can improve yield and throughput by preprocessing 1 Common and 2A Common hardwood lumber. This can be achieved by using a chop saw to separate poorer quality board segments from better ones and remove waste areas with little or no yield. This preprocessing is in addition to major production benefits from crosscutting out crook or sidebend.

Long-term productivity of mixed-species forests in the central Appalachian region of the United States may be threatened by changes in base cation availability of the soil. These changes may be due to increased intensity of harvest removals and a shift toward shorter rotations that result in increased removal of calcium and magnesium in aboveground biomass, and through altered nutrient cycling. Atmospheric deposition, particularly of nitrogen, also affects nutrient cycling by increasing leaching of base cations from the soil in soil solution, and by altering the rate of nutrient cycling....

Butternut (Juglans cinerea L.) (Fig. 1a), also known as white walnut or oilnut, is a hardwood species in the family Juglandaceae, section Trachycaryon (Manning, 1978), or more appropriately, section Cardiocaryon (Fjellstrom & Parfitt, 1994). This hardwood species is valued for its wood and edible nuts. Native to North America from New Brunswick to Georgia, and west to Minnesota and Arkansas (Fig. 1b), butternut is not an abundant species and is seldom found in pure stands, but rather in association with several other tree species such as cherry, basswood, oak, walnut, ash, maple, elm, and...

We approach the benefits and burdens of interdisciplinary research (IDR) from the perspective that science involves both constructive and critical approaches. The constructive aspect generates concepts, theories, and data to understand the observable world, while criticism tests the internal consistency of understanding and its fit to the observable world (Pickett and others 1994). IDR is the linkage of phenomena, research approaches, and conceptual tools that had previously been pursued independently (Parker 1993). Such linkages produce new research questions, new approaches to problems,...

This review presents information related to defoliation by the European gypsy moth (Lymantria dispar L.) and subsequent tree mortality in the eastern United States. The literature describing defoliation-induced tree mortality is extensive, yet questions still remain concerning (1) the association between initial stand composition and subsequent tree mortality, (2) the influence of site quality on tree mortality, and (3) observed differences between mortality rates in initial and subsequent outbreaks. Our review and analysis of the available literature indicates that initial species...

Stocking guides are basic tools for forest managers. They provide estimates of the range in acceptable stocking for full occupancy of the site. The first stocking guide for white pine was developed by Philbrook et al (1973). It was of conventional format: showing trees and basal area per acre (in the main crown canopy) by mean stand dbh (the tree of average basal area). The so-called A-line represented maximum stocking, the B-line represented minimum stocking for full site occupancy - the suggested minimum residual stocking after thinning. Lancaster and Leak (1978) incorporated the...

The gypsy moth (Lymantria dispar L.) nuclear polyhedrosis virus was genetically engineered for nonpersistence by removal of the gene coding for polyhedrin production and stabilized using a coocclusion process. A β-galactosidase marker gene was inserted into the genetically engineered virus (LdGEV) so that infected larvae could be tested for its presence using a colorimetric assay. In 1993, LdGEV-infected gypsy moths were released in a forested plot in Massachusetts to test for spread and persistence. A similar forested plot 2 km away served as a control. For 3 years (1993-1995), gypsy...

Missouri's natural communities have been shaped by humans and wildland fires for thousands of years. In many ways, the history of fire in Missouri also is a history of human population, culture and migration. Fires caused by natural ignition, like lightning, are rare. Despite as many as 50 to 70 thunderstorm days per year, Conservation Department studies indicate that less than 1 percent of modern day fires are started naturally. Humans have been, and continue to be, the primary cause of most wildland fires in Missouri.

A study was initiated in 1994 to evaluate the degree of bole damage and crown decline residual overstory trees would experience because of prescribed burning of shelterwood stands. Three oak-dominated shelterwood stands, partially harvested 2 to 4 yr earlier, were divided into four treatments (unburned control, spring burn, summer burn, and winter burn). Fifteen permanent sampling points were systematically located in each 5 to 12 ac treatment area, and overstory trees were selected from these points with a 10 BAF prism. Before burning, each tree was evaluated for lower bole and crown...