Treesearch

Beech (Fagus sylvatica L.) bark was wounded in early April of 1993 and tissue changes followed on days 7, 14, 21, 28, 35, 42, 49, 56, 84, 112, and 140. In 7 days, tissue at the wound surface became necrotic and discoloured. In 14 days the walls of the parenchyma cells immediately underneath the necrotic tissue became thickened and after 21 days became lignified. In 28 days these lignified cells showed intracellular-suberisation. In 42 days the ligno-suberised layer was continuous with the phellem of the superficial periderm. In 35 days we first noted differentiation of the necrophylactic...

Pin cherry (Prunus pensylvanica L.) develops an early height advantage over associated species. Data from three long-term studies, extending up to 70 years after complete overstory removal, were used to evaluate the effects of pin cherry density on associates. Survival of seedling-origin stems of black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), and sugar maple (Acer saccharum Marsh.) at age 15 decreased as the density of pin cherry >1.5 m tall at age 3 increased. The regression of pin cherry with black cherry was particularly strong (R = 0.632). Height of the tallest black...

The use of group-selection methods is becoming more widespread as landowners and forest managers attempt to respond to public pressure to reduce the size of clearcut blocks. Several studies have shown that harvesting timber in smaller groups or clumps increases the cost of operations for both cable and ground-based logging systems. Recent regeneration studies have shown that the number of stems, numbers of shade-tolerant and intolerant species, basal area, and volume are affected by the size of the opening created. The size of the opening and resulting vegetation also affects the wildlife...

Yes, oak wilt is still around and killing large numbers of oaks annually in Minnesota. Although the progress of oak wilt has been slowed through the concerted efforts of State agencies, private contractors, and determined homeowners, the battle to "control" this infectious disease is ongoing and will continue to be as long as there are oaks in Minnesota.

In recent years foresters managing hardwoods in the Southern Appalachians have been investigating a variety of regeneration methods that lead to the development of a two-aged stand. The reserved trees that make up the older age class usually meet a variety of objectives such as timber, wildlife food and cover, and aesthetic values. A series of 20 operational cuts in Appalachian hardwood stands was evaluated 2 to 5 years post-logging. Residual stand characteristics such as species composition, density, volume, grade, and damage were investigated to determine the early fate of the reserve...

The utility of releasing sheltered northern red oak was examined in mesic hardwood stands in north central West Virginia. Different levels of release were applied in the spring of 1996 - six growing seasons after planting 2-0 seedlings that were protected with 5 ft corrugated plastic shelters. The planting was done in a 7.77 acre forest opening that developed abundant natural regeneration, but lacked a self-sustaining oak component. The most intensive release consisted of cutting all stems within a 5 ft radius of the sheltered tree (n = 20). A less intensive release consisted of the...

Biogenic emissions of volatile organic compounds {VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regions of the world to understand regional and global impacts and to implement possible mitigation strategies. The mixed deciduous and coniferous forests of northern Wisconsin, USA were predicted to have significant VOC emission rates because they are comprised of many genera (i.e. Picea, Populus, Quercus, Salix) known...

Inputs of mercury (Hg) and dissolved organic carbon (DOC) in throughfall and stemflow waters were measured for an upland/bog watershed in northern Minnesota, and were compared to the deposition in a nearby opening to determine the influence of tree canopies on Hg and DOC deposition. Twice as much Hg and seven times as much DOC was deposited in the forested watershed compared to the opening. Mass balance studies that are based on wet-only deposition in openings severely underestimate atmospheric deposition of Hg in forests. Conifer canopies are more efficient filters of airborne, particulate...

Carbon dioxide, water vapour, and sensible heat fluxes were measured above and within a spruce dominated forest near the southern ecotone of the boreal forest in Maine, USA.

The conversion of scientific measurements has become commonplace in the fields of - engineering, research, and forestry. Foresters? Metric Conversions is a Windows-based computer program that quickly converts user-defined measurements from English to metric and from metric to English. Foresters? Metric Conversions was derived from the publication "Metric Conversions for Foresters," by Edwin S. Miyata, Helmuth M. Steinhilb, and Lynne A. Coyer, USDA Forest Service, North Central Forest Experiment Station, St. Paul, Minnesota (originally published in 1981).