Treesearch

In the present study, we investigated the relationship between sugar maple health and 1) glacial history, 2) topographic or physiographic position, 3) site (elevation, aspect) and stand characteristics (species composition, structure, density), 4) disturbance history (management, defoliation), and foliar nutrition.

Decline of sugar maple (Acer saccharum Marsh.) has been a problem on the Allegheny Plateau of Pennsylvania since the mid-1980's (Kolb and McCormick 1993; Williams et al. 1996). Horsley et al. (this volume) found that declining stands were distinguished from non-declining stands by a combination of repeated insect defoliation and low foliar calcium and magnesium concentrations. Stands that exhibited only one of these two conditions remained healthy. Information is needed (1) to determine whether low foliar nutrient concentrations are related to soil quality, (2) to determine key parameters...

Sugar maple dominates the northern hardwood forest, but grows over a broader geographic area. Conditions of soil and climate largely limit its distribution, and account for its less continuous cover along fringes of the range. Sugar maple regenerates readily following a wide range of overstory treatments. Success depends upon its status as advance regeneration, particularly under strategies favorable to less shade-tolerant species. In even-aged stands, trees of upper canopy positions grow well following release by cutting. Those of lower canopy positions do not. in uneven-aged stands, both...

Traditionally, most enzyme assays utilize homogenized cell extracts with or without dialysis. Homogenization and centrifugation of large numbers of samples for screening of mutants and transgenic cell lines is quite cumbersome and generally requires sufficiently large amounts (hundreds of milligrams) of tissue. However, in situations where the tissue is available in small quantities, or one needs to study changes in enzyme activities during development (e.g. somatic embryogenesis), it is desirable to have rapid and reproducible assay methods that utilize only a few milligrams of tissue and...

Several attempts at the genetic improvement of tree species have been made, but in comparison with crop plants the efforts as well as the results have been rather limited. The most commonly used approaches have involved selection of superior genotypes from natural outbred populations, mutations, and intra- and inter-specific hybridization under controlled conditions. While the conventional methods have proven remarkably successful in yielding improved genotypes that could be stabilized by back crossing, the techniques of cloning, marker-aided selection, and genetic engineering when...

Provides current and historical information on primary and secondary hardwood products, production, prices, international trade, and employment.

High demand for a variety of timber products from New York's forests has stimulated increased timber utilization and product recovery. Utilization studies in New York suggest that the recovery of timber has improved over the years. Although current methods of multiproduct harvesting have improved recovery of residual material, an estimated 38.6 million cubic feet, or 16 percent of the total volume harvested for industrial roundwood products, remain unused. There are many opportunities to recover additional amounts of wood materials from the tops of trees, trees destroyed by harvesting, and...

Provides current and historical information on primary and secondary hardwood products, production, prices, international trade, and employment.

Provides current and historical information on primary and secondary hardwood products, production, prices, international trade, and employment.

This paper reports the results of analyses of six years of written public comments on forest management plans and projects pertaining to the Hoosier National Forest in Indiana. The goal of the research was to gain an understanding of public concerns for the use of the forest lands, within the fabric of their underlying values and emotions. Research methods included the development of a comprehensive taxonomy of expressed values, emotions, and desired outcomes found in the data set, followed by the computerized coding and analysis of the text. Quantitative and qualitative analyses revealed...