Treesearch

Re-inventories completed for each of four Central Hardwood States (Kentucky, Ohio, Pennsylvania, and West Virginia) show that forest area is increasing and stocking hit new highs; there is 27 percent more growing-stock volume than a decade ago. Large increases in volume have been recorded for all but the smallest diameter classes. Volume in trees 15 inches in diameter and larger is up 48 percent. There is more high quality hardwood sawtimber. The extent to which the resource is needed and utilized will depend on the same complex set of interrelated factors that it always has. These factors...

A study tour of four areas of France and Germany (two in each country) was conducted to examine oak silvicultural and managerial practices and the influence of insect defoliators on the ecology and management of oak forests. The French and German situations may provide useful information for managing oak forests and gypsy moth in the United States, especially the central hardwood region.

In 1990, 72, 0.50-acre permanent plots were laid out and tree and regeneration data was collected on four sites which showed evidence of red oak decline in the Missouri Ozarks. In the fall of 1990, three treatments were applied; a control, selection cutting, and clearcutting.

The development and diffusion of new technologies have had tremendous impacts on wildland recreation in recent decades. This article examines the potential economic impacts of research and technical change in wildland recreation. Two evaluation models are presented, a cost-price approach and a research intensity model, which are intended to shed some light on the question of whether society has over- or underinvested in recreation research. These two evaluation models are applied to the case of recreation on the U.S. National Forest system. The cost-price analysis indicates that the...

This chapter deals broadly with the North American (NA) sawflies in the two superfamilies Megalodontoidea (Xyelidae and Pamphiliidae, listed phylogenetically) and Tenthredinoidea (Pergidae, Argidae, Cimbicidae, Diprionidae, and Tenthredinidae). The larvae of these sawflies are all phytophagous, and many are significant pests.

Today's forest managers are challenged by issues such as soil productivity, biodiversity, threatened and endangered species, and ecosystem sustainability; and ecosystem management has been proposed as a way to deal with them. The Society of American Foresters (1993) defines this term as keeping forest ecosystems functioning well over long periods of time in order to provide resilience to short-term stress and adaptation to long-term change.

Nosema scripta (Microsporida: Nosematidae), a new species of microsporidian parasite, is described from the cottonwood leaf beetle, Chrysomela scripta F. (Coleoptera: Chrysomelidae), in North America. Studies using light and electron microscopy reveal that this species completes its life cycle in direct contact with the cytoplasm of the cells within the fat body, midgut, hindgut, muscles, central nerve cord, Malpighian tubules, tracheal end cells, and ovaries. The microsporidium is monomorphic, all life stages are diplokaryotic, and spores develop from disporous sporonts. The mature spores...

Thinning oak stump sprouts to a single stem at an early age will increase diameter growth of the released stem. However, percommercial thinning represents a substantial investment which must be carried for many years before any returns are realized. We estimated the incremental gains in yield and the present net worth for five crop-tree release treatments of 5-yr-old coppice sprouts in the southeastern Missouri Ozarks and compared them to the results from unthinned control plots. The treatments involved thinning 100, 150, 200, 250, and all clumps of sprouts on the plots to a single stem....

Discusses recent Minnesota forest industry trends; production and receipts of pulpwood, saw logs, and veneer logs; and production of other timber products in 1990. Reports on logging residue, wood and bark residue generated at primary wood-using mills, and disposition of mill residues.

Discusses recent Michigan forest industry trends; production and receipts of pulpwood, saw logs, and veneer logs; and production of other timber products in 1990. Exports on logging residue, on wood and bark residue generated at primary wood-using mills, and on disposition of this mill residue.