Treesearch

Harvesting cost and revenue models were used to evaluate yarding costs by yarder type and to compare stump-to-mill harvesting costs to revenues available from multiproduct thinnings in eastern hardwoods. This analysis includes six types of cable yarders and thinnings in stands where the average diameter at breast height of trees harvested ranged from 7 to 12 inches. To include market factors, the analysis also includes four types of primary products, three product price levels, and three truck-haul distances. Results show that substantial cost savings can be realized by selecting the...

Data from 113 sample thinning plots and a microcomputer program called APTHIN were used to demonstrate the impact of mean stand diameter and product markets on revenue gains from multiproduct versus single-product pulpwood harvests in poletimber and small sawtimber stands of Appalachian hardwoods. The analysis of revenue gains included product mix as a function of the quadratic mean diameter at breast height (DBH), product market prices, and haul cost as a function of market location. Yields of sawlogs, sawbolts, pulpwood-fuelwood, and chips were estimated with APTHIN to determine shifts...

Contemporary harvest planning graphic software is highlighted with practical applications. Planning results from a production study of the Clearwater Cable Yarder are summarized. Application of the planning methods to evaluation of proposed silvicultural treatments is included. Results show that 3-dimensional graphic analysis of proposed harvesting or silvicultural treatments can provide insight toward arriving at visually and aesthetically acceptable management plans for highly visible and sensitive areas. Most importantly, use of contemporary graphic planning software can avoid visually...

This study was conducted at the University of Kentucky's Robinson Forest located in Breathitt, Knott, and Perry counties in eastern Kentucky. Three treatments including two levels of croptree release, leaving 20 and 34 crop trees per acre, and a control treatment were replicated 4 times and randomly distributed among l.2 white oak (Quercus alba L.) stands. Details of the plot layout, determination of treatment levels, and results including treatment costs, volume removed, and three-year crop tree growth response were reported. This report focuses on residual stand damage from the two crop...

Small-sawtimber white oak crop trees in Kentucky were released by a crown-touching technique. In two cutting treatments, 20 and 34 crop trees were released per acre at a total cost of $35 and $42, respectively. Both treatments yielded commercial volumes of cut material. Total mean merchantable volume (> 5.0 inches d.b.h.) in cut trees was 693 cubic feet/acre, with approximately 2,400 board feet/acre in sawtimber( >=11.0 inches d.b.h.). On the basis of early crop-tree stem response, the released trees are growing 0.16 inch/year compared with 0.13 inch/year for the unreleased trees.

Forest managers can use the data presented here to determine the least-cost herbicide application method for precommercial thinning treatments in hardwood sapling stands. Herbicides used in managing immature hardwood stands must be applied ustng individual-tree methods: broadcast applications in hardwoods are not selective and may result in signtficant damage to preferred crop trees. Individual-tree herbicide application methods include variations of infection, basal spraying, and cut stump treatments after mechanical felling operations. Total costs per acre for these methods and for chain...

Two even-age management systems, progressive strip cutting and block clearcutting, have been studied since 1970 on small watersheds at the Hubbard Brook Experimental Forest, New Hampshire. In the strip cutting, all merchantable trees were harvested in a series of three strips over 4 years (1970-74). In the block clearcutting, all trees were harvested in a single operation in 1970. This paper contrasts progressive strip cutting and block clearcutting for the 10-year period after initiation of harvest in terms of hydrologic response, erosion losses, stream water ions, nutrient leaching,...

A method is proposed for rapidly estimating the nymphal population of the Saratoga spittlebug on alternate host plants in young red pine plantations. The method is based on an assumption that the number of nymphs per sample unit is distributed within an infested plantation according to the negative binomial distribution. This method can be 1.1-11.0 times more efficient depending upon the density of plants and the nymphal population level.

Mowing of first-year erect, annual, colonizing vegetation ( especially Kochia scoparia and Salsola collina) was beneficial in the growth and establishment of wheatgrasses (Agropyron caninum, A. smithii and A. elongatum) on restored mined land in western North Dakota. Sample plots containing primarily Kochia, Salsola and Agropyron spp. were mowed in mid- and late-July and mid-August during the first year of growth after re-contouring, replacing topsoil, fertilizing with N, P and K, and seeding with a mixture of grasses and legumes. Kochia densities were reduced to about 2% and biomass to...

Observation shows that three types of horizontal vortices may form during intense wildland fires. Two of these vortices are longitudinal relative to the ambient wind and the third is transverse. One of the longitudinal types, a vortex pair, occurs with extreme heat and low to moderate wind speeds. It may be a somewhat common structure on the flanks of intense crown fires when burning is concentrated along the fire's perimeter. The second longitudinal type, a single vortex, occurs with high winds and can dominate the entire fire. The third type, the transverse vortex, occurs on the upstream...