Treesearch

A 43-year-old, even-aged stand of advance reproduction of grand fir and Shasta red fir in central Oregon responded to release and thinning with diameter and height growth two to three times the prerelease rate. The response began the first growing season after the overstory was killed with 2,4-D. Diameter growth during the second and third 5-year periods after release increased significantly over that of the first 5 years. Differences in spacing had no effect on diameter growth during the first 5 years, but growth at the wider spacings increased considerably during the second and third...

PLANS, a software package for integrated timber-harvest planning, uses digital terrain models to provide the topographic data needed to fit harvest and transportation designs to specific terrain. MAP, an integral program in the PLANS package, is used to construct the digital terrain models required by PLANS. MAP establishes digital terrain models using digitizer-traced contour lines from topographic maps, which are, in turn, processed into an elevation grid and stored in matrix form. MAP builds continuous digital terrain models that can cover large planning areas and builds them to any...

Even though Texas consumes more forest products than it produces, its forest products industry has a conspicuous record. Between 1970 and 1980, employment in the forest products industry increased by 12,000. Only one Southern State, North Carolina, showed a larger absolute gain. Texas was also second to North Carolina in improving its comparative advantage during the 1970's. In 1977, it ranked fourth among the 13 Southern States in value added, but first in growth of value added.

White spruce trees and tops were chipped and placed in a pile near Fairbanks, Alaska, in February 1983. The pile was 6 meters in diameter and 6 meters high in a cylindrical shape. Thermocouples were placed at 25 locations within the pile so that temperatures could be tracked over time. Gypsum blocks were placed at 10 locations to determine changes in moisture content. The first evidence that the pile was generating heat appeared at the end of May 1983. This heat accelerated the warming and thawing of the pile. By early August, all thermocouple points were above freezing. The highest...

The paper previews a computer-aided design system, PLANS, that is useful for developing timber harvest and road network plans on large-scale topographic maps. Earlier planning techniques are reviewed, and the advantages are explained of using advanced planning systems like PLANS. There is a brief summary of the input, output, and function of each program in the PLANS program set. The set presently includes programs for harvest unit design for a variety of cable logging systems, road locations, visual analyses, yarding costs, and slope attributes and a method for producing the elevation...

PPSIM simulates yields of natural and managed ponderosa pine stands. Management practices and effects that can be simulated include commercial thinning, fertilization, genetic improvement, and presence of dwarf mistletoe. An option is available that adjusts growth to simulate local conditions. Equations used in PPSIM describe growth of natural stands, estimate the volume increment of thinned stands, and predict the amount and timing of mortality in natural stands. The Fortran IV program is available from the authors on request.

Results of five spacing trials on the University of British Columbia Research Forest, covering a range of plantation spacings from 1 to 5 meters, showed that choice of initial spacing is among the most important factors influencing bole and crown development and stand growth and yield. The trials include Douglas-fir (Pseudotsuga menziesi), western hemlock (Tsuga heterophylla), and western redcedar (Thuja plicata). The results to date should help managers to choose optimum spacings for their purposes. Initial wide spacings with rectangularities up to 2:1, such as 6 by 3 meters, resulted in...

Experimental plantings of different genotypes of cottonwood were examined. The four clones tested were: a Populus hybrid (Dula, D-01), a P. trichocarpa x P. deltoides hybrid (Hybrid 11), and two native P. trichocarpa clones (Nisqually 1 and Orting 5). Establishment success and characteristics of hardwood cuttings or resulting plants that might be related to success were determined. Establishment success varied significantly (P < 0.01) among the four clones in the order, orting = dula > Hybrid 11 > Nisqually. Also, there was much variation among the clones in the relative proportion of...

Accounting for one of every six basic jobs, the forest products industry in Arkansas is the second largest component of the State's economic base. Furthermore, Arkansas is the most timber-dependent State in the South. Between 1970 and 1980, employment increased in the paper and allied products segment but decreased in the wood furniture and the lumber and wood products Segments. Arkansas was one of two Southern States that had a smaller share of the Nation's employment in the forest products industry in 1980 than in 1970. This trend resulted partially from a shakeout of the southern pine...

Snow depth and density were measured in 33 stands of western hemlock-Sitka spruce (Tsuga heterophylla [Rat] Sarg.-Picea sitchensis [Bong.] Carr.) over a 3-year period. The stands, near Juneau, Alaska, provided broad ranges of species composition, age, over-story canopy coverage, tree density, and wood volume. Stepwise multiple regression analyses indicated that both overstory canopy coverage and gross wood volume were negatively related to snow depth in the forest, which was expressed as a proportion of the depth in a nearby open area. Multiple regression equations accounted for 53-79...