Treesearch

The timber resource inventory model (TRIM) has been adapted to run on person al computers. The personal computer version of TRIM (PC-TRIM) is more widely used than its mainframe parent. Errors that existed in previous versions of TRIM have been corrected. Information is presented to help users with program input and output management in the DOS environment, to understand the differences between PC-TRIM and mainframe TRIM, and to avoid common mistakes that can lead to program-generated errors.

Two consecutive timberland inventories collected from permanent plots in the natural pine type in North Carolina were used to evaluate the timber resource inventory model (TRIM). This study compares model predictions with field measurements and examines the effect of inventory data aggregation on the accuracy of projections. Projections were repeated for two geographic areas with two data aggregation schemes. The sensitivity of the model to harvest was tested with historical and adjusted values. For each simulation, the TRIM growth projection mechanism was tested with two types of yield...

Growth, winter injury, and mortality were evaluated for 12-year-old trees of 11 subarctic lodgepole pine provenances and a jack pine provenance at Fairbanks, Alaska. Provenances from northeast British Columbia grew more than 0.003 cubic meter of wood per tree annually from 9 to 12 years after outplanting. The species sustained snow damage and winter injury, however, and could be at high risk in long-term management on severe sites in Alaska. Provenance x site interactions were not significant for mortality, tree height, and volume after the same stock grew for 10 seasons at Fairbanks and...

A sample of 130 incense-cedar (Libocedrus decurrens Torr.) trees was selected from the Eldorado National Forest in California. The trees were felled and bucked into 403 woods-length logs and processed through a sawmill cutting Shop and Common grades of lumber. Recovery estimates are shown for woods-length logs based on Scribner board-foot scale and cubic-foot scale. Analysis showed that board-foot recovery ranged from 169 percent for 6-inch logs to 103 percent for 34-inch logs. Cubic-volume recovery of rough green lumber increased from 50 percent to 62 percent for the same range of...

The forest products industry is one of Mississippi's basic industries, and in 1980, it accounted for about one of six basic jobs. Mississippi was one of the majority of Southern States in which the forest products industry improved its competitive position during the 1970's. Between 1972 and 1977, growth in productivity of Mississippi's forest products industry was exceeded by only three other States in the South.

Chemical output of nitrate, calcium, magnesium, sodium, potassium, and organic nitrogen were determined on a grams-per-hectare-per-day basis for five treatment watersheds and a control watershed. Water samples were collected from April to October during 3 pretreatment and 3 posttreatment years (1978 to 1983). Except for increased calcium and sodium in several streams, regression equations comparing treatment with control showed no significant difference for pretreatment and posttreatment output. Output generally declined in the posttreatment years. Cyclic changes in output from these and...

Two computer programs to help timber-harvest planners evaluate terrain for logging operations are presented. The first program, VISUAL, produces three-dimensional perspectives of a digital terrain model. The second, SLOPE, produces map-scaled overlays delineating areas of equal slope, aspect, or elevation. Both programs help planners familiarize themselves with new terrain and obtain a general feel for the land. Included are descriptions of operating procedures, descriptions of major algorithms, suggested applications, and limitations. Guides for the programs are available from the authors.

Studies of the mating habits of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) have shown that wind-pollination families contain a small proportion of very slow-growing natural inbreds.The effect of these very small trees on means, variances, and variance ratios was evaluated for height and diameter in a 16-year-old plantation by systematically deleting from analyses the shortest individuals in wind-pollination (W) and diallel (D) progenies of six parent trees. The progenies were growing together in a common field test. The D population served as a control (no inbreds).The low-vigor...

Large, fallen trees in various stages of decay contribute much-needed diversity of ecological processes to terrestrial, aquatic, estuarine, coastal beach, and open ocean habitats in the Pacific Northwest. intensive utilization and management can deprive these habitats of large, fallen trees. This publication presents sound information for managers making resource management decisions on the impact of this loss on habitat diversity and on ecological processes that have an impact on long-term ecosystem productivity.

Pricing represents an important step in the allocation of scarce resources. Markets, which set the price policy, are not restricted by a simple buyer-seller relation. The Federal grazing-fee policy is at the forefront of controversy surrounding the pricing of all uses of public lands. The pricing process of grazing fees has been cyclical. With few exceptions, the cycle, which takes 8 to 14 years, includes (1) initial study, (2) fee implementation or proposal, (3) lawsuit, (4) congressional hearings, and (5) fee compromise. The tradeoff between strict market pricing and political market...