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Full-Text Articles in Physical Sciences and Mathematics
Predicting Slash Depth For Fire Modeling, United States Department Of Agriculture, Forest Service
Predicting Slash Depth For Fire Modeling, United States Department Of Agriculture, Forest Service
Forestry
Slash or debris created by harvesting and thinning are a major fire management problem because these residues can create unacceptable fire behavior hazards. Treating slash to maintain an acceptable fire hazard is expensive and requires skillful decisionmaking. An inexpensive, simple-to-use, yet objective means of appraising the potential fire behavior of slash is added to aid decisions in managing slash. Knowledge of potential fire behavior can help determine treatment alternatives, the financing of slash treatment activities, and even determine whether the slash should be created. This report describes a method for predicting depth of slash fuels for analytical modeling of fire …
Timelag And Equililbrium Moisture Content Of Ponderosa Pine Needles, United States Department Of Agriculture, Forest Service
Timelag And Equililbrium Moisture Content Of Ponderosa Pine Needles, United States Department Of Agriculture, Forest Service
Forestry
The ponderosa pine (Pinus ponderosa Laws.) timber type covers nearly 9 million acres in the Rocky Mountains. The needle litter cast by these trees produces a highly flammable fuel when conditions are dry. The capability for fires to start and spread depends largely on the moisture content of surface fuels and their response to environmental changes. This report summarizes the results of laboratory tests to determine equilibrium moisture contents and absorption-desorption timelags below fiber saturation of ponderosa pine needles. Conducting the tests at conditions below fiber saturation eliminated consideration of the movement of free water and possible leaching of the …
Low-Cost Harvesting Systems For Intensive Utilization In Small-Stem Lodgepole Pine Stands, United States Department Of Agriculture, Forest Service
Low-Cost Harvesting Systems For Intensive Utilization In Small-Stem Lodgepole Pine Stands, United States Department Of Agriculture, Forest Service
Forestry
The study reported here had two objectives: (1) examine the feasibility of using inexpensive skidding equipment in a small-stem lodgepole pine stand in western Montana, and (2) determine forest residues volumes (unused wood) resulting from different ground skidding methods and utilization standards. Preharvest volumes, volumes removed, residues left on the ground, and unusable material hauled from the site were determined for various utilization standards. The efficiency of skidding with a horse, small tractor, and small rubber-tired skidder were compared.
A Hydrologic Model Of Aspen-Conifer Succession In The Western United States, United States Department Of Agriculture, Forest Service
A Hydrologic Model Of Aspen-Conifer Succession In The Western United States, United States Department Of Agriculture, Forest Service
Forestry
Hydrologic impacts of grass-forb to aspen to conifer succession in the Rocky Mountain area are simulated by means of a fundamental model. Model algorithms representing hydrologic processes are sensitive to vegetational changes within the subalpine vegetation zone. Reductions in water yield are predicted as the vegetation on a small Utah watershed proceeds from a grass-forb type to aspen to conifers. Streamflow changes are largely attributable to an interaction between seasonal consumption for each vegetation type and the influence of vegetation type on snowpack. The model synthesizes present understanding and provides a framework for future watershed research.
Weight And Density Of Crowns Of Rocky Mountain Conifers, United States Department Of Agriculture, Forest Service
Weight And Density Of Crowns Of Rocky Mountain Conifers, United States Department Of Agriculture, Forest Service
Forestry
Relationships between live and dead crown weight and d.b.h. (ranging from 0 to 40 inches), tree height, and crown ratio are presented for 11 conifer species in the Rocky Mountains. D.b.h. was highly correlated with crown weight; however, for most species, addition of height, crown length, and especially crown ratio improved precision. Site index and stand density improved precision of estimates slightly for about one-half of the species. Crown ratio accounted for most of the differences in crown weight between dominant and intermediate crown classes. Relationships between bole weights and d.b.h. and height are presented for trees up to 4 …
Grazing On National Forest System Lands: Cost Of Increasing Capacity In The Northern Region, United States Department Of Agriculture, Forest Service
Grazing On National Forest System Lands: Cost Of Increasing Capacity In The Northern Region, United States Department Of Agriculture, Forest Service
Forestry
Sample grazing allotments on Ranger Districts in the Northern Region (USDA Forest Service) were surveyed by questionaire to determine the feasibility of increasing grazing capacity through additional range improvements. The survey included an inventory of existing grazing capacity and the specific kind and cost of proposed improvements. Costs of improvements were amortized and aggregated for each Forest Service Planning Area. The resulting costs were compared with the increased grazing capacity measured in animal unit months (AUM) to determine the cost per additional unit of capacity.
Linear Measurement: A Method Of Estimating Fascicle Numbers For Larch Casebearer Population Sampling, United States Department Of Agriculture, Forest Service
Linear Measurement: A Method Of Estimating Fascicle Numbers For Larch Casebearer Population Sampling, United States Department Of Agriculture, Forest Service
Forestry
Branch samples collected from 23 plots in northern Idaho and western Montana in 1975 had a combined mean distribution of 3.13 fascicles/inch (1.23 fascicles/cm) of branch length. By subsampling, it is possible to determine cumulative lineal inches of branch necessary to obtain a sampling unit of 100 fascicles for a plot, eliminating the need for counting fascicles on each sample.
Variation In Suckering Capacity Among And Within Lateral Roots Of An Aspen Clone, United States Department Of Agriculture, Forest Service
Variation In Suckering Capacity Among And Within Lateral Roots Of An Aspen Clone, United States Department Of Agriculture, Forest Service
Forestry
Excised roots were used to determine variation in suckering capacity among and within lateral roots of an aspen (Populus tremuloides Michx.) clone. Differences among lateral roots were significant. Within segments of a lateral root sucker production showed a high degree of polarity, increasing from the distal to proximal ends. There was no evidence of a gradient in suckering capacity in a segmented root; i.e., distal segments were not significantly different from proximal ones. This indicated that aging was not a factor regulating suckering within lateral roots. Sucker production was not affected by root length.
Effect Of Growing Season On Sprouting Of Blue Huckleberry, United States Department Of Agriculture, Forest Service
Effect Of Growing Season On Sprouting Of Blue Huckleberry, United States Department Of Agriculture, Forest Service
Forestry
Vaccinium globulare, blue huckleberry, was clipped on five dates from May 19 to August 4. All clipping treatments caused more lateral bud release than occurred in control plants. May, June, and early July treatments caused the same amount of dormant bud release. The amount of shoot growth from released buds corresponded to the amount of growing season remaining after treatment. Irregularity between plants in shoot development after the July 8 treatment and the lack of bud development after the August 4 treatment are attributed to the onset of seasonal bud dormancy.
Genetic Variation In Susceptibility Of Western White Pine To Needle Blight, United States Department Of Agriculture, Forest Service
Genetic Variation In Susceptibility Of Western White Pine To Needle Blight, United States Department Of Agriculture, Forest Service
Forestry
Ten clones of western white pine differed in their susceptibility to white pine needle blight. Two clones were significantly less infected than the average and two clones were significantly more infected than the average. This variability suggests a simple inheritance, maybe just one or two genes.
Converting Forest Residue To Structural Flakeboard - The Fingerling Concept, United States Department Of Agriculture, Forest Service
Converting Forest Residue To Structural Flakeboard - The Fingerling Concept, United States Department Of Agriculture, Forest Service
Forestry
Structural-grade flakeboard experimentally manufactured from forest residues showed mean strengths above 5,500 psi and stiffness (MOE) above 600,000 psi. For economical transport, residues are chipped into "fingerlings" in the woods. Chipping rates are estimated at 50 tons per hour for large residues, and 15 tons per hour for small residues -- using different machines. Depending on the harvesting system selected, estimated costs of fingerlings delivered to the mill range from $25 to $33 per bone-dry ton for systems other than cable yarders.
Terpenes For Indirect Selection Of Growth Potential In Rocky Mountain Douglas-Fir, United States Department Of Agriculture, Forest Service
Terpenes For Indirect Selection Of Growth Potential In Rocky Mountain Douglas-Fir, United States Department Of Agriculture, Forest Service
Forestry
Possibilities of using terpene composition for indirect selection of growth potential were explored for Rocky Mountain Douglas-fir. Volatile leaf oil analyses were made on 170 5-year-old seedlings that represented full-sib hybrid families, wind-pollinated parental lines of inland origin, and wind-pollinated parental lines of coastal origin. Correlation analyses showed that terpenes could not be used efficiently for indirect selection of growth potential in the inland variety. But, terpenes may be useful in selecting parental lines in programs of intervarietal hybridization.
Grindstone Flat And Big Flat Exclosures - A 41-Year Record Of Changes In Clearcut Aspen Communities, United States Department Of Agriculture, Forest Service
Grindstone Flat And Big Flat Exclosures - A 41-Year Record Of Changes In Clearcut Aspen Communities, United States Department Of Agriculture, Forest Service
Forestry
Deer browsing prevented aspen regeneration in both uncut stands and small 1/20-hectare clearcuts, even though nearby large burns regenerated successfully. Size of the clearcut or burned area may be critical in determining success of aspen regeneration; areas less than about 2 hectares in size may adversely concentrate deer use. Shrub production was less under deer use and forb production was less under cattle use than on protected areas. More apsen suckers were produced in uncut stands where cattle grazed than in stands protected from grazing, suggesting a possible relationship between sucker initiation and reduced competition from the herbaceous understory. Removal …
Estimating Merchantable Volume And Stem Residue In Four Timber Species: Ponderosa Pine, Lodgepole Pine, Western Larch, Douglas-Fir, United States Department Of Agriculture, Forest Service
Estimating Merchantable Volume And Stem Residue In Four Timber Species: Ponderosa Pine, Lodgepole Pine, Western Larch, Douglas-Fir, United States Department Of Agriculture, Forest Service
Forestry
Presents tables and equations for estimating total cubic volumes of wood, wood residue, and bark for ponderosa pine, lodgepole pine, western larch, and Douglas-fir. Tables represent second-growth trees 80 years old or less, ranging in size from 1-1/2 inches d.b.h. to the maximum diameter measured for the respective species. The equations and tables provide a means for estimating wood bark residue volumes from tops, bole sections, and smaller submerchantable stems. Tables and equations can also be used to estimate total cubic volume for the size classes, species, and locale sampled.
Regeneration And Early Growth On Strip Clearcuts In Lodgepole Pine/Bitterbrush Habitat Type, United States Department Of Agriculture, Forest Service
Regeneration And Early Growth On Strip Clearcuts In Lodgepole Pine/Bitterbrush Habitat Type, United States Department Of Agriculture, Forest Service
Forestry
Establishment and growth of seedlings 13 years after strip clearcutting was investigated on a lodgepole pine/bitterbrush habitat type in southwestern Montana. Ingress of new seedlings (all from open-coned lodgepole pine) on areas that had been heavily bulldozer scarified was considerably better than on areas without bulldozer scarification. Seed:seedling ratios (established seedlings) ranged from 625:1 to 2,160:1 on scarified sites, and from 1,876:1 to 6,480:1 on unscarified sites. Only 3 years out of 13 resulted in significant numbers of seedlings being established. Advanced regeneration released by logging was growing as rapidly as seedlings established following logging.