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Full-Text Articles in Physical Sciences and Mathematics
Woodland Tree Volume Estimation: A Visual Segmentation Technique, United States Department Of Agriculture, Forest Service
Woodland Tree Volume Estimation: A Visual Segmentation Technique, United States Department Of Agriculture, Forest Service
Forestry
Visual segmentation, a technique for estimating cubic foot volume of woodland tree species, was compared with actual volume measurement. Comparison was made during a forest inventory of pinyon-juniper woodlands in Nevada and Utah. The visual technique's accuracy, its usefulness in developing volume equations, and applicability to volume inventory were studied. This study indicated visual segmentation is not reliable for estimating volume for a single tree. However, a sample of visually estimated volumes proved adequate for developing volume equations. In an application, a bias of 0 to -9 percent of the mean cubic foot volume per acre resulted from summary of …
Response Of Grass Species To Tree Harvesting In Singleleaf Pinyon-Utah Juniper Stands, United States Department Of Agriculture, Forest Service
Response Of Grass Species To Tree Harvesting In Singleleaf Pinyon-Utah Juniper Stands, United States Department Of Agriculture, Forest Service
Forestry
Cover, yield, and nutrient concentrations of grasses were sampled on tree-harvested and nonharvested plots on north, west, and south aspects of a singleleaf pinyon (Pinus monophylla)-Utah juniper (Juniperus osteosperma) stand. Grass cover increased rapidly the first 2 years following tree harvest, but the rate of increase declined over the next 2 years. Grass yield varied among aspects and soil microsites on tree-harvested plots but not on the nonharvested plots where tree competition masked aspect and microsite effects. All grass species had greater yield and greater percentage nitrogen and phosphorus on harvested than on nonharvested plots. Low digestibility of some species …
Costs Of Managing Nontimber Resources When Harvesting Timber In The Northern Rockies, United States Department Of Agriculture, Forest Service
Costs Of Managing Nontimber Resources When Harvesting Timber In The Northern Rockies, United States Department Of Agriculture, Forest Service
Forestry
When National Forest Timber is sold, land managers are required to protect other forest resources such as wildlife, soil and water, and scenic qualities. Measures taken to protect nontimber resources can raise administrative costs, lower the quantity of timber sold, and can reduce stumpage receipts. The costs of sale administration and the reduction in timber harvested can be readily derived from accounting and planning records. But little information is available on how much nontimber resources cost in terms of stumpage receipts. To provide such information, some 187 timber sales were studied on seven National Forests in the Northern Region between …
Applying Height Growth And Site Index Curves For Inland Douglas-Fir, United States Department Of Agriculture, Forest Service
Applying Height Growth And Site Index Curves For Inland Douglas-Fir, United States Department Of Agriculture, Forest Service
Forestry
Methods for estimating both site index and dominant height growth for inland Douglas-fir in the Northern Rocky Mountains are presented and discussed. The methods should be applicable over a wide range of stand conditions because no restrictions were placed on species composition, stand density, spacing, or age structure in the original stem analysis sample. Increased accuracy can be obtained if habitat type is considered, because the shape of the site index curves varied with respect to three major habitat series groupings. Results are summarized in the form of equations, tables, and graphs. Precision curves are used to illustrate the relationship …
Predicting Duff And Woody Fuel Consumed By Prescribed Fire In The Northern Rocky Mountains, United States Department Of Agriculture, Forest Service
Predicting Duff And Woody Fuel Consumed By Prescribed Fire In The Northern Rocky Mountains, United States Department Of Agriculture, Forest Service
Forestry
This paper presents numerical relationships of known precision for predicting duff consumption. They were established by assembling and analyzing data from three previous prescribed fire investigations and then testing them against other published data. Fuel loadings by diameter classes that differed among the studies were converted to a common set of diameter classes. The purpose of assimilating data from several studies was to develop predictive models that could be easily used by practitioners and that would apply over a wide range of conditions.
Measurement Of Field Resistance, Rust Hazard, And Deployment Of Blister Rust-Resistant Western White Pine, United States Department Of Agriculture, Forest Service
Measurement Of Field Resistance, Rust Hazard, And Deployment Of Blister Rust-Resistant Western White Pine, United States Department Of Agriculture, Forest Service
Forestry
Three white pine plantations, composed of materials of several levels of resistance from early generations of the blister rust resistance breeding program, were compared on the basis of annual infection and mortality rates. The sites varied in blister rust hazard; resistant materials were consistent in their performance, and the infection data behaved as one would expect if the genetic and environmental assumptions of the simple interest disease progress model were violated. Presumably, the resistant populations violate the genetic assumptions to the extent of their resistance, and any assessment of resistance performance must take into account both environmental as well as …
Release Of A Thinned Budworm-Infested Douglas-Fir/Ponderosa Pine Stand, United States Department Of Agriculture, Forest Service
Release Of A Thinned Budworm-Infested Douglas-Fir/Ponderosa Pine Stand, United States Department Of Agriculture, Forest Service
Forestry
Current and past defoliation by western spruce budworm (Choristoneura occidentalis Freeman) in an 80-year-old predominantly Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) stand thinned to 14 by 14 feet was significantly lower than in a nearby untreated stand of similar age, species, and site conditions. Analysis of periodic radial growth ratios indicated that prior to thinning, Douglas-fir had been heavily defoliated by budworm and growth was seriously depressed. Following thinning, the host leave trees developed dense crowns and 10-year radial growth increased an average of 57 percent: meanwhile, radial growth of nonhost ponderosa pine (Pinus ponderosa Dougl.) increased 38 percent. …
Attaining Visual Quality Objectives In Timber Harvest Areas - Landscape Architects' Evaluation, United States Department Of Agriculture, Forest Service
Attaining Visual Quality Objectives In Timber Harvest Areas - Landscape Architects' Evaluation, United States Department Of Agriculture, Forest Service
Forestry
When management activities such as timber harvest are undertaken on National Forest lands, landscape architects establish plans and guidelines so the project will meet a desired level of visual quality. This visual quality objective (VQO) for a given project is based on forest conditions, topography, and the type of viewing that is anticipated (viewing distance, number and type of visitors, etc.). Although landscape architects provide criteria and guidelines to achieve these visual objectives, there is no direct feedback mechanism with which to monitor the public's reaction or ascertain the extent to which visual objectives are met.
Soil Water And Temperature In Harvested And Nonharvested Pinyon-Juniper Stands, United States Department Of Agriculture, Forest Service
Soil Water And Temperature In Harvested And Nonharvested Pinyon-Juniper Stands, United States Department Of Agriculture, Forest Service
Forestry
Tree harvesting increased soil water content, but the effect diminished over 4 years. The mean increase in soil water content was 2 to 4 percent the first year following harvest and 0 to 3 percent after 4 years. Although tree harvesting released soil water previously used by tree species, other biotic and abiotic demands increased. We speculate postharvest increases in wind and solar energy at the ground surface and increased understory transpiration in part explain the decline in soil water content differences between harvested and nonharvested plots over time.
Effects Of Bifenox, Dcpa, And Napropamide On Ectomycorrhizal Development Of Conifer Seedlings In Central And Northern Rocky Mountain Nurseries, United States Department Of Agriculture, Forest Service
Effects Of Bifenox, Dcpa, And Napropamide On Ectomycorrhizal Development Of Conifer Seedlings In Central And Northern Rocky Mountain Nurseries, United States Department Of Agriculture, Forest Service
Forestry
Postseeding and postgermination treatments with three weed control herbicides (Bifenox, DCPA, Napropamide) at two rates of application caused little reduction of ectomycorrhizal development on 1- and 2-year-old conifer seedlings in Central or Northern Rocky Mountain nurseries. In many cases, herbicide treatment increased ectomycorrhizal development, particularly with DCPA. In general, herbicide treatment effects on ectomycorrhizal development were species and nursery specific.
Pinyon-Juniper Volume Equations For The Central Rocky Mountain States, United States Department Of Agriculture, Forest Service
Pinyon-Juniper Volume Equations For The Central Rocky Mountain States, United States Department Of Agriculture, Forest Service
Forestry
Gross cubic foot volume equations are now available for pinyon-juniper and several other woodland species in Nevada, Idaho, Utah, Colorado, Wyoming, and South Dakota. The volume equations are based on data collected as a subsample of woodland inventories conducted by Federal and State land management agencies. In these inventories, volumes of 4,705 trees were estimated by a visual sampling method.
An Application Of Discrete Optimization For Developing Economically Efficient Multiple-Use Projects, United States Department Of Agriculture, Forest Service
An Application Of Discrete Optimization For Developing Economically Efficient Multiple-Use Projects, United States Department Of Agriculture, Forest Service
Forestry
A discrete version of the continuous joint production model in economic theory is presented for use in designing multiple-use projects and identifying efficient management prescriptions for forest planning. Data requirements are less demanding than the continuous theoretical model, yet some of the more important features are maintained. Models can be formulated graphically or as mixed-integer programming problems that are easily solved via computerized routines.