bluuebunny/crossref_metadata_2025_split huggingface dataset:
Productivity and Cost of Partial Harvesting Method to Control Mountain Pine Beetle Infestations in British Columbia
Authors: Han Han-Sup , Renzie Chad 
Published: August 2019

Abstract
Small patch cutting (<1 ha in size) in mature lodgepole pine (Pinus contorta Douglas var. latifolia Engelmann) stands has been introduced in central British Columbia, Canada to slow the spread of mountain pine beetle (Dendroctonus ponderosae Hopk.) populations. This practice is locally referred to as “Snip and Skid” logging. This article addresses the operational challenges of implementing the method, with an emphasis on the cost of each phase of logging. Total stump-to-truck expenses incurred with Snip and Skid logging in each patch at an average of C$17.00/m3 (C$14.98 to C$19.71/m3). However, if one includes other cost allowances, such as overhead and profit for the logging contractor, the overall cost is C$22.28/m3. These costs greatly increase when trees are smaller. Other costs for implementing the Snip and Skid method, such as planning and layout, ground probing, and baiting, further increase the total cost of implementation. Walking and low-bedding, that are not required for typical timber-production logging operations, accounted for 57% of the total delay in Snip and Skid logging. In this particular study, five trees were damaged per 100 m along the skid trails created to access the patches, but we found no high stumps or significant impacts on soils. West. J. Appl. For. 20(2):128–133.
Basal Area and Diameter Distribution Prediction Equations for Young Douglas-Fir Plantations with Hardwood Competition: Coast Ranges
Authors: Knowe Steven A. , Radosevich Steven R. , Shula Robert G. 
Published: August 2019

Abstract
A stand-level modeling system for young Douglas-fir plantations applicable to the Coast Ranges of the Pacific Northwest was developed by using data from 84 growth-monitoring plots. Specific components of the system for predicting current size distributions of planted Douglas-fir include: dominant height and survival of planted Douglas-fir; a basal area projection equation for hardwoods; and diameter distribution percentile prediction functions for planted Douglas-fir. Prediction equations for height, crown width, and height to crown base of individual trees describe stand structure of the planted Douglas-fir. The stand- and tree-level equations include both direct and indirect effects of hardwood competition and site preparation, competition release, and precommercial thinning treatments. With the exception of minimum dbh, stand-level equations for planted Douglas-fir explained at least 92% of the observed variation. Basal area dynamics were simulated through plantation age 20 years for site preparation and competition release treatments of different effectiveness by varying hardwood basal area at plantation age 5 years. The simulations indicate that site preparation must reduce hardwood basal area at plantation age 5 years by 75% or more to realize an increase in Douglas-fir basal area and shift of the diameter distribution toward larger trees. This is due to increased growth of hardwoods that survive site preparation. In contrast, competition release treatments exhibited positive Douglas-fir response with 50% efficacy or more. Therefore, ineffective site preparation treatments need to be followed with competition release treatments having at least 50% efficacy to produce similar Douglas-fir basal area and diameter distributions at age 20 as in stands with no site preparation. West. J. Appl. For. 20(2):77–93.
Survival of the Douglas-Fir Beetle in Peeled and Unpeeled Logs and in Stumps
Authors: Shore Terry L. , Riel William G. , Safranyik Les , Castonguay Julie 
Published: August 2019

Abstract
The Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) can cause significant mortality to mature Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco) during epidemics. Treatment methods are required to reduce local beetle populations to less-damaging levels. We conducted a study to compare the effect on beetle survival of peeling bark from infested logs at two times of year. By Aug., all beetles in bark from logs peeled in July were dead compared with 155.2 beetles/m2 bark in unpeeled logs. In bark from logs peeled at the end of Aug. and left over winter, there were 3.4 beetles/m2 of bark surface compared with 62.3/m2 in unpeeled logs. It was concluded that peeling logs reduces beetle populations, particularly if done early in the summer. We also examined beetle survival in stumps over winter and found that a mean of 70.4 beetles/stump, or 125.6/m2 of stump surface survived winter. It is estimated that it would take beetles emerging from 24 stumps to kill a tree. West. J. Appl. For. 20(3):149–153.
Persistence of Pinyon Pine Snags and Logs in Southwestern Colorado
Authors: Kearns H.S. J. , Jacobi W. R. , Johnson D. W. 
Published: August 2019

Abstract
We examined the persistence of pinyon pine (Pinus edulis Engelm.) standing snags and downed logs in southwestern Colorado pinyon-juniper woodlands. The time since death of pinyon pines killed by bark beetles, black stain root disease, or unknown causes in three study areas in southwestern Colorado was determined through monitoring of permanent plots and dendrochronological crossdating methods. The structural condition and form of the trees was recorded and related to the time since death. Pinyon snags may persist for up to 25 years, with persistence of intact snags averaging 8.4 years and broken snags averaging 13.2 years. Sound logs had been dead for a mean of 9.8 years, whereas more fragmented logs had been dead for a mean of 14.4 years. Extremely fragmented trees had been dead for 16.2 years. There was no statistically significant difference in the time since death for snags versus logs in similar condition classes. A simplified rating system to determine the number of years dead for pinyon pine based on form and condition is provided. West. J. Appl. For. 20(4):247–252.
Evaluation of Risk Assessment of Mountain Pine Beetle Infestations
Authors: Dymond Caren C. , Wulder Michael A. , Shore Terry L. , Nelson Trisalyn , Boots Barry , Riel Bill G. 
Published: August 2019

Abstract
Decision support systems to aid the management of mountain pine beetles combine characteristics of the stand and beetle infestation to estimate risk of damage. Beetle infestation information is now available in a format amenable to the operational implementation of risk. In this study, an established risk rating system was evaluated to determine the utility of the values generated. For a study area located in British Columbia, Canada, global positioning systems were used to survey an infestation. The annual data was used to generate risk for a given year and to compare the ratings with survey data from the subsequent year. Under epidemic conditions, 30% to 43% of the stands rated as high risk were subsequently infested. Of the infested stands, 72% to 76% had a high risk rating. In general, the risk rating system accurately predicted risk in stands that were infested, but not all high risk stands were subsequently attacked. This highlights the difficulty of modeling processes that have a stochastic component. For operational contexts, the estimation of risk on an annual basis is sufficiently reliable to aid in the strategic planning of forest managers.
Douglas-Fir Beetle Response to Artificial Creation of Down Wood in the Oregon Coast Range
Authors: Ross Darrell W. , Hostetler Bruce B. , Johansen John 
Published: August 2019

Abstract
Douglas-fir beetle populations were monitored before and after thinning and felling of trees to create down wood in an 88-year-old Douglas-fir plantation in the Oregon Coast Range. Treatments included an unthinned control, thinning to a target of 75 trees/ha, and thinning to a target of 150 trees/ha. Actual mean tree densities on the plots after thinning were 406, 102, and 154, for the control, 75 trees/ha, and 150 trees/ha treatments, respectively. Fifty trees/ha were felled and left on all thinned plots to create down wood for ecological values. Catches in pheromone-baited traps indicated that the local beetle population increased for 1 year in response to felling and leaving large diameter trees in partial shade. Douglas-fir beetle entrance holes and brood were significantly more abundant on the sides of felled trees and wood borers were significantly more abundant on the upper surface suggesting that treatments that provide maximum exposure of felled trees will create the least favorable habitat for Douglas-fir beetles. However, there were no differences in Douglas-fir beetle entrance holes or brood densities in felled trees between the two thinning intensities. Douglas-fir beetle-caused tree mortality was significantly higher on thinned plots with residual felled trees compared with unthinned controls, although infestation levels were low on all plots (<2 trees/ha). The small increase in beetle-caused tree mortality associated with leaving felled trees would be unlikely to interfere with resource management objectives. These results are applicable to mature, managed forests west of the Cascades with relatively low Douglas-fir beetle populations. In different regions and stand types, or under different environmental conditions, beetle populations could increase to higher densities, remain at high densities longer, and cause higher levels of tree mortality. West. J. Appl. For. 21(3):117–122.
Soil Disturbance and Hill-Slope Sediment Transport After Logging of a Severely Burned Site in Northeastern Oregon
Authors: McIver James D. , McNeil R. 
Published: August 2019

Abstract
Despite considerable public debate in recent years on the practice of postfire logging, few studies have directly evaluated its effects. Soil disturbance and hill-slope sediment transport were measured after a postfire logging operation conducted two years after the 1996 Summit Wildfire (Malheur National Forest), in northeastern Oregon. The wildfire was relatively severe, killing an average of 86% of the trees in experimental units, and leaving an average of 34% mineral soil exposed one year after the fire. Soil disturbance was measured both pre- and postharvest in four replicate units in each of three postfire harvest treatments (unlogged control, commercial harvest [most dead merchantable trees removed], fuel reduction harvest [most dead merchantable trees removed plus most dead trees >10-cm diameter]). There was a significant difference among treatments in the percentage of mechanically disturbed soil area, with an average of 19.4% disturbed in fuel reduction units and 15.2% in commercial units. Displacement (13.7% of soil area), apparent compaction (3.1%), and erosion (0.4%) were the most common types of machine-caused soil disturbance. Controls had significantly less change in mean displacement from pre- to posttreatment compared to fuel reduction units, and significantly less change in erosion compared to commercial units. At the experimental unit level, there was a significant correlation between the number of stems removed and the total amount of mechanical soil disturbance observed. Multiple regressions indicated that logging activity, reflected by the number of stems removed, explained more variation in soil disturbance than relative fire severity, reflected by tree mortality, forest floor mass, or the percentage of mineral soil exposed. There was no correspondence between disturbance within units and hill-slope sediment collected in silt fences below units. Visual inspections and sediment collected in silt fences indicated that little sediment exited the experimental units in the short term, and that the existing road system caused most of the observed hill-slope sediment transport. Low observed levels of sediment transport were likely due to a combination of low-to-moderate slopes, low-to-moderate—risk soils, logging over snow or dry ground, hand felling, no new roads, two years recovery of ground cover between the fire and the logging, problems with measuring hill-slope sediment, and the absence of severe weather events in the two years after postfire logging. Given these mitigating factors, hill-slope sediment transport measured in this study should be considered as representative of the low end of the range that would be expected in a postfire tractor logging operation on similar soils and under similar burn severity conditions. West. J. Appl. For. 21(3):123–133.
Using Airborne Lidar to Discern Age Classes of Cottonwood Trees in a Riparian Area
Authors: Farid A. , Goodrich D.C. , Sorooshian S. 
Published: August 2019

Abstract
Airborne lidar (light detecting and ranging) is a useful tool for probing the structure of forest canopies. Such information is not readily available from other remote sensing methods and is essential for modern forest inventories. In this study, small-footprint lidar data were used to estimate biophysical properties of young, mature, and old cottonwood trees in the San Pedro River basin near Benson, Arizona. The lidar data were acquired in June 2004, using Optech’s 1233 ALTM during flyovers conducted at an altitude of 600 m. Canopy height, crown diameter, stem dbh, canopy cover, and mean intensity of return laser pulses from the canopy surface were estimated for the cottonwood trees from the data. Linear regression models were used to develop equations relating lidar-derived tree characteristics with corresponding field acquired data for each age class of cottonwoods. The lidar estimates show a good degree of correlation with ground-based measurements. This study also shows that other parameters of young, mature, and old cottonwood trees such as height and canopy cover, when derived from lidar, are significantly different (P < 0.05). Additionally, mean crown diameters of mature and young trees are not statistically different at the study site (P = 0.31). The results illustrate the potential of airborne lidar data to differentiate different age classes of cottonwood trees for riparian areas quickly and quantitatively. West. J. Appl. For. 21(3):149–158.
Risk Rating Systems for the Douglas-Fir Beetle in the Interior Western United States
Authors: Dodds Kevin J. , Garman Steven L. , Ross Darrell W. 
Published: August 2019

Abstract
Douglas-fir beetle (DFB), Dendroctonus pseudotsugae, risk rating systems were developed for four USDA Forest Service ranger districts in northern Idaho. Risk rating systems were developed using a geographic information system, USDA Forest Service aerial detection survey maps, and nearest neighbor distances. Years where epidemic populations of DFB occurred over the four ranger districts were selected and risk rating systems were developed for each district. Nearest neighbor distances for between-year (t + 1) and between-2-year (t + 2) infestations were measured. Percentiles of nearest neighbor distances were determined and used to estimate distances at which 50, 75, and 90% of infestations occurred. On average, there was a 50% chance of an infestation occurring within 176 m from previous year infestations, 75% chance from within 517 m, and 90% chance from within 1,188 m. The between-2-year risk rating determined that there is a 50% chance of infestation occurring on average within 249 m, 75% within 627 m, and 90% within 1,332 m from infestations that occurred 2 years earlier. West. J. Appl. For. 21(4):173–177.
Predicting Age of Pinyon and Juniper Using Allometric Relationships
Authors: Gascho Landis Andrew M. , Bailey John D. 
Published: August 2019

Abstract
Management of pinyon-juniper ecosystems often is hampered by insufficient tree age structure data. We developed allometric relationships based on visible and easily measured tree characteristics as tools for predicting tree age. In this study, we tested tree height, diameter at root collar, and crown radius using both single- and multiple-regression analyses to determine which attributes best correlated with tree age. Because soil type and site productivity often affect growth rates of pinyon and juniper, three common soil types in northern Arizona were assessed to determine variation in regression equations. Stepwise regression analysis determined that height and diameter at root collar of juniper were the best variables for predicting age. For pinyon, crown radius on basalt-derived soil and diameter at root collar on limestone-derived soil were the variables of best fit; however, we suggest using diameter at root collar across all sites. We developed models from these allometric relationships to aid in the management of the pinyon-juniper ecosystem.
Role of Foliar Moisture Content in the Silvicultural Management of Forest Fuels
Authors: Keyes Christopher R. 
Published: August 2019

Abstract
In combination with measured stand data and assumed environmental conditions, reasonable estimates of foliar moisture content (FMC) are necessary to determine and justify silvicultural targets for canopy fuels management strategies. FMC often is overlooked in fuels planning, with default values substituting for more precise estimates, but its role is operationally significant in the selection of silvicultural targets even at modest surface fire intensities. This article discusses the role of FMC in canopy ignition and summarizes the results of 11 studies on the FMC values and trends for 16 North American conifers. FMC values ranged from 73 to 480% but varied by species, foliage age, and season. The information presented here will be helpful to managers engaging in canopy fuels planning with the use of popular fire behavior and fuels management software (e.g., NEXUS, Fuels Management Analyst, and the Forest Vegetation Simulator's Fire and Fuels Extension). West. J. Appl. For. 21(4):228–231.
Helicopter Logging Productivity on Harvesting Operations in Southeast Alaska, Using Ecologically Based Silvicultural Prescriptions
Authors: Christian Linda E. , Brackley Allen M. 
Published: August 2019

Abstract
This study examines production rates and costs for felling and helicopter yarding on eight units harvested in accordance with ecologically based silvicultural prescriptions in southeast Alaska. The prescriptions included harvesting to create gaps, harvesting to leave trees in clumps, individual tree selection, and combinations of these treatments. In combination, the treatments represented five levels of basal area (BA) retention. The levels of retention had irregular spatial arrangements caused by gaps and clumps that ranged from 0% retention (clearcut) to 75% of BA retained. Turn time (TT), as adjusted to a standardized distance, and turn weight were used as the basis for estimating productivity. There were statistically significant differences in adjusted TT, depending on the treatment. Areas with higher levels of removal tended to have lower adjusted TTs. With the exception of one unit with a short yarding distance, average turn weights increased as levels of retention decreased. Weighted average cost per thousand board feet (mbf) harvested was $322. The cost per mbf for cutting and yarding together ranged from $305 to $353.
Future Prospects for Private Timber Harvest in Eastern Oregon
Authors: Adams Darius M. , Latta Gregory S. 
Published: August 2019

Abstract
Projections of eastern Oregon private sawtimber harvest are developed using a market model linked to a subplot level projection of growth and inventory. The “base” projection envisions nearly a 50% drop in forest industry harvest relative to recent historical levels, while nonindustrial private forestland harvest remains roughly stable. In this scenario the region would lose nearly one-third of its remaining lumber mills and processing capacity within the first 30 years of the projection. Log prices would show little long-term trend. Simulations of two hypothetical public policies show the impacts of changes in public harvest and the private land base. In a case of expanded riparian protection, which reduces the harvestable private land base by about 11%, private harvest falls by roughly 18% between 2003 and 2033. Large harvest reductions are projected on industrial lands because of limited merchantable inventories. A restoration thinning program on public lands that raises public harvest by 40 million board feet per year over 20 years, sustains recent mill numbers for the next 25 years (although total harvest continues to decline). Substitution of public harvest for private harvest would enable continuation of a higher private cut for several years after the thinning program has ended.
Assessing State-Sponsored Tax Incentive Programs for Nonindustrial Private Forest Landowners in the Western United States
Authors: Eckhoff Mike , Mackes Kurt , Reader Tim 
Published: August 2019

Abstract
In 1982 Colorado approved a constitutional amendment that, in part, provided a lowered property tax rate for agricultural lands. Forested lands were not considered agricultural lands until 10 years later when a statute passed providing for such a consideration, under the Forest Ag program. This new program has created a number of unanticipated consequences, such as increasing stress on county government coffers. This stress may cause the program to be terminated and suggests a need for program reevaluation. As an initial step toward reevaluation, property tax programs affecting nonindustrial private forestland in the western United States were examined. Of the 11 contiguous states, 18 distinct programs were cataloged. Although these programs hold a number of rudimentary features in common, most notably lowering a property owner's tax bill in exchange for land-management activities, further analysis should provide in-depth quantitative analysis.
Monitoring Soil Strength Conditions Resulting from Mechanical Harvesting in Volcanic Ash Soils of Central Oregon
Authors: Parker Robert T. 
Published: August 2019

Abstract
The volcanic ash-derived soils in central Oregon have been shown to compact readily and remain compacted for long periods of time, leading to significant reductions in ponderosa pine (Pinus ponderosa, Laws) tree growth. Concerns over the potential for long-term reduction in forest site productivity on private forestlands in the region led to the development of a soil monitoring process for precisely quantifying changes to the soil environment caused by mechanical harvesting in second-growth ponderosa pine stands. For this study, soil strength was used as an indicator for soil compaction. A recording penetrometer was used to measure soil strength to a depth of 2 ft at intervals of 5 ft along transects established across harvest units. At each sampling point, the number of machine passes was estimated as no disturbance, 1–2 machine passes, 3–5 machine passes, or main skid trails. The penetrometer data were then summarized for each of the four categories. The results show a rapid rise in soil strength with increasing machine activity and 40–70% of the harvest units compacted in a single harvest cycle. The process proved to be an unbiased and practical system for quantifying the extent and intensity of soil strength conditions resulting from mechanical harvesting.