bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Approach to Managing Fuelwood Harvest Using Bark Beetle Pheromones
Authors: Vandygriff J.C. , Rasmussen L.A. , Rineholt J.F.
Published: August 2019

A multiyear study of synthesized mountain pine beetle (Dendroctonus ponderosae) pheromones was conducted within lodgepole pine (Pinus contorta) stands on the Sawtooth National Recreation Area to demonstrate their potential use as a management tool for fuelwood harvest. The use of mountain pine beetle aggregant baits was shown to be highly effective in relocating beetles into designated bait blocks, dramatically increasing the amount of beetle-related tree mortality. Treatment of blocks with antiaggregant verbenone capsules appeared to provide little or no additional protection when compared with associated control blocks. Given defined objectives and appropriate stand and insect population conditions, pheromone baits can be used to improve management of fuelwood harvest and potentially improve stand health. West. J. Appl. For. 15(4):183–188.
Estimating Large-Root Biomass from Breast-Height Diameters for Ponderosa Pine in Northern New Mexico
Authors: Omdal Daniel W. , Jacobi William R. , Shaw Charles G.
Published: August 2019

An important component of forest ecosystems in the southern Rocky Mountains is the belowground biomass associated with mature stands of ponderosa pine (Pinus ponderosa). Information on root biomass is fundamental to understanding the dynamics of ecological systems and designing studies of those systems. Ponderosa pine trees from a stand in northern New Mexico were cut and their root systems excavated. Biomass of all roots > 0.6 cm in diameter and the belowground portion of the stump was determined on a dry-weight basis. A regression model was constructed using data on breast-height diameter and belowground stump and coarse-root biomass from 42 trees in the stand. Diameter at breast height ranged from 18.3 to 67.6 cm, and belowground biomass ranged from 3 to 576 kg. West. J. Appl. For. 16(1):18–21.
The Role of Postfire Coarse Woody Debris in Aspen Regeneration
Authors: Ripple W.J. , Larsen E.J.
Published: August 2019

The paucity of aspen (Populus tremuloides) regeneration in the western United States and on Yellowstone National Park's (YNP) northern range has been of concern to managers and scientists for much of the 20th century, with the effects of ungulate browsing, climate fluctuation, and fire suppression being vigorously debated. We analyzed the interaction of fire and elk (Cervus elaphus) browsing in YNP, specifically the role of coarse woody debris as a mechanism for assisting aspen regeneration. We hypothesized that fallen conifers killed in the 1988 YNP fires would provide refugia, allowing a limited amount of aspen regeneration under the current levels of heavy ungulate browsing. We located burned sites on YNP's northern range and searched for “jackstraw piles,” where fallen conifers provided aspen refugia from ungulate browsing. We discovered that aspen suckers protected by fallen conifer barriers were on average over two times the height of adjacent unprotected suckers. Paired t-tests showed a highly significant difference between the aspen heights within the protected jackstraw sites (>0.8 m high) and those in the open that were subjected to elk browsing (P = 0.000). These results illustrate the role that fallen conifers can play in aspen regeneration as well as the interaction of the ecological processes of wildfire, ungulate browsing, and seral stage development. West. J. Appl. For. 16(2):61–64.
Fall Fertilization with N and K: Effects on Douglas-Fir Seedling Quality and Performance
Authors: Birchler Todd M. , Rose Robin , Haase Diane L.
Published: August 2019

Coastal Douglas-fir (Pseudotsuga menziesii) 1+1 seedlings were fertilized with two fertilizers [NH4NO3+K2SO4 and (NH4)2SO4+KCl] at four rates (0, 80, 160, 320 kg N and K/ha) split over three application dates (September 19, October 13, November 1, 1996). Fertilizer type did not affect total Kjeldahl nitrogen (TKN) levels on any of the sampling dates. By January 10, TKN concentrations had increased 16, 30, and 34%, and chloride concentrations had increased 57, 77, and 112% relative to the unfertilized seedlings for the 80, 160, and 320 kg N+K/ha treatments, respectively. Nitrate levels increased briefly after the first application of NH4NO3+K2SO4. Potassium levels remained relatively unchanged. Levels of most other nutrients, as well as foliar dry weight, increased between September 16 and January 10, but these increases were generally unrelated to the fertilizer treatments. Root growth potential and cold hardiness did not differ among treatments. Seedlings that received 160 or 320 kg N/ha broke bud an average of 3 days earlier than did the unfertilized seedlings. Chlorophyll fluorescence (Fv/Fm) of fertilized seedlings was consistently higher than that of unfertilized seedlings on November 13 and December 30. These treatment differences were not reflected in seedling outplanting performance after one growing season. West. J. Appl. For. 16(2):71–79.
Dwarf Mistletoe-Induced Mortality in Northwest Ponderosa Pine Growing Stock
Authors: Roth Lewis F.
Published: August 2019

After the careful removal of a ponderosa pine overstory infested with western dwarf mistletoe, the development of small poles and saplings in the infested residual thickets was followed in 48 plots over a period of 27 yr. The high incidence of mortality caused by mistletoe, which has not been previously reported to occur in significant amounts in Northwest ponderosa pine growing stock, was surprising and is important to management of the species. Death of 73, 38, 24 and 17% of the trees, respectively, occurred in the unthinned plots and those thinned to 500, 250, and 125 trees/ac. West. J. Appl. For. 16(3):136–141.
Damage to Residual Trees by Four Mechanized Harvest Systems Operating in Small-Diameter, Mixed-Conifer Forests on Steep Slopes in Northeastern Washington: A Case Study
Authors: Camp Ann
Published: August 2019

Dense stands of small-diameter timber present unique challenges for land managers. In the inland West, trees in high-density stands often grow slowly and may be at risk to insects, diseases, and catastrophic fires. In 1996, the U.S. Congress recognized a need to address forest health issues and stimulate local resource-based economies in northeastern Washington. Funds were provided for “implementation and evaluation of controlled silvicultural treatment in designated, fire-generated, overstocked, small-diameter stands” (U.S. Congress House Report 104-625).

As part of this Congressionally mandated research effort, four harvest units, each thinned to a 20 ft spacing using different harvesting technologies, were surveyed for damage prior to and following commercial thinning. Comparisons were made among the systems tested to assess damage to the residual stand. Overall incidence of wounds, incidence of wounds in different size and severity classes, and wound locations were compared. Each system performed better when judged by some criteria than by others. In general, cut-to-length processing caused less damage to the residual stand than whole-tree harvest; skyline yarding was less damaging than forwarder yarding. Some of the damage may have been a function of the silvicultural prescription and season of harvest. Appropriate silvicultural prescriptions and harvesting technologies can reduce wounding to acceptable levels. West. J. Appl. For. 17(1):14–22.
Growth of Young Douglas-Fir Plantations Across a Gradient in Swiss Needle Cast Severity
Authors: Maguire Douglas A. , Kanaskie Alan , Voelker William , Johnson Randy , Johnson Greg
Published: August 2019

During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted in 1997 to quantify retrospectively the relationship between growth losses and visual symptoms in 10- to 30-yr-old Douglas-fir plantations in coastal northwestern Oregon, a population totaling 75,700 ha. A random sample of 70 Douglas-fir plantations was selected from the population and evaluated for Swiss needle cast severity. One 0.02 ha plot was destructively sampled in each plantation to reconstruct past height and basal area growth trends and to characterize foliage loss and distribution. The SNC “effect” was assessed by comparing growth of plantations with varying degrees of Swiss needle cast to growth of those that retained maximal amounts of foliage, after correcting for initial stand density, Douglas-fir growing stock, age, and site index. Of numerous possible SNC indices, mean needle retention (yr) explained the largest amount of variation in both basal area and top height growth. Prior to 1990, top height growth was similar across all plantations after correcting for site quality and plantation age; but, by 1992, top height growth losses appeared and were proportional to apparent foliage losses. In 1996, top height growth was reduced by up to 25% relative to plantations with little or no SNC. Basal area growth reductions began to appear around 1990, and in 1996 basal area growth of the most heavily damaged plantations was 35% less than the growth that would be expected in absence of SNC damage. The inferred volume growth loss for 1996 averaged 23% for the 75,700 ha target population, but this loss averaged as high as 52% for the most severely impacted plantations. West. J. Appl. For. 17(2):86ߝ95.
Site Preparation Effects on 20 Year Survival and Growth of Douglas-Fir (Pseudotsuga menziesii) and on Selected Soil Properties
Authors: Harrington C.A. , Piatek K.B. , DeBell D.S.
Published: August 2019

Long-term effects of site preparation on tree performance and soil properties are not well known. Five site preparation treatments were evaluated to determine how they affected survival and growth of Douglas-fir 3, 10, and 20 yr after planting, and soil bulk density, C, N, P, and organic matter concentrations at 0 to 20 cm soil depth 21 yr after planting. The site preparation treatments were imposed following logging of three harvest units of old-growth forest on a volcanic soil in southwestern Washington; the units were logged to leave 17, 38, and 53 ton/ha of woody residue. The site preparation treatments were hand-pile-and-burn, machine-pile-and-burn, scarification, broadcast burn, and control. Mean survival ranged from 86% at age 3 to 70% at age 20, and average tree heights at 3, 10, and 20 yr were 0.6, 4.1, and 11.7 m. The scarification treatment had the best growth; at age 20, its average tree was 21% taller, 26% larger in diameter, and 82% greater in volume than the control. The hand-pile-and-burn treatment did not differ from the control in tree growth; the machine-pile-and-burn and broadcast burn treatments were intermediate in their growth response. Average soil bulk density was 0.74 g/cm3, organic matter concentration was 118 g/kg, and C, N, and P concentrations were 49, 1.6, and 0.7 g/kg with no significant treatment effects. Site preparation may have benefited growth of the trees on these units by decreasing competition from invading and regrowing vegetation, increasing nutrient availability, or increasing soil temperature. West. J. Appl. For. 18(1):44–51.
Stocking Control Procedures for Multiaged Ponderosa Pine Stands in the Inland Northwest
Authors: O'Hara Kevin L. , Valappil Narayanan I. , Nagel Linda M.
Published: August 2019

Multi-aged management of forest stands in western North America is a viable option in many areas where traditional even-aged management is undesirable. Procedures for guiding stocking control for multi-aged ponderosa pine (Pinus ponderosa) stands were developed using the PP-MASAM model (Ponderosa Pine–Multi-aged Stocking Assessment Model). These procedures allow the user to divide stands into components such as age classes or canopy strata that are the basic unit for growing space allocation. Growing space is represented by leaf area index. Stocking regimes are assessed over a single cutting cycle through projections of volume increment, stand density, and tree vigor. The approach is flexible for guiding stocking in ponderosa pine stands for diverse structural objectives including retention of ancient trees, development of presettlement structures, stands with two to four age classes, or stands with short or long cutting cycles. Example stocking regimes and internet links are provided to access the model. West. J. Appl. For. 18(1):5–14.
Applying Logistic Regression to Determine Regeneration Risk to Stand Replacement Fire on the Kootenai National Forest, Montana
Authors: Hall Wendy L. , Zuuring Hans R. , Hardy Colin C. , Wakimoto Ronald H.
Published: August 2019

In 1994, fire managers on the Kootenai National Forest observed that wildfires had produced regeneration loss in some stands but not in others. They questioned what site characteristics and management activities were related to this loss. To address this question and to establish guidelines to “triage” stands and prioritize management efforts, we applied a logistic regression model to data from a set of regeneration stands (n = 135) located on the Libby, Rexford, and Three Rivers Ranger Districts. The occurrence of a stand replacement fire was modeled as a logistic function of Aspect, Habitat Type, Fuel Treatment, and logarithm of trees/ac (log_TPA), with R2 = 0.523 (P < 0.05). Odds ratios derived from logistic regression identified the descriptor characterizing regeneration stands “most at risk” for a stand replacement fire and provided a means to triage stands. Southwest and south aspects had the highest odds ratios (22 and 9) and largest coefficients of variation (3.07 and 2.22) for the Aspect variable. Western hemlock/queencup beadlilly (Tsuga heterophylla/Clintonia uniflora) and western red-cedar/queencup beadlilly (Thuja plicata/Clintonia uniflora), with respective odds ratios of 30 and 17, had the largest coefficients of variation (3.40 and 2.83) for the Habitat Type variable. For the Fuel Treatment variable, the “no fuel treatment” category had the highest odds ratio (11) and coefficient of variation (2.38). Stands with stand replacement fire had a mean log_TPA significantly lower than that of non-stand replacement fire stands (P < 0.001). Competition from understory vegetation may explain these findings. Bracken fern (Pteridium aquilinum), commonly found in cedar-hemlock stands and on southerly aspects, may outcompete tree seedlings and provide a fine-fuel hazard. West. J. Appl. For. 18(3):155–162.
Environmental Effects and Economics of Mechanized Logging for Fuel Reduction in Northeastern Oregon Mixed-Conifer Stands
Authors: McIver J.D. , Adams P.W. , Doyal J.A. , Drews E.S. , Hartsough B.R. , Kellogg L.D. , Niwa C.G. , Ottmar R. , Peck R. , Taratoot M. , Torgersen T. , Youngblood A.
Published: August 2019

Fuel reduction by mechanical thinning and removal was studied in mixed-conifer stands in northeastern Oregon between 1995 and 1997. A single-grip harvester was coupled with either a forwarder or a skyline yarding system, and operational economics, fuel reduction, stand damage, soil disturbance, effects on soil biota and down-woody material were measured in three replicates of paired stands. After logging with the harvester, the two log-extraction systems achieved nearly equivalent fuel reduction with 45.7 and 46.8% mass reduction by the forwarder and skyline system, respectively. Fine-woody fuel increased slightly in all units, but mass of heavy fuels decreased. Most mass reduction in the forest floor occurred in the duff layer with 56 and 49% reduction in forwarder and skyline units, respectively. Reduction in stem density and basal area were similar for the two extraction systems; in forwarder units stem density was reduced by 61.6% and basal area by 55.4%, while in skyline units stem density was reduced by 66.5% and basal area by 51.1%. Of seedlings and trees examined, 32% had noticeable damage after harvest. Damage included bole wounding (38.9% of damaged stems), bark scraping (35.0%), wrenched stems (28.9%), broken branches (26.5%), broken terminal leaders (15.4%), and crushed foliage (4.1%). More damage occurred to residual large trees than to seedlings. Both log-extraction systems met the silvicultural prescription of reducing fuel and protecting residual large-diameter western larch, Engelmann spruce, Douglas-fir, and lodgepole pine. While fuel, stem, and basal area reduction lowered fire risk from a model 10 to a model 8 in all stands, large-woody material for wildlife also changed. Mean log length was lower in harvested units relative to unharvested controls, but this did not decrease occupation of logs by ants or the activities of woodpeckers feeding on them. Of 37 logged hectares, 1.4% (0.5 ha) of the soil area was compacted, mostly in forwarder units, within landings, and within trails close to landings. The percent area with displaced soil varied from 5 to 43% among units and was located within trails or in intertrail areas between the trails. Light displacement of soil resulted in a short-term increase in the abundance of soil microarthropods. The effects of compaction on litter microarthropods was more persistent, with lower numbers in compacted litter a year after harvest. While revenue was similar for forwarder and skyline units ($68 vs. $70/metric ton, respectively), total operational costs were $81/metric ton in the skyline units, compared to $46/metric ton in the forwarder units. These results are discussed in the context of options available to managers for balancing fuel reduction needs with both environmental and economic constraints. West. J. Appl. For. 18(4):238–249.
Hybrid Poplar in the Willamette Valley
Authors: Hibbs David , Withrow-Robinson Brad , Brown Dina , Fletcher Rick
Published: August 2019

Hybrid poplar (Populus spp.) is the newest tree crop in the Pacific Northwest. We have been studying its management and growth in the Willamette Valley of western Oregon on poorly drained soils with no irrigation. We found very good growth rates—up to 4000 ft3/ac in 6 yr—on soils considered poor for many kinds of agriculture. For plantation establishment, we found that after 1 yr, simple no-till methods were as effective as the often-used ripping and tilling approaches. An herbicide screening study resulted in good poplar growth with some herbicides and reduced growth with two others commonly used in site preparation. Our investigation of root development indicates that the good growth on these poorly drained, nonirrigated soils is associated with poplar's deep and extensive root development. West. J. Appl. For. 18(4):281–285.
An Application of LiDAR in a Double-Sample Forest Inventory
Authors: Parker Robert C. , Evans David L.
Published: August 2019

Multireturn LiDAR data (2-m posting) were used in a double-sample forest inventory in central Idaho. Twenty-four 15-plot (0.2 ac) strips were established with a real-time Differential Global Positioning System. Tree dbh and height were measured on every 5th plot. Volume and basal area were computed for eight encountered species. LiDAR trees were selected with a focal max filter and height computed as the z-difference between interpolated canopy and DEM surfaces. LiDAR-derived trees/ac, height, and dbh had mean differences of −4.4 trees, −10.7 ft, and −1.01 in. from ground values. Four dbh-height models were fitted. Predicted dbh was used to compute LiDAR estimates of basal area and volume on 360 Phase 1 plots. Phase 2 LiDAR estimates on 60 plots were computed by randomly assigning heights to species classes using a 500-iteration Monte Carlo simulation. Regression estimators for Phase 2 ground and LiDAR ft3 and ft2 were computed by single and composite species. Phase 1 estimates were partitioned to obtain species volumes. The regression estimate of composite volume was partitioned by percent species distribution of trees, basal area, and volume. There was no statistical difference between individual and partitioned composite species estimates. Sampling error was ±11.5% on a mean volume estimate of 1,246 ft3/ac with standard error ±72.98 ft3/ac. West. J. Appl. For. 19(2):95–101.
Minimizing the Cost of Stand Level Management for Older Forest Structure in Western Oregon
Authors: Latta Greg , Montgomery Claire A.
Published: August 2019

The area of old-growth forest in the Pacific Northwest is estimated to have declined dramatically from historical levels. Active management involving repeated thinning that leaves substantially fewer trees than a typical commercial thin has been proposed as a way to speed the development of older forest structure in the region. This study uses a random search heuristic and an individual tree simulation model, ORGANON, to search for cost-effective old forest management regimes for a wide range of stand types that occur on private land in western Oregon. The regimes were designed to meet older forest structural criteria, as defined by the Oregon Department of Forestry, for 30 years prior to clearcut harvest. The opportunity cost of managing for older forest structure was estimated for each stand type as the value of forgone timber production under maximum net present value management. Opportunity cost was found to be positively correlated with site quality, stand age, and stocking. Cost-effective management for older forest structure is important because the lower the cost of conservation, the more likely it will occur. West. J. Appl. For. 19(4):221–231.
Largest-Crown-Width Prediction Models for 53 Species in the Western United States
Authors: Bechtold William A.
Published: August 2019

The mean crown diameters of stand-grown trees 5.0-in. dbh and larger were modeled as a function of stem diameter, live-crown ratio, stand-level basal area, latitude, longitude, elevation, and Hopkins bioclimatic index for 53 tree species in the western United States. Stem diameter was statistically significant in all models, and a quadratic term for stem diameter was required for some species. Crown ratio and/or Hopkins index also improved the models for most species. A term for stand-level basal area was not generally needed but did yield some minor improvement for a few species. Coefficients of variation from the regression solutions ranged from 17 to 33%, and model R2 ranged from 0.15 to 0.85. Simpler models, based solely on stem diameter, are also presented. West. J. Appl. For. 19(4):245–251.
Equations for Predicting Uncompacted Crown Ratio Based on Compacted Crown Ratio and Tree Attributes
Authors: Azuma David , Monleon Vicente J. , Gedney Donald
Published: August 2019

Equations to predict uncompacted crown ratio as a function of compacted crown ratio, tree diameter, and tree height are developed for the main tree species in Oregon, Washington, and California using data from the Forest Health Monitoring Program, USDA Forest Service. The uncompacted crown ratio was modeled with a logistic function and fitted using weighted, nonlinear regression. The models were evaluated using cross-validation. Mean squared error of predicted uncompacted crown ratio was between 0.1 and 0.15, overall bias was negligible, and correlation between the predicted and observed uncompacted crown ratio was high for most species. The sensitivity of crown fire risk to crown ratio estimation method was evaluated using the Fire and Fuels Extension of the Forest Vegetation Simulator. Torching index, an estimate of the wind speed needed for a crown fire to develop, was significantly greater when compacted crown ratio was used instead of uncompacted crown ratio. The close agreement in torching indices simulated using predicted and observed uncompacted crown ratio provides further evidence of the utility of the models developed in this study. West. J. Appl. For. 19(4):260–267.
A Sustained-Yield Scheme for Old-Growth Douglas-fir
Authors: Newton Michael , Cole Elizebeth C.
Published: August 2019

From analysis of two Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands, 120 and 140 years old, we conclude that managed stands can meet established criteria for old-growth Douglas-fir and simultaneously produce near-maximum yields of good-quality timber. With the management approach outlined here, average annual volume growth may approach that of shorter-rotation culture, but in logs of a size and quality normally found only in older stands, and with minimal impact on high-risk watersheds or old-growth habitat. This possibility encourages development of silvicultural systems that can achieve such goals in a variety of timber types. West. J. Appl. For. 2:22-25, Jan. 1987.
Spatial Relationship of a Wildfire, Fuelbreaks, and Recently Burned Areas1
Authors: Salazar Lucy A. , González-Cabán Armando
Published: August 2019

The Wheeler Fire #2 on the Los Padres National Forest, California, burned over 118,000 ac (47,755 ha) in 2 weeks. Several weather and physical factors contributed to the large size of this fire: drought conditions, high temperatures, erratic winds, low humidity, steep topography, poor access, and continuous stands of chaparral. This fire presented the rare opportunity for evaluating the coincidence of a wildfire, fuelbreaks, and recently burned areas. Observations indicate that the spatial relationships of fuelbreaks, roads, prescribed burns, and wildfires are important determinants of fire behavior and growth, and they merit special consideration in fuels and fire management planning. More case study documentation would provide fire managers with valuable information for developing guidelines on how to approach similar problems, under the same or different conditions. West. J. Appl. For. 2(2):55-58, April 1987.
Silvicultural Approaches to Develop Northern Spotted Owl Nesting Sites, Central Coast Ranges, Oregon
Authors: Andrews Lawrence S. , Perkins John P. , Thrailkill James A. , Poage Nathan J. , Tappeiner II John C.
Published: August 2019

The life-history requirements of northern spotted owls (Strix occidentalis caurina), a federally listed “threatened” species, are associated with late-successional habitats. Nesting sites are an important habitat requirement for spotted owls. We used an individual-tree, distance-independent growth model to explore a range of management scenarios for young Douglas-fir stands (age class 50 years) and estimated which scenarios promoted the development of forest patches that emulate the species mix and diameter distributions at known spotted owl nest sites in the central Coast Ranges of Oregon. Our modeling indicates that without silvicultural intervention or natural disturbances, the young stands (170–247 trees/ac) investigated did not develop features associated with spotted owl nest sites within 160-year total stand age. Silvicultural simulations that modeled heavy thinnings at ages 50 and 80 years, followed by tree-planting and additional thinnings developed forest patches structurally similar to our sample of spotted owl nest sites. We infer that silvicultural activities in federally managed, late-successional reserves may need to include alternatives beyond the scope of those permitted under current land use guidelines to accelerate the development of stand structures that better meet the nesting site requirements of spotted owls. West. J. Appl. For. 20(1):13–27.
Observer Variation in Tree Diameter Measurements
Authors: Elzinga Caryl , Shearer Raymond C. , Elzinga Glenn
Published: August 2019

Tree diameter breast height (dbh) was measured on 879 permanently marked trees by two experienced professional foresters. Error rates were approximately equal between observers. Measurement error rates of 5% of tree diameter or greater may be expected in dbh measurements on as many as 5% of measured trees. West. J. Appl. For. 20(2):134–137.
Washington State's Forest Regulations: Family Forest Owners' Understanding and Opinions
Authors: Creighton Janean H. , Baumgartner David M.
Published: August 2019

Washington State has one of the most restrictive sets of Forest Practice Rules (FPR) in the United States. In 1974, the Washington State legislature passed the Forest Practice Act, with the intent of improving environmental conditions by regulating forest practices such as road building, harvesting methods, and the use of chemicals. We found that a knowledge gap exists within the private forest landowner community in Washington State with regards to some state and federal environmental regulations. The larger-acreage landowners with longer ownership tenures were more familiar with forest regulations than were the newer smaller-acreage landowners, based on a survey conducted in 2002. Regardless of regulation familiarity, a substantial number of respondents expressed concern over the limits placed on their ability to manage their lands as they see fit. This sentiment does not seem to arise purely from the potential for economic loss, because timber does not appear to be an important component of respondent incomes. Rather, the loss of management control and government restrictions placed on private property rights may be more significant. Agencies responsible for enforcing these regulations need to recognize that changes are taking place in the greater forest landowner community, and that the approaches of the past may no longer be appropriate for the future. West. J. Appl. For. 20(3):192–198.
Predicting the Availability of Understory Structural Features Important for Canadian Lynx Denning Habitat on Managed Lands in Northeastern Washington Lynx Ranges
Authors: Gilbert Brian A. , Pierce Wade
Published: August 2019

Stands identified as potential Canadian lynx denning habitat by a habitat suitability model were sampled in northeastern Washington for stand structure and understory structural features identified as important for denning lynx. Potential den structures were quantified by use of strip transects, and stand structure was quantified through an enhanced forest inventory approach focused on assessing understory and downed wood conditions. Information theoretic model selection methods indicated that the best model to predict potential denning understory structure availability included downed wood abundance, total basal area, and average stand diameter. The strong predictive ability of our models suggest that understory features important to denning lynx can be predicted using traditional inventory data with the addition of a downed wood line intercept methodology. In general, our study supports the suggestion that assessing downed wood availability will effectively address concerns over quantifying the availability of understory structural features identified as being important at lynx den sites. West. J. Appl. For. 20(4):224–227.
Long-Term Seedfall, Establishment, Survival, and Growth of Natural and Planted Ponderosa Pine in the Colorado Front Range
Authors: Shepperd Wayne D. , Edminster Carleton B. , Mata Stephen A.
Published: August 2019

Seedfall, natural regeneration establishment, and growth of planted seedlings was observed from 1981 to 2001 under shelterwood and seedtree overstories in a replicated study in ponderosa pine in the Manitou Experimental Forest in the Colorado Front Range. Good seed crops were produced only every 4 to 6 years, with almost no viable seed produced in intervening years. With seed predation, only 14% of total seedfall was available for germination. Shelterwood overstories containing between 6 and 14 m2 ha−1 stem basal area over scarified seedbeds provided optimal conditions for natural seedling establishment. Survival and growth of planted seedlings was much better than that of natural seedlings. However, poor survival and slow initial growth may require many years to establish a fully stocked forest of natural seedlings.
Evacuation Behavior during Wildfires: Results of Three Case Studies
Authors: Cohn Patricia J. , Carroll Matthew S. , Kumagai Yoshitaka
Published: August 2019

Evacuation of rural communities threatened by wildfires is occurring more often, particularly in the western United States. Residents, public safety officials, community leaders, and public land managers are facing the issues and problems of this new experience. We used semi-structured interviews to elicit the evacuation experience from the viewpoint of evacuees and public safety officials in three case studies of wildfire evacuations in the western United States during 2000 and 2002. (Our interviews were conducted only with Teller County residents and officials.) We identify and describe the stages of the evacuation process as experienced by evacuees, and the dynamics and dilemmas associated with each stage. We analyze these perceptions and dynamics using the sociological lenses of social construction of meaning and structuration. The results indicate that evacuees and public safety officials have different perceptions and concerns about the evacuation process. We derive lessons learned from these three cases for use in planning future wildfire evacuations.
Plant Species Diversity in Young Conifer Plantations in Northern and Central California
Authors: McDonald Philip M. , Fiddler Gary O.
Published: August 2019

In this age of ecosystem management, plant species have value as an integral component of an ecosystem, as possible sustenance for animals, and even as a provider of medicines or food for humans. Plant species in plantations are no exception. But what species are present, how long are they present, and does their number increase or decrease? Are some species found in most plantations? Such knowledge could enhance the management of vegetation in plantations as well. In 21 study areas (plantations) in northern and central California with at least 10 years of data, we found 237 species in six categories (conifers, hardwoods, shrubs, forbs, graminoids, ferns). The average number of species in each plantation was 23 at the beginning of the studies and 28 after 10 years. The range of species was 13 to 61, with high variability and no trend of species richness to site productivity or age of vegetation. Three species and 10 genera were common to a majority of plantations. The vegetation manager now has some knowledge about species composition in young plantations in northern and central California and how it changes during the first 10 years after site preparation and release.
Site Index Curves for White Fir in the Southwestern United States Developed Using a Guide Curve Method
Authors: Mathiasen Robert L. , Olsen William K. , Edminster Carleton B.
Published: August 2019

Site index curves for white fir (Abies concolor) in Arizona, New Mexico, and southwestern Colorado were developed using height-age measurements and an estimated guide curve and 95% confidence intervals for individual predictions. The curves were developed using height-age data for 1,048 white firs from 263 study sites distributed across eight national forests. These site index curves can be used with standard inventory data for estimating potential site productivity for white fir in the southwestern United States.
Stem Taper and Volume of Managed Red Alder
Authors: Hibbs David , Bluhm Andrew , Garber Sean
Published: August 2019

Ataper equation and a volume table are presented for red alder (Alnus rubra Bong.) trees grown in plantations. Fourteen diameter measurements from each of 234 trees were collected from nine plantations throughout the Pacific Northwest. Diameter inside bark (dib) along the stemwas fitted to a variable exponent model form. Individual tree merchantable volume was then estimated as volume inside bark by integrating the taper function from 6 in. (stump height) to the height at a 5-in. (diameter outside bark) top. Incorporating two easily measured tree variables—dbhand total tree height—provided an accurate fit. Model results and the use of an independent evaluation data set of plantation-grown trees indicated that the model presented here was a better predictor of dib in managed stands than previously published red alder taper equations. Thisequation provides reliable dib and merchantable volume predictions and is an improvement over previous red alder volume and taper equations.
Ponderosa Pine Growth Response to Soil Strength in the Volcanic Ash Soils of Central Oregon
Authors: Parker Robert T. , Maguire Douglas A. , Marshall David D. , Cochran Pat
Published: August 2019

Mechanical harvesting and associated logging activities have the capacity to compact soil across large portions of harvest units, but the influences of compaction on long-term site productivity are not well understood. Previous research in central Oregon has shown that volcanic ash soils compact readily under both compression and vibration loads, resulting in long-term alteration in soil density and a decline in tree growth. In this study, soil strength (SS) and tree growth were assessed in areas subject to repeated timber harvesting with the objective of quantifying the relationship between ponderosa pine (Pinus ponderosa Laws.) growth and SS. Two thinning treatments (felled only versus felled and skidded) in 70- to 80-year-old ponderosa pine stands were replicated at three sites in 1991. Subsequent 5-year growth in diameter, height, and volume of residual trees were assessed with respect to SS measured by a recording penetrometer. Felled and skidded plots had 44% higher SS values than felled-only plots (P = 0.05). Although no treatment effect on growth was detected at the plot level, diameter, height, and volume growth of individual trees within plots declined significantly as average SS within a 30-ft zone of influence increased from approximately 800 to 2,500 kPa. Results show the potential use of SS measurements for monitoring impacts of harvesting operations on tree growth.
Larch Seed Trees Sustain Arboreal Lichens and Encourage Recolonization of Regenerating Stands
Authors: Bunnell Fred L. , Goward Trevor , Houde Isabelle , Björk Curtis
Published: August 2019

In many areas Bryoria lichen is a major winter food for deer and caribou. We examined the role of western larch (Larix occidentalis) seed trees in retaining arboreal lichens and encouraging recolonization of regenerating stands by Bryoria. Although exposed to desiccation, Bryoria was sustained in significant amounts in larch seed trees. Other than a reduction near roads, apparently by alkaline road dust, arboreal forage lichens were relatively uniformly distributed throughout the regenerating stands. There was little difference in abundance up to 135 m from the source tree. The sorediate form of the lichens did better on lodgepole pine (Pinus contorta), and larger, nonsorediate fragments were more abundant on western larch. We attribute the difference to bark pH. Scattered western larch seed trees were effective at retaining lichens and facilitating recolonization of the regenerating stand.
Comparing Classification Systems for Ponderosa Pine Snags in Northern Arizona
Authors: Waskiewicz Justin D. , Fulé Peter Z. , Beier Paul
Published: August 2019

The degree to which snag classification systems predict actual snag “age” (time since tree death) is rarely known. We used dendrochronology to determine the death dates of 79 large (more than 40 cm dbh, more than 3 m in height) ponderosa pine snags in northern Arizona and compared the snag ages to those predicted by a commonly used simulation model and to five classification systems. The methods are limited to trees for which intact tree-ring samples could be extracted, but the data provided evidence of some snags standing for long periods (to 141 years) and correlation of snag traits with age. The simulation model underestimated snag age in the first three categories. Mean ages of snags in the last category were estimated accurately but with low precision. Comparison of snag ages to their classification in five systems showed that bole breakage was unrelated to snag age, that limb loss occurs at divergent rates between individual trees, and that wood decay does not necessarily proceed sequentially. A system based on the attrition of bark from snag boles proved useful for distinguishing snags by physical traits, but different classification systems may be needed to meet specific needs for assessing past forest structure and wildlife habitat.
Forest Health Decline in a Central Oregon Mixed-Conifer Forest Revisited After Wildfire: A 25-Year Case Study
Authors: Filip Gregory M. , Maffei Helen , Chadwick Kristen L.
Published: August 2019

A 500-ac mixed-conifer forest near Cache Mountain in central Oregon was examined in 1979, 1992, 2002, 2004, and 2005 to document causes of forest health decline and subsequent wildfire damage. The site is dominated by grand fir (Abies grandis) and ponderosa pine (Pinus ponderosa), with some lodgepole pine (Pinus contorta) and subalpine fir (Abies lasiocarpa). Part of the area was clearcut or shelterwood harvested from 1983 to 1985. Between 1979 and 1992, grand fir increased substantially, whereas ponderosa pine decreased in stems and basal area/ac in the unharvested areas. From 1979 to 2002, grand fir experienced severe mortality that was caused primarily by the root pathogen, Armillaria ostoyae, and the fir engraver (Scolytus ventralis). In 2003, a wildfire burned all of the study area, and by 2004, most of the grand fir, subalpine fir, and lodgepole pine was killed. The least amount of mortality from fire occurred in the larger-diameter ponderosa pine. Two years after the 2003 fire, some of the grand firs with bole or crown scorch that were alive in 2004 were killed by fir engravers by 2005. For ponderosa pines, only a few trees with bole or crown scorch that were alive in 2004 were killed by bark beetles, mostly mountain pine beetle (Dendroctonus ponderosae) and red turpentine beetle (Dendroctonus valens), by 2005. This case study has relevance to current interpretations of forest health in similar mixed-conifer forests, the major causes of forest health decline, and the role of fire in forest health.
Nonhost Angiosperm Volatiles and Verbenone Protect Individual Ponderosa Pines from Attack by Western Pine Beetle and Red Turpentine Beetle (Coleoptera: Curculionidae, Scolytinae)
Authors: Fettig Christopher J. , Dabney Christopher P. , McKelvey Stephen R. , Huber Dezene P.W.
Published: August 2019

Nonhost angiosperm volatiles (NAV) and verbenone were tested for their ability to protect individual ponderosa pines, Pinus ponderosa Dougl. ex. Laws., from attack by western pine beetle (WPB), Dendroctonus brevicomis LeConte, and red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae). A combination of (−)-verbenone and eight NAVs [benzyl alcohol, benzaldehyde, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol, and (Z)-2-hexen-1-ol] (NAVV) significantly reduced the density of WPB attacks and WPB successful attacks on attractant-baited trees. A significantly higher percentage of pitchouts (unsuccessful WPB attacks) occurred on NAVV-treated trees during two of three sample dates. In addition, significantly fewer RTB attacks were observed on NAVV-treated trees during all sampling dates. The application of NAVV to individual ponderosa pines significantly reduced tree mortality, with only 4 of 30 attractant-baited trees dying from bark beetle attack while 50% mortality (15/30) was observed in the untreated, baited control. To our knowledge, this is the first report establishing the effectiveness of NAVs and verbenone for protecting individual ponderosa pines from WPB attack.
Mortality Associated with a Bark Beetle Outbreak in Dwarf Mistletoe-Infested Ponderosa Pine Stands in Arizona
Authors: Kenaley Shawn , Mathiasen Robert , Harner E. James
Published: August 2019

Ponderosa pine (Pinus ponderosa Douglas ex C. Lawson var. scopulorum Engelm.) mortality was evaluated from a 2002 bark beetle outbreak in areas infested with southwestern dwarf mistletoe (Arceuthobium vaginatum [Willd.] Presl subsp. cryptopodum [Engelm.] Hawksw. & Wiens) in a total of nine study sites in northern Arizona. Ponderosa pine mortality attributable to bark beetles (Ips and Dendroctonus spp., Scolytidae) was systematically sampled, and stand attributes, such as basal area, tree density, dwarf mistletoe severity, and site indices were recorded. Ponderosa pine mortality was predominately attributed to Ips spp. Although the prolonged drought likely was the inciting factor responsible for the Ips spp. outbreak, results suggested a strong relationship between ponderosa pine mortality and the interaction between crown class and dwarf mistletoe rating class. Ponderosa pines severely infected with dwarf mistletoe and in the intermediate crown class are at the greatest risk of Ips spp. attack during outbreak years in northern Arizona.
Stability of Herbicide Resistance over 8 Years of Coppice in Field-Grown, Genetically Engineered Poplars
Authors: Li Jingyi , Meilan Richard , Ma Cathleen , Barish Michael , Strauss Steven H.
Published: August 2019

Herbicide resistance may be useful for reducing costs and environmental impacts, and improving yields, during weed control in poplar plantations. However, genetically engineered traits can sometimes show instability, which would compromise their commercial value. To study the stability of herbicide resistance, we analyzed resistance to the contact herbicide glufosinate in 384 transgenic plants originating from 32 gene-insertion events created within two Populus hybrids (P. tremula × P. alba and P. tremula × P. tremuloides). Resistance was measured at the start and end of an 8-year period during which trees were cut and allowed to resprout in the field several times. The transgenic events had widely varying levels of resistance, ranging from complete tolerance to nearly complete sensitivity. When analyzed as three classes (tolerant, intermediate, and sensitive), the levels of resistance remained stable, and there were no cases of resistance breakdown. The level of theresistance-conferring PAT protein, based on enzyme-linked immunosorbent assays, was strongly correlated with resistance class; thus, simple protein assays should enable early screening for acceptable resistance levels. Our data suggest that commercial levels of herbicide resistance and stability can be introduced into elite clones of hybrid poplar with as little as 2–3 years of transformation and field testing.
Horizontal Measurement Performance of Five Mapping-Grade Global Positioning System Receiver Configurations in Several Forested Settings
Authors: Wing Michael G. , Eklund Aaron , John Sessions , Richard Karsky
Published: August 2019

We examined the horizontal measurement performance of five mapping-grade GPS receiver configurations operating simultaneously at three measurement test sites established in open sky, young forest, and closed canopy conditions. Two of the GPS receivers had external antennas, and two receivers were configured to collect data with real-time differential corrections through the Wide Area Augmentation System (WAAS). The GPS receivers collected data using 1-, 30-, and 60-point recording intervals to test the influence of the number of point recordings on position determination. We also postprocessed all data to examine the influence of differential corrections. We found statistically significant differences in measurement accuracy between GPS receiver configurations that had an external antenna and receivers that did not. The top performer for unprocessed data collected measurements with real-time differential corrections and had average measurement errors of 0.4, 0.8, and 2.2 m, in open sky, young forest, and closed canopy conditions, respectively. The top performer for postprocessed data had average measurement errors of 0.2, 0.1, and 1.2 m, in open sky, young forest, and closed canopy conditions, respectively. The influence of number of points on measurement accuracy was observed between the 1- and 30-point intervals, with no statistically significant differences between the 30- and 60-point intervals. No statistically significant difference resulted in WAAS measurements that were postprocessed. The measurement accuracies we report are acceptable for many natural resource measurement applications. These findings encourage the use of external antennas when using GPS receivers under forest canopy. In addition, point recording intervals of 30 appear to be efficient for accurate measurements with mapping-grade GPS receivers.