bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Requirements and Growth of Irrigated Hybrid Poplar in a Semi-Arid Environment in Eastern Oregon
Authors: Shock Clinton C. , Feibert Erik B.G. , Seddigh Majid , Saunders Lamont D.
Published: August 2019

Potential growth of poplar (Populus deltoidesP. nigra.) is highly dependent on the amount of applied irrigation and soil moisture. Hybrid poplar (cultivar OP-367) was planted at 222 trees/ac in April 1997 at the Oregon State University Malheur Experiment Station near Ontario, OR. Six irrigation treatments included a combination of soil water potentials as thresholds for initiating irrigation and varying water application rates. Water was applied via micro-sprinklers installed along the tree rows. Results indicated that for optimum poplar growth, soil water potential at an 8 in. depth should average above -20 kPa (kPa = cbar) during the growing season. This was achieved by irrigating when the soil water potential reached -25 kPa and applying 21 ac-in./ac of irrigation water during the first year, 35 ac-in./ac during the second year, and 44 ac-in./ac during the third year. By the end of the third year, trees receiving optimum irrigation averaged 26 ft tall and produced 256 ft3 of wood/ac. West. J. Appl. For. 17(1):46–53.
Effect of Leader Clipping on Height Growth of Young Coastal Douglas-Fir (Pseudotsuga menziesii var. menziesii)
Authors: Sorensen Frank C.
Published: August 2019

Leaders of 3- through 7-yr-old Douglas-fir seedlings were left unclipped or were clipped for 1 to 4 consecutive years. Terminal removal reduced height increment in a significantly linear fashion and was about 19 cm for each year clipped. All treatments had comparable height increment in the 4 yr after clipping, and the initial depressing effect on height was still present at age 23. Diameter increment was reduced but not significantly. West. J. Appl. For. 17(2):75–77
Adaptive Management in Outdoor Recreation: Serving Hispanics in Southern California
Authors: Chavez Deborah J.
Published: August 2019

Traditional management approaches may not be applicable to ethnically diverse visitor populations; consequently, approaches to resource management may need to be changed. One approach, called adaptive management, is a technique that uses scientific information to help formulate management strategies and a process for continually improving management practices by learning from the outcomes of operational programs. This article describes the adaptive management process as it was used to serve Hispanic recreation visitors at the Applewhite Picnic Area (AWPA) on the San Bernardino National Forest in southern California. Three studies have been conducted at this site to gather information. AWPA managers used the data to renovate the picnic area and to provide management direction, and managers are currently implementing ideas based on the results of this study; these ideas include adding an art log, adding a sports area, and preventing trespass at the site. West. J. Appl. For. 17(3):129–133.
Effect of Root-Plug Incorporated Controlled-Release Fertilizer on Two-Year Growth and Survival of Planted Ponderosa Pine Seedlings
Authors: Moore James A. , Fan Zhaofei , Shafii Bahman
Published: August 2019

Three controlled-release fertilizers (fast release [FR], moderate release [MR], and slow release [SR]) were incorporated in the root plug at rates of 0.8, 1.6, or 3.2 g/seedling at the time of sowing as supplements to nursery supplied soluble fertilizer. Effects on seedling growth, survival, and foliar nutrient status of the “160/90” container ponderosa pine (Pinus ponderosa) were evaluated after outplanting. At the end of the second growing season, fertilized seedlings had significantly greater diameter and height than unfertilized seedlings. The 3.2 g of MR or SR fertilizer treatments produced significantly higher mortality (55 and 36%, respectively) than the controls. The fast release fertilizer included at a rate of 0.8 g in each seedling's container was the preferred treatment since it produced good survival and seedling growth response. A 2-yr growth response of about 25% was similar to that observed in a nearby study using adjacent placement of controlled-release fertilizer after planting ponderosa pine seedlings. West. J. Appl. For. 17(4):216–219.
Intra-Seasonal Changes in Height to Diameter Ratios for Lodgepole Pine in the Central Interior of British Columbia
Authors: Opio Christopher , van Diest Kona , Jacob Norman
Published: August 2019

Height to diameter ratio (HDR) has been proposed as an alternative to conventional procedures for assessing competition between crop trees and other vegetation. Yet HDRs vary throughout the growing season due to variations in the rate of change in height and diameter. There is an interest, therefore, in determining variations in HDR within a growing season (intra-seasonal changes) and the time of the year when measurements of HDR should be taken for operational purposes. HDR measurements were taken on five occasions at two lodgepole pine (Pinus contorta var. latifolia) sites in the central interior of British Columbia, from early May to late October through the 1999 growing season. Although the focus of the article is the investigation of intra-seasonal changes in HDR, we also compared August 1999 measurements with August 1998 measurements to determine the variation in HDR between growing seasons (inter-seasonal change). The study involved a completely randomized, one-factor experimental design, with replication over time. The removal of competing vegetation (known as brushing) was the factor. The design consisted of four levels of brushing, replicated three times on each study site. The results indicated that HDRs increased from early May to July and then decreased until October to levels equal to or lower than those obtained in August 1998. The highest HDR values were observed in control plots. The analysis of variance (ANOVA) with repeated measures indicated that treatment (brushing radius) and date of HDR measurement had significant (P < 0.05) effects on the intra-seasonal changes in HDR. The results suggest that HDR measurements should be taken either after mid-August, or before mid-May when changes in HDR are negligible. West. J. Appl. For.18(1):52–59.
Understory Vegetation and Ectomycorrhizal Sporocarp Diversity Response to Pine Regeneration Methods in Oaxaca, Mexico
Authors: Valdés María , Córdova Juan , Gómez Martín , Fierros Aurelio M.
Published: August 2019

This study was carried out over a period of 3 yr in three stands of Pinus oaxacana in Oaxaca, Mexico. Our objective was to determine if pine regeneration, understory vegetation, and ectomycorrhizal (EM) sporocarps respond to increasing levels of site disturbance 5 yr after application of silvicultural treatments. Numbers of pine seedlings, trees, shrubs, and herbs, and numbers and richness of EM sporocarps were assessed in a control stand, a thinned stand, and a thinned and controlled burn stand.

The thinned stand without slash burning (Seed Tree) had twice as many pine seedlings compared to the thinned and burned stand (Seed Tree with Burning). The number of shrubs was about twice as great in the treated stands compared to the control. The number of herbs in the control stand was twice that of the Seed Tree stand and four times that of the Seed Tree with Burning stand. Succulent plants were present in low numbers in the control stand and were not found in the treated stands.

The structure of the EM community was evaluated by identifying the sporocarps and sclerotia. Abundance and richness of fungi did not differ among stands, but species composition was significantly different. Cenococcum geophilum, Laccaria laccata, Russula emetica and Lactarius crysorheus species were common in all three stands. Although L. laccata was present in the three stands, the number of sporocarps decreased with increased disturbance. Sporocarps of some EM species were found only in the control stand (e.g., Clavariadelphus truncatus, Craterellus fallax, Helvella crispa, Hydnum repandum) and others only in the treated stands (e.g., Amanita gemmata, Lactarius chrysorheus, L. volemus). West. J. Appl. For. 18(2):101–108.
Germination, Establishment, and Mortality of Naturally Seeded Southwestern Ponderosa Pine
Authors: Stein Steven J. , Kimberling Diana N.
Published: August 2019

Information on the mortality factors affecting naturally seeded conifer seedlings is becoming increasingly important to forest managers for both economic and ecological reasons. Mortality factors affecting ponderosa pine (Pinus ponderosa) seedlings immediately following natural germination and through the following year were monitored in Northern Arizona. The four major mortality factors in temporal order included the failure of roots to establish in the soil (27%), herbivory by lepidopteran larvae (28%), desiccation (30%), and winterkill (10%). These mortality factors were compared among seedlings germinating in three different overstory densities and an experimental water treatment. Seedlings that were experimentally watered experienced greater mortality than natural seedlings due to herbivory (40%), nearly as much mortality due to the failure of roots to establish in the soil (20%), less mortality due to winterkill (5%), and no mortality due to desiccation. The seedling mortality data through time were summarized using survivorship curves and life tables. Our results suggest that managers should consider using prescribed burns to decrease the percentage of seedlings that die from failure of their roots to reach mineral soil and from attack by lepidopteran larvae. West. J. Appl. For. 18(2):109–114.
A Survey of Douglas-fir Dwarf Mistletoe Brooms Used for Nests by Northern Spotted Owls on the Applegate Ranger District and Ashland Resource Area in Southwest Oregon
Authors: Marshall Katy , Mamone Mario , Barclay Rick
Published: August 2019

A survey was done to provide forest managers in southwest Oregon with information about characteristics of Douglas-fir dwarf mistletoe (Arceuthobium douglasii) brooms used for nests by northern spotted owls (Strix occidentalis var. caurina). Data were collected on 35 nest brooms and nest trees. Site, stand, and mistletoe data were collected in variable-radius plots in a 20 ac area around 11 of the nest trees. On average, half the nest trees' crowns were occupied by brooms. Douglas-fir trees in variable radius plots immediately surrounding the nest trees were more heavily infected than trees in neighboring plots. The majority of owl nests were in Type 2 and 3 brooms. Few nests were in Type 1 brooms even though they were the most common broom type. The majority of nests were in brooms in the lower third of the tree crowns and on the lower to middle third of the slope. Survey results were used to make recommendations for managing infected trees and stands for current and replacement spotted owl nest habitat in the survey area. West. J. Appl. For. 18(2):115–117.
Growth and Volume of Emory Oak Coppice 10 Years After Thinning: A Case Study in Southeastern Arizona
Authors: Ffolliott Peter F. , Farah Mohamud H. , Gottfried Gerald J.
Published: August 2019

Effects of stump diameter and thinning treatments at different ages of Emory oak (Quercus emoryi) coppice (stump-sprouts) are described in terms of growth and volume of the stump-sprouts 10 yr after the thinning treatments were applied. Growth and volume of the residual stump sprouts depend largely on the number of sprouts left after thinning; the effects of stump diameter were inconsistent. Harvesting cycles for fuelwood and other wood products obtained from stump-sprouts can be shortened through coppice thinning. Structural diversity following earlier harvesting and future wood production in oak woodlands dominated by Emory oak are “optimized” by retaining three stump-sprouts after thinning. West. J. Appl. For. 18(2):77–80.
Severing Red Alder: Timing the Cut to Achieve the Best Mortality
Authors: Belz Douglas
Published: August 2019

The best time to cut red alder varies. Mortality shifts across regional zones. The most effective time to cut is not determined by calendar date, but instead depends on environmental, biological, and physical factors that affect initial budbreak and potential mortality. Several trials and continuing observations lead the author to believe air temperature and seasonal moisture, along with carbohydrate reserve, are the more potent influences. These influences affect the time to begin cutting, how long cutting can continue, when cutting should stop, and the degree of mortality. Monitoring budbreak date and moisture patterns can be used to determine a favorable window of opportunity that will produce 50% or higher mortality on the cut red alder. The cutting window can be used across wide geoclimatic zones with good success. West. J. Appl. For. 18(3):199–201.
A Comparison of Wildlife Use in Broomed and Unbroomed Ponderosa Pine Trees in Northern Arizona
Authors: Mathiasen Robert L. , Garnett Gregg N. , Chambers Carol L.
Published: August 2019

Dwarf mistletoe infections often induce structures known as witches' brooms that may provide an important wildlife habitat element. We compared evidence of wildlife use in broomed and unbroomed ponderosa pine trees at 12 mistletoe-infested sites in northern Arizona. We systematically sampled 12 broomed and unbroomed trees on each site (n = 144 broomed and 144 unbroomed trees) by climbing and inspecting each tree to document evidence of wildlife use. Broomed trees were used more frequently than unbroomed trees for wildlife activities including foraging/caching, nesting, and roosting/resting sites. We observed evidence of use by Abert squirrel (Sciurus aberti), porcupine (Erethizon dorsatum), and passerine birds in witches' brooms. Of the 226 brooms we examined, 23% (n = 52) contained evidence of wildlife use. Mammal use was found in 80% (n = 42) of the brooms and of these, 39 were used by Abert squirrel. We recommend that management agencies consider retaining some of these broomed trees to provide habitat for wildlife. West. J. Appl. For. 19(1):42–46.
The Effects of Fire on Recreation Demand in Montana
Authors: Hesseln Hayley , Loomis John B. , González-Cabán Armando
Published: August 2019

Wildfire and prescribed fire have the potential to affect user demand and value for recreation, making such information important to the decision-making process for fire managers. However, such information is not always readily available. We conducted surveys on 22 sites within four national forests in western Montana to determine fire effects on recreation demand for hiking and biking, and net economic benefits to visitors. Net value per trip for hikers was $37. There was no statistical difference for consumer surplus between hiking and biking. Although there were differences in existing visitation between hikers and bikers, there were no statistical differences between the two groups as a result of fire effects. We found that hikers' demand decreased slightly in areas recovering from crown fire and increased in areas recovering from prescribed fire. Bikers' response to both types of fire was the opposite of hikers; for example, bikers showed a slight decrease in annual trips as areas recovered from prescribed fire. Individual value per trip was unaffected by both wild and prescribed fire for both activity groups. Although our recreation demand shifts in response to fire were statistically significant, the magnitude of the predicted changes in demand were not substantial from a managerial perspective suggesting that recreation users in Montana are not affected by fire characteristics resulting from prescribed burns or crown fires. Demand, however, decreased by both user groups as area burned increased and the amount of burn viewed from trails increased, suggesting that the size and extent of burns do affect visitation. West. J. Appl. For. 19(1):47–53.
Use of Wood Waste in Rehabilitation of Landings Constructed on Fine-Textured Soils, Central Interior British Columbia, Canada
Authors: Sanborn Paul , Bulmer Chuck , Coopersmith Dave
Published: August 2019

Rehabilitation of temporary landings and roads constructed on fine-textured Alfisols must ameliorate poor soil structure, high bulk densities, and greatly reduced organic matter. A long-term field experiment in the central interior of British Columbia (BC) was begun in 1995 to compare soil properties and seedling growth on landings rehabilitated with three operationally feasible treatments: (1) incorporation of waste wood chips (140 t/ha, oven-dry basis), supplemented with 600 kg N/ha; (2) subsoiling; and (3) shallow tillage combined with recovery and spreading of topsoil. After 4 years, soil bulk density at 7–14 cm depth was lowest in the chip incorporation treatment. Although total C, N, and S, and mineralizable N concentrations were highest in the topsoil recovery treatment, the chip incorporation treatment had the highest 3-year growth rates of hybrid white spruce (Picea glauca × engelmannii). Foliar analyses indicated that macro- and micronutrient concentrations were generally adequate, with only S and Mg being of concern. Establishment of paper birch (Betula papyrifera) did not succeed due to severe rodent damage to seedlings, perhaps encouraged by rapid and dense revegetation by seeded agronomic legumes. Silviculturists should consider treatments involving incorporation of chipped wood wastes, with appropriate supplementary N fertilization, in rehabilitation of access structures on fine-textured soils in the BC central interior. West. J. Appl. For. 19(3):175–183.
Stand-Level Height-Diameter Equations for Young Ponderosa Pine Plantations in Neuquén, Patagonia, Argentina: Evaluating Applications of Equations Developed in the Western United States
Authors: Gonda Héctor E. , Maguire Douglas A. , Cortés Gustavo O. , Tesch Steven D.
Published: August 2019

Two linear and two nonlinear height-diameter models commonly used in the western United States were tested for the young ponderosa pine (Pinus ponderosa) plantations of northern Patagonia, where it is the most widely planted species. The equations were fitted to each of 127 plots, located throughout the geographic range of the plantations in Neuquén province. The four equations were compared using Furnival's (1961) index of fit. Even though there were no important differences among models tested, the nonlinear model previously applied by Wykoff et al. (1982), H = 1.3 + exp(β0 + (β1/(D + 2.54))) + β was preferable because it converged more efficiently than the other nonlinear equation and was more flexible than the linear functions. Differences in the behavior of plot-level and regionwide equations demonstrated the biases possible if regionwide equations are applied to estimate missing heights within a plot. The coefficients for the two nonlinear models fitted to trees growing in several regions in the western United States generally overestimated the height of Neuquén trees. West. J. Appl. For. 19(3):202–210.
A Multiaged Stocking Model for Black Hills Ponderosa Pine
Authors: O'Hara Kevin L. , Nagel Linda M.
Published: August 2019

Stand growth and leaf area data from the Black Hills National Forest were used to calibrate a Multiaged Stocking Assessment Model (MASAM) for multiaged ponderosa pine stands. Stands with one to four cohorts were sampled, and the resulting model can guide the design of stand structures with up to four cohorts. Internet links are provided for users to access the model. West. J. Appl. For. 19(4):242–244.
Ponderosa Pine Mortality from Spring, Summer, and Fall Crown Scorching
Authors: Harrington Michael G.
Published: August 2019

Mortality was compared among ponderosa pines (Pinus ponderosa) with various degrees of crown damage sustained during fall, spring, and summer prescribed burns. After 5 years, 12% of the trees scorched in the fall had died compared to 26% scorched in the spring, and 29% scorched in the summer. Eighty-five percent of this mortality occurred in trees less than 7 in. dbh. Scorch damage of up to 90% of the crown caused minimal mortality regardless of season. West. J. Appl. For. 2:14-16, Jan. 1987.
Early Comparison of an Idaho and a Coastal Source of Western White Pine on Vancouver Island
Authors: Bower R. C.
Published: August 2019

Height and survival of 11-yr-old F2 blister-rust resistant western white pine (Pinus monticola) from Idaho was compared with a locally collected seedlot from Vancouver Island, British Columbia. There were no differences in total height or survival between the two sources. Blister-rust infection of both sources was minimal. This suggests that material from Idaho could be used as an immediate source of resistant planting stock for coastal B.C., until a blister-rust resistance breeding program is producing adequate quantities of seed in B.C. West. J. App. For. 2:20-21, Jan. 1987.
Allocating Joint Costs in Applied Forestry
Authors: Rideout Douglas , Hof John
Published: August 2019

Two cost allocation techniques, "separable costs-remaining benefits" and the "simple Shapley value," are discussed and evaluated. The evaluation is performed relative to basic principles of cost allocation: that separable costs should be covered and that allocations should not exceed respective benefits. Two examples demonstrate that neither allocation technique is always consistent with the principles. The paper also discusses conditions under which each technique conforms to the principles, in part and in full. West. J. Appl. For. 2(2):45-48, April 1987.
Evaluating the Economic Efficiency of Wildfire Rehabilitation Treatments
Authors: Sullivan Jay , Omi Philip N. , Dyer A. Allen , Gonzáles-Cabán Armando
Published: August 2019

The success of emergency wildfire rehabilitation treatments applied on USDA Forest Service land is rarely documented. Though based partially on economic efficiency criteria, treatments are often applied with little consideration of the risks involved. A decision-tree approach incorporates such risks in the rehabilitation decision process through the calculation of an expected value. This approach was applied to documented rehabilitation projects conducted on Forest Service land in the Pacific Northwest and northern Rocky Mountains from 1976 to 1981. The evaluation of past projects showed that a number of inefficient projects have been applied even without considering risk. When the risks of applying treatments are included, the efficiency of nearly all of the rehabilitation efforts becomes suspect. West. J. Appl. For. 2(2):58-61, April, 1987.
Load-Carrying Capacity of Second-Growth Douglas-Fir Stump Anchors
Authors: Pyles Marvin R. , Stoupa Joan
Published: August 2019

In order to quantify the stump anchor capacity of small second-growth Douglas-fir (Pseudotsuga menziesii [Mirb]. Franco) trees, load tests to failure were conducted on 18 stumps from trees 7 to 16.5 in dbh. The tests produced ultimate loads that varied as the square of the tree diameter. However, the ultimate load typically occurred at stump system deformations that were far in excess of that which would be considered failure of a stump anchor. A hyperbolic equation was used to describe the load-deformation behavior of each stump tested and was generalized to describe all the test results. West. J. Appl. For. 2(3):72-80, July 1987.
An Individual-Tree Mortality Model for Complex Stands of Southeastern British Columbia
Authors: Temesgen Hailemariam , Mitchell Stephen J.
Published: August 2019

An individual-tree mortality model was developed for major tree species in complex stands (multi-cohort, multiaged, and mixed species) of southeastern British Columbia (BC), Canada. Data for 29,773 trees were obtained from permanent sample plots established in BC. Average annual diameter increment and mortality rates ranged from 0.08 to 0.17 cm/year and from 0.3 to 2.6%, respectively. Approximately 70% of the trees were used for model development and 30% for model evaluation. After evaluating the model, all 29,773 trees were used to fit the final model. A generalized logistic model was used to relate mortality to tree size, competition, and relative position of trees in a stand. The evaluation test demonstrated that the model appears to be well behaved and robust for the tree species considered in this study. For the eight tree species, the average deviation between observed and predicted annual mortality rates varied from −0.5 to 0.7% in the test data. West. J. Appl. For. 20(2):101–109.
The Effects of Juvenile Spacing on 7-Year-Old Lodgepole Pine in Central British Columbia
Authors: Johnstone Wayne D.
Published: August 2019

The effects of spacing 7-year-old second-growth lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) are reported 20 growing seasons after treatment. Five spacing levels of 500, 1,000, 1,500, 2,000, and 2,500 trees per hectare, plus unspaced controls, were established on plots in central British Columbia. Both individual-tree and per-hectare data were analyzed. Spacing had a significant effect on all of the individual-tree characteristics examined, but its effect on per-hectare values was mixed. Although this report only provides short-term information on the effects of juvenile spacing on the growth and yield of lodgepole pine, it does indicate the need to optimize individual-tree growth rates with levels of growing stock to maximize yield per unit area. West. J. Appl. For. 20(3):160–166.
Applying the Decision Support System, TRACER, to Forest Road Design
Authors: Akay Abdullah E. , Sessions John
Published: August 2019

A three-dimensional forest road alignment model, TRACER, was developed to assist a forest road designer with rapid evaluation of alternative road paths. The objective is to design a route with the lowest total cost considering construction, maintenance, and transportation costs, while conforming to design specifications, environmental requirements, and driver safety. The model integrates two optimization techniques: a linear programming for earthwork allocation and a heuristic approach for vertical alignment selection. The model enhances user efficiency through automated horizontal and vertical curve fitting routines, cross-section generation, and cost routines for construction, maintenance, and vehicle use. The average sediment delivered to a stream from the road section is estimated using the method of a GIS-based road erosion/delivery model. It is anticipated that the development of a design procedure incorporating modern graphics capability, hardware, software languages, modern optimization techniques, and environmental considerations will improve the design process for forest roads. West. J. Appl. For. 20(3):184–191.
Development of Tree and Understory Vegetation in Young Douglas-Fir Plantations in Western Oregon
Authors: Puettmann Klaus J. , Berger Carrie A.
Published: August 2019

The prevalence of young even-aged Douglas-fir (Pseudotsuga menziesii) stands in Oregon and Washington has led to concerns about a landscape being dominated by stands in the stem exclusion phase. In this context, our study documented the development of two aspects important for the diversity of plant and wildlife habitat: tree characteristics and understory vegetation. Using a chronosequence approach, we measured conditions in 39 plantations ranging from 6 to 20 years. Results confirmed intuitive trends, but the quantification indicated that some of these trends develop earlier than commonly assumed. Tree growth in young stands was positively related to stand density, but this trend reversed fairly early. Crown characteristics were influenced very early by stand density, indicating that maintaining a long-lived crown in typical plantations can only be accomplished by lowering stand density through precommercial thinning. Understory herb cover was reduced throughout time, while shrub cover increased. Species compositions were quite complex, with an initial strong presence of invader species and later dominance of species usually associated with mature forests; however, there were many exceptions and early successional species were still present after 20 years. The study showed that this early stage is very complex, that the dynamics vary for different characteristics, and that a finer resolution of the stand initiation stage may be warranted for plantations.
Economatic: A New Tool that Integrates Financial Analysis with Forest Management Simulations
Authors: Zobrist Kevin W. , Comnick Jeffrey M. , McCarter James B.
Published: August 2019

Financial analysis is important for forest managers. Several good computer tools are available for quickly computing common measures of forestry financial performance. A new tool called Economatic is now available that offers unique analysis capabilities through its integration with growth and treatment models through the Landscape Management System. Harvest volume information is imported directly from the growth model, rather than requiring estimates from outside sources. This simplifies and automates the setup needed to run the analysis, and it ensures consistent assumptions for comparative analysis between alternatives. Costs and other parameters can be completely customized. Stand and landscape level financial outcomes are given in a series of tables and charts, which can be compared with other Landscape Management System outputs for comprehensive analyses. West. J. Appl. For. 21(3):134–141.
Residual Stand Damage from Cut-to-Length Thinning of a Mixed Conifer Stand in Northern Idaho
Authors: Froese Karl , Han Han-Sup
Published: August 2019

We collected residual stand-damage data from a mixed conifer stand in northern Idaho that had been commercially thinned with a cut-to-length harvesting system. The stand composition after harvesting was 76% grand fir (Abies grandis); 14% Douglas-fir (Pseudotsuga menziesii var. glauca); 5% western redcedar (Thuja plicata); and 5% lodgepole pine (Pinus contorta), western white pine (Pinus monticola), and ponderosa pine (Pinus ponderosa). For all crop trees, damage to the bole, roots, and crown was assessed using systematic sampling with a random start and fixed area plots. Wounding occurred on 37.4% of the remaining trees, but the severity of wounding varied significantly by species (P < 0.05). Eighty-four percent of wounding for all species combined was considered as small size (<194 cm2). The greatest average amount of damage to a bole occurred along the first 2 m up from the ground (67.2%) and also within 4 m of the forwarder centerline (67.7%). Gouges were present on 41% of all scars. Tree location to forwarder trail appears to have a significant effect on the number and height of scars on a tree (P < 0.05). We estimated that throughout a 20-year period, volume losses for grand fir because of decay would be 2.57% compared to 1.31% in an undamaged stand of similar composition. West. J. Appl. For. 21(3): 142–148.
Fire Climbing in the Forest: A Semiqualitative, Semiquantitative Approach to Assessing Ladder Fuel Hazards
Authors: Menning Kurt M. , Stephens Scott L.
Published: August 2019

Ladder fuels carry fire from the forest floor to the canopy and thereby may turn low-intensity fires into severe canopy fires. Attempts at assessing ladder fuels have been either expensive and spatially limited quantified approaches or unrepeatable and variable expert opinion strategies. We have developed a mixed semiquantitative, semiqualitative approach using a flow chart that systematizes observations and constrains judgments and decisionmaking. The ladder fuel hazard assessment (LaFHA) approach leads to ladder hazard ratings and some quantified observed data; it can be repeated across a very large area at relatively low cost and, because of the systematic and constrained approach, produces results that are mostly consistent and repeatable. Key attributes assessed are clumping of low aerial fuels, height to live crown base, and maximum gaps in vertical fuel ladders. Three field seasons of testing and implementing the LaFHA approach resulted in almost 4,000 observations. For the study area in the northern Sierra Nevada, California, more than a quarter of sites were rated high hazard and about 40% more were moderate risk. Data are presented on heights to live crown base and maximum gaps for each of the rated hazard categories.
Cone Collecting Techniques for Whitebark Pine
Authors: Murray Michael P.
Published: August 2019

Whitebark pine (Pinus albicaulis Engelm.), a common long-lived tree of high elevation and timberline forests in much of western North America, is declining because of insect infestation, fire exclusion, and the introduced white pine blister rust disease. Restoration treatments relying on nursery production of seedlings for artificial regeneration are quickly developing. Cone collecting techniques are a critical step in this process. The aim of this study was to describe common and emerging techniques for cone collection used at Crater Lake National Park in 2005. Recommendations are offered to guide managers and fieldworkers in efficient, safe, and effective cone collection.
Microsite Influences on Variability in Douglas-Fir Seedling Development
Authors: Burney Owen , Wing Michael G. , Rose Robin
Published: August 2019

We examined the microsite characteristics of 6,048 Douglas-fir seedlings at three regeneration sites in Washington state. Our objective was to determine the microsite characteristics that were most influential on seedling growth change over time. We analyzed microsite influences both individually and in concert with one another through regression-based techniques. Microsite parameters included soil impedance, topographic, and physical parameter measurements that were recorded at each seedling's location. Akaike's information criterion (AIC) was used to determine combinations of microsite parameters that were most strongly correlated with seedling growth. Multiparameter models explained between 15 and 39 percent of the variance in diameter growth. Prevalent terms from the strongest multiparameter models included soil penetration, log presence, stump presence, skid road presence, and topography. Individual microsite parameters for each regeneration site were also assessed for importance in explaining diameter growth using two additional methods. The first approach was to isolate the parameters that appeared in the strongest multiparameter models and to sum and contrast the AIC weights of all models in which they appeared. The second approach was to regress single parameters against seedling diameter growth. Results varied by site for both methods. AIC weight sums revealed that topographical depression and berms, the presences of logs and stumps, and soil penetration (pounds per square inch) as measured by a penetrometer were most influential, with values ranging from 0.31 (berm) to 0.82 (log). Regression analysis revealed that topographical depression, log presence, and soil penetration were significantly related to diameter growth, explaining between 6 and 29 percent of the variance in diameter growth. Combined results from the three regeneration sites suggest that preferred planting locations are near berms, in the transition zone associated with skid roads, and in soil that is neither too loose nor too compacted. Results from the Randle and Orting sites indicate that planting in topographical depressions should be avoided. Results from Orting indicate that seedlings should not be placed near logs, and Randle findings suggest not planting next to stumps.
Taper Equations for Five Major Commercial Tree Species in Manitoba, Canada
Authors: Klos Ryan J. , Wang G. Geoff , Dang Qing-Lai , East Ed W.
Published: August 2019

Kozak's variable exponent taper equation was fitted for balsam poplar (Populus balsamifera L.), trembling aspen (Populus tremuloides Michx.), white spruce (Picea glauca [Moench] Voss), black spruce (Picea mariana [Mill.] B.S.P.), and jack pine (Pinus banksiana Lamb.) in Manitoba. Stem taper variability between two ecozones (i.e., Boreal Shield and Boreal Plains) were tested using the F-test. Regional differences were observed for trembling aspen, white spruce, and jack pine, and for those species, separate ecozone-specific taper equations were developed. However, the gross total volume estimates using the ecozone-specific equations were different from those of the provincial equations by only 2 percent. Although the regional difference in stem form was marginal within a province, a difference of approximately 7 percent of gross total volume estimation was found when our provincial taper equations were compared with those developed in Alberta and Saskatchewan. These results suggest that stem form variation increases with spatial scale and that a single taper equation for each species may be sufficient for each province.
Coast Redwood Regeneration Survival and Growth in Mendocino County, California
Authors: Jameson Marc J. , Robards Timothy A.
Published: August 2019

Three stands of second-growth redwood forest were clearcut, and the logging slash in two of the units was broadcast burned following logging. Three types of redwood seedlings (plug, plug-one, and 2-year bareroot) were planted following logging and burning. Seedling survival rates were high, and there were no significant differences between survival and growth of stock types after 9 years. The native redwood sprouts were substantially larger than the planted seedlings, in both height and diameter, which could affect future growth of some seedlings. The status and dimensions of seedlings and native regeneration were periodically checked. The burned units were fully occupied by a dense, tall growth of brush within a few years, and the brush became re-established after a successful initial herbicide treatment.
Estimating Suppression Expenditures for Individual Large Wildland Fires
Authors: Gebert Krista M. , Calkin David E. , Yoder Jonathan
Published: August 2019

The extreme cost of fighting wildland fires has brought fire suppression expenditures to the forefront of budgetary and policy debate in the United States. Inasmuch as large fires are responsible for the bulk of fire suppression expenditures, understanding fire characteristics that influence expenditures is important for both strategic fire planning and onsite fire management decisions. These characteristics then can be used to produce estimates of suppression expenditures for large wildland fires for use in wildland fire decision support or after-fire reviews. The primary objective of this research was to develop regression models that could be used to estimate expenditures on large wildland fires based on area burned, variables representing the fire environment, values at risk, resource availability, detection time, and National Forest System region. Variables having the largest influence on cost included fire intensity level, area burned, and total housing value within 20 mi of ignition. These equations were then used to predict suppression expenditures on a set of fiscal year 2005 Forest Service fires for the purpose of detecting “extreme” cost fires—those fires falling more than 1 or 2 SDs above or below their expected value.
Effects of Alternative Silvicultural Treatments on Cable Harvesting Productivity and Cost in Western Washington
Authors: Hartley Damon S. , Han Han-Sup
Published: August 2019

Increasingly, alternative silvicultural methods have been considered to meet the demand for nontimber values such as visual quality and biodiversity in the Pacific Northwest. The successful implementation of these alternative silviculture treatments requires careful consideration of economics and operational efficiencies in timber harvesting. This study used detailed time study and shift-level data to assess the effect of alternative silvicultural treatments on the production and cost of cable harvesting in western Washington. Four silvicultural treatments were examined: clearcut, two-age, patch cut and thin, and group selection. Silvicultural treatments greatly affected the production and cost of timber harvesting, especially in felling and yarding processes. The average yarding cycle time (3.74 minutes/cycle) in the clearcut unit was shorter than those in other partial cutting treatment units because there were no residual trees to work around and higher harvest volumes per acre, compared with the partial cut units. The average tree size greatly affected yarding cost: the clearcut unit had the second-highest yarding cost ($52.38/thousand board feet [mbf]) because of the smallest piece size (69.6 board feet/piece). Stump-to-truck cost for this study ranged from $70.49/mbf for the patch cut and thin to $120.19/mbf for the group selection. Carriage types and yarding direction also had an impact on yarding productivity.
Assessing the Applicability of Growth Models to New Species and Regions: An Example Comparing Mediterranean Maritime Pine in Central Spain to Ponderosa Pine in Southwestern Oregon, USA
Authors: Pascual D. , Maguire D.A. , Bravo F.
Published: August 2019

Evaluations of response to variable silvicultural treatments play a key role in developing sustainable forest management. To evaluate silvicultural response, a growth and yield model is needed. A comparison between similar species could act as a logical first step toward building a growth and yield model and to test the efficiency of the calibration of an existing ponderosa pine (Pinus ponderosa Dougl. ex Laws.) growth model to a Mediterranean maritime pine (Pinus pinaster Ait. ssp. mesogeensis) growth model. This study aimed at (1) comparing the diameter growth pattern between ponderosa and Mediterranean maritime pine, and (2) assessing the potential of ORGANON for simulating Mediterranean maritime pine growth and yield. The first objective was addressed by fitting a diameter growth equation for Mediterranean maritime pine and comparing it with patterns in ponderosa pine growth represented by the corresponding equation in ORGANON. The second objective was addressed by growing Mediterranean maritime pine as ponderosa pine in ORGANON, conditional on observed diameter growth rates of Mediterranean maritime pine in Spain. The results emphasized the unsuitability of ORGANON for predicting diameter growth of Mediterranean maritime pine in Spain. Mediterranean maritime pine diameter growth depended on basal area in trees with a diameter larger than the subject tree, (BAL) which, in our context is a subrogate of competition from above.
Biomass Inventory and Regrowth Rate of Harvestable Tree and Shrub Moss in the Oregon Coast Range
Authors: Peck JeriLynn , Muir Patricia
Published: August 2019

The commercial moss harvest industry is at a crossroads. Concerns about the sustainability of harvest have led to moratoria on moss harvest from public lands, limiting access to this nontimber forest resource in most of the highest production regions of the United States. Resumption of legal harvest depends on improved knowledge about resource inventory and yield, which will enable the development of appropriate management scenarios. We present here the results of an inventory of current readily available legally harvestable moss and of a 10-year biomass regrowth study from the Coast Range of western Oregon. Harvestable tree and shrub moss was removed from 21 sites on the Siuslaw National Forest, using typical harvest methods and following the Forest's standards and guidelines for commercial moss harvest. Biomass across these sites averaged only 19 kg/ha (fresh weight). Only 52% of sites bore any harvestable moss, and only 38% had commercial quantities. Moss mats regrowing on experimentally stripped vine maple (Acer circinatum) shrub stems accumulated mass at a mean rate of 3.0 g/m-stem/year across six sites. At this rate, moss mats of equivalent biomass to the originally harvested mats would require approximately 27 years to develop. These data provide estimates of input parameters needed to develop schedules for commercial moss harvest.
Wood Production and Native Vegetation Conservation in Hawaii's Uplands
Authors: Ares Adrian , Fownes James , Simmons Peter
Published: August 2019

Stand basal area, a stochastic growth model (KOA), and GIS were used to simulate and spatially integrate potential timber production of the native koa (Acacia koa) in uplands on the island of Hawaii. Vegetation patterns were examined to estimate potential impacts on the ecosystem from increased forest activities and to select suitable areas for wood production and ecological preservation. The KOA model predicted a production of 82,200 m3 of merchantable koa wood at age 30 from nonmanaged, naturally regenerated stands. The spatial analysis revealed four corridors with high wood production. Mean vegetation patch size was 69 ha, with a greater frequency of small patches than of large patches. An index of patch shape and complexity was similar for patches from different categories, but it was inversely correlated to patch size, indicating different processes affecting landscape structure. A shape diversity index was greater for savannah patches than for closed canopy units, implying higher complexity in more disturbed areas. Patches within the same category were highly aggregated, and the core of the area with lower degree of disturbance matched low-productivity sites for koa.
Response of Bark and Woodboring Beetles to Host Volatiles and Wounding on Western Juniper
Authors: Hayes Jane L. , Johnson Patricia L. , Eglitis Andris , Scott Donald W. , Spiegel Lia , Schmitt Craig L. , Smith Steven E.
Published: August 2019

In central Oregon, management of western juniper (Juniperus occidentalis var. occidentalis Hook.) has included use of prescribed fire and mechanical removal. After these treatments, several species of bark and woodboring beetles have been observed on treated trees and also occasionally on trees outside management areas, suggesting that these insects might contribute to juniper mortality. In this 2-year (2002–2003) study, we identified bark and woodboring beetles that attack western juniper along with associated beetle predators and examined whether these insects can be manipulated for use in juniper management. Using funnel traps and sticky traps on trees wounded by pruning or treated with host volatiles (juniper berry oil, cade oil, and ethanol) that may attract insects, we captured beetles in the families Buprestidae, Cerambycidae, and Scolytidae (20 species in 17 genera) and known predators in the families Cleridae and Trogositidae (8 species in 7 genera). Cedar bark beetles (Phloeosinus spp.) were the most prevalent insects captured on trees treated with host volatiles and/or wounded. Treatments that included ethanol plus wounding were most attractive to these beetles. However, there was no obvious insect-caused damage or mortality of treated trees in either year of this study.
A Comparison of Statistical Methods for Estimating Forest Biomass from Light Detection and Ranging Data
Authors: Li Yuzhen , Andersen Hans-Erik , McGaughey Robert
Published: August 2019

Strong regression relationships between light detection and ranging (LIDAR) metrics and indices of forest structure have been reported in the literature. However, most papers focus on empirical results and do not consider LIDAR metric selection and biological interpretation explicitly. In this study, three different variable selection methods (stepwise regression, principle component analysis [PCA], and Bayesian modeling averaging [BMA]) were compared using LIDAR data from three study sites: Capitol Forest in western Washington State, Mission Creek in central Washington State, and Kenai Peninsula in south central Alaska. Separate aboveground biomass regression models were developed for each site as well as common models using three study sites simultaneously. Final biomass models have R2 values ranging from 0.67 to 0.88 for three study sites. PCA indicates that three LIDAR metrics (mean height, coefficient variation of height, and canopy LIDAR point density) explain the majority of variation contained within a larger set of metrics. Within each study area, forest biomass models using these three predictor variables had similar R2 values as the stepwise and BMA regression models. Individual site models using these three variables are recommended because these models are straightforward in terms of model form and biological interpretation and are easily adopted for application.