bluuebunny/crossref_metadata_2025 huggingface dataset:
Production, Cost, and Soil Compaction Estimates for Two Western Juniper Extraction Systems
Authors: Dodson Elizabeth M. , Deboodt Tim , Hudspeth Glen
Published: August 2019

Harvesting trials were performed during the winter and spring of 2003–2004 in central Oregon to compare the costs, production rates, and soil compaction impacts of two systems for harvesting western juniper (Juniperus occidentalis). The two systems compared were a conventional system consisting of manual felling, delimbing, and bucking using a chainsaw and skidding logs with a rubber-tired grapple skidder and a mechanical system that used a feller-buncher, a rubber-tired grapple skidder to skid whole trees, and a stroke-boom delimber. Stump to deck harvesting costs ranged from $32.15 to $49.48/ton for the conventional system and from $60.07 to $63.11/ton for the mechanical system. A limited trial was conducted with the mechanical system that merchandized fence posts as well as sawlogs. When fence posts were produced also, stump to deck costs were reduced to $31.56/ton. Soil compaction was measured pre- and postharvest using a soil penetrometer. Paired t-tests showed a statistically significant difference between harvested sites and nonharvested sites at depths of 2 and 4 in. (P = 0.032 and 0.001, respectively) but no difference between harvest systems. West. J. Appl. For. 21(4):185–194.
Lumber Manufacturing, Log Exports, and Timber Availability in Western Washington
Authors: Perez-Garcia John , Barr J. Kent
Published: August 2019

We analyzed historical data on timber use and projected timber availability to 2045 to examine whether timber volumes would be available to meet the harvest requirements of existing or expanding lumber manufacturing and log export sectors in western Washington. Biennial mill surveys from the Washington Department of Natural Resources were used to describe past timber demand by the sawmilling and log exporting sectors. A simple linear programming model was used to project timber availability into the future. Our analysis revealed that current harvest levels could continue into the future, under some restricting assumptions, and can provide adequate timber volume to maintain the current lumber manufacturing sector. The projection also suggested that sawmilling capacity could expand if log exports should continue to decline. The projections are further analyzed with respect to historical distributions by species.
The Opportunity Cost of Forest Certification on Private Land in Western Oregon
Authors: Busby Gwenlyn M. , Montgomery Claire A. , Latta Greg S.
Published: August 2019

In this report, we use a timber supply model for western Oregon to estimate the economic and ecological effects of forest certification. We estimate opportunity cost, the foregone value of wood production as a result of complying with certification standards, in the case of a $28/1000 board feet (mbf) and a $56/mbf certification bonus payment. Results indicate that, within the 100-year time horizon, 20 and 60% of total acres choose to certify, respectively. However, we find that the ecological benefit of certification, measured in terms of acres of old forest structure, is minimal. We also estimate certification levels when “group certification” is considered. When aggregated areas are permitted to certify as a group, we find that significantly more acres choose to certify and that they do so earlier.
Timber Trends on Private Lands in Western Oregon and Washington: A New Look
Authors: Adams Darius M. , Latta Gregory S.
Published: August 2019

Market model projections of private harvest in the Douglas-fir region over the period to 2054 suggest that harvests in western Oregon could be sustained at or above recent levels for the full period with ending inventories at least as high as in 2004. Western Washington, in contrast, may face some harvest reductions, particularly on other private ownerships, as a result of high harvests in the 1980s and continued rapid land loss. Projected silvicultural regimes in both half-states shift toward more use of commercial thinning on all private ownerships. No trend in future log prices is foreseen. In policy simulations, applying Washington's riparian protection policy to western Oregon led to a 4.4% annual private harvest reduction. Extension to intermittent streams in western Washington reduced annual harvest by 1.9%. Quintupling national forest harvest across the region increased annual regional harvest by 3.2% with more than a quarter of the public increment offset by private harvest reductions.
In Situ Gene Conservation of Six Conifers in Western Washington and Oregon
Authors: Lipow Sara R. , Vance-Borland Kenneth , St. Clair J. Bradley , Henderson Jan A. , McCain Cindy
Published: August 2019

Agap analysis was conducted to evaluate the extent to which genetic resources are conserved in situ in protected areas for six conifer species in the Pacific Northwest (Sitka spruce, sugar pine, western white pine, ponderosa pine, western redcedar, and western hemlock). The gap analysis involved producing a GIS database detailing the location of protected areas and the distribution and abundance of tree species as inferred from data on potential plant association groups, actual plant associations, and actual land cover type. We used two schemes for stratifying the distribution of each species into genetic populations for gap analysis: seed zones and ecoregions. The results show that most seed zones and ecoregions contain at least 5,000 mature individuals in protected areas, indicating strong in situ gene conservation. Protection is less complete, however, for western white pine in the Puget lowlands, where urbanization and disease have reduced populations below safe levels. These populations represent the highest priority for additional gene conservation. Other species and areas warranting further evaluation include Sitka spruce in some parts of the Puget lowlands, remnant western white pine stands in the Oregon Coast Range, and sugar pine within the white pine blister rust zone.
Does Variable-Density Thinning Increase Wind Damage in Conifer Stands on the Olympic Peninsula?
Authors: Roberts Scott D. , Harrington Constance A. , Buermeyer Karl R.
Published: August 2019

Silvicultural treatments designed to enhance stand structural diversity may result in increased wind damage. The ability to avoid conditions that might lead to excessive wind damage would benefit forest managers. We analyzed wind damage following implementation of a variable-density thinning at four sites on the Olympic National Forest in northwest Washington. The prescription created small canopy gaps and retained unthinned patches within a uniformly thinned matrix, thus creating substantial amounts of internal edge. Our objective was to determine whether variable-density thinning resulted in elevated wind damage and whether the damage was spatially related to elements of the treatment, i.e., canopy gaps and uncut patches. Wind damage on the thinned plots averaged slightly more than 8.0 trees/ha. Although precise determinations of residual stem densities were not available, we estimate that total wind damage amounted to 1.3% of total stems remaining following treatment. Approximately 80% of the wind damage was blowdown, the remaining damage being stem breakage, leaning, or bowing. Nearly 54% of the damaged stems were less than 20 cm dbh. The maximum amount of damage observed was 51 trees/ha, but only 3 of 13 thinned plots had wind damage exceeding 7 trees/ha. The overall level of wind damage across all thinned plots after two growing seasons was not statistically greater than on unthinned control plots. Internal edges created by gaps, skid trails, and unthinned patches did not inherently increase wind damage risk; however, where gaps were located in topographically vulnerable positions, greater wind damage did occur. Overall wind damage was not excessive on any of the plots, and after 2 years, all residual stands remained intact and in a manageable condition. Our preliminary results suggest that variable-density thinning that includes creation of small canopy gaps does not necessarily predispose stands to greater risk of wind damage than uniform thinning. However, care must be taken in locating gaps and skid trails away from topographically vulnerable positions.
Effects of a Western Spruce Budworm Outbreak on Private Lands in Eastern Oregon, 1980–1994
Authors: Azuma David L. , Overhulser David L.
Published: August 2019

Forest Inventory and Analysis data from three inventory periods were used to examine the effects of a western spruce budworm outbreak on private lands in eastern Oregon. Growth was negatively related to defoliation with differences between crown ratio and species. The mortality and salvage harvesting caused changes in stand structure on private lands. Although many stands showed a decrease in basal area, there was no detectable decrease in host species as a percentage of basal area. The combined effect of mortality, harvest, and loss in predicted growth may be as much as 30% of the initial standing volume.
Changes in Stream Channel Morphology Caused by Replacing Road-Stream Crossings on Timber Harvesting Plans in Northwestern California
Authors: Harris Richard , Gerstein Jared , Cafferata Peter
Published: August 2019

Past studies have shown that roads used for timber management and recreation are major sources of sedimentation in many streams throughout the Pacific Northwestern United States. Stream crossings are portals for the entry of sediment derived from road surface erosion. They are also prone to catastrophic failure during stressing weather events if they are undersized or otherwise deficient in design or construction. In recent years, public and private landowners have replaced or removed numerous deficient crossings in forested watersheds throughout California and elsewhere in the West. The benefits of replacing these crossings include eliminating both chronic and episodic inputs of sediment to streams. When old crossings are replaced with new, properly designed and installed crossings, there is a potential for construction-related erosion. This research examined the postconstruction erosion associated with the replacement of 30 stream crossings in coastal California. Channel surveys were conducted immediately after construction and after the passage of one winter rainy season. The results indicated very little erosion on most sites; 11 experienced no erosion at all. On those sites where erosion did occur, the amounts did not exceed 10 cubic yards. A few sites experienced aggradation or erosion unrelated to upgrading but due to upstream landslides. This research shows upgraded stream crossings on commercial timberland may contribute little sediment to streams after construction under moderate weather conditions if adequate erosion control measures are implemented.
Direct Sampling for Stand Density Index
Authors: Ducey Mark J. , Valentine Harry T.
Published: August 2019

A direct method of estimating stand density index in the field, without complex calculations, would be useful in a variety of silvicultural situations. We present just such a method. The approach uses an ordinary prism or other angle gauge, but it involves deliberately “pushing the point” or, in some cases, “pulling the point.” This adjusts the usual limiting distances in prism sampling to match the limiting distances required for sampling with a specified stand density factor (SDF). The estimate of stand density associated with a point is just the number of trees tallied times the SDF; no diameter measurements are needed. We give guidelines on choosing an SDF on the basis of expected stand characteristics and equations for calculating the limiting distances and the amount of “push.” Field implementation of the resulting method is extremely fast and simple.
Growth Response of Mature Trees versus Seedlings to Gaps Associated with Group Selection Management in the Sierra Nevada, California
Authors: York Robert , Battles John
Published: August 2019

Radial growth response of mature conifer trees to creation of gaps using group selection was measured along transects extending from gap edges into a surrounding forest in central Sierra Nevada, California. A reference sample of trees between gaps was measured for comparison. Edge depth was quantified as the distance from gaps to where radial growth of trees near gaps converged with growth of trees from the reference sample. Trees within 10 meters of gaps grew more than trees from the reference sample, with no detectable differences in this depth caused by gap size (0.1 to 1.0 ha), species (Douglas-fir, incense-cedar, ponderosa pine, and white fir), or orientation (cardinal direction) relative to the gap. The lack of orientation influence suggests increased underground resource availability and possibly an allometric adjustment to preferential radial growth as the causes of the positive edge effect. When considering these results with those reported previously from the same study, details of the stand level tradeoff between growth of planted regeneration within gaps and growth of larger trees surrounding them reveal implications of gap size choice in gap-based silvicultural regimes. Whereas early height suppression of seedlings was avoided with gap sizes above approximately 0.3 to 0.5 ha, radial growth in the unharvested forest was substantially increased with gap sizes below that same size range.
Efficacy of Individual Barriers to Prevent Damage to Douglas-Fir Seedlings by Captive Mountain Beavers
Authors: Runde Douglas E. , Nolte Dale L. , Arjo Wendy M. , Pitt William C.
Published: August 2019

We tested the ability of individual tree seedling protectors to deter mountain beavers from damaging Douglas-fir seedlings. Using captive mountain beavers in field pens, we tested 20 products representative of a wide range of barriers suitable for protecting individual tree seedlings from rodent damage. Eleven products protected 95% or more of seedlings from damage. Tree shelters and fabric shelters provided the most protection; 98 and 95% of seedlings were undamaged, respectively. Rigid mesh protector tubes protected 81% of seedlings, and protection netting protected 55% of seedlings. Purchase prices varied widely; protection netting was least expensive, followed by rigid mesh tubes, fabric shelters, and tree shelters. Seedling growth was greatest within fabric shelters and plastic tree shelters. Materials used to construct 15 of the 20 tree protectors were tested using captive mountain beavers in small sheltered pens. Here, samples of barrier materials were used to block access to a favored food. The four materials that excluded all test animals in all trials were from unvented tree shelters with solid seamless walls. Seven materials failed to exclude any animals in the sheltered-pen trials.
Taper and Volume Responses of Douglas-Fir to Sulfur Treatments for Control of Swiss Needle Cast in the Coast Range of Oregon
Authors: Younger Nicole L. , Temesgen Hailemariam , Garber Sean M.
Published: August 2019

For nearly 20 years, foresters in the Oregon Coast Range have been witnessing a substantial decease in Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco.) vigor and volume, caused by Swiss needle cast (SNC) disease. Currently, there are no solutions and disease severity is expected to worsen in coming years, but there is hope that aerially applied treatments of sulfur may be able to alleviate the effects of SNC. In this trial, volume, taper, and other attributes were examined on 120 Douglas-fir trees heavily infected with SNC for response to treatments of (1) sulfur, (2) sulfur + nutrients, and (3) control, which received no treatment. Tree attributes such as crown ratio, crown width, and sapwood area at crown base showed no statistically significant differences between treatments. Means of both foliage mass and years of needle retention also were not different between sulfur and control treatments. However, both of these attributes were different between the sulfur + nutrient and control treatments (P = 0.0599, 0.0205). Using a modified Kozak's (1988) variable exponent model form, taper analysis indicated that the taper of trees within the sulfur treatment was not significantly different from the taper of the control, while the sulfur + nutrient treatment showed decreased taper compared with the control (P =<0.0246). This improvement of taper in the sulfur + nutrient stand, however, has not translated into a statistically significant increase in cubic foot volume removed in the first thinning after adjusting for tree size differences between treatments. Comparing treatments by monetary value of removed trees in the first thinning also showed no significant differences, thereby implying that sulfur and sulfur + nutrient treatments are not able to increase volume enough in 4 years to produce additional profits in the first commercial thinning. It should be noted, however, that all conclusions drawn from this study are essentially from a single replication, and the scope of inference applies only to this particular type of stand in the Oregon Coast Range.
Simulating Multiaged Coast Redwood Stand Development: Interactions between Regeneration, Structure, and Productivity
Authors: Berrill John-Pascal , O'Hara Kevin L.
Published: August 2019

Multiaged management regimes and harvesting scenarios were simulated in coast redwood (Sequoia sempervirens [D. Don.] Endl.) stands using models of stand growth and yield (CRYPTOS) and stocking assessment (redwood MASAM). Various stocking and age-class combinations were modeled on site index 100 and 130 ft (50 years). Results demonstrated how the number of cohorts, upper limit of stocking, and cohort densities affected growth and yield. Board foot volume increment reached a plateau in stands with a prescribed upper limit of stocking above leaf area index 7.2 to 8.6. Productivity did not differ between stands with two to five cohorts producing the same tree size at harvest. It was affected by stand structure when a cutting cycle of 20 years was prescribed in stands with three to five cohorts. Stands with the same density returned to the upper limit of stocking much sooner on better sites. Prolonging the cutting cycle by reducing stand density resulted in larger tree sizes at harvest and greater productivity. The growth of trees remaining after cutting 10–50% of stand basal area and growth of new stump sprouts were also simulated. Stands quickly returned to preharvest stocking after light cutting, implying that heavy or frequent light cutting is needed to sustain growth and vigor of regeneration in multiaged coast redwood stands.
The Ratio of Additive and Traditional Stand Density Indices
Authors: Ducey Mark J.
Published: August 2019

The ratio between additive and original versions of Reineke's stand density index (SDI) has been used as a descriptor of stand structural complexity. That ratio also can be informative for designing efficient sampling methods and for the design of silvicultural experiments. Previous analyses of this ratio have assumed a diameter distribution without truncation, such that trees from zero to infinite dbh are possible. Truncation of the diameter distribution, e.g., by tallying only trees larger than some minimum dbh, moves the ratio much closer to one when the stand has a classic balanced uneven-aged structure. Minimum values of the ratio are found not with classic reverse-J distributions, but with sharply bimodal distributions that might be typical of a two-cohort stand. The implications for the use of novel sampling methods and for experimental designs to test whether the additive or original SDI provides better prediction in irregular stands are discussed.
Summer Water Temperatures in Alluvial and Bedrock Channels of the Olympic Peninsula
Authors: Hunter Mark A. , Quinn Timothy
Published: August 2019

To better understand how stream geomorphology may affect water temperature, we recorded water temperatures along two channels, one with deep alluvium and the other composed of bedrock and shallow alluvium. Study channels were located in managed forestlands on the Olympic Peninsula. Water temperatures were recorded hourly at 75-m intervals along 1.6 and 1.4 km of the alluvial and bedrock channels, respectively, during the summers of 2003 and 2004. Seasonal maximum and minimum daily water temperatures (i.e., season-long means for individual temperature dataloggers) in the alluvial channel tended to vary less over the course of the summer than temperatures in the bedrock channel. In addition, the means of all the individual dataloggers' daily maximums for each stream (reach mean maximum) and, similarly, the daily minimums (reach mean minimum) varied less for the alluvial channel. Changes in temperature from the upstream to downstream were greater for the bedrock channel, but only at low flow.
Evaluating Economic and Wildlife Habitat Considerations for Snag Retention Policies in Burned Landscapes
Authors: Eklund Aaron , Wing Michael G. , Sessions John
Published: August 2019

Wildfires have become more frequent and intense in recent years in the western United States. Previous studies have investigated the potential environmental and economic impacts of active management in burned forest landscapes. No previously published study, however, has considered wildlife requirements for snags while planning salvage logging operations in postburned landscapes. We examined the potential impacts of 19 snag retention strategies using cable-based yarding systems over a 3-year time period since burn. The strategies were based on current research recommendations, operational needs, and state and federal policies. Potential impacts on two cavity-nesting bird habitats and the feasibility of each strategy were examined. We found that most snag retention strategies generated net revenues per unit volume of merchantable wood greater than $70/m3 immediately after a burn and $60/m3 3 years after a burn. Those strategies that focused snag retention on smaller-diameter stems had the highest net revenue values and higher productivity rates. We also found that the strategy that removed all merchantable snags did not produce the highest revenue. In general, decreased yarding distance and a smaller yarding system (e.g., shovel loader) resulted in greater net revenue per unit volume with increased time since burn. The salvage strategy that provided the most favorable habitat for the two cavity-nesting birds left all snags standing in the half of the salvage unit farthest away from the yarder. Our findings indicate that it is possible to provide adequate cavity-nesting bird habitat and generate net revenue during fire salvage operations.
Temporary Logging Roads Surfaced with Mulched Wood
Authors: Lyons Kevin , Day Ken
Published: August 2019

This article summarizes the results of a field trial where logging residue was mulched on site to produce a running surface for temporary in-block roads. The results of this trial indicate roads with a mulched wood surface outperform soil roads when the subgrade consists of a saturated fine-grained soil. Failure of the mulched wood roads was caused by excessive localized rutting, which could be repaired by hand or with a skidder blade under operational conditions.
An Accuracy Assessment of Positions Obtained Using Survey- and Recreational-Grade Global Positioning System Receivers across a Range of Forest Conditions within the Tanana Valley of Interior Alaska
Authors: Andersen Hans-Erik , Clarkin Tobey , Winterberger Ken , Strunk Jacob
Published: August 2019

The accuracy of recreational- and survey-grade global positioning system (GPS) receivers was evaluated across a range of forest conditions in the Tanana Valley of interior Alaska. High-accuracy check points, established using high-order instruments and closed-traverse surveying methods, were then used to evaluate the accuracy of positions acquired in different forest types using a recreational-grade GPS unit and a Global Navigation Satellite System (GLONASS)-enabled survey-grade unit, over a range of acquisition and postprocessing alternatives, including distance to base station, or baseline length (0ߝ10, 10ߝ50, 50ߝ100, and >100 km), use of Russian GLONASS satellites, and occupation times (5, 10, and 20 minutes). The accuracy of recreational-grade GPS was 3ߝ7 m across all sites. For survey-grade units, accuracies were influenced by forest type and baseline length, with lower errors observed with more open stands and shorter baseline lengths. The use of GLONASS satellites improved positions by a small but appreciable amount, and longer observation times (20 minutes) resulted in more reliably accurate positions across all sites. In general, these results indicate that if forest inventory plots in interior Alaska and other high-latitude regions of the world are occupied for 20 minutes with survey-grade instruments, positions with submeter error can be consistently obtained across a wide range of conditions.
Comparing Timber and Lumber from Plantation and Natural Stands of Ponderosa Pine
Authors: Lowell Eini C. , Todoroki Christine L. , Thomas Ed
Published: August 2019

Data derived from empirical studies, coupled with modeling and simulation techniques, were used to compare tree and product quality from two stands of small-diameter ponderosa pine trees growing in northern California: one plantation, the other natural. The plantation had no management following establishment, and the natural stand had no active management. Fifty trees of similar diameter classes were selected from each site, measured, bucked into logs, and sawn into boards, and the boards were scanned for defects. Trees from the plantation stand demonstrated less variability in tree height, crown length, and age structure. The plantation trees were on average 4 years younger than their natural cohorts, yet for all but the smallest diameter there were no significant differences between mean tree height or crown length. Predicted merchantable volumes differed significantly for the largest diameter class. Merchantable volume was estimated to be 5% greater for the plantation trees than for the natural stand trees. More logs were bucked from the plantation stands, resulting in greater lumber production and greater value overall. Butt logs from the plantation stand had an average of 9 whorls per log, whereas natural butt logs averaged 10 whorls per log. The most numerous defects, outnumbering knots and wane, were needle traces. These occupied some 31% of natural board surface area, in comparison with 19% for plantation boards. Given the shorter time frame required to grow plantation trees, the greater merchantable volumes, and more consumer-acceptable defects, plantation stands, even with a minimal level of management, offer greater product potential than natural stands.
Perceptions of Change in the US Pacific Northwest Forest Practices on Certified and Noncertified Holdings
Authors: Tikina Anna , Kozak Robert , Bull Gary , Larson Bruce
Published: August 2019

A mail survey of certified and noncertified forest managing entities (public agencies, forest industry, and nonindustrial private forest owners) in the US Pacific Northwest region (PNW) was conducted to better understand forest practitioners' perceptions related to the degree of change in forest practices. The results of this study reveal that forest managers perceive relatively small changes in practices in the US PNW, regardless of the certification standard used, although the degrees of change differed for public, forest industry, and nonindustrial private forest owners. This conclusion applies to both certified and noncertified holdings.
Analysis of Conifer Mortality in Colorado Using Forest Inventory and Analysis's Annual Forest Inventory
Authors: Thompson Michael T.
Published: August 2019

Aerial detection surveys indicate that widespread conifer mortality has been steadily increasing in Colorado, particularly since 2002. The Forest Inventory and Analysis (FIA) annual inventory system began in Colorado in 2002, which coincided with the onset of elevated conifer mortality rates. The current mortality event coupled with collection of 6 years of annual inventory data provided an opportunity to test the usefulness of the FIA annual inventory system for quantifying rapid change in the conifer resource over a large geographic area. The estimate of conifer mortality during the 2002–2007 period indicated an average of 44 million trees that died each year, which represents more than twice the average recorded in the 1997–2002 period. The estimate of insect-killed lodgepole pine averaged 10.5 million trees during the 2002–2007 period, which represents a 10-fold increase compared with the estimate recorded for the 1997–2002 mortality period.
Object-Oriented Classification of Forest Structure from Light Detection and Ranging Data for Stand Mapping
Authors: Sullivan Alicia A. , McGaughey Robert J. , Andersen Hans-Erik , Schiess Peter
Published: August 2019

Stand delineation is an important step in the process of establishing a forest inventory and provides the spatial framework for many forest management decisions. Many methods for extracting forest structure characteristics for stand delineation and other purposes have been researched in the past, primarily focusing on high-resolution imagery and satellite data. High-resolution airborne laser scanning offers new opportunities for evaluating forests and conducting forest inventory. This study investigates the use of information derived from light detection and ranging (LIDAR) data as a potential tool for delineation of forest structure to create stand maps. Delineation methods are developed and tested using data sets collected over the Blue Ridge study site near Olympia, Washington. The methodology developed delineates forest areas using LIDAR data and object-oriented image segmentation and supervised classification. Error matrices indicate classification accuracies with a kappa hat values of 78 and 84% for 1999 and 2003 data sets, respectively.
Effects of Forest Biomass Use on Watershed Processes in the Western United States
Authors: Elliot William J.
Published: August 2019

As society looks to our nation's forests as sources of energy, there is a risk of increased runoff and erosion. This report gives an overview of watershed processes, discusses the impacts of biomass removal on those processes, provides some guidelines to minimize adverse impacts, anddescribes an approach for estimating the effects of biomass removal on soil erosion.
Nonnative Plant Response to Silvicultural Treatments: A Model Based on Disturbance, Propagule Pressure, and Competitive Abilities
Authors: Sutherland Steve , Nelson Cara R.
Published: August 2019

Invasion by nonnative plants can result in substantial adverse effects on the functions of native forest ecosystems, including nutrient cycling and fire regimes. Thus, forest managers need to be aware of the potential impacts of management activities, including silvicultural treatments,on nonnative vegetation. To aid in that effort, we created a conceptual model of potential responses of nonnative plants to silvicultural treatments, used the model to make a general set of predictions, and tested our predictions against observed responses published in the scientific literature.Of a total of 42 studies that addressed the effects of silvicultural treatments on nonnative plants, 90% found a posttreatment increase in at least one nonnative plant species. All of the studies that assessed the effect of disturbance intensity on nonnative plants found that invasion successincreased with increasing disturbance intensity or number of management entries. As predicted by the model, there was substantial among-species and among-site variation in nonnative plant responses to silvicultural treatments; variation in responses were probably driven by local conditionsincluding propagule pressure, condition of the forest community, or characteristics of the local flora (native and nonnative species). Because species- and location-specific changes in nonnative plants are dependent on local conditions, local knowledge is important for predicting invasionpotential. In addition, monitoring is essential for early detection of postharvest invasions and/or expansions of nonnative plants.
Effects of Biomass Removal Treatments on Stand-Level Fire Characteristics in Major Forest Types of the Northern Rocky Mountains
Authors: Reinhardt Elizabeth D. , Holsinger Lisa , Keane Robert
Published: August 2019

Removal of dead and live biomass from forested stands affects subsequent fuel dynamics and fire potential. The amount of material left onsite after biomass removal operations can influence the intensity and severity of subsequent unplanned wildfires or prescribed burns. We developed a set of biomass removal treatment scenarios and simulated their effects on a number of stands that represent two major forests types of the northern Rocky Mountains: lodgepole and ponderosa pine. The Fire and Fuels Extension to the Forest Vegetation Simulator was used to simulate effects including stand development, fire behavior, and fire effects prior to the biomass removal treatment and 1, 10, 30, and 60 years after the treatment. Analysis of variance was used to determine whether these changes in fuel dynamics and fire potential differed significantly from each other. Results indicated that fire and fuel characteristics varied within and between forest types and depended on the nature of the treatment, as well as time since treatment. Biomass removal decreased fire potential in the short term, but results were mixed over the long term.
Returns from the Management of Noble Fir Stands for Bough Production and Sawtimber
Authors: Blatner Keith A. , Cohn Patricia J. , Fight Roger D.
Published: August 2019

Noble fir (Abies procera Rehder) bough harvest has been part of the nontimber forest products industry in the Pacific Northwest for decades. The boughs are used for seasonal decorations and command a higher pricethan most other decorative bough species. However, noble fir boughs that are harvested in the region have been merely a byproduct of noble fir plantations managed for timber products. This article presents the results of a study assessing the financial desirability of managing noble fir plantationsin the southern Cascade Mountains of Washington State for the production of both timber and bough products. The Landscape Management System software program was used to simulate the growth of noble fir in four different plant associations on the Gifford Pinchot National Forest. Data from recentlyestablished noble fir plantations were used in the simulations. Harvestable bough weights were estimated using a previously published noble fir bough weight model. Comparisons of estimated harvest volumes for sawlogs and noble fir boughs showed positive present net worth (PNW) values for eachstand under a combined timber production and bough harvest scenario and negative PNW values for each stand with a timber production management scenario only. Bough harvest is compatible with other land use activities, and the harvest revenue can cover stand establishment and precommercialthinning costs.
Effects of Bear Damage on Douglas-Fir Lumber Recovery
Authors: Lowell Eini C. , Dykstra Dennis , McFadden George
Published: August 2019

Bear activity resulting in injury to Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees has been documented as early as the mid-1850s in the Pacific Northwest. The study reported in this article was designed to help managers decide whether the common practice of removing the damaged but potentially valuable butt section of the bottom log and leaving it in the woods is warranted. Thirty-four damaged and 28 undamaged trees were selected from three sites in western Washington where bear damage has been a persistent problem. Trees were felled and bucked into 16-ft lengths. The damaged trees in the sample had been injured at ages between 10 and 15 years at two sites and between 10 and 65 years at the third site. The primary scaling deductions were for ring and scar defects. The 16-ft butt logs from the damaged and undamaged trees were sawn into dimension lumber. Bear-damaged logs were found to have lower cubic volume recovery than undamaged logs having the same small-end diameters. Lumber grade recovery was also influenced by bear damage; logs from damaged trees had a lower percentage of high-value lumber. The analysis suggests that the optimal harvesting policy is to haul the entire butt log to the mill rather than leaving the damaged portion in the woods. Although the value of the damaged portion is lower, most of the lumber recovered from that section can be used, with only a modest reduction in grade and value.
Developing and Comparing Silvicultural Alternatives: Goals, Objectives, and Evaluation Criteria
Authors: Long James N. , Smith Frederick W. , Roberts Scott D.
Published: August 2019

We outline an approach for developing and comparing silvicultural alternatives. The approach has multiple advantages, including explicit links between goals, management approaches, and outcomes; efficient development of alternative means of accomplishing the goals; and effective communication of potential tradeoffs between both objectives and alternatives.
Engineering Considerations in Road Assessment for Biomass Operations in Steep Terrain
Authors: Sessions John , Wimer Jeff , Costales Forrest , Wing Michael G.
Published: August 2019

With the increasing interest in the use of biomass for energy, conventional and alternative delivery systems are being evaluated for transporting biomass generated from harvest residuals on steep terrain in the Pacific Northwest. Conventional delivery systems include chipping or grinding of harvest residues (comminution) at the landing or a satellite yard in the forest and transporting the material with chip trucks to a power facility. To address some of the challenges of conventional methods of transporting biomass in steep terrain, chip van manufacturers have been making trailer modifications to increase vehicle maneuverability on forest roads. To evaluate the proper van configurations for implementing a successful biomass transportation system, planners should understand the limitations of the various chip van options. We present guidelines for designing new roads and evaluating existing road systems for chip truck access to forest residuals, as well as some practical field assessment procedures to evaluate accessibility on existing roads.
Predictive Habitat Modeling of Rare Plant Species in Pacific Northwest Forests
Authors: Buechling Arne , Tobalske Claudine
Published: August 2019

Certification requirements associated with the Sustainable Forestry Initiative include efforts to identify and protect occurrences of endangered plant species. Habitat models were constructed in this study using maximum entropy and random forest algorithms to generate independent predictions for four selected rare plants, Castilleja chambersii, Erythronium elegans, Filipendula occidentalis, and Sidalcea nelsoniana, associated with divergent physical environments. Explanatory variables used to model rare plant occurrence included Landsat Enhanced Thematic Mapper Plus spectral imagery, spectral-based vegetation indices, climatic data, and several terrain variables derived from a digital elevation model. Models were trained with known occurrence records obtained from the Oregon Biodiversity Information Center. Subsequent field surveys were conducted to acquire randomly located test data for comparative model evaluation. A range of accuracy statistics was computed that indicated generally high prediction accuracy for both methods. Model performance was highest for species with narrow, well-defined ecological requirements at scales comparable to the resolution of the calibration data. Species with relatively broad ecological distributions or with extremely specific habitat requirements were less accurately predicted. Random forest-based models generally produced higher rates of prediction success than maximum entropy when model performance was limited by the ecology of a species. Field surveys identified 22 previously unknown populations of the target rare plants, suggesting the efficacy of habitat models for predicting rare species occurrence and their utility as a prescriptive tool for land management planning.
Growing Space Management in Boreal Mixedwood Forests: 11-Year Results
Authors: Kabzems Richard D. , Harper George , Fielder Peter
Published: August 2019

Managing boreal mixed stands of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca [Moench] Voss) is more likely to sustain a diversity of values and has the potential to increase productivity at both the site and landscape levels compared with pure broadleaf or conifer management. In this study, we examine growth of white spruce and aspen after 11 growing seasons over a range of aspen densities created by spot and broadcast treatment of broadleaves using manual and chemical means, aspen spacing, and an untreated control. Results indicate that survival and growth of both spruce and aspen were similar across the range of treatments. Spruce groundline diameter was greater, and height to groundline diameter ratio was lower, for the treatments in which aspen was chemically controlled or uniformly spaced compared with the control. Light measurements at the individual tree level suggested that increased light availability improved white spruce diameter growth. Spruce height growth did not vary by treatment. The status of these experimental mixedwoods was compared with current conifer and mixedwood regeneration evaluations, as well as the preharvest composition of the original stand. After 11 growing seasons, growth of aspen and white spruce indicated that opportunities exist to further modify aspen density to enhance treatment longevity and effectiveness to produce a greater range of boreal mixedwood stand types.
Landowner Perceptions of Habitat Protection Policy and Process in Oregon
Authors: Giampaoli Peter , Bliss John C.
Published: August 2019

Nonindustrial private forestland (NIPF) owners in the United States are subject to state and federal regulations designed to protect fish and wildlife habitat, wetlands, and other sensitive resources. Oregon state regulations restrict forest operations on private lands that might potentially conflict with specified resource sites, including nest sites of certain bird species and wetland sites. Research undertaken in 2004 examined the extent and distribution of sensitive resource site actions and examined the perceptions, attitudes, and behaviors of affected NIPF owners regarding specified resource site policies and procedures. Methods included statistical analysis of state databases and semistructured interviews with key informants. Interviews were recorded, transcribed, and analyzed to elicit central themes. Our findings suggest that NIPF owners' responses to sensitive resource protection reflect not only economic concerns but also landowner management objectives and values and their perceptions of policy implementation. Themes related to power and control, perceptions of habitat protection, policy implementation, and trust and credibility are identified as driving informant views of resource protection policy.
A New Look at Pruning Coast Douglas-Fir
Authors: Fight Roger D. , Cahill James M. , Fahey Thomas D. , Snellgrove Thomas A.
Published: August 2019

Pruning of coast Douglas-fir for (Pseudotsuga menziesii var. menziesii) lumber was evaluated by using new product-recovery information and new computer software. The results showed that higher financial returns from pruning are achieved by pruning early in stands that have a higher site index and that will be fertilized. Interest rates and the premium for clear lumber will have major impacts on the dollar return from pruning. West. J. Appl. For. 3(2):46-48, April 1988.
Consulting Foresters in the Pacific Northwest
Authors: Schnepf Christopher C. , Baumgartner David M.
Published: August 2019

In 1986, 83% of an estimated total of 218 consulting foresters in Washington, Oregon, Idaho, and Montana were surveyed; 56% consulted full-time and 44% consulted part-time. In total, consultants provided 155 person-years of service to all owners. Most respondents believed the number of consultants in the areas they served was about right. Consultants averaged 24 years of forestry experience, including 10 years in consulting. Consultants belongs to a variety of professional and other organizations and most had completed at least a four-year degree. Consultants primary clients were nonindustrial private forest (NIPF) owners, industry, and federal government. In the last year, consultants provided 57 person-years of assistance to over 2,130 NIPF owners holding over 2 million acres. Most of these NIPF clients were assisted with services related to timber management or harvest. West. J. Appl. For. 3(3):74-76, July 1988.
Christmas Tree Cutting: Demand and Value as Determined by the Travel Cost Method
Authors: Markstrom Donald C. , Donnelly Dennis M.
Published: August 2019

The travel cost method was used to determine the value of trips to cut Christmas trees in northern Colorado. The analysis indicated an average value of $9 37 to the Christmas tree collectors for an uncut Christmas tree at the collection site This value includes a $5.00 cutting fee and an average consumer surplus of $4.37 per tree. West. J. Appl. For. 3(3):83-86, July 1988.
Early Development of Three Douglas-Fir Stocktypes on a Droughty Skeletal Soil
Authors: Hobbs Stephen D. , Crawford Michael S. , Yelczyn Beverly A.
Published: August 2019

Three stocktypes of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) were planted in a droughty, skeletal soil in southwest Oregon. After 5 years, container-grown plugs and plug-1 transplants survived significantly better than 2-0 bareroots. Seedling root systems were largely confined to the surface soil, with relatively little development upslope or deeper than 15 cm. Stocktype morphology differed significantly at planting. However, annual absolute growth, annual relative growth, and shoot and root characteristics did not differ significantly after 5 years. These results suggest that, on similar sites, seedling morphological characteristics within the range of those measured in this study may not affect growth and that stocktype designation along may not be adequate for predicting field performance. West. J. Appl. For. 4(1):21-24, January 1989.
The Use of Fire Weather Indices in the Prediction of Extreme Fire Loads
Authors: Mees Romain , Bednar Larry
Published: August 2019

We examined the correlation between fire activity and weather records for a 15-year period and a number of National Forests located in Oregon and California. Correlations between burned area and personnel usage, and fire weather indices of the National Fire Danger Rating System were weak. But time periods for which the fire weather indices showed extreme values also have a considerably larger proportion of extreme fire activity. In this sense, the indices can serve as predictors of extreme fire acitvity. This holds true in areas of widely divergent climates and differing fuel types. The joint influence of time-clustering of fires and extreme fire conditions, as reflected by the burning index, is also quantified. West. J. Appl. For. 4(2):46-48, April 1989.
Effects of Nitrogen Fertilization on Growth of Grand Fir and Douglas-Fir Stands in Northern Idaho
Authors: Shafii Bahman , Moore James A. , Olson John R.
Published: August 2019

A study of nitrogen fertilization response in thinned and unthinned stands of grand fir (Abies grandis) and Douglas-fir (Pseudotsuga menziesii) in northern Idaho showed that the application of one urea nitrogen treatment applied at a rate of 200 lb N/ac resulted in a significantly higher average basal area growth over a 6-year post-treatment period. Nitrogen fertilization also resulted in a significant height increment increase over the same period. Fourteen years after treatment, fertilization had increased average tree size, in terms of total cubic volume, by 14% in unthinned and by 23% in thinned stands. A comparison of thinned and unthinned stands suggested an increase in tree size (>300%) over the same period without significant reduction in average total cubic volume per acre. Patterns of stand development were altered by nitrogen fertilization. West. J. Appl. For. 4(2):54-57, April 1989.