bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Sampling for Stand Density Index
Authors: Ducey Mark J. , Valentine Harry T. 
Published: August 2019

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.