bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between Soil Productivity and Tree Volume in Primeval Forest Ecosystems in Northeastern China
Authors: Yang John , Hu Yuanman , Bu Rencang 
Published: April 2024

Abstract
Soil properties are well known to influence plant productivity. Site-specific studies were conducted in primeval forest ecosystems in northeastern China to determine a quantitative relationship between soil productivity and tree volume. Three species-dominant primeval forest ecosystems (subalpine, spruce and fir, and Korean pine and hardwood) within the Changbai Mountain Natural Reserve area were selected as study sites. Soil properties of three landscape positions (convex, linear, and concave) in each of the three ecosystems were characterized, and the productivity was quantified using a soil-based productivity index (PI) model. On-site measurements of tree volume were used to assess their correlation with the soil PI values. A range of soil PI values occurred in landscape positions because of differential soil properties in each forest ecosystem. The PI values generally increased along the convex to concave transect and decreased with elevation. Soil pH and depth were identified as primary factors that limited the soil productivity, accounting for 52–56% of the PI variance. Tree volumes of each of the three ecosystems were positively correlated with soil PI values, with R2 of 0.82 to 0.87. The tree volume response to soil PI was dependent on the forest types. This field study demonstrated that the soil-based PI model would be a useful tool in identifying undesirable soil conditions of tree growth for site management and effectively predicting tree productivity based on soil properties within the site- and species-specific forest ecosystems.
Modeling Tree Mortality in Low- to Medium-Density Uneven-Aged Hardwood Stands Under a Selection System Using Generalized Estimating Equations
Authors: Kiernan Diane , Bevilacqua Eddie , Nyland Ralph , Zhang Lianjun 
Published: April 2024

Abstract
Tree mortality was modeled through time in uneven-aged northern hardwood stands managed under a selection system using long-term remeasurement data. Two models were fitted and compared: a traditional logistic regression model that predicted the probability of individual tree mortality over discrete time periods and a logistic regression model estimated using generalized estimating equations (GEEs) to account for autocorrelation in the longitudinal data. Model evaluation was based on the mean prediction error, mean absolute prediction error, variance of prediction errors, and mean square error calculated using an independent validation data set. The GEE model produced smaller evaluation statistics, especially for the smaller diameter classes. The predicted probability of mortality from the two models was compared with the observed mortality across 5-cm diameter classes for two time periods. Our results indicate that the GEE model was better able to capture the change in the probability of mortality over time, especially for the smaller diameter classes, than the more traditional logistic model.
Effects of Timber Harvest on Aquatic Macroinvertebrate Community Composition in a Northern Idaho Watershed
Authors: Gravelle John A. , Link Timothy E. , Broglio Justin R. , Braatne Jeff H. 
Published: April 2024

Abstract
Annual macroinvertebrate sampling was performed from 1994 to 2005 in the Mica Creek Experimental Watershed in northern Idaho to examine the relationship between contemporary timber harvest practices and the structure and diversity of aquatic macroinvertebrate assemblages. Four years of calibration, 4 years of postroad, and 4 years of postharvest (roads + harvest) data were used to analyze treatment effects. Metrics used to assess change included functional feeding group composition, organism densities, taxa richness indices, species diversity, and sediment tolerance indices. These assessments included changes to three macroinvertebrate taxa commonly used as bioindicators of stream habitat quality: Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddis flies) (EPT). In relation to pretreatment conditions, there were generally no major changes in functional feeding group composition or species diversity. Increases were observed in overall abundance and EPT abundance, but they largely can be explained by natural population variability. These results suggest that little or no change in macroinvertebrate communities resulted from road construction and timber harvest activities in the watershed. Substantial interannual variability was also observed, suggesting that infrequent biomonitoring may not provide adequate information to assess subtle disturbance effects in watersheds but can be an effective part of a comprehensive watershed monitoring program when coupled with other biotic and abiotic metrics.
Profit Efficiency in Timber Supply: Marginalization and Other Relevant Influences
Authors: Baardsen Sjur , Lien Gudbrand , Størdal Ståle 
Published: April 2024

Abstract
The objective of this article was to explore how marginalization of revenues from timber sales relative to income from agriculture and employment affects profit efficiency (the ratio of actual profit to maximum obtainable profit). We also sought to identify and measure the effects of other relevant inefficiency factors. A translog profit frontier function with an inefficiency module was estimated using a panel of 2,265 observations of 385 active Norwegian forest owners for 1991–2004. We found that profit efficiency decreases as the revenues from timber sales fall relative to agricultural or wage income. Other factors decreasing the efficiency were logging distance (beyond what can be explained by logging costs), fragmentation of the forest property, and time. Factors increasing profit efficiency were experience (age), information (possession of a management plan), and geographical location (centrality). On the basis of our results we make recommendations on how forest owners can improve their profit efficiency. We also suggest further developing and streamlining contract regimens as policy instruments for promoting efficiency.
Restoration Treatment Effects on Stand Structure, Tree Growth, and Fire Hazard in a Ponderosa Pine/Douglas-Fir Forest in Montana
Authors: Fiedler Carl E. , Metlen Kerry L. , Dodson Erich K. 
Published: April 2024

Abstract
Crown fires that burned thousands of ha of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests in recent years attest to the hazardous conditions extant on the western landscape. Managers have responded with broad-scale implementation of fuel reduction treatments; however. because threats to pine forests extend beyond fire, so too must the approaches to address them. This western Montana study evaluated four treatments in a randomized complete block experiment for their effects on stand structural characteristics, growth increment, and crown fire potential. Evaluation of control, burn-only, thin-only, and thin-burn treatments showed that the combined thin-burn treatment had the greatest number of desired effects, the burn-only had the fewest, and the thin-only was intermediate. The thin-burn significantly reduced stand density, canopy cover, torching hazard, and crowning hazard and increased average diameter, height-to live-crown, and basal area increment; the thin-only reduced stand density, canopy cover, and crowning hazard and increased average diameter and basal area increment; and the burn-only reduced torching hazard and increased height-to-live crown. These structural and growth effects are related to or influence numerous stand/ecosystem properties at our site, including diameter distributions, species composition, large-tree development potential, overall tree vigor, potential for shade-intolerant tree regeneration, and resiliency to fire. Results demonstrate that well-designed restoration treatments can promote key short-term stand and ecosystem responses while significantly reducing crown fire potential.
Fuels and Predicted Fire Behavior in the Southern Appalachian Mountains After Fire and Fire Surrogate Treatments
Authors: Waldrop Thomas , Phillips Ross A. , Simon Dean A. 
Published: April 2024

Abstract
This study tested the success of fuel reduction treatments for mitigating wildfire behavior in an area that has had little previous research on fire, the southern Appalachian Mountains. A secondary objective of treatments was to restore the community to an open woodland condition. Three blocks of four treatments were installed in a mature hardwood forest in western North Carolina. Fuel reduction treatments included chainsaw felling of small trees and shrubs (mechanical treatment), two prescribed fires 3 years apart, a combination of mechanical and burning treatments, and an untreated control. Mechanical treatment eliminated vertical fuels but without prescribed burning; the mechanical treatment added litter (11%) and woody fuels (1 hour 167%; 10 hours 78%) that increased several measures of BehavePlus4-simulated fire behavior (rate of spread, flame length, spread distance, and area burned) for 5 years. Prescribed burning reduced litter mass by 80% and reduced all simulated fire behavior variables for 1 year but had no residual effect by the third year. The combined mechanical and burning treatments had hot prescribed fires (mean temperature of 517°C at 30 cm aboveground) during the first burn that killed some overstory trees, resulting in increased amounts of woody fuels on the forest floor. All active treatments (fire, mechanical, and combined) reduced simulated wildfire behavior, even after a severe ice storm that added fine fuels. Prescribed burning in combination with the mechanical treatment was the most effective in reducing all measures of fire behavior and advancing restoration objectives. Each of the active treatments tested must be repeated to reduce fuels and lower wildfire behavior, but prescribed burning must be repeated frequently.
Influence of Crown Biomass Estimators and Distribution on Canopy Fuel Characteristics in Ponderosa Pine Stands of the Black Hills
Authors: Keyser Tara , Smith Frederick W. 
Published: April 2024

Abstract
Two determinants of crown fire hazard are canopy bulk density (CBD) and canopy base height (CBH). The Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) is a model that predicts CBD and CBH. Currently, FFE-FVS accounts for neither geographic variation in tree allometries nor the nonuniform distribution of crown mass when one is estimating CBH and CBD. We develop allometric equations specific to ponderosa pine (Pinus ponderosa Dougl. ex Laws.) in the Black Hills to predict crown mass and use the Weibull distribution to model the vertical distribution of crown mass within individual trees. We present parameter prediction models that, in turn, predict the vertical distribution of crown mass based on stand- and tree-level attributes. With use of an FFE-FVS executable incorporating local crown mass equations and the parameter prediction models, new estimates of CBD and CBH were produced. Locally derived biomass equations predicted substantially greater estimates of foliage mass than currently predicted by FFE-FVS. The increase in CBD resulting from the local biomass and vertical distribution models averaged 78% over original estimates. Our results suggest that locally derived crown mass equations in addition to nonuniform estimates of crown mass distribution be used to calculate CBH and CBD as used in fire prediction models.
Net Benefits of Wildfire Prevention Education Efforts
Authors: Prestemon Jeffrey P. , Butry David T. , Abt Karen L. , Sutphen Ronda 
Published: April 2024

Abstract
Wildfire prevention education efforts involve a variety of methods, including airing public service announcements, distributing brochures, and making presentations, which are intended to reduce the occurrence of certain kinds of wildfires. A Poisson model of preventable Florida wildfires from 2002 to 2007 by fire management region was developed. Controlling for potential simultaneity biases, this model indicated that wildfire prevention education efforts have statistically significant and negative effects on the numbers of wildfires ignited by debris burning, campfire escapes, smoking, and children. Evaluating the expected reductions in wildfire damages given a change in wildfire prevention education efforts from current levels showed that marginal benefits exceed marginal costs statewide by an average of 35-fold. The benefits exceeded costs in the fire management regions by 10- to 99-fold, depending on assumptions about how wildfire prevention education spending is allocated to these regions.
Forestry Practices and Veneer Log Value—Manufacturer's Assessments of Veneer Log Attributes
Authors: Alderman Delton R. , Brinberg David , Wiedenbeck Jan 
Published: April 2024

Abstract
Hardwood veneer logs comprise less than 1% of the eastern hardwood forest resource in the United States; yet the typical range for veneer log prices is 2–10 times greater than that of grade 1 sawlogs. In this article we examine attributes and defects known to affect the value of veneer logs and shed light on forest management considerations that affect veneer log production. Veneer attribute data were collected for black cherry (Prunus serotina Ehrh.), black walnut (Juglans nigra L.), northern red oak (Quercus rubra L.), sugar maple (Acer saccharum Marsh.), and white oak (Quercus alba L.). Social judgment theory was used to assess veneer attributes and defects. Color (hue and consistency) and rings (density and texture) are the drivers in veneer log selection, and the results are also indicated by a “Species by Color” interaction and a “Species by Rings” interaction. Other cues are important but do not appear to drive log selection. Hardwood forest management practices, in which partial cuttings are performed, can affect the potential product value of face veneer quality residual stems by changing the rate of diameter growth.
Genetic Contributions to Phenotypic Variation in Physiology, Growth, and Vigor of Western Aspen (Populus tremuloides) Clones
Authors: Clair Samuel B. St. , Mock Karen E. , LaMalfa Eric M. , Campbell Robert B. , Ryel Ronald J. 
Published: April 2024

Abstract
In aspen and other plant species the effects of environment on phenotype are generally better characterized than genotypic influences. Furthermore, little is known about how genetic influences on tree phenotype change over time. We assessed clonal differences in 417 ramets, representing 18 clones, in a common garden of quaking aspen (Populus tremuloides Michx.) that have developed over 27 years. Genetic contributions to variation in physiology, growth, and vigor were determined over seasonal and multidecadal time scales. The 18 aspen clones exhibited wide-ranging phenotypic variation with two- to threefold differences in physiology and growth traits and more than sevenfold differences in canopy decline and mortality. For growth traits, strong genetic correlations (typically greater than 0.70) and heritability (estimates maintained in a range of 0.25 to 0.36), indicate that genotype had a moderate and consistent influence on growth over the three decades of the study. Physiological traits had much lower genetic correlations and heritability estimates, and they changed significantly within a single growing season. Climatic data suggest that dry conditions in the common garden as the summer progressed may have had a controlling influence on physiological trait responses. Characterizing genetically based phenotypic variation and how it contributes to clone vigor provides a critical link to understanding constraints to aspen viability in its western range.
Estimating Individual Stand Size–Density Trajectories and a Maximum Size–Density Relationship Species Boundary Line Slope
Authors: VanderSchaaf Curtis L. 
Published: April 2024

Abstract
Understanding self-thinning patterns of a species helps resource managers make decisions about proper planting densities and timings of thinnings. It is generally assumed that size–density trajectories of even-aged, monospecific, self-thinning stands consist of three phases: first, a curved approach to a linear portion that represents moderate rates of intraspecific mortality; second, a linear portion where tree density/ha (N) is at its maximum for a particular quadratic mean diameter (Dq), often termed the maximum size–density relationship (MSDR) dynamic thinning line; and third, a divergence from the linear portion. In this article, segmented regression was used to determine what observations are within various phases of self-thinning for a loblolly pine (Pinus taeda L.) planting density trial located in central Mississippi. Those observations estimated to be within the MSDR dynamic thinning line phase of individual plots were combined to estimate a MSDR species boundary line slope (−1.640) using a linear mixed-effects model approach. Based on the N and Dq, where the MSDR dynamic thinning line phase was estimated to begin using segmented regression analyses, and the estimated MSDR species boundary line slope of −1.640, planting density-specific maximum values of Reineke's stand density index were predicted.
Using Linear Mixed Effects in Helicopter Logging Data
Authors: Lyons Kevin , Xing Li , Nelson John D. 
Published: April 2024

Abstract
This article applies a linear mixed-effects model (LME) to an unpublished helicopter logging productivity data set. The data were clustered in units, and the silviculture treatments varied between units, where units are cutblocks. When the covariance matrix was considered, it was found that the interunit variance was significant and the intraunit variance was heterogeneous. The significant interunit variance results in significant intraunit correlation, and this indicates the need to use LME to analyze these data. When turn time was considered, unit 4, which had the lowest level of group retention, had a conditional predicted value that was significantly less than the marginal predicted value. When turn weight was considered, unit 2, which had small patch cuts, had a conditional predicted value that was significantly less than the marginal predicted value, and unit 4 had a conditional predicted value that was significantly higher than the marginal predicted value. When productivity was considered, the conditional predicted value for unit 4 was significantly greater than the marginal predicted value, and unit 2 was significantly less than the marginal predicted value. In this data set it is interesting to note that productivity is independent of the number of logs in a turn and that turn weight was relatively insensitive to the available explanatory variables.
A New Look at Spread Rates of Exotic Diseases in North American Forests
Authors: Evans Alexander M. , Finkral Alex J. 
Published: April 2024

Abstract
Exotic pathogens threaten ecosystems in novel ways, particularly where they are facilitated by stresses such as climate change and forest fragmentation. Although chestnut blight (CB), Dutch elm disease (DED), beech bark disease (BBD), and white pine blister rust (WPBR) are well-studied pathogens, this investigation is the first to provide estimated rates of spread based on an expansive geospatial database and a consistent, rigorous analytical framework. We use quantile regression to analyze 850 records of infection over the last (20th) century. The results show that in the past, forest disease complexes have spread at rates between 7.4 and 31 km year−1, and two-thirds of the estimates were less than 17 km year−1. We estimated the spread of CB at 31 km year−1, DED in eastern North America at 25 km year−1, DED in western North America at 14 km year−1, BBD at 16 km year−1, WPBR in eastern North America at 7.4 km year−1, and WPBR in western North America at 10 km year−1. These results do not predict the rate of spread of future exotic pathogens in North American forests; rather they provide context for predictive models and a heuristic guide until more scientific data are available.
Valuation of Timber Harvest Contracts as American Call Options with Modified Least-Squares Monte Carlo Algorithm
Authors: Petrasek Stanislav , Perez-Garcia John M. 
Published: April 2024

Abstract
This article presents a Monte Carlo methodology for the valuation of timber harvest contracts in the presence of stochastic timber prices, flexibility in harvest timing, and penalty clauses. Harvest contracts are treated as American call options on the value of timber. The modifications to the least-squares Monte Carlo algorithm necessary to incorporate penalty clauses are presented. The application of the proposed methodology is then demonstrated on a valuation problem characteristic of harvest contracts sold by the Washington Department of Natural Resources.
Evaluation of Parameter Estimation Methods for Fitting Spatial Regression Models
Authors: Lu Junfeng , Zhang Lianjun 
Published: April 2024

Abstract
Two types of spatial regression models, a spatial lag model (SLM) and a spatial error model (SEM), were applied to fit the height-diameter relationship of trees. SEM had better model fitting and performance than both SLM and ordinary least squares. Moran's I coefficients showed that SEM effectively reduced the spatial autocorrelation in the model residuals. Both real data and Monte Carlo simulations were used to compare different parameter estimation methods for the two spatial regression models, including maximum likelihood estimation (MLE), Bayesian methods, two-stage least squares (for SLM) and generalized method of moments (GMM) (for SEM). Our results indicated that GMM was close to MLE in terms of model fitting, much easier in computation, and robust to non-normality and outliers. The Bayesian method with heteroscedasticity did not effectively estimate the spatial autoregressive parameters but produced very small biases for the regression coefficients of the model when few outliers existed.
Measuring the Value of Information in Multicriteria Decisionmaking
Authors: Kangas Annika S. , Horne Paula , Leskinen Pekka 
Published: April 2024

Abstract
Decisions in forestry typically include uncertainty. The decisionmaker then has two options: either to make the optimal choice between different alternative actions with the current information or to try to reduce the uncertainty by collecting more information. The value of information is due to the ability to make better decisions with new information. When the decisions only affect provision of goods that have market value, evaluation of alternative decisions is in principle a straightforward exercise of cost-benefit analysis. In sustainable forest management, however, multiple objectives typically exist, and these objectives may be related to provision of public goods and services. Because such goods and services cannot be directly measured in monetary terms, the problem of value of information is more complicated. The possible solutions are to assess the monetary value separately for all goods and services and evaluate the decisions with cost-benefit analysis or to evaluate the decisions in terms of utility with multicriteria analysis and calculate the (monetary) value of decisions based on these utilities. The aim of this study was to present these two cases for evaluating decisions and analyze their similarities and differences and to discuss the usefulness of these approaches in evaluating the value of information from different perspectives.