bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Behavior of Douglas-Fir Tussock Moth Populations in the Pacific Northwest
Authors: Mason Richard R. 
Published: April 2024

Abstract
Larval densities of the Douglas-fir tussock moth (Orgyia pseudotsugata [McDunnough] [Lepidoptera:Lymantriidae]) were monitored annually to construct population time series in five different forest ecosystems. The time series were generated in parts of five national forests in three geographical provinces: the northern Blue Mountains of northeastern Oregon, the southern Cascade Range of south-central Oregon, and the northern Cascade Range of north-central Washington. The five series ranged in length from 12 to 23 yr and represented the broad numerical behavior of tussock moth populations in those provinces. Time series with the most variable fluctuations were recorded in the Blue Mountains, a region with a long history of regular tussock moth outbreaks. The least variable series was in the southern Cascades, an area with no previously documented outbreaks. Characteristics of series in the Blue Mountains and the northern Cascades were significantly correlated with one another, but not with those of the series in the southern Cascades. The density-dependent structure of each time Series was examined by autocorrelation and partial autocorrelation functions, which indicated that fluctuations were quasi-periodic, even at low densities, and that the most significant autoregressive process was a second-order feedback. Each time series was fit with a linear second- order autoregressive model and a discrete nonlinear logistic model with a single time delay. The models, based on density-dependent processes associated with preceding insect generations, accounted for an average of 44.6% of the variation in the time series. The remaining 55.4% of variation was due to unknown density-independent factors related to different years in the series. The models showed that the principal dynamics of tussock moth populations are generated by direct and delayed density-dependent processes. In outbreak-prone ecosystems, like those in the Blue Mountains and the northern Cascades, the primary regulation of insect numbers is by delayed feedback processes that result in populations sometimes having extreme fluctuations in density. Conversely, in nonoutbreak ecosystems, as in the southern Cascades, feedback is more balanced between both direct and delayed processes that stabilize populations at lower densities. External factors, like weather, also may influence the numerical behavior of populations to some extent, but their specific contribution to tussock moth dynamics is largely unknown. For. Sci. 42(2):182-191.
Nutritional Status and Deficiency Diagnosis of Pinus radiata Plantations in Spain
Authors: Romanyà Joan , Vallejo V. Ramon 
Published: April 2024

Abstract
Twenty-one plots of Pinus radiata D. Don were selected for nutritional diagnosis on the basis of parent material (nine different substrates) and climate (Atlantic and Mediterranean). After foliar analysis, nutritional diagnoses were conducted, using the critical level method and the DRIS system. The nutrient content in fresh litter (L horizon) was also measured, and nutrient levels of green pine needles were compared with leaves of three native hardwood species (Quercus ilex L., q. robur L. and Fagus sylvatica L.) growing near each pine plot. In most cases, deciduous trees showed higher nutritional levels than evergreen trees. Foliar levels of Ca were always higher in hardwood trees, irrespective of leaf longevity. Phosphorus (P) deficiency was the most common among pines (eight plots showed severe P deficiency). Nitrogen and magnesium deficiencies were also detected in a few cases. The DRIS system diagnosed a larger number of deficiencies than the critical level method, but after intercalibration both methods gave the same diagnosis. In the plots studied, litter analysis appeared to be an alternative to foliar analysis for P, S, Ca, and Mg diagnosis but not for N or K. For. Sci. 42(2):192-197.
Parental Rank Changes Associated with Seed Biology and Nursery Practices in Douglas-Fir
Authors: El-Kassaby Y. A. , Thomson A. J. 
Published: April 2024

Abstract
The impact of container-nursery management practices on the genetic composition of seedling crops was evaluated in an experimental study designed to determine the cumulative effects of: (1) differences in parental reproductive output in bulk seedlots, (2) parental variation in germination parameters (percent and speed), and (3)the interaction of these parameters with container-nursery practices of thinning and culling, and their effect on the genetic representation of parents in the resultant seedling crops. Results from the experimental study were compared to predictions of a stochastic simulation designed to estimate the consequences of differential parental seed contribution, and seed-germination percent and germination speed on indicators of crop performance. The experimental study was conducted on a Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) bulk seedlot that was representative of the differential seed contributions from 19 seed orchard parents. The nursery study included a total of 42,000 seeds. Seeds were sown at three seeds per cavity. Within the 14,000 cavities used, the identity of every seed was maintained throughout the study. Parents were compared based on: (1) changes in their rank order from sowing to postthinning and postculling status, and (2) relative performance from seed contribution to seedling production. Changes were observed in both assessments. Path analysis was used to determine the percent contribution of each factor to seedling production. It was determined that germination, thinning, and culling contributed 66, 20, and 14%, respectively, to seedling production, indicating the presence of three consecutive bottlenecks in the process. Single seed or individual family sowing in the nursery was recommended for seedling production to maintain genetic diversity. For. Sci. 42(2):228-235.
A Cross-National Investigation of Softwood Sawmill Marketing Strategies
Authors: Niemelä Juha S. , Smith Paul M. 
Published: April 2024

Abstract
The concept of marketing strategy at the interface between a company and its environment (customers, competitors, and stakeholders) has been a topic of lively discussion since the late 1970s. The marketing strategy concept has evolved from the fundamental marketing management questions regarding elements of the marketing mix to a more extensive concept whereby the ultimate objective is to gain competitive advantage.
This paper provides primary data collected from 102 companies in 3 nations/5 regions: Finland, Western Coast USA, Western Inland USA, Coastal British Columbia, Canada, and Interior, British Columbia, Canada. Empirical testing was conducted by measuring a firm's marketing strategy, determined by making strategic decisions concerning products, customers, market areas, and marketing competences. Factor analysis discovered five underlying dimensions of market strategy which were subsequently measured and plotted graphically by the five producing regions included in the study. Comparisons and contrasts of the marketing strategies of the various regions are examined and discussed. For. Sci. 42(3):290-299.
Sustainable Forest Ecosystems and Management: A Review Article
Authors: Toman M. A. , Ashton P. M.S. 
Published: April 2024

Abstract
Concerns about the sustainability of forest resources and ecosystems have been expressed almost from the beginning of modern studies of forest management by ecologists, biologists, economists, and other specialists. However, the focus of this concern has gone through several transformations. Environmental scientists have emphasized the maintenance of forest ecosystems in the face of different types of human intervention. Economists and forest managers, on the other hand, have emphasized the capacity of forest systems to provide valued ongoing flows of goods and services for human societies.
This paper takes stock of forest resource and ecosystem sustainability from both ecological and economic perspectives. It seeks to identify how these disciplinary perspectives contribute to a better understanding of sustainability, and where the most significant conceptual and factual gaps are found. Of particular interest are two related themes: how economic efficiency and sustainability may differ in their implications for forest system management, and how criteria for forest system sustainability are related to the scale of management decisions (e.g., individual forest site versus region versus the global biosphere). For. Sci. 42(3):366-377.
Projection Variance Partitioning of a Conceptual Forest Growth Model with Orthogonal Polynomials
Authors: Gertner George , Parysow Pablo , Guan Biing 
Published: April 2024

Abstract
An uncertainty analysis was performed for a conceptual forest growth model for red pine (Pinus resinosa Ait.). Low order orthogonal response surface models were developed to predict the variance of projections made with the conceptual model. Based on these orthogonal response surface models, it was possible to partition the variance of the projections. Approximate error budgets were developed, and the power of hypotheses tests based on model predictions were assessed. For. Sci. 42(4):474-486.
Results from Genetic Tests of Selected Parents of Douglas-Fir (Pseudotsuga menziesii [Mirb.] Franco) in an Applied Tree Improvement Program
Authors: Stonecypher R. W. , Piesch R. F. , Helland G. G. , Chapman J. G. , Reno H. J. 
Published: April 2024

Abstract
Results from genetic tests, and genotype by environment interaction studies in six low-elevation breeding zones of Weyerhaeuser Company's Western Washington and Oregon Douglas-fir tree improvement program are summarized. Phenotypic selection in natural stands resulted in a 5% improvement in juvenile height over nonselect seed lots. Comparisons with nonselect sources, of offspring from parents in the top 50% performers in tests, indicated a 10% increase for the same trait. Seed produced in a 50% rogued seed orchard is thus expected to provide improved planting stock with a gain of 10% in juvenile height growth. Several select parents are producing offspring that are consistently performing in excess of 10% over nonselects.
Estimates of breeding zone, breeding zone by location, and family by location interaction effects are small relative to family and planting location effects. Tests of families established on environmentally diverse sites indicate a striking lack of large family by planting location interaction. In tests showing statistically significant interactions, such interactions are caused by a relatively small number of families. We did observe earlier budbreak and a higher spring frost susceptibility of Oregon sources established on Washington sites.
We conclude that allocation and utilization of select families within Weyerhaeuser's Oregon and Washington ownership should not be constrained by the currently defined breeding zone boundaries, but based on parental performance and stability for growth and adaptive traits in general. We further suggest that the necessity for maintaining separate breeding zones, within Washington and Oregon, in subsequent cycles of recurrent selection is questionable.
Average individual tree heritability, from 65 6-parent disconnected diallels, is 0.13 for age 6 and age 8 height. Dominance genetic variance is estimated to be one-half that of additive genetic variance for the same traits.The environmental designs and test establishment methods used resulted in acceptable levels of statistical precision for juvenile growth traits. Individual test least significant range values (LSR) resulted in significant family mean percent height differences of 8 to 26, and averaged 13% for diallels, and full-sib and half-sib tests. For. Sci. Monogr. 32:1-35.
An Optimization Approach to Area-Based Forest Pest Management Over Time and Space
Authors: Hof John , Bevers Michael , Kent Brian 
Published: April 2024

Abstract
This paper discusses spatial optimization approaches to managing aggressively reproducing and dispersing pests. The relevant land planning area is divided into cells, and pest growth and dispersal across those cells are accounted for in integer programs that include choice variables for applying control treatments to those cells. Two model formulations are developed and demonstrated in a simple case example: one that assumes no limit to host capacity and one that assumes a limit to host capacity accumulated over time. The formulation with no host capacity limit is shown to be potentially unrealistic if control treatments are not limited. Different objective functions and amounts of control treatment result in optimal strategies that vary from immediate containment near the pest's origin to delayed containment at an area away from the pest's origin. Both formulations are difficult to solve, reflecting the exploratory nature of this paper. For. Sci. 43(1):121-128.
Wildlife Conservation Planning Using Stochastic Optimization and Importance Sampling
Authors: Haight Robert G. , Travis Laurel E. 
Published: April 2024

Abstract
Formulations for determining conservation plans for sensitive wildlife species must account for economic costs of habitat protection and uncertainties about how wildlife populations will respond. This paper describes such a formulation and addresses the computational challenge of solving it. The problem is to determine the cost-efficient level of habitat protection that satisfies a viability constraint for a sensitive wildlife population. The viability constraint requires a high probability of attaining a population size target. Because of the complexity of wildlife prediction models, population survival probabilities under alternative protection plans must be estimated using Monte Carlo simulation. The computational challenge arises from the conflicting effects of sample size: fewer replications used to estimate survival probability increases the speed of the search algorithm but reduces the precision of the estimator of the optimal protection plan. Importance sampling is demonstrated as a simulation technique for reducing estimator variance for a given sample size, particularly when the tail of the population distribution is of critical importance. The method is demonstrated on a hypothetical problem involving gray wolf management in the Great Lakes region of the United States. In comparison to random sampling, importance sampling produces a 21-fold reduction in the variance of the estimator of the minimum-cost protection plan. Results from the optimization model demonstrate the extreme sensitivity of the minimum-cost protection plan to the structure of the growth model and the magnitude of environmental variation. This sensitivity is not widely recognized in the literature on wildlife habitat planning and is a strong reason for using optimization methods that can handle stochastic population models with a wide range of structures. For. Sci. 43(1):129-139.
Using Pheromone-Baited Traps To Control the Amount and Distribution of Tree Mortality During Outbreaks of the Douglas-Fir Beetle
Authors: Ross Darrell W. , Daterman Gary E. 
Published: April 2024

Abstract
Multiple-funnel traps baited with strong aggregation pheromone lures were placed throughout three 259 ha plots in northeastern Oregon during an outbreak of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins. Mean numbers (± SEM) of Douglas-fir beetles collected per plot for the entire flight periods of 1992 and 1993 were 277,921 ± 40,447 and 268,834 ± 37,088, respectively. Mean numbers (± SEM) of the most abundant predator, Thanasimus undatulus (Say), collected per plot in 1992 and 1993 were 43,527 ± 3,553 and 35,652 ± 3,514, respectively. Douglas-fir beetle-caused tree mortality was concentrated around the trap sites in the treated plots, even though traps were located an average of 40 m from the nearest host tree. Managers can influence the spatial distribution of tree mortality during an outbreak by selective placement of traps across the landscape. Selective trap placement, plus the removal of trapped beetles from the population, may reduce tree mortality within the general area. For. Sci. 43(1):65-70.
Inoculation of Tree Roots with Plant Growth Promoting Soil Bacteria: An Emerging Technology for Reforestation
Authors: Chanway C. P. 
Published: April 2024

Abstract
Seedling root systems are colonized heavily by asymbiotic soil bacteria, many of which have the potential to influence plant growth significantly. A heterogeneous group of these microorganisms is well known for their ability to colonize roots and stimulate growth of agricultural plant species, sometimes doubling seedling biomass accumulation only a few weeks after inoculation, but more usually resulting in less spectacular biomass gains (e.g., 15%-30% greater than uninoculated controls within a growing season). Plant growth promoting soil bacteria may exert such effects through a variety of mechanisms, and include microorganisms that stimulate seedling emergence or infection by symbiotic fungi and bacteria. Other plant beneficial soil bacteria possess biological control activity or are capable of transforming plants genetically. Inoculation of tree seedlings with such bacteria before outplanting would be an inexpensive, environmentally benign, and easily applied nursery treatment, but comparatively little work has been performed with these microorganisms in forestry. Recent results with various tree species, however, indicate that seedling performance can be significantly enhanced through bacterial inoculation of root systems: pine and spruce biomass increased 32%-49% 1 yr after inoculation and outplanting at a reforestation site. In addition, infection by desired species of ectomycorrhizal fungi can also be enhanced by inoculation with certain strains of root colonizing bacteria. Results from studies performed with beneficial asymbiotic tree root associated bacteria are reviewed in this article in relation to the possible uses of such microorganisms for artificial forest regeneration. For. Sci 43(1):99-112.
Using Tabu Search To Generate Stand-Level, Rule-Based Bucking Patterns
Authors: Laroze Andre J. , Greber Brian J. 
Published: April 2024

Abstract
A Tabu Search (TS) heuristic was developed for generating easily implementable bucking rules that are applicable to entire stands (as opposed to individual stem classes), and for selecting the rule-set that provides the best feasible solution (given log prices and market constraints). The tabu restrictions used for guiding the search process are based on the frequency of the export logs' attributes, and the profit corresponding to the local optima found during the search. Parallel tabu lists of different time-spans were considered. The aspiration criterion for revoking a tabu status consisted of improving upon the best feasible solution. The model was applied to a set of radiata pine (Pinus radiata, D. Don) stands, considering different market constraints and price sets. The TS approach leads to bucking outcomes that are reasonably close, in profit terms, to the solutions obtained by an integer programming model designed for selecting the optimal set of stem-specific bucking patterns. For. Sci. 43(2):157-169.
A Qualitative Comparison of Fire Spread Models Incorporating Wind and Slope Effects
Authors: Weise David R. , Biging Gregory S. 
Published: April 2024

Abstract
Wind velocity and slope are two critical variables that affect wildland fire rate of spread. The effects of these variables on rate of spread are often combined in rate-of-spread models using vector addition. The various methods used to combine wind and slope effects have seldom been validated or compared due to differences in the models or to lack of data. In this study, rate-of-spread predictions from the Canadian Fire Behavior Prediction (FBP) system, McArthur's Mark V forest fire danger meter, the Rothermel empirical model, and the Pagni and Peterson physical model were compared with spread rates observed in a designed laboratory experiment in which wind velocity and slope were varied. Methods of combining wind and slope developed by Albini, McAlpine, and Rothermel were applied to two forms of Rothermel's model. Rothermel's model (original and modified) coupled with Albini's method and Pagni's model predictions closely reproduced the observed shape of the rate-of-spread response to wind and slope. Rothermel's method and McAlpine's method worked well in all cases except in upslope spread with opposed flow. However, Rothermel's model failed to predict a nonzero rate of spread in fuel beds with moisture contents of 35%. Possible causes of overprediction by McArthur's model and the FBP model included: (1) application of equations derived from full-scale fires to laboratory-scale fires, (2) improper selection of fuel type to represent artificial fuel beds, and (3) inaccurate estimation of wind velocity 10 m above the vegetation surface using a logarithmic profile. For. Sci. 43(2):170-180.
Aggregation Procedures in Forest Management Planning Using Cluster Analysis
Authors: Weintraub Andrés , Sáez Guillermo , Yadlin Marisa 
Published: April 2024

Abstract
Typical linear programming models used in forest planning can be very large. It is often of interest to analyze more compact, less detailed versions. One form of reducing the size of the problem is through an aggregation process. One way in which this has been done is through a column aggregation process, where sets of similar columns are replaced by one representative. A second alternative is to aggregate the original data, in which case the stands and management alternatives are grouped before building a model. Typical approaches for the aggregation processes have been analytical. We present an alternative approach for aggregation based on cluster analysis. Computational results for both types of aggregation show that using cluster analysis can be advantageous. For. Sci. 43(2):274-285.
Exploring the Error Structure of Taper Equations
Authors: Williams Michael S. , Reich Robin M. 
Published: April 2024

Abstract
Much work has been done fitting taper equations to specific tree bole shapes, but few researchers have investigated what effect the correlated error structure has on the fit of a taper equation. The Max and Burkhart (1976) taper equation was used in conjunction with a number of equations which modeled the covariance structures. The equations proposed were continuously differentiable, which simplifies the fitting process, and selected to minimize the number of parameters. A maximum likelihood method was proposed to fit these equations and test the statistical significance of the correlated errors. Accounting for the correlated errors structure in the equation fitting process significantly improved fit. Tests showed a small, but significant, bias of 1.05% (± 0.143%) when the correlated errors were ignored. For. Sci. 43(3):378-386.