bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing Public Inputs to Multiple Objective Decisions on National Forests Using Conjoint Analysis
Authors: Dennis Donald F. 
Published: April 2024

Abstract
Faced with multiple objectives, national forest managers and planners need a means to solicit and analyze public preferences and values. A conjoint ranking survey was designed to solicit public preferences for various levels of timber harvesting, wildlife habitats, hiking trails, snowmobile use, and off-road-vehicle (ORV) access on the Green Mountain National Forest. The survey was completed by 76 respondents during public involvement meetings. An ordered probit model was used to estimate linear and quadratic main effects. Respondents preferred moderate levels of timber harvesting and snowmobile access and lower levels of ORV access. They favored a mixture of mature closed canopy and younger more open forests over either extreme and were somewhat indifferent toward extending the network of hiking trails. For. Sci. 44(3):421-428.
The Effects of Fixed-Area Plot Width on Forest Canopy Height Simulation
Authors: Nelson Ross F. , Gregoire Timothy G. , Oderwald Richard G. 
Published: April 2024

Abstract
Mapped-stand data which includes tree location and mensuration data may be used to simulate the height characteristics of a forest canopy in a computer. The dimensions of the rectangular, fixed-area ground plot which is used to collect the tree location and mensuration data can profoundly affect the accuracy of the resultant computer reconstruction of forest canopy heights. Thin fixed-area plots result in forest canopy height constructs (i.e., canopy height models, or CHMs) which are shorter and less dense than the actual forest stand. Ninety-nine 0.405 ha forest stands in the southeastern and south central United States were analyzed. For each stand, a top-of-canopy height model was generated for the entire stand on a 0.25 m x 0.25 m grid. The mean canopy height and the canopy density of the simulated stand was calculated. A Monte Carlo simulator established randomly located sample plots of varying plot width (1 m to 20 m) at three different sampling intensities (1%, 5%, and 10% of stand area) in the mapped stand. The trees selected on any particular plot were used to generate a CHM, and the sample mean canopy height and canopy density were compared with the corresponding stand values. Samples collected using 1 m wide plots resulted in height models which underestimated average canopy height and canopy closure with deviations greater than 5% of the stand value, 95-100% of the time. The underestimation results from the construction of top-of-canopy architecture based on measurements of crowns belonging only to trees whose boles are within the plot. This construction technique omits crowns extending over the plot belonging to tree boles located off the plot. Thinner plots tend to miss more of the trees which support the canopy over the plot. For the 99 stands considered in this study, ground plot widths on the order of 6 to 8 m were required in order to acquire ground data which could be used to accurately model forest canopy height characteristics. The minimum ground plot width required to produce an accurate height model decreased with increasing stem density; a plot width of 4 m, for instance, may be used at stem densities of ~2000 stems ha-1. For. Sci. 44(3):438-444.
Allometry and Growth
Authors: Broad L. R. 
Published: April 2024

Abstract
A theory of multivariate allometry is developed. Bivariate and multivariate allometry are then shown to be compatible, the defining differential equations being analogs of each other and invariant under analogous allometric transforms. The relevance of allometric equations to growth modeling is examined. Commonly used growth models that are invariant under allometric transforms are capable of being formulated in terms of allometric (growth) differential equations. Methods for formulating and solving multivariate growth models are demonstrated. For. Sci. 44(3):458-464.
Regional Cost Function Analysis of the Logging Industry in the Pacific Northwest and Southeast
Authors: Smith Phillip , Munn Ian A. 
Published: April 2024

Abstract
Nonhomothetic translog cost functions with two variable inputs, labor and capital, were estimated to compare the underlying production structure of the logging industry in the Pacific Northwest and Southeast regions of the United States from 1963 to 1992. The parent cost function and capital share equation for each region were estimated using Maximum Likelihood Estimation techniques. Both equations were significantly different between regions. The industry in both regions was capital-using over the study period. Labor and capital were substitutes in each region, but substitution possibilities were limited. Input substitution was more elastic in the Southeast, and therefore the industry in the Southeast would be better able to adjust to changes in input prices or output demand. Additional tests determined that homothetic, homogeneous, and time invariant functions would be inappropriate for the logging industry in either region. For. Sci. 44(4):517-525.
Tree-Ring Responses to Drought Across Species and Contrasting Sites in the Ridge and Valley of Central Pennsylvania
Authors: Abrams Marc D. , Ruffner Charles M. , Morgan Todd A. 
Published: April 2024

Abstract
Annual tree-ring variation between 1984 and 1995 was measured in ten hardwood species in central Pennsylvania (USA) to assess differential drought impacts on xeric ridge, dry-mesic barrens, mesic valley, and wet-mesic riparian sites. Each tree species occurred on two or more sites. Four droughts of moderate to severe intensity occurred during the study period. In general, trees on the xeric ridge and wet-mesic riparian sites were more frequently impacted with reductions in the ring width index, whereas trees on the mesic valley and dry-mesic barrens sites had fewer growth reductions. Annual variation in growth was negatively correlated with summer temperature, particularly for species on the riparian site. Six of twenty-three species-by-site combinations had above average growth during one or more of the droughts, while 8 of 23 species-by-site combinations had below average growth the year following drought. The species with the largest decrease in the ring width index during drought varied among the sites, and included Acer rubrum in the valley, Prunus serotina in the barrens and riparian sites, and Quercus rubra and Acer rubrum on the ridge. Comparing tree-ring data from this study with leaf gas exchange data from other studies resulted in several inconsistencies in drought responses; therefore, information from both approaches may be needed in accurately assessing species drought tolerance rating. For. Sci. 44(4):550-558.
Genetic Parameters and Breeding Value Predictions for Eucalyptus Nitens Wood Fiber Production Traits
Authors: Tibbits Wayne , Hodge Gary 
Published: April 2024

Abstract
A base breeding population of 13,000 trees from about 300 Eucalyptus nitens families of open-pollinated origin in 6 provenances of native forest stands, was established in 8 tests, analyzed for genetic parameters and used for breeding value and gain prediction. Traits considered were basal area (BA), basic density (BD), and kraft pulp yield (PY) in 4- to 8-yr-old trees. Measurement of PY, whether taken as individual trees (PYI) or composites (PYC), were considered as the same trait, since the average Type B genetic correlation (rBg) between PYI and PYC was 0.94. Trees with the "early-adult form" typically from the Errinundra provenance appeared to have the poorest PY, averaging 1 to 3% points lower than all the other provenances. This provenance was excluded from detailed genetic analyses. Significant differences among the other five provenances were found for all traits. Four provenances were reasonably similar, but northern New South Wales was estimated to be lowest for BA and PY, and highest for BD. Single-site biased heritabilities (h2b) varied substantially from site to site, and averaged 0.32 ± 0.05 for BA, 0.43 ± 0.09 for BD, 0.37 ± 0.08 for PY. Heritability estimates from combined-site analyses were 0.19 for BA, 0.42 for BD, and 0.37 for PY. Genotype x environment (g x e) interaction was estimated using rBg. For BD and PY, rBg was 0.94, indicating no major g x e. Moderate g x e interactions were detected for SA, with rBg at 0.60. Genetic correlation between BA and PY, and between BD and PY were favorable, but between BA and BD was unfavorable (genetic correlation = 0.24, 0.41 and -0.24 respectively). For. Sci. 44(4):587-598.
Within-Stem Variation in Tropolone Content and Decay Resistance of Second-Growth Western Redcedar
Authors: DeBell Jeffrey D. , Morrell Jeffrey J. , Gartner Barbara L. 
Published: April 2024

Abstract
Western redcedar (Thuja plicata Donn) is a commercial species valued for its high decay resistance, which is due to the presence of toxic extractives (tropolones) in the heartwood. We measured tropolone content and weight loss in soil block tests using samples taken from 11 second-growth western redcedar trees. Tropolone content increased with rings from the pith, and in the outer heartwood, increased from the top to the base of the tree. We did not find any consistent increase or decrease in tropolone content with height in the tree for samples the same number of rings from the pith. Our data suggest that the lower tropolone content near the pith is largely a juvenile effect, associated with wood formed near the active crown. This has implications for choosing a rotation length if wood of uniformly high decay resistance is desired, because younger trees contain a greater proportion of wood close to the pith. However, we also found large tree-to-tree differences in the rate of tropolone increase with age from the pith. This may have promise for maintaining uniformly high decay resistance if the factors underlying the tree-to-tree differences can be discovered and managed. Our results from soil block tests for decay resistance were more variable, but in general, wood near the pith, which was low in tropolones throughout the tree, was extremely variable in decay resistance; outer heartwood with high tropolone content showed higher, less variable decay resistance, while outer heartwood with low tropolone content remained variable in decay resistance. For. Sci. 45(1):101-107.
Three-Year Survival and Growth of Douglas-Fir Seedlings Under Various Vegetation-Free Regimes
Authors: Rose R. , Ketchum J.S. , Hanson D. E. 
Published: April 2024

Abstract
Responses of Douglas-fir seedlings were studied for 3 yr following eight vegetation-control treatments in three western Oregon clearcuts. The objectives were to determine seedling growth response to different areas of spot vegetation control and to determine the relative influence of early woody and herbaceous competition on seedling growth. Herbicide treatment areas varied in size from those receiving no control to full control (9.3 m2). Controlled areas were maintained free of herbaceous vegetation for 2 yr and all woody vegetation was controlled for 3 yr. Two additional treatments, complete control of woody vegetation only and complete control of herbaceous vegetation only, were also examined. On two sites (Summit and Marcola), seedling growth parameters were maximized at or near full vegetation control with a tree spacing of 3 m x 3 m. On the third site (Pedee), maximum growth response occurred between 5 and 6 m2; of control. Herbaceous vegetation control resulted in increased seedling growth at all sites while woody vegetation control yielded increased seedling growth only at the Pedee site. Cumulative 3 yr herbaceous cover accounted for 68% and 41% of the variability in stem volume at Summit and Marcola, respectively. Adding cumulative 3 yr woody cover to the model accounted for an additional 18% and 49% of the variability in stem volume at Summit and Marcola, respectively. At Pedee, neither herbaceous nor woody cover significantly influenced 3 yr stem volume, suggesting that factors other than vegetation cover were responsible for differences measured. For. Sci. 45(1):117-126.
Mexican Spotted Owl Home Range and Habitat Use in Pine-Oak Forest: Implications for Forest Management
Authors: Ganey Joseph L. , Block William M. , Jenness Jeffrey S. , Wilson Randolph A. 
Published: April 2024

Abstract
To better understand the habitat relationships of the Mexican spotted owl (Strix occidentalis lucida), and how such relationships might influence forest management, we studied home-range and habitat use of radio-marked owls in ponderosa pine (Pinus ponderosa)-Gambel oak (Quercus gambelii) forest. Annual home-range size (95% adaptive-kernel estimate) averaged 895 ha ± + 70 (SE) for 12 individuals and 997 ha ± 186 (SE) for 7 pairs of owls. On average, the 75% adaptive-kernel contour (a probability contour containing 75% of the owl locations) included 32 and 30% of the annual home range for individuals and pairs, respectively, suggesting high concentration of activity in a relatively small portion of the home range. Relative area of three cover types (ponderosa pine forest, pine-oak forest, and meadow) did not differ between seasonal ranges, and owls used these cover types in proportion to their relative area during both breeding and nonbreeding seasons. In contrast, relative area of four canopy-cover classes varied between seasons. Breeding-season ranges contained greater proportions of areas with canopy cover ≥ 60% and lower proportions of areas with 20-39% canopy cover than nonbreeding-season ranges. Owls roosted and foraged in stands with ≥ 60% canopy cover more than expected during both breeding and nonbreeding seasons, and used stands with 20-39% canopy cover less than expected except for foraging during the breeding season. Stands used for foraging did not differ in structure between seasons and had greater canopy cover and less rock cover than stands with no documented use. Stands used for roosting differed between seasons in a multivariate comparison, but no individual habitat variables differed between seasons in subsequent univariate comparisons. In both seasons, stands used for roosting had greater canopy cover than stands with no roosting use. Closed-canopy forests, which were used heavily by owls, were relatively rare on the study area, suggesting that such forests warrant special protection in areas managed for spotted owls. This may conflict with efforts to restore more open conditions in ponderosa pine forests. For. Sci. 45(1):127-135.
Simulation of Thinning with a Single-Grip Harvester
Authors: Eliasson Lars 
Published: April 2024

Abstract
A simulation model of a single-grip harvester was constructed to evaluate different silvicultural treatments and to compare different machine concepts with a minimum of confounding factors. The model simulates machine movement, boom movement, felling, delimbing, and cross-cutting in stands where both size and position of each tree are known. To validate the model, model output was compared with data from recent time studies. Effects on harvester productivity of three harvesting intensities (extraction of 30, 40, and 50% of the basal area when thinning from below) and four distances between machine positions were studied. Productivity increased with harvesting intensity and with distance between machine positions. For. Sci. 45(1):26-34.
Stakeholder Perspectives on Appropriate Forest Management in the Pacific Northwest
Authors: Kearney Anne R. , Bradley Gordon , Kaplan Rachel , Kaplan Stephen 
Published: April 2024

Abstract
One potential source of the controversy over forest management in the Pacific Northwest is differences in stakeholders' conceptualizations, or perspectives, on appropriate forest management. This study explores the nature of stakeholders' perspectives and identifies some of the differences and commonalities among them. Study participants included 23 individuals from 3 forest stakeholder groups: the USDA Forest Service, timber industry, and environmentalists. Participants' perspectives on appropriate forest management were assessed using a conceptual content cognitive map (3CM) task. Results indicate the existence of a wide range of concerns including issues related to the focus, setting, and process of management. The pattern of differences and similarities among stakeholder groups with respect to these concerns was found to be complex and to deviate substantially from common stereotypes. In addition, participants' perceptions of the other stakeholder groups were found to be highly stereotypical and were not supported by the data. For. Sci. 45(1):62-73.
Realized Gain and Prediction of Yield with Genetically Improved Pinus radiata in New Zealand
Authors: Carson Susan D. , Garcia Oscar , Hayes Judy D. 
Published: April 2024

Abstract
Pinus radiata D. Don seedlots of varying genetic quality were compared in block-plot genetic-gain trials at 10 locations representing most of the site types in New Zealand. Permanent sample plots were measured annually for growth from age 6-8 yr from planting to ages 15-17 (midrotation). Seedlots from first-generation open-pollinated seed orchards and a mix of crosses that all involved the top-performing parent were, respectively, on average 4.5% and 5.3% taller and had 6% and 11% larger mean diameter, 12% and 30% more basal area, and 15% and 34% more stem volume than seedlots originating from mild mass selection in harvested stands ("climbing select"). The observed growth increases were quantified as changes in the rate of growth from that predicted by preexisting growth models in order to account for tree size and stocking differences. Seedlots from first-generation seed orchards and crosses of the top clone, respectively, grew 5.1% and 4.5% faster in height, and functions for basal area and stocking changed 13% and 26.4% faster, respectively, than the baseline growth models, which were based on climbing select. This implies that increased basal area growth must be taken into account in order to obtain accurate prediction of gain in stem volume. The incorporation of these observed increases in growth rates into stand growth models as "genetic-gain multipliers" in order to extrapolate predictions of growth of genetically improved seedlots beyond the sites, silvicultures, and seedlots represented in the genetic gain trials is discussed. For. Sci. 45(2):186-200.
Selecting Loblolly Pine Parents for Seed Orchards to Minimize the Cost of Producing Pulp
Authors: Lowe W. J. , Byram T. D. , Bridgwater F. E. 
Published: April 2024

Abstract
Southern pine cooperative breeding programs currently emphasize genetic improvement of growth rates. When a deployment population, typically a seed orchard, is established, there is an opportunity to emphasize traits other than growth rate to maximize the profit of individual cooperators in the breeding program. We studied a Southeast Texas breeding population and developed selection indexes to optimize profits for Kraft and mechanical pulp mills. The relative economic weights for volume and wood density were 1:8.1 and 1:8.6 for Kraft and mechanical pulp mills, respectively. Choosing parents with these indexes increased expected profit per ton of dry pulp by 3.4% for both mill types. Expected gains in profit were 3.3% when parents were chosen based on wood density alone. If parents were chosen based solely on volume growth, expected gains in profit were only 0.3%--0.4%. For. Sci. 45(2): 213-216.
Projecting Timber Inventory at the Product Level
Authors: Teeter Lawrence , Zhou Xiaoping 
Published: April 2024

Abstract
Current timber inventory projections generally lack information on inventory by product classes. Most models available for inventory projection and linked to supply analyses are limited to projecting aggregate softwood and hardwood. The research presented describes a methodology for distributing the volume on each FIA (USDA Forest Service Forest Inventory and Analysis) survey plot to product classes given a type characterization, volume, and average dbh (diameter at breast height, 1.37 m above average ground level) for the plot. A multinomial logit model was developed to estimate sets of product proportion functions to distribute plot volumes by product class for each forest type and size class. A discussion of the performance of the model using Alabama and Mississippi FIA plot level data is provided. For. Sci. 45(1):226-231.
An Analysis of Monte Carlo Integer Programming, Simulated Annealing, and Tabu Search Heuristics for Solving Spatial Harvest Scheduling Problems
Authors: Boston Kevin , Bettinger Pete 
Published: April 2024

Abstract
Heuristics are commonly used to solve spatial harvest scheduling problems. They can generate spatially and temporally feasible solutions to large problems that traditional mathematical programming techniques are unable to solve. A common complaint about heuristics is that the quality of the solutions is unknown. We compared three heuristic techniques commonly used to solve spatial harvest scheduling problems: Monte Carlo integer programming, simulated annealing, and tabu search. Five hundred solutions to four problems, which had between 3000 to 5000 0-1 integer variables, were generated with each heuristic technique. In addition to the heuristic solutions, the optimal solution value was found to each problem using integer programming. Simulated annealing found the highest solution value for three of the four planning problems, and was less than 1% from the highest objective function value in the fourth problem. Tabu search located the best solution for the fourth planning problem. Monte Carlo integer programming had the lowest objective function for all four problems. Tabu search had the smallest range of solutions, followed by simulated annealing. Monte Carlo integer programming had the largest range of solutions. Using the Anderson-Darling statistics, the hypothesis that the solutions from each heuristic technique were distributed as a Weibull distribution was rejected for 10 of the 12 set of values. For the two solutions where the Weibull distribution was not rejected, the estimated optimal solution was found to be an unreliable estimate of the actual optimal solution. It appears that the reliability of using extreme value statistics to estimate the optimal solution is dependent on the quality of solutions generated by the heuristic procedure. For. Sci. 45(2):292-301.