bluuebunny/crossref_metadata_2025_split huggingface dataset:
PAPYRUS: A Model of the North American Pulp and Paper Industry
Authors: Gilless J. Keith , Buongiorno Joseph 
Published: April 2024

Abstract
A spatial equilibrium model of the North American pulp and paper industry was developed to provide long-range projections of production, consumption, imports, exports, equilibrium prices, and fiber inputs. The model consists of a price-endogenous linear program that describes the industry in one year, and a set of recursive relationships that update this linear program from year to year to reflect endogenous and exogenous changes. The linear program incorporates supply curves for raw materials, an activity analysis representation of manufacturing and transport activities, and demand curves for final products and exports. The optimal solution to the linear program is the competitive equilibrium for the industry in a given year. Fourteen commodities are recognized in the model: softwood and hardwood roundwood and residues, mechanical, semichemical, and chemical pulp, newsprint, paper, and paperboard, and four recycled commodities. The United States and Canada are divided into 11 supply and 9 demand regions; the rest of the world consists of 3 net demand regions. A baseline simulation is presented that covers the period from 1980 to 2000. The results of alternative simulations, in which key assumptions of the baseline simulation are altered, are also presented.
An Ecological Climatic Classification of Michigan: A Quantitative Approach
Authors: Denton S. R. , Barnes B. V. 
Published: April 2024

Abstract
An ecological climatic classification method that emphasizes variables important to tree growth and survival was developed for Michigan. Separate classifications of weather station data were made for winter variables, growing season temperature variables, and growing season water balance variables. Each classification was based on the combined results of 6 cluster analysis procedures and principal component analysis. Hierarchical agglomerative average link cluster analysis using a modified Canberra metric as a distance measure (CANA) was generally most effective in reflecting the underlying structure of the climatic data. A single unified classification was then made combining the climatic information with physiographic patterns. Three regions and 20 districts were identified. The final classification was evaluated with canonical discriminant analysis and analyses of variance. The importance of such classifications for forest management and relationships with other climatic classification methods were discussed. For. Sci. 34(1):119-138.
Estimating Nitrogen Lost from Forest Floor During Prescribed Fires in Douglas-Fir/Western Hemlock Clearcuts
Authors: Little Susan N. , Ohmann Janet L. 
Published: April 2024

Abstract
Nitrogen loss from consumption of forest floor was studied on 33 treatment blocks burned on 11 clearcuts in western Washington and western Oregon. In most cases, nitrogen concentration in forest floor did not change significantly following prescribed fire. Change in the amount of nitrogen in forest floor ranged from an increase of 192 kg/ha to a loss of 666 kg/ha. In most cases, nitrogen loss was directly proportional to the amount of forest floor consumed. Total nitrogen loss can therefore be estimated by multiplying expected loss of forest floor by its nitrogen concentration before the burn. For. Sci. 34(1):152-164.
Reproductive Mode and Mechanisms for Self-Replacement of Northern Red Oak (Quercus rubra) - A Review
Authors: Crow T. R. 
Published: April 2024

Abstract
The requirements for regenerating northern red oak can be hypothesized from an understanding of the species' ecological life-history characteristics along with a knowledge of past and present disturbance patterns. The abundance of oak in the eastern forest is closely related to past land use and extensive disturbances. Frequent fires and heavy cutting favored oak because of its sprouting ability, while fires reduced common competitors. Northern red oak is neither an aggressive colonizer that is characteristic of early successional species nor an enduring, shade-tolerant, slow-grower that is typical of late successional species. Its regeneration requires an edge environment; one that is more mesic than exposed, open sites, but less competitive than the deep shade of a forest understory. To regenerate northern red oak, foresters need to create these conditions. Numerous cutting studies, however, have shown that overstory manipulation (partial or complete removal) alone will not regenerate northern red oak. Intense competition can be expected on the mesic sites suitable for northern red oak, and this competition must be controlled when regenerating this species. For. Sci. 34(1):19-40.
A Reevaluation of the Wagon Wheel Gap Forest Watershed Experiment
Authors: Van Haveren Bruce P. 
Published: April 2024

Abstract
The original, published streamflow data from the Wagon Wheel Gap watershed deforestation study were analyzed using modem computational and statistical methods. Annual hydrograph parameters were generated for the two paired watersheds for the pre- and postreatment periods and tested using regression and covariance analyses. Average annual water yield, maximum daily discharge, high-flow volumes, recession flows, and baseflow were all increased significantly following complete deforestation of one watershed. With the exception of the first full year after treatment, deforestation had little effect on hydrograph timing. Deforestation increased both the slope and intercept of a linear equation describing the flow duration curve of Watershed B. The results for these major hydrograph parameters agree with the results reported from the original study, conducted between 1910 and 1926 at Wagon Wheel Gap, Colorado. However, some of the original study results for other hydrograph parameters could not be statistically supported. For. Sci. 34(1):208-214.
A Stochastic Efficiency Approach for Determining the Economic Rotation of a Forest Stand
Authors: Caulfield Jon P. 
Published: April 2024

Abstract
Existing risk-rotation models for forest stands assume risk-neutrality on the part of decision makers. The criterion by which the optimal economic rotation is chosen in such models is based on the maximum expected discounted value of the site. Economic theory suggests, however, that many individuals are risk-averse and do not make investment decisions based solely on the mean of the distribution of investment returns. Models assuming risk-neutrality do not necessarily identify the appropriate economic rotation for such investors. Stochastic dominance analysis is employed to incorporate risk-aversion into the rotation decision. An example demonstrates how to apply the technique in practice, and results are compared with alternative decision rules, these being the (1) deterministic land expectation value, (2) mean-variance rule, and (3) mean-coefficient of variation rule. Results are consistent with previous work in that the inclusion of risk identifies risk-efficient rotations that may be shorter than in the deterministic case. Unlike previous efforts, more than one risk-efficient rotation may be identified. The mean-variance rule cannot usefully be applied to the rotation decision, and the mean-coefficient of variation rule defines a much larger efficient set than does stochastic dominance analysis. A sensitivity test shows that the degree of stochastic efficiency attained for a given rotation age changes with the annual probability of fire. For. Sci. 34(2):441-457.
The Relationship Between Western Spruce Budworm Defoliation Levels and Growth of Individual Douglas-Fir and Grand Fir Trees
Authors: Nichols Thomas J. 
Published: April 2024

Abstract
Regression models were fit relating foliage levels to height and basal area growth of 192 trees from 26 stands representing a wide range of site and stand conditions. The study confirmed that deteriorated tree conditions in prior years (often resulting from defoliation) affect current-year growth at specific foliage levels. Absolute height and basal area growth at specific foliage levels were found to be linearly related to absolute height and basal area growth before defoliation, indicating that proportional growth losses resulting from specified levels of defoliation do not vary between fast-growing and slow-growing trees. Various site, stand, and tree variables showed no effect on the relationship between foliage levels and proportional growth loss. Models that included predicted nondefoliated growth, foliage level, and preceding-year condition variables explained up to 61 and 91% of the variation in height and basal area growth (In-In transformation), respectively. For. Sci. 34(2):496-504.
Use of Stochastic Production Coefficients in Linear Programming Models: Objective Function Distribution, Feasibility, and Dual Activities
Authors: Pickens James B. , Dress Peter E. 
Published: April 2024

Abstract
The theoretical impact resulting from use of stochastic production coefficients on the objective function values of unconstrained and constrained linear programming problems was discussed. It was shown that the objective function value that is observed will be a biased and optimistic estimator of the true response of the natural resource system. In addition, it was shown that stochastic production estimates either have no impact or result in suboptimality when the stochastic production coefficients do not affect feasibility. The distribution of the optimal objective function value observed when stochastic production estimates are used, the objective function value of the true response of the system, and a linear combination of these random variables are hypothesized. These hypothesized distributions are then tested using a simulation approach with three error distributions and levels of variability. The simulations indicate that, when global constraints are applied, the dual activities of the global constraints in the presence of stochastic production coefficients are biased estimates of the dual activities with correct production information. In addition, truly infeasible solutions were selected nearly all of the time when feasibility could be violated. For. Sci. 34(3):574-591.
Predicting Fertilizer Response of Loblolly Pine Using Foliar and Needle-Fall Nutrients Sampled in Different Seasons
Authors: McNeil Robert C. , Lea Russ , Ballard Russell , Allen H. Lee 
Published: April 2024

Abstract
Nitrogen (N) and phosphorus (P) concentrations in loblolly pine (Pinus taeda) foliage and needle-fall were determined five times during 1979 on ten fertilizer trials installed between 1971 and 1973. Bole volume responses to fertilizers were regressed on initial stand basal area, and the residual errors were used as dependent variables in regressions with the nutrient variables. The only sampling period during which the N response residuals had a significant relation to foliar nutrients was early fall. The needle-fall N/P ratio was significantly related to the N response residuals in late winter, late spring, and early fall. Phosphorus response residuals were significantly related to foliar nutrients during all sampling periods and to needle-fall N/P in all sampling periods except late winter. The maximum R2;, 0.73, was for the regression of the P response residuals versus a foliar N/P ratio in late spring. The N + P response residuals were not significantly related to foliar or needle-fall nutrients. For. Sci. 34(3):698-707.
Growth Response of Green and White Ash Seedlings to Ozone, Sulfur Dioxide, and Simulated Acid Rain
Authors: Chappelka A. H. , Chevone B. I. , Burk T. E. 
Published: April 2024

Abstract
Nine-week-old green (Fraxinus pennsylvanica Marsh.) and white (F. americana L.) ash were exposed to O3 and/or SO2 (control, 0.10 ppm O3, 0.08 ppm SO2 or 0.10 ppm O3 + 0.08 ppm SO2) for 4 h d-1, 5 d wk-1 in combination with simulated rain (pH 3.0, 4.3 or 5.6, 1 h d-1, 2 d wk-1 at 0.75 cm h-1) for 6 weeks, under controlled laboratory conditions, with rain applied either just before or after fumigation. Across all rain treatments, white ash biomass was suppressed by the application of O3 and cumulative shoot elongation of green ash exposed to O3 and/or SO2 was less than controls. The combination of O3 + SO2 did not affect the growth of either species more than the pollutants applied alone. Leaf area ratio (LAR) and root to shoot ratio (RSR) exhibited quadratic responses to rain pH in green ash, across all pollutant treatments. Significant pollutant x pH interactions occurred in leaf weight ratio (LWR) in green ash and LAR and RSR in white ash. Significant linear increases in LAR and decreases in RSR, with decreasing pH, were observed for O3 and SO2-treated white ash. These findings are discussed relative to implications of the effects of gaseous pollutants in combination with acid rain on green and white ash growth. For. Sci. 34(4):1016-1029.
Sources of Variation in Osmotic Potentials with Special Reference to North American Tree Species
Authors: Abrams Marc D. 
Published: April 2024

Abstract
The purpose of this review is to discuss sources of variation in osmotic potentials (ψπ), with special reference to North American tree species. Lowering of osmotic potentials by solute accumulation (osmotic adjustment) has been reported in a wide variety of tree species during drought, but not in all species. Osmotic potentials at zero turgor for 37 tree species throughout the United States and Canada averaged (± s.e.) - 2.06 ± 0.13 MPa and - 2.54 ± 0.06 MPa for leaves or shoots under moist and dry conditions, respectively. The low standard error associated with the mean values suggest that, as a group, North American trees develop fairly similar osmotic potentials for a range of moisture conditions. Substantial solute accumulation often routinely occurs in developing leaves and in over-wintering leaves. Drought preconditioning can increase physiological activity in plants during subsequent drought by lowering ψπ. However, if drought is imposed too rapidly osmotic adjustment may not occur. Physiological plasticity in trees may cause variations in ψπ in responses to light regime and leaf canopy position. Light and nutrient regimes that promote high net photosynthesis should also promote the ability to osmotically adjust. However, stomatal responses and growth during water and nutrient stress may be unrelated to osmotic potentials because of species differences in rooting and water transport, guard cell turgor not being closely coupled with that of the bulk leaf, and changes in plant growth regulator concentrations. When examining changes in osmotic potentials using pressure-volume curves, it is important to rehydrate plant material to a water potential characteristic for that species at full hydration in the field. Moreover, as with most physiological measurements, sampling variation in light regime, canopy position, nutrient status, temperature, age, phenology, drought history, and diurnal timing of harvesting of the leaves and shoots should be minimized. For. Sci. 34(4):1030-1046.
Stratification of Seeds of Western and Utah Juniper
Authors: Young James A. , Evans Raymond A. , Budy Jerry D. , Palmquist Debra E. 
Published: April 2024

Abstract
Seeds of western juniper (Juniperus occidentalis subsp. occidentalis Hook.) and Utah juniper [J. osteosperma (Tort.) Little] are highly dormant when freshly harvested. Cool-moist stratification at 5°C for 14 weeks in vermiculite enhanced subsequent emergence of seedlings of both species, but total emergence was still low. The year of seed production greatly influences the viability of seedlots. Dry storage for 1 to 4 years at room temperatures did not enhance germination. Outdoor stratification, over winter, in sand, enhances subsequent emergence depending on the environment of the stratification site. The year of seed production also interacts with outdoor situations. Repeat stratification treatments, interrupted by 8-week continuously wet-emergence-assay periods in the greenhouse and dry storage during the summer were cumulative for increased seed germination of both species. Interrupted treatments were more effective than continuous stratification in excess of the optimum duration to enhance germination. Stratification in aqueous solutions with near saturation of the solution with oxygen increased subsequent emergence of seedlings of western and Utah juniper to about 50%. Similar treatments using aqueous solutions of 0.289 m mol L-1 gibberelin (GA3) enhanced subsequent emergence of seedlings of western juniper to better than 80%. For. Sci. 34(4):1059-1066.
Modeling Tree Growth Potential Based on Effective Evapotranspiration
Authors: Wickramasinghe A. 
Published: April 2024

Abstract
Annual tree growth potential is assessed by modeling effective evapotranspiration and taken as an index expressing interaction between atmospheric energy, tential evapotranspiration (PET), and soil moisture supply. The model has been calibrated for 11 forest stands of two evergreen species, Scots pine (Pinus Sylvestris) and Corsican pine (Pinus Nigra), located in England. Four calibrated effective evapotranspiration values (EET) together with a simple climatic index (PET/R), which expresses the balance between potential evapotranspiration and rainfall, were subsequently multiplied by tree age to incorporate the physiological efficiency of trees. The derived potential growth indexes (PGIs) were comparatively examined with actual annual tree growth data for a period of 30 to 40 years. Regression analysis was carried out in evaluating the model performance and the applicability of the model to predict environmental potential. All four predictions based on assessment of effective evapotranspiration were positively correlated with annual tree growth, having coefficients of determination above 0.40, and often reaching 0.70, with significance at the 0.001 level of probability. For. Sci. 34(4):864-881.
A Statistical Model of Root Geometry
Authors: Wu Tien H. , Bettadapura Dayanand P. , Beal Philip E. 
Published: April 2024

Abstract
The number, diameter, and length of lateral roots are related to the stem diameter of the tree. The diameter of branch roots is related to the diameter of the main lateral at the branch point. Statistical correlations were used to establish the relationships. Statistical correlations were also found for the change in root diameter and root orientation with distance along the root. These relations were used to formulate a model of root geometry, which allows one to estimate the frequency of root diameters as a function of distance from the stem of a tree with a given stem diameter. Application of the model to estimation of root density is described in an example problem. For. Sci. 34(4):980-997.
Thinning Red Alder: Effects of Method and Spacing
Authors: Hibbs David E. , Emmingham William H. , Bondi Michael C. 
Published: April 2024

Abstract
A 14-year-old fully stocked red alder (Alnus rubra Bong.) stand on a site index 30 m (50 yr) site in northwest Oregon was precommercially thinned and growth measured for 5 years. Treatments were (1) 4.3 x 4.3 m spacing (541 trees/ha), chemically thinned, (2) 6.1 x 6.1 m spacing (269 trees/ha), chemically thinned, (3) 6.1 x 6.1 m spacing, chain-saw thinned, and (4) control (1754 trees/ha). Chemical thinning was done by trunk injection of 2,4-D and caused some damage (flashback) to neighboring crop trees.
Thinning increased individual-tree radial growth 49% to 100% and decreased tree height growth by as much as 56%. In combination, this resulted in no significant change in tree volume growth with thinning. The lack of tree volume growth increase combined with the decrease in stem density with thinning produced a net decrease in stand volume growth with thinning. A review of the literature showed height growth reductions to be common among other alder studies. Tree basal area growth on the chemically thinned plots did not increase as much as on the chain-saw thinned plots, suggesting a prolonged growth reduction effect from the herbicide treatment. Diameter growth decreased with increasing degree of herbicide-induced crown damage. Thinning increased the size but not the numbers of epicormic branches. The longevity or effects on wood quality of these branches is not known. For. Sci. 35(1):16-29.
Considerations for Throughfall Chemistry Sample-Size Determination
Authors: Edwards Pamela J. , Mohai Paul , Halverson Howard G. , DeWalle David R. 
Published: April 2024

Abstract
Both the number of trees sampled per species and the number of sampling points under each tree are important throughfall sampling considerations. Chemical loadings obtained from an urban throughfall study were used to evaluate the relative importance of both of these sampling factors in tests for determining species' differences. Power curves for detecting differences among species derived from the noncentrality parameter developed herein indicated that the number of trees sampled per species affects power more than the number of points sampled under each tree. For. Sci. 35(1):173-182.
Terrain Shape Index: Quantifying Effect of Minor Landforms on Tree Height
Authors: McNab W. Henry 
Published: April 2024

Abstract
In the southern Appalachians, the distribution and growth of trees are highly correlated with local topography, but the relationships have been difficult to describe quantitatively. A quantitative expression of the geometric shape of the land surface (terrain shape index) is described and correlated with overstory tree heights and site quality. Application of the index in three even-aged stands of yellow-popular (Liriodendron tulipifera L.) on high-quality uniform sites shows that it is highly correlated with total height of trees in a stand, with r2 ranging from 0.45 to 0.74. In comparisons among stands, the index accounted for an average of 51% of the variation in site index. The relationship was validated in two supplementary stands and accounted for about 49% of variation in site index. The terrain shape index was more accurate in predicting tree height than was lateral shape class, a subjective measure of slope shape occasionally used in soil-site studies. For. Sci. 35(1):91-104.
Multiple-Occasion Partial Replacement Sampling for Growth Components
Authors: Van Deusen Paul C. 
Published: April 2024

Abstract
The Ware and Cunia (1962) method for estimating volume at time 2 from sampling with partial replacement is proven to be equivalent to a generalized least squares estimator (GLS). The GLS approach is advantageous because it extends easily to encompass multiple occasion sampling with partial replacement (MOSPR). An iterative GLS procedure is given for simultaneously estimating population parameters and their variances that avoids incompatibility problems that arose with some previously published methods. The MOSPR theory is also extended to include growth component estimation with additivity constraints. For. Sci. 35(2):388-400.
Identifying NIPF Management Motivations with Qualitative Methods
Authors: Bliss John C. , Martin A. Jeff 
Published: April 2024

Abstract
Most studies of nonindustrial private forest (NIPF) owners are constrained by the intrinsic limitations of survey research. This paper contrasts survey methodology with qualitative methodology, demonstrates the utility of the latter with an example from research on management motivations of NIPF managers in Wisconsin, and suggests ways in which the two methodologies can complement each other in future NIPF research. Sixteen case studies of Wisconsin NIPF managers were developed from transcribed tape recordings of unstructured interviews, management records, and field examinations. Cases were compared and analyzed for recurring motivations, attitudes, and values. The authors discuss how forest ownership and management contribute to owner identity, and the influence of ethnic, family, and personal identity on management activities. For. Sci. 35(2):601-622.