bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific Gravity Variation in a Loblolly Pine Seed Source Study in the Western Gulf Region
Authors: Byram T. D. , Lowe W. J. 
Published: April 2024

Abstract
Specific gravity in 28 plantings of the Western Gulf Forest Tree Improvement Program seed source study varied by provenance, family within provenance, and test location. Trees from south Arkansas had the highest specific gravity (0.424) while those from south Louisiana had the lowest (0.398). Southeast Texas and north Louisiana trees were intermediate with an average specific gravity of 0.405. Trees from a North Carolina coastal source had the lowest specific gravity in the five plantings in Arkansas and Oklahoma in which they were included.
Families generally ranked the same in all tests. This implied that specific gravity was under strong genetic control and genotype by environment interaction was not operationally meaningful. However, specific gravity was environmentally sensitive as it varied significantly among locations. Environmental and genetic patterns of variation did not agree; therefore, in situ studies of regional specific gravities should not be used for making seed movement decisions. For. Sci. 34(3):798-803.
Forest Inventory and Management-Based Visual Preference Models of Southern Pine Stands
Authors: Rudis Victor A. , Gramann James H. , Ruddell Edward J. , Westphal Joanne M. 
Published: April 2024

Abstract
Statistical models explaining students' ratings of photographs of within-stand forest scenes were constructed for 99 forest inventory plots in east Texas pine and oak-pine forest types. Models with parameters that are sensitive to visual preference yet compatible with forest management and timber inventories are presented. The models suggest that the density of sawtimber-sized trees and the proportion of visual penetration are positively associated with scenic beauty. Foliage, twig, and small stem screening, and the density of small-diameter trees are negatively associated with scenic beauty. Results generally concur with other visual preference studies of within-stand forest scenes. Such models and associated parameter estimates can be used to objectively assess within-stand forest scenes and to routinely monitor scenic beauty of southern pine forest resources. Unlike similar scenic beauty studies, the limited amount of downed wood encountered was positively associated with scenic beauty. Also suggested is a decline in perceived scenic beauty during the summer season (May-October) coincident with sampling from northeast to southwest sections of east Texas. For. Sci. 34(4):846-863.
A Method to Estimate Input-Output Multipliers for the Forestry Sector Without an I-O Table
Authors: Zheng Chinlong , Harou Patrice A. 
Published: April 2024

Abstract
An input-output (I-O) multiplier can help quantify the relationship between an initial investment and the subsequent increase in the total production of an economy. A method for quickly estimating I-O multipliers without an I-O table is presented. It requires only two variables, which can be obtained at a low cost. Five I-O models with significant forestry sectors are used to validate the analysis empirically by comparing the actual and estimated multipliers. The applicability of the method is then discussed. For. Sci. 34(4):882-893.
A Height Prediction Model with Random Stand and Tree Parameters: An Alternative to Traditional Site Index Methods
Authors: Lappi Juha , Bailey Robert L. 
Published: April 2024

Abstract
A new method for predicting the height development of dominant trees is presented and illustrated with slash pine plantation data. The prediction procedure is based on a statistical model that explicitly describes the major random components in the variation of height curves. The average height of dominant and codominant trees in the population is expressed as a function of age. Then a model is developed for the variance-covariance structure of deviations from this average height curve due to stands and trees within stands. The model takes into account the fact that, within a given stand, heights of trees at a specific age are correlated, and tree heights and average stand height are correlated over time. The ability to specify and estimate this special covariance structure is obtained by including random stand and tree parameters in the height growth model. With the estimates of variances and covariances, and of the parameters of the function for average height, the height development of a given stand or single tree can be predicted using statistical prediction methods that utilize all available height measurements. With an example that includes two trees on one plot, one measured at one age only and the other measured at two ages, calculation of the variances of prediction errors is illustrated, and confidence limits on predicted values are calculated. For. Sci. 34(4):907-927.
Relationship Between Volume and Biomass of Early Successional Vegetation and the Prediction of Loblolly Pine Seedling Growth
Authors: Byrne Stephen V. , Wentworth Thomas R. 
Published: April 2024

Abstract
A simple and nondestructive method of measuring plant volume was developed to test the following two hypotheses: (1) plant volume is an effective substitute for plant biomass in the prediction of competitive potential; and (2) the plant biomass-volume relationship is affected by plant growth form. In 1983, above-ground volume and biomass were determined for all plants in 40 1-m² plots in an experimental loblolly pine (Pinus taeda L.) plantation having varying degrees of successional regrowth. After natural log transformations of plant biomass and volume, separate regression equations were developed for grass, forb, shrub, and tree growth forms. A test of homogeneity indicated that the slopes and intercepts for the four regression equations were not all identical. Specific contrasts among the regression equations were also tested for common slopes and intercepts to determine the source of overall significance. Results of the contrasts were explained by differences in plant allocation patterns. The variation in plant biomass accounted for by the volume models ranged from 78% for grasses to 94% for trees. As an application of this approach, volume was measured and biomass was estimated from the regression equations for successional plants within a 2m radius (the "neighborhood") of each of 69 loblolly pine seedlings. Total plant volume and total estimated biomass each accounted for approximately 40% of the variation in pine growth. For. Sci. 34(4):939-947.
Species Composition and Diversity During Secondary Succession of Coniferous Forests in the Western Cascade Mountains of Oregon
Authors: Schoonmaker Peter , McKee Arthur 
Published: April 2024

Abstract
Species diversity and community composition were studied at 23 sites on similar western hemlock/Douglas-fir forest habitats, in undisturbed old-growth stands and stands at 2, 5, 10, 15, 20, 30, and 40 years after clearcutting, broadcast burning, and planting with Douglas-fir. Vegetation was sampled with three 5 x 60 m transects at each site. Invading herbs, then invading and residual shrubs, and finally conifers dominated through the first 30 years. Late seral species, which account for 99% of cover in old-growth stands, are nearly eliminated immediately following disturbance, but account for almost 40% of vegetative cover after 5 years, 66% after 10 years, 83% after 20 years, and 97% at 40 years. After an initial drop following disturbance, species diversity trends weakly upward with heterogeneity peaking at 15 years and richness at 20 years. This initially high diversity (higher than that of old-growth stands) is short-lived. After the tree canopy closes, species diversity declines reaching its lowest values at 40 years. Only two species were eradicated after disturbance, both mycotrophs. Pacific Northwest old-growth forests are relatively poor in species, but moderately high in heterogeneity values. For. Sci. 34(4):960-979.
Relationships Between Fuel Properties and Slashburning-Induced Nutrient Losses
Authors: Feller M. C. 
Published: April 2024

Abstract
The relationships between slash load, slash and forest floor consumption variables, and species origin of slash (slash type), and nutrient (N, P, S, K, Na, Mg, and Ca) losses to the atmosphere during slashburning, were studied by burning 50 plots, each 2.25m² in area. The plots contained known amounts of slash materials derived from four major southwestern British Columbia tree species (Tsuga heterophylla, Thuja plicata, Chamaecyparis nootkatensis, and Pseudotsuga menziesii) and were burned under different fire weather conditions. Nutrient losses (g/m²) decreased in the order: N &gt; Ca &gt; S &gt; K &gt; Mg &gt; P &gt; Na and were generally within the range of such losses recorded for operational prescribed burns in western North America. Losses of all nutrients except Na were positively correlated with fuel consumption. Nitrogen and S exhibited the best correlations, whereas no correlations were found for Na. Of the fuel consumption variables considered, depth of forest floor consumed, then total slash consumption, were best correlated with nutrient loss. Losses (g/m²) of most nutrients generally increased with slash load and as slash type changed from Tsuga, to Pseudotsuga to Thuja/Chamaecyparis. This was partly due to the effects of slash load and slash type on fuel consumption, and partly due to their effects on burning-caused changes in nutrient concentrations in slash materials. The study suggests that nutrient losses to the atmosphere during operational slashburns can be minimized by minimizing forest floor and large diameter slash consumption during burning. For. Sci. 34(4):998-1015.
Forest Taxation and Timber Supply Under Price Uncertainty: Perfect Capital Markets
Authors: Koskela Erkki 
Published: April 2024

Abstract
This paper provides a detailed analysis of timber harvest decisions under price uncertainty. Specifically, the relationship between timber supply—in the sense of whether to bring harvest to the market now or in the future—and various forest taxes is analyzed by using an intertemporal consumption-savings model, which is extended to allow for harvesting decisions. In the presence of perfect capital markets and certainty, harvesting decisions of nonindustrial forest owners are independent from their consumption preferences. However, under future timber price uncertainty and risk aversion, harvesting decisions depend on the consumption preferences of forest owners. The implications of this nonseparability between consumption and harvesting decisions are developed for various individual forest taxes as well as for various changes in the structure of forest taxes, which will keep the government's tax revenue constant. Due to the nonseparability, harvest responses to changes in tax rates and in the structure of taxes may differ considerably from those under certainty. For. Sci. 35(1): 137-159.
Forest Taxation and Timber Supply under Price Uncertainty: Credit Rationing in Capital Markets
Authors: Koskela Erkki 
Published: April 2024

Abstract
This paper provides a detailed analysis of timber harvest decisions under price uncertainty and credit rationing. Under these circumstances the Fisherian separation theorem no longer holds. Instead, the harvesting decisions of forest owners depend on their consumption preferences. The implications of this nonseparability between consumption and harvesting decisions under credit rationing are developed for various individual forest taxes as well as for various changes in the structure of forest taxes, which will keep the government's tax revenues constant. The importance of credit rationing lies in the fact that the distribution of revenues between the current and future period affects harvesting decisions. Hence, the taxes and tax policies that affect this revenue distribution bring about liquidity effects, which may make the effects of taxes sharply different from those found in the presence of perfect capital markets. For. Sci. 35(1):160-172.
Radial Gradients in the Specific Gravity of Wood in Some Tropical and Temperate Trees
Authors: Wiemann Michael C. , Williamson G. Bruce 
Published: April 2024

Abstract
Pith to bark wood samples from 20 Costa Rican tropical wet forest and 17 United States temperate forest tree species showed wide variability in specific gravity trends among species. Specific gravity increased significantly from pith to bark in 16 of the tropical tree species. The increases were most dramatic (90-270%) in species that are typically colonizers of clearings and disturbed sites; species of later stages of succession showed moderate increases (20-70%) or, in some instances, no change in specific gravity from pith outward. Statistically significant linear pith to bark trends were found in only four temperate species—two of these increased specific gravity with diameter and two decreased. None of the temperate species showed a change greater than 40%, and no clear relationship between specific gravity pattern and shade tolerance was evident. In tropical wet forests, increase in wood specific gravity with diameter may be an adaptation by shade intolerant species to the highly competitive conditions on disturbed sites. For. Sci. 35(1):197-210.
Anthocyanins in Autumn Leaves of Quaking Aspen in Colorado
Authors: Chang Kuo-Gin , Fechner Gilbert H. , Schroeder Herbert A. 
Published: April 2024

Abstract
Two to three natural clones of quaking aspen (Populus tremuloides Michx.), selected for their yellow-, orange-, and red-colored autumn foliage, were observed during late summer and early autumn for 5 years. Pigments were extracted from both colored and green leaves and the extracts analyzed by paper chromatography. The timing and change of color varied with elevation, between clones at similar elevations, and between years, some clones reaching different peak colors in different years. An apparent, unidentified carotenoid pigment was found to be synthesized in all colored leaves during autumn. Two anthocyanin pigments, previously unreported for quaking aspen, cyanidin-3-glucoside and very probably cyanidin-3-galactoside, were found in both orange- and red-colored leaves but were lacking in yellow-colored leaves. For. Sci. 35(1):229-236.
An Alternative Estimator for Horizontal Point Clusters
Authors: Van Deusen Paul C. , Grender Julie Myers 
Published: April 2024

Abstract
A new approach is suggested here for estimating stand attributes when horizontal point clusters (HPCs) are used. The approach is unbiased with smaller variance than the traditional unbiased estimator for HPCs. The necessary formulas for equidistant 3-point clusters are derived. The new estimator offers an opportunity to reduce variance without changing the sample design. For. Sci 35(1):257-262.
True Separable Costs Versus Accounting-Based Separable Costs in Multiple-Use Forestry
Authors: Hof John G. , Field Richard C. 
Published: April 2024

Abstract
This paper evaluates, theoretically and empirically, the consistency or lack thereof between an economically correct definition of separable costs and a definition commonly applied to accounting data. Conditions under which accounting separable costs would accurately reflect true separable costs and would provide lower bounds for true separable costs are developed theoretically. And, a test case involving multiple-use forestry demonstrates a case where these conditions are not met and biases in both upward and downward directions result. For. Sci 35(1):263-270.
Tree Bucking for Optimal Stand Value with Log Allocation Constraints
Authors: Sessions J. , Olsen E. , Garland J. 
Published: April 2024

Abstract
Many log sellers in the western United States face price schedules requiring that a given percentage of the volume be delivered in logs of a specified length. A simple heuristic procedure was developed for deriving a set of log prices which, when used in making decisions for bucking individual trees, provides nearly optimal stand value while meeting volume-length restrictions. For. Sci. 35(1):271-276.
An Approach to the Estimation of Import Price Elasticities by Supplier
Authors: Blatner Keith A. 
Published: April 2024

Abstract
An approach to the estimation of import price elasticities by supplier was developed for the analysis of multilateral commodity flows, where the brevity of available annual time-series data and the lack of quarterly or monthly series precludes the direct application of more rigorous estimation procedures. Import demand functions were estimated for four commodities and four Western European and Asian countries to empirically evaluate the approach and to identify potential supplier differentiation in the market. Products considered included sulfate and sulfite pulp, and kraft paper and paperboard and paper and paperboard n.e.s. due to the relatively large number of suppliers of these products and the tendency of many importers to regularly purchase these products from a variety of suppliers. Importing countries considered included Italy, Japan, West Germany, and the United Kingdom due to their prominent market positions. Estimated differences in import price elasticities identified in 6 of the 16 models considered were relatively small in magnitude, but significantly different from one another, suggesting that some importers do differentiate among suppliers of selected forest products. For. Sci. 35(1):30-41.
Disturbance-Mediated Accelerated Succession in Two Michigan Forest Types
Authors: Abrams Marc D. , Scott Michael L. 
Published: April 2024

Abstract
In northern lower Michigan, logging accelerated sugar maple (Acer saccharum) dominance in a northern white cedar (Thuja occidentalis) community, and clear-cutting and burning quickly converted certain sites dominated by mature jack pine (Pinus banksiana) to early-successional hardwoods, including Prunus, Populus, and Quercus. In both forest types the succeeding hardwoods should continue to increase in the future at the expense of the pioneer conifer species. In the cedar example, sugar maple was also increasing in an undistrubed, old-growth stand, but at a much reduced rate than in the logged stand. Traditionally, disturbance was thought to set back succession to some earlier stage. However, our study sites and at least several other North American forest communities exhibited accelerated succession following a wide range of disturbances, including logging, fire, ice storms, wind-throw, disease, insect attack, and herbicide spraying. For. Sci. 35(1):42-49.
Variable Selection in Dendroclimatology: An Example Using Simulated Tree-Ring Series
Authors: Arbaugh Michael J. , Peterson David L. 
Published: April 2024

Abstract
Regression analysis is often used to select important climatic variables from a group of candidate variables in dendroclimatology. Model R² and F statistics are commonly used as a measure of the importance of these variables. The reliability of these selections in the presence of substantial unexplained variance has not been previously considered (with the exception of some climatic reconstruction studies). In this study multiple regression analysis with stepwise (forward inclusion and backward elimination), best subsets, and principal components was conducted on simulated tree-ring index series constructed from linear combinations of temperature and precipitation data with varying amounts of white noise. Regression techniques increasingly failed to select correct and/or complete sets of variables with increasing proportions of introduced noise, even with a limited number of candidate variables and a known relationship between predictor and dependent variables. R² estimates were inflated with increasing noise for all techniques used. The results imply that climatic regression models may be incorrectly specified when large proportions of unexplained variability are present. There are implications for the analysis of data in other areas of forestry in which variable selection is attempted with datasets containing large amounts of unexplained variability. For. Sci. 35(2):294-302.
Inbreeding Effective Population Size Under Some Artificial Selection Schemes. II. Normal Distribution of Breeding Values
Authors: Kang Hyun 
Published: April 2024

Abstract
Two selection systems, truncation selection followed by a balanced mating (truncation selection) and a selection scheme that assigns mating frequencies to individuals according to their breeding values (weighting system), were compared with respect to inbreeding effective population size. This comparison was made with the condition that both selection schemes give the same expected performance of selected individuals (selection differential). Breeding values of selected individuals were assumed to be normally distributed on a performance scale. Two functions, linear and Beta, were used to represent weighting systems. The results showed that (1) depending on the distribution of breeding values, inbreeding effective population number of some weighting systems can be greater than that of a truncation selection that generates the same selection differential, and (2) because the difference in inbreeding effective population size using different systems can be substantial, it is worth examining for the presence of desirable weighting systems in practical tree breeding situations. For. Sci. 35(2):303-318.
A Model of National Forest Timber Supply and Stumpage Markets in the Western United States
Authors: Adams Darius M. , Haynes Richard W. 
Published: April 2024

Abstract
This paper presents an aggregate regional model of the National Forest timber supply process and the interaction of National Forest and non-National Forest supply in the determination of regional stumpage prices and harvest volumes. Endogenous elements of National Forest supply include establishment of the appraised price, bid price, volumes sold and unsold, the uncut volume under contract, volumes harvested, and harvest price. Components of the model describe the distribution of volumes sold and harvested by bid price and contract duration classes. Estimation results for bid price relations in several western regions indicate that prices bid for stumpage depend on a short (one-year) distributed lag in product prices and production costs. Application of the full model in the Douglas-fir region suggests that short-term National Forest supply may be more elastic with respect to harvest price than industrial private supply. Model simulations track actual behavior in the Douglas-fir region stumpage market with reasonable accuracy over the period of extreme price and volume movements during 1977-1985. Model projections also appear reasonable and internally consistent in a projection to the year 2000 under a less volatile product market scenario. For. Sci. 35(2):401-424.
Selecting Populations in Tree Breeding: An Alternative to Multiple Comparisons
Authors: Falkenhagen Emile R. , Gibbons Jean D. 
Published: April 2024

Abstract
This paper explains the indifference zone and subset selection methods of selecting populations. We recommend them as preferable to pairwise multiple comparisons for selecting the best genetic material in tree breeding, especially when a large number of groups with small differences must be tested. Subset selection permits the data to determine the number of groups designated as including the best genetic material with preassigned probability. Numerical examples of selection procedures are given. For. Sci. 35(2):425-436.