bluuebunny/crossref_metadata_2025_split huggingface dataset:
Econometric Analysis of the Factors Influencing Forest Acreage Trends in the Southeast
Authors: Alig Ralph J. 
Published: April 2024

Abstract
Econometric models of changes in land use acreages in the Southeast by physiographic region have been developed by pooling cross-section and time series data. Separate acreage equations have been estimated for the three major private forestland owner classes and the three major classes of nonforest land use. Observations were drawn at three or four different points in time for the 21 Forest Survey Units in the Southeast. Of the variables examined, population and personal income measures were the major significant explanatory variables in the land use equations. Forest Sci. 32:119-134.
Predicting Site Hazard to Fusiform Rust
Authors: Froelich R. C. , Snow G. A. 
Published: April 2024

Abstract
Nine plantations of slash pine (Pinus elliottii Engelm. vat. elliottii) were established in 1974 in southern Mississippi to study conditions affecting incidence of fusiform rust. Variables studied included climate, seed source, soil properties, pine growth, fungus and host phenology, abundance of aeciospore-producing galls and telia, number of basidiospores trapped, and the spatial relationships of oaks to the plantations. From 1974 through 1978, the amount of pine infection varied considerably by year according to frequency of rain or nights with prolonged high relative humidity. There also were large, but inconsistent, differences in annual infection among sites, due to a complexity of factors. Seed source, soil properties, and pine growth were unrelated to site hazard. The hazard of each area depended on the relationships of oaks to the pine plantations—how near they were, what directions from the plantation, and the number of oaks. Criteria are presented for differentiating among low-, medium-, and high-hazard sites for fusiform rust. Forest Sci. 32:21-35.
A Dynamic Cost and Factor Demand Analysis for the Pacific Northwest Lumber and Plywood Industries
Authors: Merrifield David E. , Singleton William R. 
Published: April 2024

Abstract
A dynamic capital adjustment model is used to describe the Pacific Northwest lumber and plywood industries. The industries' derived demand for stumpage, labor, and capital inputs along with the behavior of costs over output levels are assumed dependent on the quasi-fixed nature of industry capital. Results obtained from data over the period 1954-80 suggest that own and cross-price elasticities of derived demand generally increase as the industries adjust towards long-run desired capital levels. Measures of short, intermediate, and long-run input requirement elasticities revealed relatively constant proportions of stumpage requirements to output levels in both industries, relatively constant proportions of labor to output in the plywood industry, yet relatively volatile employment levels in the Pacific Northwest lumber industry over the long run. Further, adjustments in capital levels appear to have had only a limited effect on the behavior of production costs in the two industries. Forest Sci. 32:220-233.
Distribution of Biomass Within Small Tree and Shrub Form Quercus gambelii Stands
Authors: Clary Warren P. , Tiedemann Arthur R. 
Published: April 2024

Abstract
Gambel oak (Quercus gambelii Nutt.) occupies approximately 3.5 million ha in the states of Arizona, Colorado, New Mexico, and Utah. It is becoming recognized as an important fuelwood resource. Design of appropriate management strategies requires information on the biomass distribution characteristics within these stands. Biomass components of eight Gambel oak small tree and shrub form stands (clones) were sampled in Utah. Stem densities ranged from 5,000 to 34,000 per ha of clone. Mean stem diameters varied from 36 to 117 mm. Live stems averaged 4,992 g including dead branches, while standing dead stems averaged 1,347 g. Live biomass per occupied hectare averaged 124,388 kg including 40,702 kg of bole. The ratio of aboveground to belowground live biomasses was unusually low—44:56. Total aboveground and belowground biomass including detritus was 184,292 kg per hectare of clone. Forest Sci. 32:234-242.
Fire Induced Tree Mortality in a Colorado Ponderosa Pine/Douglas-fir Stand
Authors: Wyant James G. , Omi Philip N. , Laven Richard D. 
Published: April 2024

Abstract
The impact of a fall season prescribed surface fire on Douglas-fir and ponderosa pine mortality during the first 22 months following fire was evaluated using discriminant function analysis. Crown scorch, expressed as a percentage of the prefire live crown length, was the single best determinant of tree mortality. Stem charting on the least impacted quadrant is also a relevant variable in mortality determinations. Larger diameter trees of both species withstood proportionally greater stem and crown damage than smaller trees. Crown consumption indicators added substantially to the discriminating power of the functions, but prefire live crown and maximum scorch height were not important variables. Within the same size range, there was little evidence of important differences between ponderosa pine and Douglas-fir in the levels of crown and stem damage that induce mortality. Forest Sci. 32:49-59.
Eastern Dwarf Mistletoe Seed Storage, Germination, and Inoculation of Spruce Seedlings
Authors: Livingston William H. , Blanchette Robert A. 
Published: April 2024

Abstract
Eastern dwarf mistletoe seed used for inoculation of Picea mariana and P. glauca had better germination (i.e., appearance of a red radicle) and radicle growth when stored at subfreezing temperatures (- 10°C vs. + 4°C) and high humidity for at least 10-12 weeks, and such seed remained viable for at least 40 weeks. Usually 25 percent or less of the seeds had radicle growth longer than 1 min. In greenhouse inoculations, most spruce seedlings (57 of 61) became infected if the radicle made contact with the stem. Forest Sci. 32:92-96.
A Re-Evaluation of the Site Burden Concept When Forest Land Value is Maximized
Authors: Rideout Goug , Hof John G. 
Published: April 2024

Abstract
Comparative statics of the Faustmann (1849) forest land value model are used to analyze the site burden measure of forest tax incidence. The analysis focuses on the importance of allowing management variables to respond to forest taxation, and the results are obtained within the context of land value maximization. General results are derived by applying the Envelope Theorem and ancillary comparative statics to the Faustmann formulation. The paper defines a site burden error term that is shown to increase at an increasing rate with respect to tax rates when management decisions are assumed fixed. Graphical analysis of the timber yield tax is performed, and a specific empirical example of the yield tax, using planting density and rotation age as management variables, demonstrates that site burden error is not necessarily trivial. Forest Sci. 32:511-516.
Changes in Mortality and Size-Class Spatial Distribution Patterns in Pre-Closure and Post-Closure Conifer Plantations
Authors: Ghent Arthur W. , Franson Susan E. 
Published: April 2024

Abstract
Spatial distribution patterns of first-year deaths, and of living tree vigor classes (formed by dividing height-measurement distributions at their approximate one-third points to demarcate shortest, intermediate, and tallest trees) were studied by joins-testing in 5- to 10-year-old pre-closure rectangular lattices (trees aligned in both rows and columns) of white spruce (Picea glauca (Moench) Voss) and red pine (Pinus resinosa Ait.). Frequencies of observed joins between members of the same vigor class exceeded statistical expectations for random adjacency in 86 of 100 pre-closure comparisons, 42 of these excesses being statistically significant. Only one of the 14 comparisons of opposite trend achieved borderline significance. Thus the preponderant tendency was for members of all pre-closure vigor classes to occur in clumps with other members of the same class. This pattern is interpreted as reflecting gradients of soil conditions, a conclusion supported by a comparable preponderance of joins-count deficits between members of vigor classes separated by at least two ranks. In contrast, rectangular lattice plantings of 17- and 18-year-old post-closure red pine showed consistently significant deficits of joins between members of the most vigorous (largest diametered) class of living trees, indicating a natural trend to regular distributions of the largest trees without the intervention of thinning. Significant excesses of joins were observed between these most vigorous trees and the spaces left by presumptive first-year deaths, also a complete reversal of the pre-closure pattern. Forest Sci. 32:559-575.
Optimal Hedging in Lumber Futures Markets
Authors: Deneckere Raymond , Buongiorno Joseph , Bark Sun Il 
Published: April 2024

Abstract
This paper investigated the effectiveness of the lumber futures market in hedging unexpected price variations. The related optimum hedge ratio, i.e., the fraction of the cash position that should be hedged to minimize risk, was also studied. The measure of hedging effectiveness used was the correlation between cash and futures price, conditional on information available at the time of hedging. The analysis of weekly price data showed that during the period June 1980 to February 1985 optimum use of the lumber futures market could have reduced the variance in gain or loss by 50 to 90 percent. Longer hedges were generally more effective and so were those liquidated near the closure of the futures contract. The best strategy was to hedge the cash position entirely, except for hedges liquidated within 8 weeks of contract closure for which hedge ratios of 60 to 80 percent were most effective. Forest Sci. 32:634-642.
Aboveground Phenology in North Florida Slash Pine Plantations
Authors: Hendry L. C. , Gholz H. L. 
Published: April 2024

Abstract
Seasonality of aboveground growth and reproduction, its relationship to environmental conditions, and the composition and development of the understory were studied for 2 years on young and mature slash pine (Pinus elliottii var. elliottii Engelm) plantations in north Florida. Despite relatively mild environmental conditions year-round, tree and understory growth were strongly unimodal, peaking in late spring-early summer when air and soil temperatures and precipitation were highest. Length of spring shoots in pines appeared to be directly related to soil temperature and precipitation of the previous fall-winter when winter buds were forming. Presence of summer shoots appeared to be dependent upon the environmental conditions of the current growing season, age of the tree, and branch position in the canopy. Site preparation practices, notably chopping and burning, in part dictated the species composition and development of the understory until about midrotation, at which time shading and forest floor development became more important. Fine root studies reflected the same compositional changes as seen above ground. Although aboveground understory biomass was a small fraction of pine biomass by midrotation, pine and understory fine root biomass and foliar turnover rates were comparable. Forest Sci. 32:779-788.
A Mechanistic Computer Model of Mountain Pine Beetle Populations Interacting with Lodgepole Pine Stands and Its Implications for Forest Managers
Authors: Raffa Kenneth F. , Berryman Alan A. 
Published: April 2024

Abstract
A computer simulation model based on laboratory and field studies of mountain pine beetle (Dendroctonus ponderosae Hopkins) interactions with lodgepole pine (Pinus contorta var. latifolia) is presented. The experimental results provide the basis for the underlying assumptions and equations concerning host resistance, beetle numbers, and nutrient availability. This simulation is not intended to predict numerical levels in any particular region, but instead provides a basis for considering how host and beetle factors can interact to affect population behavior.
The model generates patterns of population behavior characteristic of D. ponderosae and other primary bark beetle species, and shows a variable relationship of population density with population growth. The system has two equilibrium points, one of which is stable, and the other is unstable. The unstable equilibrium represents a threshold that separates regions of qualitatively different population behavior (endemic from epidemic). Each stand is characterized by a unique population outbreak threshold, and this value is strongly affected by age class.
The simulation model was used to evaluate management practices for controlling D. ponderosae outbreaks. The most important factors were found to be those that directly affect host vigor. Stand thinning seems to provide the most effective long-term protection from beetle outbreaks. Forest Sci. 32:789-805.
Effects of Herbaceous Weed Control Using Herbicides on a Young Loblolly Pine Plantation
Authors: Zutter B. R. , Glover G. R. , Gjerstad D. H. 
Published: April 2024

Abstract
On an Upper Coastal Plain site in east-central Alabama, herbicides were used to create three herbaceous vegetation treatments based on duration and degree of herbaceous vegetation control during the first two growing seasons following planting of loblolly pine (Pinus taeda L.): (1) low—near complete control for two seasons; (2) medium—single broadcast application of a herbicide at the beginning of the first growing season only; (3) high—no herbaceous vegetation control. Woody vegetation was periodically controlled on all plots. These treatments created a wide range of residual herbaceous vegetation. Soil moisture and first-year height and diameter growth of loblolly pine were negatively correlated with the level of herbaceous vegetation. A wide range in soil moisture was noted for comparable levels of herbaceous vegetation across treatment plots. This demonstrates the necessity for researchers examining effects of competition on pines to also assess soil moisture or soil attributes affecting water holding capacity. First-year seedling diameter was found to be more responsive than height to the level of herbaceous vegetation and associated levels of soil moisture. However, tip moth incidence was greater at the lowest levels of herbaceous vegetation, possibly reducing height growth below its potential. First-year pine growth was most highly correlated to soil moisture level in late August, when soil moisture was lowest, than any other sample date. During the first growing season, pine growth on medium and high herbaceous level plots fell behind that on low level plots (near complete control) once herbaceous biomass approached 25 to 45% of September biomass on high herbaceous level plots (no control). Effects of herbaceous weed levels on pine growth are attributed in part to differences in soil moisture and their effects on seedling water status and physiological processes. Forest Sci. 32:882-899.
Estimating Defoliation Using Stratified Point Intercept Sampling
Authors: Cooper Robert J. , Dodge Kevin M. , Whitmore Robert C. 
Published: April 2024

Abstract
A method of estimating percent defoliation is presented whereby foliage measurements are taken on a plot using a sighting tube and compared to foliage present at the same points on the same plot in a base year. Since measurements are not independent, a nonparametric procedure using McNemar's statistic is used to estimate percent defoliation and its standard error. Percent defoliation is estimated for an entire plot by dividing the plot into canopy height categories. An example is provided. For. Sci. 33(1): 157-163.
Approximating Precision in Simulation Projections: An Efficient Alternative to Monte Carlo Methods
Authors: Gertner George 
Published: April 2024

Abstract
Estimates of the precision of predictions made with simulation models are often desired to gauge the variability of predictions, place confidence intervals around the predictions, and test hypotheses. However, estimates of precision are not usually calculated for large multicomponent simulation models because of the huge computational costs. To overcome this, the error propagation method can be used to approximate the precision of simulation estimates. The method was used in this study to approximate the variance of predictions made with a variation of the individual tree growth and yield model, STEMS (Stand and Tree Evaluation and Modeling System). The method was compared with a crude Monte Carlo method for obtaining simulation variances. At its worse, the error propagation approximation of standard deviation diverged from the Monte Carlo approximation by 16% for a 50-year projection. The technique reduced execution time for calculating the variances by a factor of almost 2,000. For. Sci. 33(1):230-239.
Analysis of the 3/2 Power Law of Self-Thinning
Authors: Zeide Boris 
Published: April 2024

Abstract
The 3/2 power law states that the relative rate of self-thinning with respect to biomass growth per unit area is a universal constant equal to two. The law could be true in two cases: (1) when all factors of stand dynamics unaccounted for by the law (in particular, change in plant form and change in crown closure) are nonexistent; and (2) when the effects of the unaccounted factors on the rate of self-thinning cancel each other. As the presented reasons and evidence show, the major neglected factors indeed oppositely affect the rate of self-thinning. In general, however, these factors rarely balance each other, and the rate predictably changes with age, species, site quality, and other factors. The limiting line of self-thinning does not have any constant slope (on the log-log scale); generally, this line is a curve. A realistic model of self-thinning should be more inclusive than the law and particularly reflect the change in crown closure, or gap dynamics. An analysis of the law suggests the use of tree size as a predictor of their number; the utilization of the fact that diameter is better correlated with crown width and tree number than tree mass; and the development of a more adequate form of expressing allometric relationships than the elementary power function. For. Sci. 33(2):517-537.
Percentile-Based Distributions Characterize Forest Stand Tables
Authors: Borders B. E. , Souter R. A. , Bailey R. L. , Ware K. D. 
Published: April 2024

Abstract
A satisfactory characterization of stand tables need not require a prior mathematical probability distribution. The method described here uses a system of percentiles defined across the range of the stand table. Based on a uniform distribution of tree frequency between adjacent percentiles, stems-per-acre are proportioned into diameter size classes. For. Sci. 33(2):570-576.
Estimation of the Diameter Increment Function or Other Tree Relations Using Angle-Count Samples
Authors: Lappi Juha , Bailey Robert L. 
Published: April 2024

Abstract
A formula is derived for the bias when an angle-count sample is used to estimate the mean of a tree variable that is correlated with the breast height diameter. This bias occurs, for instance, if average increment is estimated with increment cores from an angle-count sample. Estimation of mean increment for a given initial diameter is studied further by assuming that increments are log-normally distributed, in which case the sampling distribution is a mixture of three log-normal distributions. An estimate obtained by weighting observations inversely to the basal area (i.e., with the estimated tree frequency) compares favorably in simulations with a parametric estimate derived from the sampling distribution of diameters. If increments are regressed on the initial diameters, then weighting proportionally to the initial basal area and inversely to the current basal area gives smaller bias and standard deviation of parameter estimates than weighting inversely to the current basal area alone. For. Sci. 33(3):725-739.
Estimating Potential Density from Thinning Experiments and Inventory Data
Authors: Sterba H. 
Published: April 2024

Abstract
By combining and modifying the Competition Density Rule of Kira et al. (1953), Reineke's concept of stand density index (Reineke 1933), and Assmann's theory of maximum basal area, a method to estimate potential density of sites has been developed. From the data of 11 thinning experiments it has been shown that the maximum stand density index, estimated in this way, is well correlated with the gross volume yield at a given height and thinning regime. Data from an inventory show that with this method of estimating and characterizing maximum stand density it is possible to evaluate differences of gross volume yield that would never have been detected if only yield tables had been used. For. Sci. 33(4):1022-1034.
In Vitro Responses of Conifer Adventitious Shoots and Calli Inoculated with Gremmeniella abietina
Authors: Abdul Rahman Nik N. , Diner Alex M. , Skilling Darroll D. , Karnosky David F. 
Published: April 2024

Abstract
Larix decidua adventitious shoots were inoculated with axenic vegetative hyphae and conidia of Gremmeniella abietina. Dense host surface mycelial growth and needle necrosis occurred after inoculation with vegetative hyphae and conidia within two weeks and four weeks, respectively. The pathogen completed its life cycle by producing pink conidial pustules on some infected propagules within one month. Light and scanning electron microscopic examination showed that hyphae penetrated commonly through or between epidermal cells and rarely through the stomates. Differential responses were evident within and between shoot clones. Inoculated calli of resistant L. leptolepis and Abies balsamea showed less mycelial growth than did L. decidua calli. Inoculation success was a function of spore inoculum density. In vitro responses correlated well with known in vivo responses. Our rapid (30-d) in vitro resolution of host resistance suggests that these methods may reduce the time required for evaluating relative disease resistance as compared to traditional field tests. For. Sci. 33(4):1047-1053.
Two-Dimensional Analysis of Logging Tail Spars
Authors: Pyles Marvin R. , Pugh Edwin V. 
Published: April 2024

Abstract
A beam-column analysis of a skyline-logging tail spar was formulated and an example analysis made of a second-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) spar (15.-in. dbh) rigged at 40 ft. The analysis takes into account the taper of the spar tree, the flexibility of the base of the spar, and the eccentric restraining load at the top provided by guylines. Allowable skyline tension on the tail spar is shown to vary with skyline angle and guyline pretension. An optimum guyline pretension that produces the greatest capacity in the spar tree was found to be within a range attainable by hand tightening. The variation of allowable skyline tension with rigging height and spar diameter also is shown. For. Sci. 33(4):971-983.