bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stochastic Log Price, Land Value, and Adaptive Stand Management: Numerical Results for California White Fir
Authors: Haight Robert G. 
Published: April 2024

Abstract
This paper presents an adaptive management formulation for determining the timing and intensity of thinning and the time of clearcut for stands with any age structure and with stochastic log prices. In contrast to previous timber management studies with stochastic prices, the formulation allows the determination of the best time to switch from forestry to another land use or from selection harvesting to plantation forestry. Harvests are determined with a piecewise linear function that relates harvest intensity and stand value. The parameters of the function include its slope, location, and length. Optimal parameter values are determined using stochastic simulation. Delivered log price is a stationary process that is the sum of a deterministic constant and a normally distributed random error. Numerical results are presented for young and mature stands of California white fir [Abies concolor (Gord. & Glend.) Lindl. (Iowiana [Gord.])]. The results include when to terminate forestry and switch land use. The expected time of clearcut is inversely related to the bare land value. The effect of price variation on the time of clearcut depends on land value. For low land values, increasing price variation decreases the expected time of clearcut; for high land values, the effect of price variation is reversed. The results include estimates of the relative economic efficiency of plantation versus uneven-age forestry. The size of trees in the initial stand rather than price variation phys the critical role in determining the relative economic returns. Because the results are dependent on the assumption that the price process is stationary, caution should be used in extending the results beyond the case presented here. For. Sci. 37(5):1224-1238.
The Acceleration of Fire from Point Source to Equilibrium Spread
Authors: McAlpine R. S. , Wakimoto R. H. 
Published: April 2024

Abstract
The acceleration phase of a forest fire, from ignition to the equilibrium rate of spread, is perhaps the most important phase of fire behavior because often it represents the only time period in which suppression efforts could be effective. A series of experimental fires in a wind tunnel were conducted to evaluate this acceleration phase. Two types of fuel and a total of three fuel loadings and four wind speeds were tested. The results were analyzed as distance/time data, and a predictive equation produced of the form: Distance = β0 X Timeβ1 The derivative of this equation relating rate of spread at a specific elapsed time since ignition compares favorably with theoretical acceleration model curve forms. The elapsed time required to achieve an equilibrium rate of spread was constant for each fuel type over the range of conditions tested. For. Sci. 37(5):1314-1337.
The Incorporation of Risk in Optimal Selection Age Determination
Authors: Newman David H. , Williams Claire G. 
Published: April 2024

Abstract
This paper explores the effect of decision-making criteria on optimal selection age determination in a loblolly pine (Pinus taeda L.) tree breeding program. Three different selection ages, 2, 4, and 6 years, are compared using biological, economic, and risk-adjusted simulation methods. The 4-year selection option is found to be superior to the other options by virtually all criteria used in this analysis. This choice of 4 years is also quite robust regarding the assumptions used in the analysis such as prices, costs, gain estimates, and breeding strategy. For. Sci. 37(5):1350-1364.
Genetic Structure and Mating System of Northern Red Oak (Quercus rubra L.) in Pennsylvania
Authors: Schwarzmann John F. , Gerhold Henry D. 
Published: April 2024

Abstract
Horizontal starch gel electrophoresis was used to estimate isozyme allele frequencies at 13 enzyme loci for each of 1048 northern red oak embryos representing 8 populations in Pennsylvania. The average expected heterozygosity over all loci and populations, HT;, was 0.233. Red oak populations were in Hardy Weinberg equilibrium (FIS = -0.008) and very weakly differentiated (GST = 0.009). In two populations the maximum likelihood multilocus estimates of outcrossing were 1.002 and 1.015. Neither estimate was significantly different from complete outcrossing (t = 1.0). Although 28 of 32 single-tree outcrossing estimates were not significantly different from t = 1.0, an analysis of singletree outcrossing rates indicated significant tree-to-tree variation in both stands. Only 2 of 24 heterogeneity G-tests were significant, indicating that pollen pool allele frequencies showed little spatial variability and/or outcrossing was independent of maternal genotype. These results suggest that (i) family clustering is weak in red oak populations, and (ii) most members of open-pollinated families are half-sibs probably derived from a large number of pollen parents. Thus, results of open-pollination progeny tests are likely to reflect real differences in mean breeding values of most families. In addition, estimates of additive genetic variances and heritabilities are not likely to be biased sharply upwards by an increased genetic correlation among family members. Furthermore, acorns derived from seed production areas are likely to be outcrossed and contain a high level of genetic variation. For. Sci. 37(5):1376-1389.
Modeling the Effect of Winter Climate on High-Elevation Red Spruce Shoot Water Contents
Authors: Boyce Richard L. , Friedland Andrew J. , Webb Elizabeth T. , Herrick Graham T. 
Published: April 2024

Abstract
During the winter of 1989-90, meteorological towers were erected at two sites (880 and 1010 m elevation) within the spruce-fir zone on Mt. Moosilauke, New Hampshire. Hourly means of temperature, wind velocity, relative humidity, and solar radiation were collected and stored on data loggers. Previous-year shoots were collected from four spruce trees at each site on a weekly basis, and their relative water contents (RWC) were determined.
Measured meteorological parameters were used to simulate changes in the RWC of previous-year spruce shoots through the winter. Our model suggests that shoot water is replenished throughout the winter, presumably from water stored in older woody structures or by root uptake. Recharge was defined to be directly dependent on shoot water saturation deficit (WSD = 100% - RWC), with a temperature cutoff of -4°C. The predicted output of the model generally followed measured RWC. According to our model, periods of high transpiration were associated with low relative humidities, sometimes accompanied by high temperatures and high levels of radiation. Our results suggest that winter water relations in spruce are governed by a balance between transpirational losses, which are primarily dependent upon meteorological conditions, and the rate of recharge, which is dependent on shoot water potential, temperature and perhaps soil water availability. For. Sci. 37(6):1567-1580.
Stand and Stock Tables from Double-Point Samples
Authors: Matney Thomas G. , Parker Robert C. 
Published: April 2024

Abstract
Double- or two-phase point sampling with a regression estimator is a common forest inventory procedure. When the first-phase sample consists of basal area points only, a diameter distribution based on the first-phase sample cannot be estimated. Thus there is no basis for adjusting the volume distribution of the second-phase sample by regression or ratio estimators within each diameter class. A weighted constrained least squares procedure to align the second-phase stand and stock tables with the first-phase volume and basal area may be applied to obtain a suitably adjusted size class volume distribution. The least squares method described in this paper produces an adjusted stand and stock table with total basal area equal to the first-phase sample total basal area and total volume equal to the regression volume estimate. Because adjustment magnitude can be made inversely proportional to class variance, this method provides better results than adjusting classes by the ratio of second- to first-phase basal area estimates. For. Sci. 37(6):1605-1613.
Using a Geographic Information System to Study a Regional Wood Procurement Problem
Authors: Brinker Richard W. , Jackson Ben D. 
Published: April 2024

Abstract
A geographic information system was used to develop a spatial pulpwood procurement modeling technique with northwestern Louisiana as an example. Overlays of spatial features were created from public information or were developed from questionnaires, regression analysis, and simulation. Manipulation of these layers provided inferences about resource location and availability. This information aided in determining current competition for stumpage and in relocating wood concentration yards to areas of less competition. The overlay structure portrayed the current total pulpwood demand and supply picture for the study region and was adjusted to forecast future market scenarios.
Three demand levels were differentiated. The effect of moving three selected woodyards within the study region was evaluated. A heuristic evaluation of key wood procurement factors included area of low demand, percentage of removals to growth, parish ranking of total growing stock per ha, and percentage of NIPF ownership. New woodyard locations were selected based on wood procurement factors, highway network, urban area location, and location of nontraversable water bodies that would impede truck movement.
Simulated relocations reduced the total area of high demand by 6.4% and increased the low demand areas by 44.0%. The relocation of these woodyards could reduce wood procurement costs for those woodyards remaining in what was originally the high demand area in the central portion of the study region. Also, the potential problem of overcutting in two parishes may be reduced while increasing removals from four northwestern parishes that had approximately 50% or less of removals to growth. Limitations of the approach are discussed as are the difficulties encountered in gathering spatial data for the analysis. For. Sci. 36(6):1614-1631.
Growth Model Predictions as Affected by Alternative Sampling-Unit Designs
Authors: Hann David W. , Zumrawi Abdel Azim 
Published: April 2024

Abstract
This study analyzed the effect on growth-model predictions of introducing differential design error to predictor variables that are influenced by the sampling-unit design, such as basal area per acre. Computer simulations of five forest stands were generated from random spatial distributions and field data coveting a range of stand conditions. Two variable-radius cluster designs and four sizes of fixed-radius circular plots were used to sample the generated stands. Sample data were used to predict single-period gross basal area growth rates in both a single-tree and a whole-stand growth model. The sampling-unit design used to develop each model was defined as the standard error-free method of measuring the predictor variables.
For both models, the average of gross basal-area growth rate predictions from 50 samples of each alternative sampling-unit design were not significantly different from the standard design. However, using a different sampling-unit design may produce large differences in individual predictions, particularly when small sampling units are used for application of models developed using relatively large sampling units. Such differences may affect decisions about treatment of a stand and could complicate the validation of a growth-and-yield model. For. Sci. 37(6):1641-1655.
Compatible Deterministic and Stochastic Predictions by Probabilistic Modeling of Individual Trees
Authors: Vanclay Jerome K. 
Published: April 2024

Abstract
A single growth model can provide both deterministic and stochastic predictions which are compatible. Change may be expressed using probabilistic functions which can represent proportions of populations or probabilities for individuals. The former represents determinism while the latter enables the stochastic implementation. The same functional relationships may thus be used to generate compatible deterministic and stochastic predictions. All components of forest growth and change, including diameter increment, can be expressed as probabilistic functions, enabling construction of a single model which provides compatible stochastic and deterministic outcomes. Users may specify the minimum expansion factor corresponding to the simulated plot size and thus control the granularity of predictions. Such a model may facilitate numerical estimation of confidence intervals about yield forecasts and sustained yield estimates. For. Sci. 37(6):1656-1663.
Technical Change in the North American Forestry Sector: A Review
Authors: Stier Jeffrey C. , Bengston David N. 
Published: April 2024

Abstract
Economists have examined the impact of technical change on the forest products sector using the historical, index number, and econometric approaches. This paper reviews econometric analyses of the rate and bias of technical change, examining functional form, factors included, and empirical results. Studies are classified as first- second-, or third-generation approaches. First-generation studies are based on simple value-added measures of output, usually employ simple functional forms to represent the production technology, and incorporate only capital and labor inputs. Second-generation studies are characterized by estimation of more complex, flexible dual cost or profit functions and typically include resource and often energy inputs. Third-generation studies also rely upon dual formulations of the production structure and include multiple factors; however, in addition they specify the dynamics of adjustment of quasi-fixed factors over time. The studies reveal a tradeoff between the richness of the theoretical structure of the production technology and the consistency of the empirical results. Most studies have reported a labor-saving and energy-using bias to technical change, but little or no wood-saving bias, and many report a wood-using bias. Since technical advances occur in spurts, the use of a simple linear time trend to represent the state of technology is a major limitation of virtually all models. Alternative measures, such as the power ratings or throughput measures, might better capture the characteristics of a technology. Use of such measures might also be combined with a cross-sectional approach in an attempt to avoid some of the statistical problems, such as serial correlation, that characterize time series data. Finally, if the goal of the analysis is to forecast factor demand and cost implications of technical change, simulation models may offer a more promising alternative. For. Sci. 38(1):134-159.
Empirical Bayes Development of Honduran Pine Yield Models
Authors: Green Edwin J. , Strawderman William E. , Thomas Charles E. 
Published: April 2024

Abstract
Occasionally it is of interest to calibrate a given growth or yield model to data from several regions. If it is expected that the parameters from different regions can somehow be regarded as similar, then a Bayesian approach suggests itself. A cursory examination of the literature reveals that most of the theoretical work on empirical Bayes estimation for the linear model has focused on simultaneously estimating the coefficients in one model. In these methods the usual least squares estimates of the model parameters are shrunk toward their mean. One set of parameter estimates results. In contrast we desire a method whereby multiple sets of parameter estimates are produced. We report the results of using such a method to calibrate yield models for unthinned Honduran pine plantations to data from 21 soil-site groups. The models compare favorably to those developed via traditional methods and allow estimation of regression coefficients even for soil-site groups for which the design matrix is not of full rank. For. Sci. 38(1):21-33.
Indirect Prediction of Breeding Values for Fusiform Rust Resistance of Slash Pine Parents Using Greenhouse Tests
Authors: de Souza S. M. , Hodge G. R. , White T. L. 
Published: April 2024

Abstract
Six-week-old greenhouse-grown seedlings of 100 open-pollinated slash pine families were artificially inoculated with fusiform rust fungus at the USDA Forest Service Resistance Screening Center (RSC). All families had been tested for rust resistance in four or more field tests. Selection indices were developed to use symptoms of rust infection observed in the greenhouse to predict parental breeding values for field resistance to fusiform rust. Of the 100 families, 75 represented an unimproved population, while 25 represented a population improved for rust resistance. A large number (56,688) of indirect selection indices were considered in an attempt to identify efficient indices which use a small number of traits. Indices were developed using three different sets of variance and covariance estimates: (1) from the unimproved population, (2) from the improved population, and (3) from the combined population. Separate indices were necessary for the two distinct populations. The new indices were more correlated with field resistance and result in more efficient indirect selection for field resistance than the equation currently in use by the RSC. However, the greenhouse test to indirectly assess field rust resistance (using the new indices) is somewhat less efficient than a single field progeny test on average. For. Sci. 38(1):45-60.
Simulation of the Collapse of Bent-Over Vortex Pairs Observed in Wildland Fires
Authors: Haines Donald A. , Smith Mahlon C. 
Published: April 2024

Abstract
During intense wildland fires a transient vortex pair sometimes occurs that may form with a near vertical axis but then bends over and becomes horizontal. Collapsing limbs of these vortex pairs threaten fire fighters. Therefore, this study simulated vortex collapse in a wind tunnel. Collapse was produced by cross air flow upstream of the heat source. Using an upstream, wing-shaped obstacle to create cross air flow, the wind tunnel experiments showed that small changes in wing angle, and thus cross air flow, could cause major changes in the structure of the vortex pair. For. Sci. 38(1):68-79.
Shoot Selection and the Rooting and Field Performance of Tropical Pine Cuttings
Authors: Haines R. J. , Copley T. R. , Huth J. R. , Nester M. R. 
Published: April 2024

Abstract
Several morphological features were significantly related to the rooting response, and subsequent field performance as rooted cuttings, of shoots collected from hedged stool plants of an F1 hybrid between Pinus caribaea var. hondurensis and P. tecunumanii. Results indicate that it will be possible to manipulate rooting and field performance by shoot selection at the time of harvest of cuttings. The cutting which best meets the objective of maximum rooting without loss of field performance is the terminal segment from a shoot over 30 cm in length, with an actively growing juvenile bud, primary needles in excess of 25 mm, secondary needles present but less than 10 mm in length, and basal diameter over 2 mm. The use of second and third segments of shoots, where these have the appropriate features, would permit greater utilization of material with only a minor decrease in rooting. Primary needle length was the best morphological predictor of both rooting and field height growth. Significant positive genetic correlations suggest that within-family selection for primary needle length will involve selection for clones which root well and which display good height growth in the field, perhaps as a result of slower stool plant aging. For. Sci. 38(1):95-101.
Thinning and Nitrogen Fertilization in a Grand Fir Stand Infested with Western Spruce Budworm. Part I: Insect Response
Authors: Mason Richard R. , Wickman Boyd E. , Beckwith Roy C. , Paul H. Gene 
Published: April 2024

Abstract
Thinning and nitrogen fertilization of a grand fir (Abies grandis [Dougl. ex D. Don] Lindl.) stand were tested as possible alternative techniques for managing outbreaks of the western spruce budworm (Choristoneura occidentalis Freeman). Treatment effects on an infestation of budworm and associated defoliating insects were evaluated over 5 years by a replicated split-plot experiment. Mean densities of budworm egg masses and larvae tended to be higher on fertilized plots than on control plots, but differences were not significant during the course of the experiment. Total herbivore biomass was, however, 40-60% greater and individual larvae were 32-38% heavier for 2-4 years after fertilization. Thinning alone produced a significantly greater dry mass of budworms in one year although the difference was relatively small. Fertilization also significantly increased the weight of male and female pupae by 6-23% for 4 years whereas thinning had no effect on pupal weight. Parasitization of late larvae and pupae was significantly reduced in one year by fertilization but was not affected by thinning. In general, defoliating insects seemed to benefit from the applied treatments, especially fertilization; however, overall budworm survival and prevailing trends of the outbreak were unaffected by the treatments and seemed to be determined mostly by other environmental factors, probably natural enemies. The ultimate value of thinning and fertilizing infested forests as a method of pest management must be viewed in the larger context of the total effect on tree and stand productivity. For. Sci. 38(2):235-251.
Spruce Budworm Defoliation and Growth Loss in Young Balsam Fir: Period Models of Needle Survivorship for Spaced Trees
Authors: Fleming Richard A. , Piene Harald 
Published: April 2024

Abstract
The age-dependent Weibull model described detailed observations of needle survivorship taken in two protected plots of young, spaced, balsam fir (Abies balsamea [L.] Mill.) on the Cape Breton Highlands, Nova Scotia, Canada. Throughout the midcrown, the rates of age-specific needlefall increased with needle age, indicating a Type I survivorship curve typical of foliage. It was shown that the needle populations experienced distinct stages of needlefall as they aged. Few needles surviving a period of "infant mortality" in their first year fell in their second. There was a low, but steady, increase in the rates up to age 4-5, with a further increase in the rates for older needles. The mean longevity of the needle populations ranged from 4.1 to 6.1 years and generally increased with tree age. Differences between trees of the same age and differences between crown levels explained little more of the variation in needle fall than that already explained by needle age alone. For. Sci. 38(2):287-304.
Chance Constraints and Chance Maximization with Random Yield Coefficients in Renewable Resource Optimization
Authors: Hof John G. , Kent Brian M. , Pickens James B. 
Published: April 2024

Abstract
This paper treats a variety of approaches to account for random yield coefficients with known means and variances in renewable resource optimization models. General formulations are discussed first, followed by a forestry case example that demonstrates the formulations and resulting optimal solutions in a renewable resource application. Different approaches to approximating the normal cumulative density function are evaluated using simulation. For. Sci. 38(2):305-323.