bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining Investment-Efficient Diameter Distributions for Uneven-Aged Northern Hardwoods
Authors: Bare B. Bruce , Opalach Daniel 
Published: April 2024

Abstract
The constant "q" of de Liocourt is often used to model the diameter distribution of uneven-aged forest stands and produces "balanced" size class distributions. Claims that such distributions are the most efficient for uneven-aged management or necessary to achieve sustention of production have led to the use of the concept in a variety of management models. Using a northern hardwood mixed-species growth model and a Weibull distribution function, we demonstrate that "balanced" diameter distributions are not investment-efficient and are not necessary to achieve sustention of production over a fixed cutting cycle. Results are very sensitive to per tree price and maximum tree size assumptions. For. Sci. 34(1):243-249.
Short-Run Actual and Least-Cost Productivities of Variable Inputs for the British Columbia Interior Softwood Lumber Industry
Authors: Meil J. K. , Singh B. K. , Nautiyal J. C. 
Published: April 2024

Abstract
A dynamic empirical cost structure analysis of the British Columbia interior softwood lumber industry was conducted using a variable cost approach. The analysis proceeds from the implicit assumption that the industry minimizes the variable cost of production in the short run, conditional on the quantity (level) of the quasifixed capital factor, rather than the usual assumption of total cost minimization. The introduction of interrelated factor demand via a simple partial adjustment model affords the measurement of productivity decline and higher costs due to incomplete implicit adjustment to least-cost levels when factor demand changes. The analysis also employs a somewhat restrictive method for accounting for the three major outputs of the industry in a single output model; however, this refinement does represent one prevelant production behaviour observed in the Canadian sawmilling industry as a whole. The resuls indicate that: (1) demand for variable inputs in the regional industry are interrelated; (2) the assumption of full and instantaneous adjustment in variable factor demands, as maintained in short-run static models, proved to be implausible; (3) small, but significant economies of scale and technology progress were present in the industry; (4) the technology was largely materials (wood) using and labor saving; (5) all input substitution possibilities were found to be substitutes on the least-cost expansion path except for materials and energy relationship, which were found to be weak complements; (6) labor productivity was positive on both the observed and least-cost productivity expansion paths, but the observed labor productivity was only 80% of the least-cost productivity; and (7), wood and energy productivities were declining on both the observed and least-cost paths, but at a slower rate on the least-cost productivity path. For. Sci. 34(1):88-101.
Classification of Airborne Multispectral Scanner Data for Mapping Current Defoliation Caused by the Spruce Budworm
Authors: Leckie Donald G. , Ostaff Donald P. 
Published: April 2024

Abstract
Airborne multispectral scanner data were acquired over a mixed fir and spruce forest affected by both current defoliation (red discoloration) and cumulative defoliation (loss of needles) caused by feeding of the spruce budworm (Choristoneura fumiferana [Clem]). The spectral bands, ratios and differences of bands, and principal components derived from the bands were examined for their usefulness for discriminating defoliation condition. Classifications were conducted using the best combinations of two through nine bands or features derived from the bands. Three levels of current defoliation could be classified (heavy, light, and healthy). Cumulative defoliation and mixed-wood areas caused confusions in the classifications. There was little advantage to including more than four bands or derived features in the classifications. For. Sci. 34(2):259-275.
Goodness-of-Fit Tests and Model Selection Procedures for Diameter Distribution Models
Authors: Reynolds Morion R. , Burk Thomas E. , Huang Won-Chin 
Published: April 2024

Abstract
The process of developing diameter distribution yield models based on probability distributions involves selecting a family of probability distributions, developing a methodology for estimating the distribution parameters, and validating the final selected model. Standard goodness-of-fit tests have been widely used at various stages of this process, often in an ad hoc manner. Goodness-of-fit tests are reviewed and formalized and problems associated with applications to diameter distribution models are discussed. The effect of correlations between tree diameters on a plot and the effect of using multistage techniques to estimate the parameters of the probability distribution are investigated. Results from a simulation of the entire fitting process suggest that, in many situations, use of goodness-of-fit tests may be inappropriate. Other testing and selection procedures that may be more appropriate than goodness-of-fit tests are reviewed. As an alternative to goodness-of-fit tests, an error index is proposed for use in selecting and validating models. The error index is used in conjunction with the fitting process simulation to investigate the effect of the fitting technique and the characteristics of the fitting data on final model selection. For. Sci. 34(2):373-399.
Effects of Whole-Tree and Stem-Only Clearcutting on Postharvest Hydrologic Losses, Nutrient Capital, and Regrowth
Authors: Mann L. K. , Johnson D. W. , West D. C. , Cole D. W. , Hornbeck J. W. , Martin C. W. , Riekerk H. , Smith C. T. , Swank W. T. , Tritton L. M. , Van Lear D. H. 
Published: April 2024

Abstract
Nutrient removal by sawlog or pulpwood harvest (SAW), and whole-tree harvesting (WTH) was determined for 11 forest stands located throughout the United States. Data from this study combined with previously published nutrient budgets indicated potential net losses of Ca and K at most sites without harvest, and net losses of N, P, K, and Ca with either SAW or WTH. Total stem biomass and nutrients were significantly correlated with total above-stump biomass, providing a means for estimating nutrient removals with WTH and SAW in commercial forests. Limited data from harvested stands indicated greater regrowth biomass with SAW than with WTH on some sites. In the 11 harvested stands, hydrologic losses of N, K, and Ca generally increased immediately after harvest, but returned to levels comparable to control areas within 3 years. Because of the short duration of elevated nutrient losses, the hydrologic losses are considered minor relative to harvest removals. Ca and K are possible exceptions. The large difference in amounts of nutrients left on site in logging slash after SAW compared with WTH did not result in major differences in leaching or runoff at sites where comparisons were made. For. Sci. 34(2):412-428.
Growth and Survival Modeling for Planted Conifers in the Great Lakes Region
Authors: Belli Keith L. , Ek Alan R. 
Published: April 2024

Abstract
In the steady advance of techniques to model forest systems, the development of models to represent the brief, but crucial, establishment phase of planted conifers has been largely ignored. A framework of prediction equations was developed for the growth and survial of red pine and white spruce during the first 5 years after planting. The model development process incorporated data synthesized from published reports of planting experiments in the Great Lakes region. Two compatible growth estimation functions were derived to accomodate observations of plantation averages in the form of either annual stem height increment or total cumulative stem height. A single function was hypothesized for total percent survival. The overall modeling effort is a "first step" in characterizing the regeneration system. For. Sci. 34(2):458-473.
Physiological and Morphological Responses of Three Half-Sib Families of Loblolly Pine to Water-Stress Conditioning
Authors: Seiler John R. , Johnson Jon D. 
Published: April 2024

Abstract
The effect of water-stress conditioning on drought tolerance of three open-pollinated families of loblolly pine (Pinus taeda L.) during water stress was investigated. Seedlings were subjected to one of two levels of prolonged, sublethal drought or were kept well watered. After the conditioning period, photosynthesis, transpiration, and growth were evaluated. Photosynthesis was decreased greatly with reduced needle water potential. Conditioned seedlings generally maintained positive net photosynthesis to water potentials 0.15 (moderate water-stress conditioning) and 0.40 (severe water-stress conditioning) MPa lower than those of control seedlings. This response was likely the result of an acclimation of the photosynthetic process resulting in less nonstomatal inhibition of photosynthesis at low needle water potentials. Under well-watered conditions, transpiration, but not photosynthesis, was reduced greatly by the conditioning treatments and resulted in improved water-use efficiency. Root growth was affected more by water stress than shoot growth, causing a decrease in root/shoot ratio. Genetic differences in photosynthetic acclimation were not apparent. However, compared to seedlings representing two Virginia seed sources, a family from Texas, known for its superior drought tolerance, had the lowest root/shoot ratio and the least change in transpiration in response to water-stress conditioning. For. Sci. 34(2):487-495.
Merchantable Height in Lieu of Total Height in Stem Profile Equations
Authors: Fowler John H. , Rennie John C. 
Published: April 2024

Abstract
A procedure that uses merchantable height in lieu of total height in an existing stem profile equation was devised and tested using data from natural hardwood stands in Tennessee. Diameter at merchantable height was subtracted from each measured stem diameter. Consequently the transformed diameter at merchantable height becomes zero and provides compatibility with existing stem profile equations while maintaining tree stem profile. A stem profile model was fitted to the transformed data and evaluated for its ability to predict upper stem diameters. Standard errors of the estimate and biases indicate a good fit based on comparison with published results using total height. Equations to predict height at a specific diameter and volume between two heights derived from the stem profile equation modified for merchantable height are presented in an appendix. For. Sci. 34(2):505-511.
Conditioning a Segmented Stem Profile Model for Two Diameter Measurements
Authors: Czaplewski Raymond L. , McClure Joe P. 
Published: April 2024

Abstract
The stem profile model of Max and Burkhart (1976) is conditioned for dbh and a second upper stem measurement. This model was applied to a loblolly pine data set using diameter outside bark at 5.3m (i.e., height of 17.3 foot Girard form class) as the second upper stem measurement, and then compared to the original, unconditioned model. Variance of residuals was reduced; however, bias was approximately the same for both the conditioned and unconditioned models. Benchmark prediction problems, which reflect common multiproduct utilization criteria for southern pines, were used to judge the practical importance of these reductions. Square root of the average squared residuals from the conditioned model were 10 to 25% less than those from the unconditioned model for most benchmark evaluations. These reductions might be of practical importance, depending on the particular objectives and the relative cost of an upper stem measurement compared to the cost of measuring more trees. For. Sci. 34(2):512-522.
Patterns of Leaf Area Distribution Within Crowns of Nitrogen- and Phosphorus-Fertilized Loblolly Pine Trees
Authors: Vose James M. 
Published: April 2024

Abstract
Field trials of nitrogen (N) and phosphorus (P) fertilization in loblolly pine plantations (Pinus taeda L.) were used to determine the effects of fertilization on within-crown leaf area distribution in a fully stocked stand, and two less than fully stocked stands. A second objective was to examine the utility of the Weibull distribution for modeling leaf area distribution in loblolly pine crowns. Results showed that leaf area increases were most evident in the mid- and lower-crown positions (2-4 m and 4-6 m crown depths), regardless of stocking level. Response patterns suggested that the Westvaco Stocking Chart, which is based on empirical relationships between stand basal area, stand density, and canopy closure, did not adequately reflect light interception in these stands because stands were ranked differently when stocking was expressed by stand leaf area index. The fully stocked stand was 50% below the theoretical optimum leaf area index value of 5. Thus, it is hypothesized that leaf area increases occurred in the mid- and lower-crown because shading in the mid- and lower-crown positions was insufficient to inhibit foliage production and survival. Fertilization-induced changes in leaf physiology may have also played an important role in leaf production and branch retention in the mid- and lower-crown. The Weibull distribution provided a good fit of within-crown leaf area distribution. For. Sci. 34(3):564-573.
Allelopathic Effects of Shrubs of the Sand Pine Scrub on Pines and Grasses of the Sandhills
Authors: Richardson D. R. , Williamson G. B. 
Published: April 2024

Abstract
Aqueous leachates prepared monthly from foliage of eight species and from litter of two of them from Florida's sand pine scrub community were tested for potential inhibitory activity on four receiver species: three grasses native to Florida's sandhill community (Andropogon gyrans, Schizachyrium scoparium, and Leptochloa dubia) and commercial lettuce (Lactuca sativa). Seed germination of the grasses was inhibited significantly by all ten leachates. Inhibition varied with month of preparation of the samples and was highly correlated with monthly precipitation. However, only two of ten leachates significantly inhibited radicle growth of the grasses, with a seasonal peak in late spring before the rainy season. Leachates from species dominant on open scrub sites were much more inhibitory than those from mature scrub. Lettuce seed germination was inhibited significantly, whereas radicle length was stimulated; neither effect exhibited significant seasonal variation. Andropogon gyrans watered with runoff from leaf misting of potted Ceratiola ericoides and Conradina canescens had significantly lower dry weights than control seedlings receiving distilled water. In a field transplant experiment designed to control resource competition, seedling pines (P. palustris, P. elliottii, P. clausa) and plugs of wiregrass (Aristida stricta) grew more slowly at scrub sites than at sandhill sites. Chemicals released from the shrubs may deter pines and grasses that otherwise provide fuel for surface fires which cause shrub mortality. For. Sci. 34(3):592-605.
Optimization with Expected Values of Random Yield Coefficients in Renewable Resource Linear Programs
Authors: Hof John G. , Robinson Kent S. , Betters David R. 
Published: April 2024

Abstract
This paper analyzes the problem of optimization when the yield coefficients are random variables with known (or acceptably approximated) means. An important distinction is demonstrated between the case where only land area constraints are included and where both area and yield constraints are included. The latter case is shown to be substantially more difficult both in problem formulation and solution. A test case that addresses the latter case empirically is presented. A bootstrap technique and Monte Carlo repetitions are used to simulate the expected value of the optimum. The test case indicates that current practice may closely emulate finding the expected value of the maximum objective function, but with uncertain feasibility. For. Sci. 34(3):634-646.
A Markov Chain Model for Evaluating Seasonal Forest Fire Fighter Requirements
Authors: Boychuk Dennis , Martell David L. 
Published: April 2024

Abstract
A model was developed to help resolve the decision of how many fire fighters a large forest fire management agency should hire for a fire season to minimize expected cost plus fire loss. It addresses the use of fire fighters for both initial and extended attack, the temporary hiring of extra fire fighters to satisfy peak demands, and the movement of fire fighters between regions within the agency's jurisdiction. It also recognizes the increase in subsequent fire fighter demand caused by fire fighter shortages. The fire management system is modeled as a Markov chain where the system state is related to the fuel moisture conditions throughout the protected area, and the total number of extended attack fires burning. Tests using representative hypothetical data demonstrated that it is a tractable approach for roughly evaluating fire fighter requirements. The model was used to evaluate the benefits of the centralized control of fire fighters, and indicated that it could reduce expected cost plus loss as much as 30% in the hypothetical example. For. Sci. 34(3):647-661.
Three-Dimensional Representation of Douglas-Fir Volume Growth: Comparison of Growth and Yield Models with Stand Data
Authors: O'Hara Kevin L. , Oliver Chadwick D. 
Published: April 2024

Abstract
Growth and yield estimates for unthinned stands from the Douglas-fir Stand Simulator (DFSIM; Curtis et al. 1981) and the Tree and Stand Simulator (TASS; Mitchell and Cameron 1985) were used to construct graphical three-dimensional representations of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stand growth on site index 44 meters (50 year). The three-dimensional models used three variables: trees per hectare, breast height age, and either mean tree volume or stand volume. The TASS and DFSIM models were in agreement over most of their common range of age and number of trees. At wider spacings and older ages, however, the volumes predicted by the DFSIM model exceeded those predicted by the TASS model by as much as 25%. Comparisons of these three-dimensional models to unthinned and thinned stand data from a similar site quality found the models to be reasonably accurate representations of unthinned stand growth. The thinned stands, however, had greater mean tree and stand volumes than those indicated by the TASS model for unthinned stands at similar spacings. Complete comparisons were not possible with the DFSIM model because of its limited range of number of trees. These results suggest the TASS model, and to a lesser extent, the DFSIM model may be underestimating the growth of widely spaced stands, or thinning may actually increase the growth of thinned trees over that of trees which had always grown at the post-thinning spacing. For. Sci. 34(3):724-743.
Root Decomposition and Nutrient Flux Following Whole-Tree Harvest of Northern Hardwood Forest
Authors: Fahey Timothy J. , Hughes Jeffrey W. , Pu Mou , Arthur Mary A. 
Published: April 2024

Abstract
Decomposition of roots of four dominant species (Acer saccharum, Betula alleghaniensis, Fagus grandifolia, Picea rubens) in a northern hardwood ecosystem was measured following whole-tree harvest of watershed 5 at Hubbard Brook Experimental Forest, New Hampshire. To quantify the importance of element release from tree root systems after forest harvest, measurements of macronutrient (N, K, P, Ca, Mg) release from roots of seven diameter (mm) classes (&lt; 0.6, 0.6-1.0, 1.0-2.5, 2.5-5.0, 5-10, 10-20, 20-100) were combined with information on root system nutrient content. Decay of fine roots (all species) was initially rapid but declined abruptly after the first summer. Ash-free weight loss from small woody roots decreased with increasing root diameter and was much slower than decay rates for corresponding aboveground tissues (twigs and branches). Weight loss rates among species generally were not significantly different; however, large woody roots (10-100 mm diameter) of sugar maple decayed much more rapidly than the other species.
Rapid release of K and Mg was observed for all roots. Initially high rates of N and P release were observed for fine roots, whereas these nutrients were effectively retained in decaying woody roots. Retention of Ca was observed for all roots, and significant accumulation of Ca was observed in the larger size classes of woody roots. Particularly for N and K, release from decaying roots was an important nutrient flux pathway supplying stream outflow and vegetation regrowth in the first two years following forest harvest. For Sci. 34(3):744-768.
Analysis of Forest Fertilizer Experiments: Obtaining Better Precision and Extracting More Information
Authors: Woollons R. C. , Whyte A. G. D. 
Published: April 2024

Abstract
Later-age forest fertilizer experiments can be quite difficult to analyze appropriately and in ways that extract all the information inherent in the collected data. Observed responses are likely to be partially confounded with variations in pretreatment stand development, most of which can be removed through analyses of covariance using quanta of initial growing stock as a covariate. Pretreatment growth rate may represent an even more discerning covariate. Rather than use covariance some authors have chosen, instead, to use arithmetical procedures to adjust treatment responses. Reanalysis of a Canadian experiment of this latter kind suggests that such methodology may be less than ideal, and should not be preferred to covariance analysis. A general and systematic procedure for examining forest nutrition experiments is proposed for those involving t treatments, and also those where the t treatments represent n factors at p levels in factorial combination. An example of adopting the recommendation methodology for the first type is given using a completely randomized experiment in naturally regenerated radiata pine in New Zealand with five replications of four treatments. Adoption of the suggested procedures in conjunction with two covariates provides a useful insight into the data, and appreciably increases precision. The system is sequential in structure, necessarily inducing some risk of erroneous hypothesis testing. Such a danger is usually minimal, however, and the suggested system, it is claimed, represents a useful method for isolating treatment and growth effects in forest fertilizer trials. For. Sci. 34(3):769-780.
Cross-Dating Cores as a Nondestructive Method for Dating Living, Scarred Trees
Authors: Sheppard P. R. , Means J. E. , Lassoie J. P. 
Published: April 2024

Abstract
The objective of this study was to validate the use of increment cores for dating scarred trees as part of fire-history studies. Thirty-seven scarred conifers from four sites in the western United States were sampled both by coring and wedging (removing a partial cross section from the scar). For each tree the cores and wedge were analyzed using dendrochronological techniques to determine absolute fire dates, and the core and wedge dates were compared. Twenty-one of the 37 sampled trees were successfully dated and had identical core and wedge dates. Given certain constraints, researchers can effectively cross-date prescar growth from cores in fire- or other disturbance-history studies, and can accurately date scars with cores when wedge sampling is inappropriate or prohibited. For. Sci. 34(3):781-789.