bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rates of Free-Living Nitrogen Fixation in Some Piedmont Forest Types
Authors: Grant Deborah , Binkley Dan 
Published: April 2024

Abstract
We examined rates of free-living (nonsymbiotic) nitrogen fixation in a successional sequence of forest types in the Piedmont of North Carolina. Annual nitrogen input through this process did not differ among ecosystems, averaging roughly 0.002 kg/ha annually. The rate in a 20- to 30-year-old stand did not increase with irrigation or additions of nitrogen, phosphorus, or molybdenum. Free-living nitrogen fixation in these forests should not be expected to compensate for nitrogen losses through natural processes or management activities. For. Sci. 33(2):548-551.
Adjusted Inclusion Probabilities with 3P Sampling
Authors: Furnival George M. , Gregoire Timothy G. , Grosenbaugh Lewis R. 
Published: April 2024

Abstract
The mean square error efficiency of Grosenbaugh's (1964) adjusted 3P estimator is examined relative to four alternative estimators which use regression estimates of the conditional inclusion probabilities and true conditional inclusion probabilities. Actual mean square errors were calculated as the result of exhaustive sampling of populations that ranged in size from 9 elements to 144 elements and that exhibited widely different proportionality between the variable of interest and the auxiliary variable used for probability selection. The adjusted 3P estimator is as efficient or more efficient than all four competitors except when the unconditional probability of inclusion neared unity for some population elements. For. Sci. 33(3):617-631.
Height and Diameter Growth Response in Loblolly Pine Stands Following Fertilization
Authors: Bolstad Paul V. , Allen H. Lee 
Published: April 2024

Abstract
Significant mean height and mean diameter responses to nitrogen and phosphorus fertilization were observed 5 years after treatment in 31 loblolly pine stands located in the southeastern United States. Stands were consistently most responsive to the addition of 112N-56P kg/ha. Gains averaged 12% for all sites, and 31% for statistically responsive sites. Responses for other N or P rates were lower, but still positive and significant. Depending on the treatment, between one-fourth to one-half of the experimental installations exhibited a statistically significant positive response to fertilization. Twenty-two of 31 installations had significantly different height growth-diameter growth relationships following fertilization, although treatment effects were not consistent. Fertilizer-induced changes in H-D equation parameters were statistically nonsignificant for 27 of the 31 studies. Changes in H-D curve parameters associated with 1 or 2 year acceleration in stand development were small compared to the errors associated with fitting H-D curves to 15 or more years of cumulative height and diameter. For. Sci. 33(3):644-653.
Predicting Growth and "Success" of Coppice-Regenerated Oak Stems
Authors: Lowell K. E. , Mitchell R. J. , Johnson P. S. , Garrett H. E. , Cox G. S. 
Published: April 2024

Abstract
Logistic regression models were derived from data collected in the Missouri Ozarks to estimate the probabilities that 5-year-old stems of red oaks and white oaks in thinned and unthinned sprout clumps would attain a specified dbh at ages 12 and 30. In deriving each model, several success criteria based on selected future dbh were specified. A stem was considered "successful" for a particular criterion if it attained that dbh or larger, but considered a "failure" if it did not achieve that criterion because of either slow growth or mortality. Consequently, each model accounted for both growth and mortality probabilistically. Growth of survivors was also estimated using linear regression models. These models were developed for two species groups using data for stems that were alive at both the beginning (age 5) and end of a measurement period (ages 12 and 30). The logistic models indicated that height at age 5 was a significant predictor of competitive success of stems in subsequent years in stands with either thinned or unthinned clumps. Diameter of the parent stump was also significantly correlated with success, but only in stands where clumps were thinned. Results indicate that under the conditions of this study, which was conducted on a single site, stems with high success probabilities could be identified early in the life of this coppice-regenerated stand, and that early clump thinning in this stand increased success probabilities and diameter growth. For. Sci. 33(3):740-749.
A Solution Procedure for the Sort Yard Location Problem in Forest Operations
Authors: Sessions John , Paredes Gonzalo 
Published: April 2024

Abstract
Sort yards placed at selected intermediate points between timber cutting sites and mills have potential for increasing the value of logs or trees destined for processing into different products. A two-phase modeling procedure is presented for identifying the efficient placement of sort yards using computations much simpler than those in standard linear mixed-integer programming methods. For. Sci. 33(3):750-762.
Simultaneous Infestation by Dwarf Mistletoe and Western Spruce Budworm Decreases Growth of Douglas-fir in the Blue Mountains of Oregon
Authors: Filip Gregory M. , Parks Catherine A. 
Published: April 2024

Abstract
One-hundred paired branches, half with dwarf mistletoe plants and half without, were sampled from 100 Douglas-fir in five stands defoliated by the western spruce budworm. The budworm completely defoliated new shoots and buds of all branches sampled including those infected by dwarf mistletoe. Radial growth of host trees (Douglas-fir) was significantly less during the budworm outbreak compared with a similar period before the outbreak. Nonhost trees (ponderosa pine) showed significantly more radial growth during the outbreak than before it. Regression analyses showed that decreases in radial growth were associated primarily with increases in dwarf mistletoe severity (R² = 16.2-18.1). Trees within all dwarf mistletoe infection classes were defoliated by the budworm, and the additional growth reduction caused by defoliation was not significantly different among dwarf mistletoe severity classes. For. Sci. 33(3):767-773.
Decay and Dynamics of Snags in the Sierra Nevada, California
Authors: Raphael Martin G. , Morrison Micheal L. 
Published: April 2024

Abstract
A study on the rates of decay, falling, and recruitment in a population of snags (standing dead trees) in the Sierra Nevada, California, during 1975-83 showed that large-diameter (&gt;38 cm dbh) snags fell slower than small-diameter snags. Firs (Abies spp.) fell at a lower rate than pines (Pinus spp.). Snags lost all needles and twigs within five years; 75% of pines and 66% of firs had lost most larger limbs within five years. Compared with the numbers of live trees in the parent stand, rates of new mortality were highest among Jeffrey pine (Pinus jeffreyi Grev. and Balf.) &lt;15 cm dbh. Live-tree morality exceeded the rate that snags fell during our study, causing an increase in the snag population from 1978 to 1983. A Leslie matrix model of this snag population was developed that accounted for falling rates, transitions among decay stages, and recruitment of snags. Use of the model was illustrated using field data from five unburned study plots. For. Sci. 33(3):774-783.
Fusiform Rust Incidence and Severity in Loblolly Pine Plantations Following Herbaceous Weed Control
Authors: Zutter Bruce R. , Gjerstad Dean H. , Glover Glenn R. 
Published: April 2024

Abstract
Seven studies established to examine the effects of herbaceous weed control on loblolly pine (Pinus taeda L.) growth were assessed for fusiform rust incidence and severity after the fifth growing season. On four sites, greater loblolly pine growth on weed control treatments was accompanied by greater rust incidence and severity. Increases in incidence of branch galls were significant on four sites, while increases in incidence of stem galls were significant on only two sites. Trees with and without stem infections at age five were found not to differ in height at age one or two within any treatment. At age five, trees with stem infections were generally smaller in dbh and height than those without infections. For. Sci. 33(3):790-800.
Dominance in a Metric Trait of Pinus Patula Schiede and Deppe
Authors: Barnes R. D. , Matheson A. C. , Mullin L. J. , Birks J. 
Published: April 2024

Abstract
In an early Pinus patula Schiede & Deppe progeny test in Zimbabwe, three out of six full-sib families produced by controlled pollinations between ten plus tree parents showed statisitically significant 3:1 segregation ratios of large: small trees; a proportion of unusually large trees also occurred in the same families. It is suggested that variation in diameter was largely controlled by a single locus with slow growth recessive to fast growth; but the hypothesis that overdominance was exhibited in the heterozygote would explain the selection of an unexpectedly high proportion of heterozygotes among the plus trees. The presence of this gene could jeopardize advance with breeding strategies based on recurrent selection for general combining ability. Nevertheless, if there is overdominance, the gene has potential value; heterozygotes could be most effectively passed on to operational forestry through vegetative propagation or through seed production from a two-clone orchard containing homozygotes for the fast and slow growth alleles. The identification of this gene highlights the importance of progeny testing and of paying close attention to the occurrence, distribution, and fate of "runts." For. Sci. 33(3):809-815.
Predicting Girdling Probability for Pine and Hardwood Saplings in Low-Intensity Backfires
Authors: Greene Thomas A. , Shilling Charles L. 
Published: April 2024

Abstract
Six hundred saplings of Pinus taeda, Quercus nigra, and Liquidambar styraciflua in four ground-line diameter (dgl) classes ranging from 3-10 cm were treated at five fire intensity levels, 0, 36, 64, 80, and 98 kJ/s/m, with a propane-fueled backfire simulator during February-April 1985. Of 200 trees of each species, 10 loblolly pines were girdled (out of 35 scarred), 98 water oaks were girdled (143 scarred), and 5 sweetgums were girdled (142 scarred).
Logistic regression models based on dgl and mean temperature exposure were developed from these data and can be used to predict probability of girdling in 3-10 cm dgl stands of loblolly pine, water oak, and sweetgum by backfires with intensities from 0-98 kJ/s/m. For. Sci. 33(4):1010-1021.
On the Possibility of Using Joint Cost Allocation in Forest Management Decision Making
Authors: Hof John G. , Field Richard C. 
Published: April 2024

Abstract
A refutable hypothesis is developed theoretically that joint cost allocation schemes are not likely to lead to correct output level decisions. This hypothesis is supported in a test case experiment involving a managed forest in Alabama. Seven allocation schemes are tested: Separable Cost-Remaining Benefits, Nucleolus, Proportional Nucleolus, Weak Nucleolus, Benefit-Included Nucleolus, Shapley Value, and a Generalized Shapley Value. None of these schemes indicate, in the test case, correct timber output levels based on timber benefits and allocated costs alone. For. Sci. 33(4):1035-1046.
Stein-Rule Estimation of Timber Removals by County
Authors: Green Edwin J. , Thomas Charles E. , Strawderman William E. 
Published: April 2024

Abstract
The Stein-rule estimator for multivariate, unequal variance problems proposed by Morris in 1983 is applied to timber volume removal data from 11 counties in Louisiana. The estimator compared favorably to the standard sample mean in simulation trials with two sampling rules. The county means were closer to each other and had larger variances for hardwood removals than for softwood removals. Thus the gains were larger (up to 50% reductions in squared error) for hardwood removals, but there were substantial gains (10-30%) for softwood removals also. For. Sci. 33(4):1054-1061.
Comparison of Volume Growth Calculation Methods for Remeasured Horizontal Line Sampling
Authors: Yang Yong-Chi , Chao Shi-Ling 
Published: April 2024

Abstract
In remeasured horizontal line sampling, there is only one commonly used method for estimating yield. However, there are several methods for estimating growth. Five different methods of growth estimation, based on how a given classification of tree could be treated in the growth estimation, were tested on four species groups (true fir and spruce, cypress, pine, mixed softwood and hardwood) in Taiwan.
The classical method (also called the Strand method, or the compatible method), where tree status was ignored, had significantly larger mean squared error of the estimators than the others. There was no interaction between species group and method. The other four methods were very similar in the precision of estimate. Based on the ease of gathering data, the revised Purdue method is recommended. If volume and growth need to be compatible, the variable diameter factor method should be used for remeasured horizontal line sampling. For. Sci. 33(4):1062-1067.
Variation in Yield of Blue Spruce Monoterpenes Associated with Crown Position and Frequency of Resin Canals
Authors: Moore P. P. , Hanover J. W. 
Published: April 2024

Abstract
Large differences were found in the yield of monoterpenes from xylem, bark, and needles of blue spruce (Picea pungens Engelm.). Yields were greatest from bark samples and least from xylem. There were significant differences among trees in yield for all tissues. Yield of xylem and needle but not bark monoterpenes varied with position in the crown. Yields of total monoterpenes in xylem and needle samples were highly correlated with the proportion of resin canals in these tissues. Needle and bark extracts showed significant among-tree differences in the relative concentrations of most monoterpenes. Concentrations of most monoterpenes in needle and xylem extracts varied significantly with position in the crown, while few bark monoterpenes varied significantly. For. Sci. 33(4):1081-1088.
Constraints on Tree Breeding: Growth Tradeoffs, Growth Strategies, and Defensive Investments
Authors: Loehle Craig , Namkoong Gene 
Published: April 2024

Abstract
Analysis of basic growth processes and between-species trait correlations suggests that because of growth tradeoffs, breeding for growth rate (volume increment) may adversely affect defensive and other properties of trees. This can lead to negative impacts on sawtimber quality and tree lifespan. Selection for yield and for pathogen resistance may conflict, separate breeding programs may be needed for pulp and saw-timber purposes, and older ages may be more appropriate for selection of plus trees. In order for breeders to consider consequences of selection on tree performance, a means is required of assessing potential adult pathogen resistance and lifespan. Four methods are proposed for accomplishing this using properties of young trees. The properties of young trees that may correlate with adult performance are (1) wood properties related to defense, (2) wound healing ability, (3) the allometric growth coefficient, and (4) age of sexual maturity. For. Sci. 33(4):1089-1097.
Marginal Productivity of Public Research in the Softwood Plywood Industry: A Dual Approach
Authors: Seldon Barry J. , Newman David H. 
Published: April 2024

Abstract
The production function approach commonly used in agricultural studies is modified to estimate returns from publicly funded forestry research. The method indirectly estimates production function coefficients using a simultaneous, constrained supply and demand system. From these estimates the value of the marginal product (VMP) of public research involving softwood plywood is used to calculate a marginal internal rate of return (MIRR) on publicly funded research. Whereas similar studies in the agricultural literature use a short-run VMP based solely on the initial impact of R&D, we develop a long-run VMP, which incorporates research impacts over time. A short-run VMP is also defined, however, and compared to the results reported in the agricultural literature. Estimates of the short-run VMP for softwood plywood are similar to other aggregate research cases, such as corn and poultry. The estimated long-run VMP, however, is large; the most conservative assumptions yield an estimated VMP of public research in softwood plywood of $33.11 in 1967 dollars. The MIRR is also large with a lower estimate of 236%. For. Sci. 33(4):872-888.
An Econometric Analysis of the Southern Softwood Stumpage Market: 1950-1980
Authors: Newman David H. 
Published: April 2024

Abstract
This paper presents an aggregate regional model of the southern softwood solidwood (combined lumber and plywood) and pulpwood stumpage markets. The derivation of stumpage supply includes direct substitution possibilities by stumpage producers. The derivation of stumpage demand follows a profit maximization framework and includes the effects of input substitution as well as production capacity. Three-stage least squares regression techniques provide simultaneous parameter estimation of the market system. Solidwood stumpage is a complement in production with pulpwood; however, in solidwood production, an asymmetrical relationship exists as pulpwood is a substitute good. With respect to demand, solidwood stumpage responds to a greater extent to changes in final good price than does pulpwood. For. Sci. 33(4):932-945.
Optimizing Species Composition in Uneven-Aged Forest Stands
Authors: Bare B. Bruce , Opalach Daniel 
Published: April 2024

Abstract
This article describes an approach for determining the optimal sustainable equilibrium diameter distribution and species composition for a mixed-species forest stand. Using the Prognosis Model-a single tree distance independent growth model and its attendant regeneration subsystem—the maximization objective is formulated in terms of three decision variables per species: (1) the scale and shape parameters of a Weibull distribution function, and (2) the total number of trees per acre. A direct search, derivative-free, constrained nonlinear programming algorithm is used to optimize the growth model under a sustainable equilibrium constraint. To facilitate optimization, the stochastic features of the Prognosis Model are transformed to their deterministic counterparts. Results are presented for the Abies lasiocarpa/Clintonia uniflora habitat type found in northern Idaho. For. Sci. 33(4):958-970.
Height Growth Rate of Douglas-Fir: A Comparison of Model Forms
Authors: Hann David W. , Ritchie Martin W. 
Published: April 2024

Abstract
Five model forms were evaluated for their ability to predict height growth rate of individual Douglas-firs (Pseudotsuga menziesii [Mirb.] Franco) growing in even or uneven-aged stands of southwest Oregon. Three models had been previously used for Douglas-fir; the fourth was a simple modification of one of these, and the fifth was developed in this study by means of multidimensional graphing and modeling. Two forms were age-dependent, in that they used transformations of stand age, and three were age-independent. The model developed by multidimensional techniques provided the lowest mean squared error for both an even-aged data set (1,763 observations) and a combined even- and uneven-aged data set (2,242 observations). The five models were verified on a randomly drawn subset of the data consisting of 241 observations. Again the model developed with multidimensional techniques had the lowest mean residual and the lowest mean squared error. Independent variables in this model are stand crown closure at the top of the tree, crown ratio, and potential height growth rate as predicted by an existing dominant height equation. The resulting model is age-independent and can be applied to trees in both even- and uneven-aged stands. Multidimensional techniques were most useful in modeling this complex nonlinear surface. For. Sci. 34(1):165-175.
Trends in Wood Quality for the British Columbia Coast and the United States, Pacific Northwest, Westside
Authors: Constantino Luis F. , Haley David 
Published: April 2024

Abstract
Two alternative methods of measuring wood quality are described—the index number approach and the hedonic approach.
Indices of wood quality are constructed for the Vancouver Forest Region (VFR), 1925-80, the Vancouver Log Market (VLM), 1925-82 and the Pacific Northwest, West-side (PNW) log market, 1957-82.
The general hypothesis that the quality of the wood supply on the British Columbia (BC) Coast has declined over time is confirmed. However, this decline proceeded at a decreasing rate between 1925 and 1970, and during the 1970s an increase in wood quality was measured. This increase was more pronounced for the VLM than for the VFR. Wood quality declined at a faster rate in the PNW than in B.C. from 1957 to 1982.
On the VLM, most of the decline in wood quality, prior to 1957, was due to deterioration in the grade mix while between 1957 and 1970 changes in the species mix was the dominant factor. On the PNW log market, quality decline between 1957 and 1982 was entirely due to deterioration in the grade mix, the species mix showing some improvement during this period. For. Sci. 34(1):176-189.
Modeling Long-Term Fire-Caused Mortality of Douglas-Fir
Authors: Ryan Kevin C. , Peterson David L. , Reinhardt Elizabeth D. 
Published: April 2024

Abstract
Mortality was determined in a stand of Douglas-fir 8 years after 20 plots were treated with light surface fires. Logistic regression was used to model long-term mortality as functions of morphological variables measured shortly after burning. Independent variables were diameter at breast height, height of needle scorch, percentage of the prefire crown volume scorched, season of burn, and the number of quadrants with dead cambium at 1.4 m bole height. Mortality increased with increasing scorch height, percent crown scorch, and dead cambium. It decreased with larger diameter. The best predictor of mortality was the number of quadrants with dead cambium. Percentage of crown volume scorched was a better predictor than lethal scorch height. For a given level of damage, mortality following fall season fires was slightly higher than following spring fires. Models may be used in planning prescribed fires and for salvaging fire-damaged Douglas-fir. For. Sci. 34(1):190-199.
Use and Characteristics of Snags in Young and Old Forest Stands in Southwest Virginia
Authors: Rosenberg Daniel K. , Fraser James D. , Stauffer Dean F. 
Published: April 2024

Abstract
Snags were sampled in chestnut oak (Quercus prinus) and oak-hickory (Quercus spp.—Carya spp.) stands in southwest Virginia. More large (≥17 cm dbh) snags were found in stands ≥100 years of age and more small (≤10 cm dbh) snags were found in stands &lt;80 years of age, than expected under the model of equal distribution among age classes (χ2 = 25.3, df = 6, P = 0.0003). Log-linear models suggested that large diameter snags are more likely to be used by foraging birds than smaller snags. Tall snags were also used more than short ones, but 4-way log-linear models suggested that this was a result of a positive dbh-height relationship, rather than a reflection of bird selection of tall snags. Similarly, cavities were found more often than expected in large dbh trees. For. Sci. 34(1):224-228.