bluuebunny/crossref_metadata_2025_split huggingface dataset:
Germination Responses of Northern Red Maple (Acer rubrum) Populations
Authors: Tremblay M.-F. , Mauffette Y. , Bergeron Y. 
Published: April 2024

Abstract
Samaras of red maple (Acer rubrum L.) were collected at six locations at the northern edge of its distribution. Two populations from southern Québec, in the deciduous forest, and four populations at its northern limit in the boreal forest were selected. Germination responses of these populations were evaluated in growth chambers and in the field. The effects of cold moist stratification, temperature (20/10°C, 10/1°C) and light intensity (750 μmol • m-2 • s-1, 160 μmol • m-2 • s-1) were evaluated in growth chambers. Seeds collected at the two most southern sites had 46% to 90% germination without stratification, while germination without stratification varied between 0% to 41% for the four most northern populations. In the six populations tested, the highest germination percentages were obtained at 10/1°C under low light conditions. Cold moist stratification enhanced germination of the four most northern populations. We observed in the field experiment that germination occurred during the summer months for sites located in the deciduous forest, while germination was delayed until the next spring for the sites located in the boreal forest. The percentages of seedling emergence in the field were similar under shade and nonshade conditions. Overall, our results indicate a marked degree of dormancy in the most northern populations. The heterogeneous germination response of northern red maple populations could be associated with the temperature regime at the collection site. For. Sci. 42(2):154-159.
Analyzing Cliques for Imposing Adjacency Restrictions in Forest Models
Authors: Murray Alan T. , Church Richard L. 
Published: April 2024

Abstract
Adjacency considerations have a significant impact on the acceptability of forest planning alternatives and have forced analysts to look for effective methods for incorporating such concerns. Various attempts have been suggested for representing adjacency restrictions within planning problem formulations. This paper investigates the use of cliques for representing adjacency conditions. Several approaches are presented for generating and incorporating cliques into operational level forest planning formulations. Properties of the various clique sets are detailed, which form a basis for understanding why certain clique sets outperform others. A number of forest planning problems are solved, demonstrating the superior performance of the clique approach presented in this paper. This work has broad implications on the types of planning problems that can be effectively modeled. For. Sci. 42(2):166-175.
Above- and Belowground Dry Matter Accumulation Pattern Derived from Dimensional Biomass Relationships
Authors: Reed David D. , Liechty Hal O. , Jones Elizabeth A. , Zhang Y. 
Published: April 2024

Abstract
A model of dry matter accumulation pattern is derived from above- and belowground dimensional biomass relationships as a function of basal diameter growth and total height increment. Without loss of generality, the model is illustrated utilizing previous results of analyses with eight years of growth records from precompetitive red pine (Pinus resinosa, Alt.) plantations in northern Michigan. Model behavior corresponds with previous knowledge concerning the seasonal patterns of dry matter accumulation in conifers and with the response of plant allocation patterns to temperature and moisture stress. Changes in accumulation fraction as a function of tree size also agree with previous observations. This model can be developed using existing above- and belowground dimensional biomass equations and functions describing the seasonal growth of diameter and height. The range of its applicability depends on the ranges of applicability of the component equations. Unification of this "mensurational" approach to modeling dry matter accumulation with previous functional balance methods can be achieved by placing appropriate constraints on model components. For. Sci. 42(2):236-241.
Sampling with Partial Replacement Extended To Include Growth Projections
Authors: Bokalo Miko , Titus Stephen J. , Wiens Douglas P. 
Published: April 2024

Abstract
The original theory of Sampling with Partial Replacement (SPR) is modified to incorporate growth model projections of the unmatched plot data on the initial measurement. The Modified Sampling with Partial Replacement (MSPR) theory is illustrated by estimating growth and current volume using simulated plot data. In addition to the assumptions required by SPR, MSPR requires that the growth projection errors be random and have a mean of zero. If these assumptions are met, the modified theory improves the precision of the volume and growth estimators over the original SPR estimator. For. Sci. 42(3):328-334.
Predicting the Present Value Distribution of a Forest Plantation Investment
Authors: Reed William J. , Haight Robert G. 
Published: April 2024

Abstract
Forestry investment decisions may be based on the probability distribution of financial return in addition to a point estimate of mean return. This study describes an approach to predicting the present value distribution of a plantation investment using actual data on timber price and yield. Changes in stumpage price are modeled with a lognormal diffusion process called geometric Brownian motion (GBM). Timber yield is modeled with a variant of GBM that includes an age-dependent growth component. Model parameters are estimated with time-series observations of loblolly pine (Pinus taeda L.) price and yield in the southeastern United States. Because GBM models have lognormally distributed errors, present value distributions are skewed with extremely long right-hand tails. The median and quartiles of the distribution provide a better measure of central tendency and spread than do the mean and standard deviation. A median-maximizing feedback cutting rule does not perform any better than a median-maximizing fixed rotation age suggesting that no economic gain can be obtained by monitoring timber price and yield under the assumptions of our models. The forecast error, measured by the distance between quartiles, is about twice the size of the median present value. System error is the primary cause, and error in the price process contributes more to the variability in present value than does error in the yield process. Parameter uncertainty increases forecast error 15 to 35%. The large forecast error raises the question of whether better predictive models can be built or whether the present value of a plantation investment is inherently uncertain. For. Sci. 42(3):378-388.
Valuing the Impacts of Forest Fires on Backcountry Forest Recreation
Authors: Englin Jeffrey , Boxall Peter C. , Chakraborty Kalyan , Watson David O. 
Published: April 2024

Abstract
A discrete choice travel cost model was developed for backcountry forest recreation using 2 yr of backcountry canoe registrations from Nopiming Park, Manitoba. A statistically significant variable explaining choice of route was the amount of forest along the route that was burned in the last 10 yr; virtually all of which occurred in two particularly severe fires during 1983. The current economic welfare loss from these fires was estimated using a discrete choice travel cost model combined with a count model of trip demand. Since the forest grows back following fire, these losses will eventually decrease to zero. A linear intertemporal damage function for one of the fires is estimated, and the present value of damages under alternative discount rate assumptions is presented. For. Sci. 42(4):450-455.
A Comparison of Dynamic Programming and A* in Optimal Forest Stand Management
Authors: Arthaud Greg J. , Pelkki Matthew H. 
Published: April 2024

Abstract
A model that adds a forward value estimator to traditional forward recursion dynamic programming (DP) is developed. State classes are used to store continuous values for stand basal area and stem density. A simple forward heuristic that estimates future value from deviations within a node is used in the model in combination with accumulated value to determine path choice (A*). A loblolly pine growth and yield model with both pulpwood and sawtimber product outputs is used in the model. The model is tested on combinations of initial planting density, site index, and interest rates to compare A* to DP in optimization of thinning age, thinning intensity, and rotation age. Results from tests using single-year stage intervals show increases of 0.0% to 1.2% in net present value for A* compared to DP. An A* approach increases computer program size very little but requires additional time for parameter searching. However, A* always generated solutions at least as high as DP. For. Sci. 42(4):498-503.
Estimating Leaf Area and Leaf Biomass of Open-Grown Deciduous Urban Trees
Authors: Nowak David J. 
Published: April 2024

Abstract
Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas. For. Sci. 42(4):504-507.
Dynamics and Stocking-Level Relationships of Multi-Aged Ponderosa Pine Stands
Authors: O'Hara Kevin L. 
Published: April 2024

Abstract
Ponderosa pine (Pinus ponderosa Dougl. ex Laws.) stands in western Montana and central Oregon were sampled to determine total leaf area index (LAI), leaf area distribution among age classes or cohorts, and stem volume increment. Stands included from one to five cohorts. LAI was assumed to represent occupied three-dimensional growing space. Within multi-aged stands, cohorts varied in their total LAI, with older cohorts generally having more LAI, or growing space, than younger cohorts. Older cohorts also produced stem volume growth more efficiently per unit of leaf area than younger cohorts. Higher individual tree leaf area, or growing space occupancy, was strongly related to increased stem volume growth in all cohorts. A general increasing relationship between growing space efficiency and number of cohorts per stand was also observed.
A model, termed PP-MASAM for Ponderosa Pine-Multi-Aged Stocking Assessment Model, was developed to assess multi-aged stocking relationships. Results indicate that residual age structures with large numbers of young trees reduce stand production from structures with fewer young trees because they grow more slowly than older trees and will die, need to be thinned, and will not become merchantable. Stocking relationships which appeared most productive are characterized by a positive linear relationship between LAI and cohort age, and a negative linear relationship between number of trees per cohort and age. These options produced the most gross and recoverable stem volume increment, produced acceptable tree vigors, and maintained sufficient growth rates in younger cohorts to sustain the structure.
Formal stocking guidelines for uneven-aged silviculture typically define stocking and residual stand structure using diameter distributions. The most common of these procedures, the q-factor, attempts to create and maintain "balanced" sustainable structures with a negative exponential diameter distribution. These size structures designed with the q-factor approach are assumed to be sustainable and to represent equal occupancy of growing space by each diameter or age class. PP-MASAM results indicate residual size structures defined by the q-factor are no more sustainable than other structures that, for example, provide linearly increasing growing space to each older age class. The q-factor approach also perpetuates ponderosa pine size structures which are atypical of structures which developed under a typical presettlement fire regime. For. Sci. Monograph 33:1-34.
Notes: Pollen Tube Growth in Quercus
Authors: Cecich Robert A. 
Published: April 2024

Abstract
Fluorescence and brightfield microscopy were used to evaluate pollen tube growth in the Erythrobalanus and Lepidobalanus subgenera of the genus Quercus. All three species had the same pattern of pollen tube growth behavior, from the time pollen landed on the stigmas to the cessation of pollen tube elongation in mid-May. Pollen tubes grew from the apertures, penetrated the stigmatic epidermis, and produced a series of callose plugs as they advanced basipetally through the transmitting tissue of the styles. Pollen tubes grew through the solid transmitting tissue until they reached the level of the visible portion of the perianth, where the three styles join. In white oak, the arrested pollen tubes resumed growth in early June, and fertilization occurred during the week of June 11. In northern red oak and black oak, resumption of pollen tube growth occurred in the following growing season. Pollen tubes of northern red oak resumed growth in the May 22 collections and fertilization occurred during the week of June 12. In black oak, however, pollen tubes resumed growth in the June 5 collections and fertilization occurred in late June. The control over pollen tube elongation may be environmental or sporophytic. For. Sci. 43(1):140-146.
Output Supply and Input Demand in the Pulp and Paper Industry: A Nonparametric Model for the United States and Canada
Authors: Hseu Jiing-Shyang , Buongiorno Joseph 
Published: April 2024

Abstract
Demand and supply relationships are needed to understand the economics of the pulp and paper industry and to make forecasts of inputs, outputs, and prices. Here, long-run supply and demand elasticities were derived with a nonparametric method exploiting the consequences of the weak axiom of profit maximization (WAPM). No assumption was required regarding the form of the profit function, and all own-price elasticities necessarily had the expected theoretical signs. But, an infinite number of quantity responses being consistent with the theory and data, finding a unique response required a new assumption: that quantities adjusted just enough to satisfy the WAPM. The data pertained to the pulp and paper industries of the United States and Canada from 1959 to 1987. They recognized four outputs and nine inputs. A price shock of 20% led to elasticities that closely satisfied local homogeneity of the supply/demand functions, and symmetry of their price derivatives. Output supplies were all elastic, or nearly so, with respect to their own prices. The own-price elasticities of input demand ranged from -0.4 to -2.2, demand for capital being one of the most elastic. Cross-price elasticities tended to be small. The method was also applied to make out-of-sample forecast of inputs and outputs conditional on observed prices, under nonregressive technical change. Forecasts for 1983 to 1987 were generally unbiased. A synthesis of parametric and nonparametric methods is still needed to improve forecasts. For. Sci. 43(1):35-45.
Radial Growth Response of Douglas-fir and Grand Fir to Larval Densities of the Douglas-fir Tussock Moth and the Western Spruce Budworm
Authors: Mason Richard R. , Wickman Boyd E. , Paul H. Gene 
Published: April 2024

Abstract
Statistical models were developed relating corrected tree-ring chronologies of grand fir (Abies grandis [Dougl. ex D. Don] Lindl.) and Douglas-fir (Pseudotsugata menziesii var. glauca [Beissn.] Franco) to population time series of Douglas-fir tussock moth (Orgyia pseudotsugata [McDunnough]) and western spruce budworm larvae (Choristoneura occidentalis Freeman) in the same stands. The study was conducted in northeastern Oregon and spanned 22 yr including 2 periods of defoliator outbreaks as well as an interval of no outbreaks. Changes in the radial increment of host trees, corrected for tree-ring age and weather, were inversely related to larval densities in the same year of growth and in each of the 4 preceding years. The strongest growth response was a delayed function of larval density with a 3 yr time delay. Regression models giving the best fit to pooled data were second-degree polynomials in which log larval density with a 3 yr delay accounted for 28.7% of the variation in rate of change in corrected tree-ring indices, and 46.4% of the variation in the absolute size of corrected indices. The results imply that reductions in radial growth are directly related to density of feeding larvae and that the cumulative maximum effect on increment in the lower bole lags defoliation by 3 yr. The models are recommended either for directly forecasting mean reductions in radial increment from monitored densities of larvae or for inversely predicting past mean densities of defoliating larvae from dendrochronology data. For. Sci. 43(2):194-205.
How to Calculate Optimum Family Number When Starting a Breeding Program
Authors: Lindgren Dag , Wei Run-Peng , Lee Steve J. 
Published: April 2024

Abstract
Methods were developed to calculate the optimum number of initial unrelated families (equivalent to founders) in a breeding program, which, following selection in a predetermined way, would result in the maximum gain. The required entries were: (1) effective population size (effective family number) after selection, (2) family type (half-sib or full-sib), (3) heritability, (4) number of selections, (5) available resources, and (6) cost per additional family in the initial population. Suggestions of optimum family numbers and other characteristics of the optimum were calculated for particular examples. It seemed important to consider cost components when planning breeding programs. The optimum initial family number was far greater than the intended effective family number when the marginal cost of adding initial families was low. If this cost was high, it was worth investing more than half of any fixed resources in obtaining many families. The value of heritability appeared rather unimportant. For. Sci. 43(2):206-212.
Estimating Foliage Area of Loblolly Pine Shoots
Authors: Murthy Ramesh , Dougherty Phillip M. 
Published: April 2024

Abstract
In this study, foliage surface area of loblolly pine (Pinus taeda L.) shoots from plants grown in a 2 x 2 factorial study of nutrients and water and three levels of CO2 was predicted by flush (growth cycle). Harms (1971) predicted foliage surface area of a flush from the weighted product of foliated flush length and average needle length. In the present study flush foliage surface area was predicted using the product of the natural log of foliated flush length and average fascicle length, and an additional independent variable fascicle density. Equations generated for each of the whole-plot treatment combinations did not differ significantly, therefore one prediction equation was developed for all whole-plot treatment combinations. Flush location significantly affected prediction of flush foliage area, therefore separate equations for predicting flush surface area were developed for the main and lateral shoots. The equations explained 96% of the variation in predicting flush foliage surface area for both main and lateral shoots with fascicle density explaining an extra 12% of the variation. The equations predicted flush foliage surface area with an average absolute percent deviation of predicted values of 16.1% and 12.6% for the main and lateral shoots. For. Sci. 43 (2):299-303.
Applying Objectively Estimated and Spatially Continuous Forest Parameters in Tactical Planning to Obtain Dynamic, Treatment Units
Authors: Holmgren Peter , Thuresson Thomas 
Published: April 2024

Abstract
Forestry planning is usually approached as the problem of combining and scheduling stand treatments. Stands are assumed to be homogeneous and spatially static and are usually delineated and described by subjective surveying methods. Because, in reality, stands vary internally, only subsets of the possible management alternatives will be considered in stand-based planning. As price expectations and other planning parameters change over time, it is likely that optimal locations, extensions, and schedules for forest operations change. This paper proposes a method whereby timber volumes and treatment priorities are estimated on objectively inventoried geo-referenced circular plots. Kriging interpolation and image analysis of scanned aerial photographs are then used to predict the variables in a spatially near-continuous raster. Treatment units are dynamically formed, based on price-expectations, and objectives defined by the forest owner. Given strategic goals, tactical plans are produced for two wood price situations, and compared with a plan based on conventional stands. The results imply that forest management planning should, perhaps, not be based on static stands if economic efficiency and planning flexibility are desirable. For. Sci. 43(3):317-326.
Communication Media and Demand for Printing and Publishing Papers in the United States
Authors: Zhang Yibing , Buongiorno Joseph 
Published: April 2024

Abstract
To predict the demand for printing and publishing papers, a model was first developed of the demand for printed materials—newspapers, books, magazines, and their substitutes--computers, and televisions and radios. A two-stage Almost Ideal Demand System (AIDS) represented the consumer demand for communication media (stage one) and for printed materials, computers, and televisions and radios (stage two). Annual United States data from 1960 to 1991 were used to estimate the expenditure share equations and related elasticities. The results suggest that during that period: (1) printed materials and computers were luxury goods; (2) the demand for printed materials was independent of the price of computers and slightly complementary of the demand for televisions and radios; and (3) the demand for printed materials was most sensitive to its price and to income. Then, the demand for paper by the printing and publishing industry was derived from a two-stage translog cost minimization model. The first stage describes the demand for paper to make printed materials together with labor, capital, and other materials. The second stage decomposes the demand for paper into that for each printing and publishing grade. Results show that during the period of observation, (1) paper demand was inelastic; (2) labor, capital, and other materials were substitutes for paper in making printed materials; and (3) technical change led to a relative decrease in the use of newsprint, and an increase in that of other paper grades. Equating production of printed materials to consumer demand led to the derived demand for each paper grade. The elasticities suggested that paper demand was not influenced much by the price of electronic media. A decomposition analysis of the growth in demand for printing and publishing papers showed that from 1981 to 1991 the positive income effects were most important, followed by the negative effects of changes in the prices of printed materials. For. Sci. 43(3):362-377.