bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency Sampling to Predict Densities in Sparse Populations of the Douglas-Fir Tussock Moth
Authors: Mason Richard R.
Published: April 2024

Density in the middle crown of the tree is a widely used index of abundance of the Douglas-fir tussock moth (Orgyia pseudotsugata [McDunnough]). Midcrown density is usually estimated by the destructive sampling of branches in the middle crown, but in sparse populations it can also be predicted by observing the frequency of occurrence of larvae or pupae on lower branches. Predictions are made from a prior calibration between the proportion of infested samples in lower branches and midcrown density. Two models for calibration were developed: an empirical relation based on regression analyses of population data, and a theoretical relation derived from the frequency distribution of individuals in a Poisson series and the vertical distribution of insects in the tree. The models produced almost identical results in predicting midcrown densities from estimated proportion values. The theoretical model is recommended because of its versatility for different-aged larvae and generality over a wider range of low densities. For. Sci. 33(1): 145-156.
An Analysis of Regional Factor Demand in the U.S. Lumber Industry
Authors: Abt Robert C.
Published: April 2024

A restricted cost function with labor and roundwood as variable inputs and capital as quasi-fixed is estimated for three lumber producing regions. Significant regional differences are found. Cost function estimates are used to decompose trends in factor demand from 1963 to 1978. Stable trends in input use are found to be due to offsetting price and technology trends rather than fixed production relationships. For. Sci. 33(1):164-173.
Expectations and Variances of Basal Area Estimates Using Remeasured Horizontal Line Sampling
Authors: Yang Yong-Chi , Wang Chao-Huan
Published: April 2024

This paper presents the expectations and variances of the estimators of basal area and basal area growth using the remeasured horizontal line sampling. The estimators are classified by fixed diameter factor method and variable diameter factor method, and the former is further subdivided into direct and indirect methods. Variances were compared on one actual forest and two hypothetical forests simulated by computer. The basal area results reveal that (1) the estimator based on the fixed diameter factor method has smaller variance than that of the variable diameter factor method for the first measurement, (2) the estimator based on the direct method has smaller variance than that of the variable diameter factor method for the first measurement, (3) the estimator based on the direct method has smaller variance than that of the indirect method for the subsequent remeasurement. The basal area growth results reveal that (1) the estimator based on variable diameter factor method has smaller variance than that of the direct method, (2) the indirect method has a smaller variance when the basal area growth is less than the original basal area. For. Sci. 33(1):174-184.
Relating Forestry Investment to the Characteristics of Nonindustrial Private Forestland Owners in Northern California
Authors: Romm Jeff , Tuazon Raul , Washburn Courtland
Published: April 2024

Logit regression is used to relate characteristics of nonindustrial private forestland (NIPF) owners and ownerships to the probability of forestry investment in Northern California. Full-time residence, high income, and young age are the most significant predictors of NIPF forestry investment in general. Absentee ownership, middle income, and old age are the most significant predictors of no investment. Large ownership size is the best predictor of investment that is associated with timber harvesting. The results are used to classify groups of owners by similar probability of forestry investment. Implications for the design and analysis of NIPF policy are discussed. For. Sci. 33(1):197-209.
Variation in Growth of Red Alder Families in Relation to Shallow Water Table Levels
Authors: Hook Donald D. , Murray Marshall D. , DeBell Dean S. , Wilson Boyd C.
Published: April 2024

Growth of 24 Alnus rubra Bong. families was studied on wet microsites within a 5-year-old progeny trial in western Washington to evaluate variation in response to waterlogged soil. Depth to water table varied from 0 to 30 cm and was determined by depth of rusting on steel rods placed in the soil near each tree. By plotting the data and use of correlation matrices and regression analyses, tree height was found to be related to water table level. Eighteen families had a linear and 6 families a curvilinear relationship between height and water table level. Analysis of covariance, with water table as the covariate, showed that family slope coefficients were heterogeneous, hence families varied in height response to water table level. Several families showed no change in height across the water table level range (30 to 0 cm), but the most sensitive families showed more than a 50% decrease in height across this range. The results suggest that growth of red alder on wet sites may be enhanced by selection and propagation of progeny tolerant of waterlogging. For. Sci. 33(1):224-229.
Dry Weight Partitioning and Its Relationship to Productivity in Loblolly Pine Seedlings From Seven Sources
Authors: Bongarten Bruce C. , Teskey Robert O.
Published: April 2024

Dry weights of leaves, stems, and roots in loblolly pine seedlings from seven diverse geographic origins were determined after one year's growth in a green-house under (a) moist and (b) droughty soil conditions. In the moist soil regime, seedlings from each of the four coastal sources produced significantly more dry weight than seedlings from each of the three continental sources. Under moist conditions, coastal trees also allocated more dry weight to leaves and less to root than trees from two of the three continental sources. Seedlings grown in the dry regime were considerably smaller and generally allocated a greater portion of their dry weight to root and less to stem than trees grown in the moist regime. Furthermore, seedlot differences in total dry weight and dry weight distribution among plant organs were much reduced in the dry regime compared to the moist regime. These patterns of dry weight allocation were correlated with differences in seedling productivity in some, but not all respects. Patterns of relative plant organ growth appear to be one of the factors causing provenance differentiation in growth rate. For. Sci. 33(2):255-267.
A Model For Recognizing Forestwide Risk in Timber Management Scheduling
Authors: Hoganson Howard M. , Rose Dietmar W.
Published: April 2024

This paper presents one method of recognizing risk in formulating and solving timber management scheduling problems. Emphasis is given to developing a schedule for the short run that will perform well over a range of plausible future conditions. The method merges linear programming formulations for specific scenarios describing the future. Separate schedules are determined for each scenario with the added requirement that all of the schedules are identical for the short run. This formulation is shown to be a simplified form of the multistage recourse problem as described by Dantzig (1963). The solution technique developed by Hoganson and Rose (1984) is proposed as a possible solution technique. This technique decomposes the problem into subproblems of manageable size. The subproblems are simply decision-tree problems describing options for individual stand types, with specific branches of the trees representing stochastic elements of the problem. The key to the solution process is the interpretation and predictability of the key dual variables of the formulation. A large-scale example is given, and results are examined to consider how methods might be refined to better deal with uncertainty. For. Sci. 33(2):268-282.
Comparison of Constant and Variable Allometric Ratios for Estimating Populus tremuloides Biomass
Authors: Ruark Gregory A. , Martin George L. , Bockheim James G.
Published: April 2024

An allometric model that incorporates a variable allometric ratio (VAR) was fitted to Populus tremuloides biomass data for bolewood, bolebark, live branch, leaf, and current twig stem components. This model was compared to a log-liner transformation of the power function, which imposes a constant allometric ratio (CAR). Although the VAR model did not improve the estimation of bolewood biomass, it significantly improved the estimation of live branch and leaf biomass, and provided less biased estimates of bolebark and current twig weights relative to the CAR model. The VAR model was superior to the power function as a model of allometric relationships that do not remain constant as the organism grows. It allowed for initially large allometric ratios that declined linearly with increasing stem diameter. For. Sci. 33(2):294-300.
Competitive Effects of Various Grasses and Forbs on Ponderosa Pine Seedlings
Authors: Elliott Katherine J. , White Alan S.
Published: April 2024

Competition between ponderosa pine seedlings and various grasses and forbs was studied on a site in northern Arizona burned in 1982 by a wildfire. Two-year-old pine seedlings were planted in 3.05 x 3.05 m plots in April 1983, followed by the sowing of grass and forb seeds on the same plots in July 1983 after summer rains had begun. Predawn xylem water potential of the pine seedlings was measured biweekly throughout the 1983 and 1984 growing seasons. Extractable soil nitrogen was measured at the beginning and end of both growing seasons. After the wildfire, nitrate and ammonium levels were significantly higher in the burned area than in an adjacent unburned area. Nitrate and ammonium concentrations in various grass treatment plots were significantly (P < 0.05) different at both the beginning and end of the growing season. Pine seedling xylem water potential differed among treatments, with potentials being lowest on plots sown with Agropyron desertorum. The differences in seedling xylem water potential and available soil nitrogen were reflected in differences in pine seedling growth. The most effective competitors were Agropyron desertorum and Dactylis glomerata. Results indicated that competition occurred for both moisture and available nitrogen. For. Sci. 33(2):356-366.
The Influence of Shoot Ontogeny on Juvenile-Mature Correlations in Loblolly Pine
Authors: Williams Claire G.
Published: April 2024

A short-term genetic test of 18 open-pollinated loblolly pine families and two checklots was destructively measured over 18 months after germination. The purposes of the study were to detect change in juvenile-mature family mean correlations as shoot development progressed and to reevaluate shoot dry weight as a juvenile indicator trait. Height at the first bud was negatively correlated with eight-year height, whereas height accrued after first budset was positively correlated (r≥ + 0.59) at all measurement ages. Juvenile-mature correlations between total seedling height and eight-year height rose as height after first budset increased. Seedling shoot length was more strongly correlated with eight-year height than was seedling dry weight. Dry weight was negatively correlated with eight-year height in the first year but in the second year the correlation rose to near zero. Date of second year growth cessation was not related to later growth performance in field tests. Length of shoot beyond first budset (cyclic growth length) was the best juvenile indicator of eight-year height. For. Sci. 33(2):411-422.
An Approach for Predicting Snow Damage to Ponderosa Pine Plantations
Authors: Megahan Walter F. , Steele Robert
Published: April 2024

Snow damage to ponderosa pine plantations is common at many locations in the mountains of central Idaho. A procedure was developed using discriminant analysis techniques to predict snow damage hazards. Two approaches were used: one based on computed values of 20-year average annual maximum snow pressures; and the other based on elevation and the average slope gradient on the sample plantations. Snow pressures were computed from plantation site properties including elevation, slope gradient, aspect, and a classification of surface roughness. Prediction success was best with the snow pressure approach and amounted to 74% for damaged plantations and 91% for undamaged plantations for an overall prediction success of 82%. A sensitivity analysis of the snow pressure equations showed that snow depth was the most important variable influencing snow pressure. Evaluations of annual variability in maximum snow pressures suggest that the 20-year average is a reasonable figure for prediction purposes. Ponderosa pine in the study area has a window of vulnerability of about 13 years. The probability of trees surviving this period without damage in high hazard snow pressure sites is very small. An evaluation of the potential benefits of predicting snow pressure damage along with suggestions for use of the procedures are provided. For. Sci. 33(2):485-503.
Summertime Radiation Balances of Clearcut and Shelterwood Slopes in Southwest Oregon
Authors: Holbo H. R. , Childs S. W.
Published: April 2024

Measurements of incoming solar radiation, reflected solar radiation, net radiation, and outgoing longwave radiation were made on three clearcuts and below three shelterwood canopies in southwest Oregon. This dataset was used to characterize the radiation balance of reforestation sites. The fraction of incoming solar energy (K ↓) producing the near surface microclimate (i.e., the net radiation, Q*) was 0.5 ± 0.06 for all sites studied. This value is appreciably lower than commonly measured values of uncut forest (Q*/K ↓ = 0.7 to 0.9). Although Q*/K ↓ is the same for clearcuts and shelterwoods, shelterwood understories have smaller net radiation because the overstory partially intercepts incoming solar radiation. Shelterwood data also exhibit the expected decrease in longwave radiation loss at night. The major factor affecting site albedo in both shelterwoods and clearcuts was slashburning, which decreased albedo to 0.13 as compared to 0.21 for unburned sites. Net radiation for entire sites was estimated with a simple model to sum ground surface net radiation and shelterwood canopy net radiation. Model calculations suggest that harvested sites average a 36% reduction in total net radiation when compared to unharvested stands. Shelterwood understory environments are less harsh than clearcut environments because much of the total site net radiation is dissipated in the overstory canopy. The model is also used to estimate the effect of canopy density on net radiation below the canopy. For. Sci. 32(2):504-516.
The Influence of Benomyl on Blue Stain Infestation, Oleoresin Synthesis, and Growth in Paraquat-Treated Loblolly Pine
Authors: Clason Terry R.
Published: April 2024

Benomyl was applied singularly or combined with paraquat to xylary tissue either on a strip of exposed xylem or in a tangential bore hole. Blue stain infestation was assayed from wood disks collected at five different levels above the treatment area of each sample tree. Oleoresin accumulation was analyzed at 15 and 60 cm above the treatment area. Blue stain was not controlled by benomyl in paraquat treated trees. However, benomyl increased resin acid yields in paraquat and nonparaquat treated trees 20 and 270%, respectively. Resin acid accumulation increased and tree growth losses decreased when paraquat plus benomyl was applied to exposed xylem. For. Sci. 33(2):552-557.
Provenance and Progeny Variation in Pitch Pine from the Atlantic Coastal Plain
Authors: Kuser John E. , Ledig F. Thomas
Published: April 2024

A test of open-pollinated pitch pine families from 17 different locations on the Atlantic Coastal Plain was evaluated at 12 years of age. Genetic variation for growth was almost totally on the provenance level and was detectable among families within provenances in only a few cases. Mean volume decreased with latitude and also with distance of the seed origin from the test site. Provenances with the largest mean volume per tree came from locations 5.3 and 24.8 km distant from the test site and those with the smallest, from 349 and 388 km distant. The frequency of trees with serotinous cones varied from 2% to 48% and followed closely the pattern observed at the provenance origin. The frequency of epicormic sprouts was generally high, but differed significantly among provenances. For. Sci. 33(2):558-564.
Photosynthesis and Growth Response of Red Spruce and Loblolly Pine to Soil-Applied Lead and Simulated Acid Rain
Authors: Seiler John R. , Paganelli David J.
Published: April 2024

Soils from red spruce (Picea rubens Sarg.) and loblolly pine (Pinus taeda L.) stands were amended with either 0, 150, 300, 600 or 1200 mg/kg Pb as PbCl2. Six-month-old spruce and six-week-old pine seedlings were planted in their respective native soils and treated for 19 weeks with simulated rain of either pH 4.5 or 3.0. Rain was applied directly to the soil at a rate of 1.5 cm per week. Net photosynthesis, height, and needle, shoot, and root dry weights were measured at the completion of the experiment. In both soils, pH decreased and nitrate concentration increased with the application of a simulated rain solution of pH 3.0. Despite these changes in soil chemistry, simulated rain pH had no significant effect on the growth of either species. Red spruce photosynthesis was 35% higher; however, at a pH of 3.0. Loblolly pine photosynthesis was not affected by solution pH. Growth and photosynthesis of red spruce were inhibited even at the 150 mg/kg Pb level, with additional Pb resulting in increasing inhibition. Growth of loblolly pine seedlings was less sensitive to Pb, and decreased only at the higher concentrations. Loblolly pine photosynthesis exhibited no decline even at the highest Pb level. These results suggest that both red spruce and loblolly pine are more sensitive to soil Pb than to acid precipitation. In addition, loblolly pine appears to be more tolerant of Pb than red spruce, when both species are grown in their respective native soils. For. Sci. 33(3):668-675.
Testing a Photographic Method for Measuring Stem Cross-Sections
Authors: Goelz J. C. G. , Burk Thomas E.
Published: April 2024

Digitized measurements from four photographic procedures using standard 3½ x 5 in. prints were evaluated for measurement of annual radial increments on cross-sectional discs from felled trees. All four procedures worked well for fast-growing trees. Growth increments for slow-growing trees were estimated relatively poorly, but varied over different photographic methods. For the slow-growing trees, 5 x 7 in. enlargements of black and white photographs of unplaned discs provided measurements that were not significantly different from hand-measured radial increments. For. Sci. 33(3):784-789.
Winter Branch Nutrients in Northern Conifers and Hardwoods
Authors: Hendrickson Ole
Published: April 2024

Distributions of N, K, Ca, and Mg were examined in branch wood and bark of five common forest species growing in a mixed stand in central Ontario. Branches were divided into the following diameter classes (cm): 0.0-0.5, 0.5-1.5, 1.5-2.5, 2.5-5.0, and 5.0-7.5. Concentrations of nutrients in both wood and bark declined exponentially with branch diameter. Wood N concentrations declined more rapidly in hardwoods than in conifers. While K and Mg were strongly concentrated in branch tips, they did not vary significantly along the length of branches >1.5 cm diameter. Levels of Ca in bark did not vary along the entire length of the branch. Proportionately greater declines in nutrient concentrations were found in wood than in bark, indicating a higher degree of nutrient recycling during branch wood formation. Total branch nutrients were greater in hardwoods than in conifers, with higher amounts in hardwood bark more than compensating for the lack of foliage in winter. Although branch bark is the major nutrient reserve for spring growth in hardwoods, nutrients stored in wood may also be significant. For. Sci. 33(4):1068-1074.
Multiattribute Decision Theory and Forest Management: A Discussion and Application
Authors: Hyberg Bengt T.
Published: April 2024

The procedures required to implement Multiattribute Decision Theory (MDT) are presented. MDT is then applied to the management of a stand of timber owned by a nonindustrial private forest (NIPF) landowner who wanted to maximize both timber income and esthetic benefits. Harvesting/regeneration procedures of intermediate intensity maximize the well-being of a segment of NIPF landowners. For. Sci. 33(4):835-845.
Age-Density Distributions of Tall Shrubs in Minnesota
Authors: Balogh James C. , Grigal David F.
Published: April 2024

Age-density distributions were developed for tall shrubs in 34 upland aspen and conifer stands in northern Minnesota. Age-density distributions of the entire population of shrubs and of most individual species were best described by a negative exponential model. Distributions of a few shrub species were better described by a power function. Slopes of the distributions for any single species or for the entire population of all species did not differ across the range of sampled stands. Intercepts of the age-density distributions differed among the sampled stands. The age-density structure of shrub stems is similar in form and in descriptive statistics among the sampled aspen and conifer stands. For. Sci. 33(4):846-857.
Root and Foliar Nutrient Concentrations in Loblolly Pine: Effects of Season, Site, and Fertilization
Authors: Adams M. B. , Campbell R. G. , Allen H. L. , Davey C. B.
Published: April 2024

Nitrogen (N) and phosphorus (P) concentrations in the roots and foliage of plantation-grown loblolly pine were examined over a period of 18 months. Samples were collected from 4 sites on the lower coastal plain of North Carolina, each representing a distinct combination of soil moisture and soil fertility. The patterns in foliar and root nutrient concentrations followed similar trends over the course of this study. However, seasonal trends were irregular, suggesting that annual climatic variation may affect seasonal nutrient levels. Nutrient concentrations varied among sites, as did effects of fertilization (225 kg N ha -1, 225 kg N ha -1 + 75 kg P ha -1) on nutrient concentrations. Significant fertilizer effects on nutrient concentrations did not always result in increased volume growth. On some sites, root N and P concentrations appeared to be more sensitive to fertilizer-induced changes than did foliar nutrient levels and may have integrated site factors more effectively than foliar concentrations. Foliage seemed more sensitive to N deficiencies, while the roots detected P deficiencies more often. For. Sci. 33(4):984-996.
PPS and Random Sampling Estimation Using some Regression and Ratio Estimators for Underlying Linear and Curvilinear Models
Authors: Schreuder H. T. , Li H. G. , Hazard J. W.
Published: April 2024

Two thousand samples of 30 units were drawn from selected populations for which linear or curvilinear underlying models were postulated between the variable of interest and a covariate. Ratio, and linear and nonlinear regression estimators were compared for bias and relative efficiency of the estimates generated.

Regression estimators were found to be the most precise estimators of totals for both random and probability proportional to size (PPS) sampling for a series of tree populations for samples of size 30. The weighted regression estimator in PPS sampling was consistently more efficient than the standard Horvitz-Thompson estimator. For the populations studied, the nonlinear and polynomial regression estimators were not efficient except in very specific cases, probably due to the absence of clear nonlinear trends in most of the populations. (Such nonlinear or curvilinear models do exist in specific stands for certain variables.) The quadratic polynomial regression estimator had the smallest variance in the case where a clear nonlinear relationship existed in the population for the variable pair considered. A general nonlinear regression estimator was inefficient for a population with a nonlinear relationship. Generally, estimation bias was small and coverage probabilities (containing the parameter of interest) were high for all estimators and populations. Jackknife variance estimates were not consistently better than the classical variance estimates of the true variances for any of the estimators. For. Sci. 33(4):997-1009.
PAPYRUS: A Model of the North American Pulp and Paper Industry
Authors: Gilless J. Keith , Buongiorno Joseph
Published: April 2024

A spatial equilibrium model of the North American pulp and paper industry was developed to provide long-range projections of production, consumption, imports, exports, equilibrium prices, and fiber inputs. The model consists of a price-endogenous linear program that describes the industry in one year, and a set of recursive relationships that update this linear program from year to year to reflect endogenous and exogenous changes. The linear program incorporates supply curves for raw materials, an activity analysis representation of manufacturing and transport activities, and demand curves for final products and exports. The optimal solution to the linear program is the competitive equilibrium for the industry in a given year. Fourteen commodities are recognized in the model: softwood and hardwood roundwood and residues, mechanical, semichemical, and chemical pulp, newsprint, paper, and paperboard, and four recycled commodities. The United States and Canada are divided into 11 supply and 9 demand regions; the rest of the world consists of 3 net demand regions. A baseline simulation is presented that covers the period from 1980 to 2000. The results of alternative simulations, in which key assumptions of the baseline simulation are altered, are also presented.
An Ecological Climatic Classification of Michigan: A Quantitative Approach
Authors: Denton S. R. , Barnes B. V.
Published: April 2024

An ecological climatic classification method that emphasizes variables important to tree growth and survival was developed for Michigan. Separate classifications of weather station data were made for winter variables, growing season temperature variables, and growing season water balance variables. Each classification was based on the combined results of 6 cluster analysis procedures and principal component analysis. Hierarchical agglomerative average link cluster analysis using a modified Canberra metric as a distance measure (CANA) was generally most effective in reflecting the underlying structure of the climatic data. A single unified classification was then made combining the climatic information with physiographic patterns. Three regions and 20 districts were identified. The final classification was evaluated with canonical discriminant analysis and analyses of variance. The importance of such classifications for forest management and relationships with other climatic classification methods were discussed. For. Sci. 34(1):119-138.
Estimating Nitrogen Lost from Forest Floor During Prescribed Fires in Douglas-Fir/Western Hemlock Clearcuts
Authors: Little Susan N. , Ohmann Janet L.
Published: April 2024

Nitrogen loss from consumption of forest floor was studied on 33 treatment blocks burned on 11 clearcuts in western Washington and western Oregon. In most cases, nitrogen concentration in forest floor did not change significantly following prescribed fire. Change in the amount of nitrogen in forest floor ranged from an increase of 192 kg/ha to a loss of 666 kg/ha. In most cases, nitrogen loss was directly proportional to the amount of forest floor consumed. Total nitrogen loss can therefore be estimated by multiplying expected loss of forest floor by its nitrogen concentration before the burn. For. Sci. 34(1):152-164.
Reproductive Mode and Mechanisms for Self-Replacement of Northern Red Oak (Quercus rubra) - A Review
Authors: Crow T. R.
Published: April 2024

The requirements for regenerating northern red oak can be hypothesized from an understanding of the species' ecological life-history characteristics along with a knowledge of past and present disturbance patterns. The abundance of oak in the eastern forest is closely related to past land use and extensive disturbances. Frequent fires and heavy cutting favored oak because of its sprouting ability, while fires reduced common competitors. Northern red oak is neither an aggressive colonizer that is characteristic of early successional species nor an enduring, shade-tolerant, slow-grower that is typical of late successional species. Its regeneration requires an edge environment; one that is more mesic than exposed, open sites, but less competitive than the deep shade of a forest understory. To regenerate northern red oak, foresters need to create these conditions. Numerous cutting studies, however, have shown that overstory manipulation (partial or complete removal) alone will not regenerate northern red oak. Intense competition can be expected on the mesic sites suitable for northern red oak, and this competition must be controlled when regenerating this species. For. Sci. 34(1):19-40.
A Reevaluation of the Wagon Wheel Gap Forest Watershed Experiment
Authors: Van Haveren Bruce P.
Published: April 2024

The original, published streamflow data from the Wagon Wheel Gap watershed deforestation study were analyzed using modem computational and statistical methods. Annual hydrograph parameters were generated for the two paired watersheds for the pre- and postreatment periods and tested using regression and covariance analyses. Average annual water yield, maximum daily discharge, high-flow volumes, recession flows, and baseflow were all increased significantly following complete deforestation of one watershed. With the exception of the first full year after treatment, deforestation had little effect on hydrograph timing. Deforestation increased both the slope and intercept of a linear equation describing the flow duration curve of Watershed B. The results for these major hydrograph parameters agree with the results reported from the original study, conducted between 1910 and 1926 at Wagon Wheel Gap, Colorado. However, some of the original study results for other hydrograph parameters could not be statistically supported. For. Sci. 34(1):208-214.
A Stochastic Efficiency Approach for Determining the Economic Rotation of a Forest Stand
Authors: Caulfield Jon P.
Published: April 2024

Existing risk-rotation models for forest stands assume risk-neutrality on the part of decision makers. The criterion by which the optimal economic rotation is chosen in such models is based on the maximum expected discounted value of the site. Economic theory suggests, however, that many individuals are risk-averse and do not make investment decisions based solely on the mean of the distribution of investment returns. Models assuming risk-neutrality do not necessarily identify the appropriate economic rotation for such investors. Stochastic dominance analysis is employed to incorporate risk-aversion into the rotation decision. An example demonstrates how to apply the technique in practice, and results are compared with alternative decision rules, these being the (1) deterministic land expectation value, (2) mean-variance rule, and (3) mean-coefficient of variation rule. Results are consistent with previous work in that the inclusion of risk identifies risk-efficient rotations that may be shorter than in the deterministic case. Unlike previous efforts, more than one risk-efficient rotation may be identified. The mean-variance rule cannot usefully be applied to the rotation decision, and the mean-coefficient of variation rule defines a much larger efficient set than does stochastic dominance analysis. A sensitivity test shows that the degree of stochastic efficiency attained for a given rotation age changes with the annual probability of fire. For. Sci. 34(2):441-457.
The Relationship Between Western Spruce Budworm Defoliation Levels and Growth of Individual Douglas-Fir and Grand Fir Trees
Authors: Nichols Thomas J.
Published: April 2024

Regression models were fit relating foliage levels to height and basal area growth of 192 trees from 26 stands representing a wide range of site and stand conditions. The study confirmed that deteriorated tree conditions in prior years (often resulting from defoliation) affect current-year growth at specific foliage levels. Absolute height and basal area growth at specific foliage levels were found to be linearly related to absolute height and basal area growth before defoliation, indicating that proportional growth losses resulting from specified levels of defoliation do not vary between fast-growing and slow-growing trees. Various site, stand, and tree variables showed no effect on the relationship between foliage levels and proportional growth loss. Models that included predicted nondefoliated growth, foliage level, and preceding-year condition variables explained up to 61 and 91% of the variation in height and basal area growth (In-In transformation), respectively. For. Sci. 34(2):496-504.
Use of Stochastic Production Coefficients in Linear Programming Models: Objective Function Distribution, Feasibility, and Dual Activities
Authors: Pickens James B. , Dress Peter E.
Published: April 2024

The theoretical impact resulting from use of stochastic production coefficients on the objective function values of unconstrained and constrained linear programming problems was discussed. It was shown that the objective function value that is observed will be a biased and optimistic estimator of the true response of the natural resource system. In addition, it was shown that stochastic production estimates either have no impact or result in suboptimality when the stochastic production coefficients do not affect feasibility. The distribution of the optimal objective function value observed when stochastic production estimates are used, the objective function value of the true response of the system, and a linear combination of these random variables are hypothesized. These hypothesized distributions are then tested using a simulation approach with three error distributions and levels of variability. The simulations indicate that, when global constraints are applied, the dual activities of the global constraints in the presence of stochastic production coefficients are biased estimates of the dual activities with correct production information. In addition, truly infeasible solutions were selected nearly all of the time when feasibility could be violated. For. Sci. 34(3):574-591.
Predicting Fertilizer Response of Loblolly Pine Using Foliar and Needle-Fall Nutrients Sampled in Different Seasons
Authors: McNeil Robert C. , Lea Russ , Ballard Russell , Allen H. Lee
Published: April 2024

Nitrogen (N) and phosphorus (P) concentrations in loblolly pine (Pinus taeda) foliage and needle-fall were determined five times during 1979 on ten fertilizer trials installed between 1971 and 1973. Bole volume responses to fertilizers were regressed on initial stand basal area, and the residual errors were used as dependent variables in regressions with the nutrient variables. The only sampling period during which the N response residuals had a significant relation to foliar nutrients was early fall. The needle-fall N/P ratio was significantly related to the N response residuals in late winter, late spring, and early fall. Phosphorus response residuals were significantly related to foliar nutrients during all sampling periods and to needle-fall N/P in all sampling periods except late winter. The maximum R2;, 0.73, was for the regression of the P response residuals versus a foliar N/P ratio in late spring. The N + P response residuals were not significantly related to foliar or needle-fall nutrients. For. Sci. 34(3):698-707.
Growth Response of Green and White Ash Seedlings to Ozone, Sulfur Dioxide, and Simulated Acid Rain
Authors: Chappelka A. H. , Chevone B. I. , Burk T. E.
Published: April 2024

Nine-week-old green (Fraxinus pennsylvanica Marsh.) and white (F. americana L.) ash were exposed to O3 and/or SO2 (control, 0.10 ppm O3, 0.08 ppm SO2 or 0.10 ppm O3 + 0.08 ppm SO2) for 4 h d-1, 5 d wk-1 in combination with simulated rain (pH 3.0, 4.3 or 5.6, 1 h d-1, 2 d wk-1 at 0.75 cm h-1) for 6 weeks, under controlled laboratory conditions, with rain applied either just before or after fumigation. Across all rain treatments, white ash biomass was suppressed by the application of O3 and cumulative shoot elongation of green ash exposed to O3 and/or SO2 was less than controls. The combination of O3 + SO2 did not affect the growth of either species more than the pollutants applied alone. Leaf area ratio (LAR) and root to shoot ratio (RSR) exhibited quadratic responses to rain pH in green ash, across all pollutant treatments. Significant pollutant x pH interactions occurred in leaf weight ratio (LWR) in green ash and LAR and RSR in white ash. Significant linear increases in LAR and decreases in RSR, with decreasing pH, were observed for O3 and SO2-treated white ash. These findings are discussed relative to implications of the effects of gaseous pollutants in combination with acid rain on green and white ash growth. For. Sci. 34(4):1016-1029.
Sources of Variation in Osmotic Potentials with Special Reference to North American Tree Species
Authors: Abrams Marc D.
Published: April 2024

The purpose of this review is to discuss sources of variation in osmotic potentials (ψπ), with special reference to North American tree species. Lowering of osmotic potentials by solute accumulation (osmotic adjustment) has been reported in a wide variety of tree species during drought, but not in all species. Osmotic potentials at zero turgor for 37 tree species throughout the United States and Canada averaged (± s.e.) - 2.06 ± 0.13 MPa and - 2.54 ± 0.06 MPa for leaves or shoots under moist and dry conditions, respectively. The low standard error associated with the mean values suggest that, as a group, North American trees develop fairly similar osmotic potentials for a range of moisture conditions. Substantial solute accumulation often routinely occurs in developing leaves and in over-wintering leaves. Drought preconditioning can increase physiological activity in plants during subsequent drought by lowering ψπ. However, if drought is imposed too rapidly osmotic adjustment may not occur. Physiological plasticity in trees may cause variations in ψπ in responses to light regime and leaf canopy position. Light and nutrient regimes that promote high net photosynthesis should also promote the ability to osmotically adjust. However, stomatal responses and growth during water and nutrient stress may be unrelated to osmotic potentials because of species differences in rooting and water transport, guard cell turgor not being closely coupled with that of the bulk leaf, and changes in plant growth regulator concentrations. When examining changes in osmotic potentials using pressure-volume curves, it is important to rehydrate plant material to a water potential characteristic for that species at full hydration in the field. Moreover, as with most physiological measurements, sampling variation in light regime, canopy position, nutrient status, temperature, age, phenology, drought history, and diurnal timing of harvesting of the leaves and shoots should be minimized. For. Sci. 34(4):1030-1046.
Stratification of Seeds of Western and Utah Juniper
Authors: Young James A. , Evans Raymond A. , Budy Jerry D. , Palmquist Debra E.
Published: April 2024

Seeds of western juniper (Juniperus occidentalis subsp. occidentalis Hook.) and Utah juniper [J. osteosperma (Tort.) Little] are highly dormant when freshly harvested. Cool-moist stratification at 5°C for 14 weeks in vermiculite enhanced subsequent emergence of seedlings of both species, but total emergence was still low. The year of seed production greatly influences the viability of seedlots. Dry storage for 1 to 4 years at room temperatures did not enhance germination. Outdoor stratification, over winter, in sand, enhances subsequent emergence depending on the environment of the stratification site. The year of seed production also interacts with outdoor situations. Repeat stratification treatments, interrupted by 8-week continuously wet-emergence-assay periods in the greenhouse and dry storage during the summer were cumulative for increased seed germination of both species. Interrupted treatments were more effective than continuous stratification in excess of the optimum duration to enhance germination. Stratification in aqueous solutions with near saturation of the solution with oxygen increased subsequent emergence of seedlings of western and Utah juniper to about 50%. Similar treatments using aqueous solutions of 0.289 m mol L-1 gibberelin (GA3) enhanced subsequent emergence of seedlings of western juniper to better than 80%. For. Sci. 34(4):1059-1066.
Modeling Tree Growth Potential Based on Effective Evapotranspiration
Authors: Wickramasinghe A.
Published: April 2024

Annual tree growth potential is assessed by modeling effective evapotranspiration and taken as an index expressing interaction between atmospheric energy, tential evapotranspiration (PET), and soil moisture supply. The model has been calibrated for 11 forest stands of two evergreen species, Scots pine (Pinus Sylvestris) and Corsican pine (Pinus Nigra), located in England. Four calibrated effective evapotranspiration values (EET) together with a simple climatic index (PET/R), which expresses the balance between potential evapotranspiration and rainfall, were subsequently multiplied by tree age to incorporate the physiological efficiency of trees. The derived potential growth indexes (PGIs) were comparatively examined with actual annual tree growth data for a period of 30 to 40 years. Regression analysis was carried out in evaluating the model performance and the applicability of the model to predict environmental potential. All four predictions based on assessment of effective evapotranspiration were positively correlated with annual tree growth, having coefficients of determination above 0.40, and often reaching 0.70, with significance at the 0.001 level of probability. For. Sci. 34(4):864-881.
A Statistical Model of Root Geometry
Authors: Wu Tien H. , Bettadapura Dayanand P. , Beal Philip E.
Published: April 2024

The number, diameter, and length of lateral roots are related to the stem diameter of the tree. The diameter of branch roots is related to the diameter of the main lateral at the branch point. Statistical correlations were used to establish the relationships. Statistical correlations were also found for the change in root diameter and root orientation with distance along the root. These relations were used to formulate a model of root geometry, which allows one to estimate the frequency of root diameters as a function of distance from the stem of a tree with a given stem diameter. Application of the model to estimation of root density is described in an example problem. For. Sci. 34(4):980-997.
Thinning Red Alder: Effects of Method and Spacing
Authors: Hibbs David E. , Emmingham William H. , Bondi Michael C.
Published: April 2024

A 14-year-old fully stocked red alder (Alnus rubra Bong.) stand on a site index 30 m (50 yr) site in northwest Oregon was precommercially thinned and growth measured for 5 years. Treatments were (1) 4.3 x 4.3 m spacing (541 trees/ha), chemically thinned, (2) 6.1 x 6.1 m spacing (269 trees/ha), chemically thinned, (3) 6.1 x 6.1 m spacing, chain-saw thinned, and (4) control (1754 trees/ha). Chemical thinning was done by trunk injection of 2,4-D and caused some damage (flashback) to neighboring crop trees.

Thinning increased individual-tree radial growth 49% to 100% and decreased tree height growth by as much as 56%. In combination, this resulted in no significant change in tree volume growth with thinning. The lack of tree volume growth increase combined with the decrease in stem density with thinning produced a net decrease in stand volume growth with thinning. A review of the literature showed height growth reductions to be common among other alder studies. Tree basal area growth on the chemically thinned plots did not increase as much as on the chain-saw thinned plots, suggesting a prolonged growth reduction effect from the herbicide treatment. Diameter growth decreased with increasing degree of herbicide-induced crown damage. Thinning increased the size but not the numbers of epicormic branches. The longevity or effects on wood quality of these branches is not known. For. Sci. 35(1):16-29.
Considerations for Throughfall Chemistry Sample-Size Determination
Authors: Edwards Pamela J. , Mohai Paul , Halverson Howard G. , DeWalle David R.
Published: April 2024

Both the number of trees sampled per species and the number of sampling points under each tree are important throughfall sampling considerations. Chemical loadings obtained from an urban throughfall study were used to evaluate the relative importance of both of these sampling factors in tests for determining species' differences. Power curves for detecting differences among species derived from the noncentrality parameter developed herein indicated that the number of trees sampled per species affects power more than the number of points sampled under each tree. For. Sci. 35(1):173-182.
Terrain Shape Index: Quantifying Effect of Minor Landforms on Tree Height
Authors: McNab W. Henry
Published: April 2024

In the southern Appalachians, the distribution and growth of trees are highly correlated with local topography, but the relationships have been difficult to describe quantitatively. A quantitative expression of the geometric shape of the land surface (terrain shape index) is described and correlated with overstory tree heights and site quality. Application of the index in three even-aged stands of yellow-popular (Liriodendron tulipifera L.) on high-quality uniform sites shows that it is highly correlated with total height of trees in a stand, with r2 ranging from 0.45 to 0.74. In comparisons among stands, the index accounted for an average of 51% of the variation in site index. The relationship was validated in two supplementary stands and accounted for about 49% of variation in site index. The terrain shape index was more accurate in predicting tree height than was lateral shape class, a subjective measure of slope shape occasionally used in soil-site studies. For. Sci. 35(1):91-104.
Multiple-Occasion Partial Replacement Sampling for Growth Components
Authors: Van Deusen Paul C.
Published: April 2024

The Ware and Cunia (1962) method for estimating volume at time 2 from sampling with partial replacement is proven to be equivalent to a generalized least squares estimator (GLS). The GLS approach is advantageous because it extends easily to encompass multiple occasion sampling with partial replacement (MOSPR). An iterative GLS procedure is given for simultaneously estimating population parameters and their variances that avoids incompatibility problems that arose with some previously published methods. The MOSPR theory is also extended to include growth component estimation with additivity constraints. For. Sci. 35(2):388-400.
Identifying NIPF Management Motivations with Qualitative Methods
Authors: Bliss John C. , Martin A. Jeff
Published: April 2024

Most studies of nonindustrial private forest (NIPF) owners are constrained by the intrinsic limitations of survey research. This paper contrasts survey methodology with qualitative methodology, demonstrates the utility of the latter with an example from research on management motivations of NIPF managers in Wisconsin, and suggests ways in which the two methodologies can complement each other in future NIPF research. Sixteen case studies of Wisconsin NIPF managers were developed from transcribed tape recordings of unstructured interviews, management records, and field examinations. Cases were compared and analyzed for recurring motivations, attitudes, and values. The authors discuss how forest ownership and management contribute to owner identity, and the influence of ethnic, family, and personal identity on management activities. For. Sci. 35(2):601-622.