bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometric Errors in Natural Resource GIS Data: Tilt and Terrain Effects in Aerial Photographs
Authors: Bolstad Paul V. 
Published: April 2024

Abstract
Simulation studies were performed to estimate geometric errors in spatial data from monoscopic interpretation of large format aerial photographs. Positional and area error were simulated for a range of photo scales (1:10,000 to 1:40,000), camera tilts (0° to 4.2°), and relief (vertical range from 0 m to 750 m). Average positional errors were observed between 4 m and 104 m and varied positively with tilt and terrain range and inversely with scale. Area errors were observed over a range of polygon sizes, from 40 to 600 ha. Average area error ranged from 0.0 to 10.7% and was positively related to tilt and terrain range and not related to scale or polygon size. The magnitude of these errors and the availability and low cost of requisite correction technologies suggest analytical methods for removing relief and tilt distortion should be employed under most circumstances. For. Sci. 38(2):367-380.
Measuring Forest Site Quality Using the Parameters of a Dimensionally Compatible Height Growth Function
Authors: McDill Marc E. , Amateis Ralph L. 
Published: April 2024

Abstract
This article presents a new approach to modeling forest site quality which centers on interpreting as measures of site quality the parameters of a stand height growth model. It is argued that site index, which relies on a single height at a particular age, is not capable of reflecting important differences in the shapes of height growth trajectories. In the proposed approach, the parameters of the height growth function and the function itself completely describe the projected dominant height growth curve. In order to make the approach applicable in a wide variety of modeling situations, a method of allowing the number of site quality parameters to vary is proposed. The most flexible model configuration allows the estimation of all parameters separately for each stand and requires remeasurement or stem analysis data that span a relatively long period of time. Less flexible model configurations involve the simultaneous estimation of parameters that are different for each stand (stand-level parameters) with parameters that are the same for all stands (global parameters). Stand-level parameters measure different aspects of site quality that are unique for each stand and global parameters measure different aspects of site quality that are unique for each stand. These less flexible model configurations may be useful when modeling objectives warrant combining stand-level and global parameters or in situations where the mixture of longitudinal and cross-sectional data precludes fitting the most flexible model form. The approach works best with a growth function that offers maximum flexibility with a minimum of parameters and when the parameters of the growth function have intuitive biological interpretations. A new growth function with these properties is presented in this paper. The new growth function is dimensionally compatible and has two biologically meaningful parameters: a rate parameter and a maximum size parameter. The integrated form of the growth function also includes initial conditions which can be specified with data or as an additional parameter to be estimated. Two applications of the approach to modeling dominant height growth of loblolly pine (Pinus taeda L.) are described: one where sufficient longitudinal data allowed fitting several model forms and another where data limitations required the use of less flexible models. For. Sci. 38(2):409-429.
A Scenario Approach to Stochastic Anticipatory Optimization in Stand Management
Authors: Valsta Lauri T. 
Published: April 2024

Abstract
A flexible model for stochastic optimization is developed that can be used with forest stand simulation models. Stochasticity is represented by a large set of scenarios, each of which is an outcome of stochastic processes. A stochastic environment is described by random yearly growth rate levels and catastrophes, such as wild fire or windthrow. The optimization model is defined in control variable space and includes the timing, intensity, and type of thinning, and rotation length for an even-aged stand. Single-tree growth and mortality models are used. Numerical results in a risk-neutral case show that the optimum rotation is shortened with an increasing probability of a catastrophe. Further, an increasing growth rate variation has mixed and weak effects that depend, in particular, on the tree mortality model. If a stand cannot be thinned, increasing risk-taking shortens the optimum rotation, given the model set used. For. Sci. 38(2):430-447.
Variation in the Constitutive Defensive System of Loblolly Pine in Relation to Bark Beetle Attack
Authors: Nebeker T. Evan , Hodges John D. , Blanche Catalino A. , Honea C. Ronald , Tisdale Robert A. 
Published: April 2024

Abstract
Total flow over a 4-hr period, rate of flow, and relative viscosity were measured on 13 full-sib families in 1987. Significant differences between families were detected for all parameters measured. These parameters have been suggested as being useful in predicting relative host susceptibility to bark beetle attack. Certain families are suggested to be potentially more resistant to bark beetle attack than other families based on these parameters of interest. During 1988, 1989, and 1900 trees of unknown parentage (woods run) were wounded at different times during the day and total resin flow measured hourly for 24 hr. Rate of flow was calculated. Significant differences in flow were found at the beginning of the 24-hr period for all years. Nineteen eighty-eight was the only year that these differences continued for the entire 24 hr. Patterns of flow were similar for all years with 70% to 87% of flow occurring within the first 8 hr after wounding. Findings presented here, although preliminary, are encouraging in that it may be possible to incorporate potential bark beetle resistance information into tree improvement programs. For. Sci. 38(2):457-466.
A Measure of Innovativeness for a Sample of Firms in the Wood Household Furniture Industry
Authors: West Cynthia D. , Sinclar Steven A. 
Published: April 2024

Abstract
Characterizing innovators and early adopters of technological innovations can benefit promoters of new technologies. Marketing researchers have found correlates between characteristics of adopters and the time of adoption which have been helpful in identifying those firms most likely to adopt and targeting them with the appropriate marketing mix. Firms in the wood household furniture industry were segmented based on their adoption of 13 processing technologies into an innovator group and a noninnovator group. These groups were contrasted on a variety of characteristics. Innovators were found to differ significantly from noninnovators in firm size, technological expertise, technological progressiveness, opinion leadership, information sources, and cosmopolitanism of the decision-making group. This information can be used by equipment suppliers, government agencies, and the furniture industry itself to encourage adoption of new processing technologies. For. Sci. 38(3):509-524.
An Assessment of Some Nonsampling Errors in a National Survey Using an Error Budget
Authors: Gertner G. , Köhl M. 
Published: April 2024

Abstract
Different error budgets are approximated for the First Swiss National Forest Inventory. An error budget displays the effects of individual errors and groups of errors on the accuracy of estimates. The goal of developing the error budgets was to account for the significant sources of errors that can be expected in the national survey. Sources of error included measurement error of quantitative and qualitative attributes, regression error, and sampling error. It was found in general that the national survey system was not very sensitive to unbiased random errors but was sensitive to systematic measurement errors. For. Sci. 38(3):525-538.
Optimal Harvesting with Stand Density Targets: Managing Rocky Mountain Conifer Stands for Multiple Forest Outputs
Authors: Haight Robert G. , Monserud Robert A. , Chew Jimmie D. 
Published: April 2024

Abstract
A solution is presented for the stand management problem of optimizing timber yields (expressed as either present value or volume production) while satisfying constraints intended to meet nontimber management objectives such as deer habitat or visual quality. The constraints are stand density targets formulated exogenously by the forest management staff and are expressed as a simple function relating both the minimum and maximum numbers of trees per acre to quadratic mean diameter. The goal is to find the sequence of diameter-class thinnings that maximizes yield while staying between the trees per acre bounds for each quadratic mean diameter. The solution method is a derivative-free coordinate-search process that incorporates penalty functions for the constraints. Examples focus on mixed-conifer stands in the Northern Rocky Mountains with three different land use designations: timber production, timber production in visually sensitive areas, and timber production in whitetailed deer winter habitat. Growth and yield is forecast dynamically with the Stand Prognosis Model. Results show that significant reductions in present value and volume production may result from meeting stand density targets. In addition, the solution algorithm quickly finds infeasible targets (all of the wildlife management constraints proved to be infeasible). Because the solution algorithm also provides near-feasible solutions, it is easy to identify specific targets that need to be relaxed to obtain feasibility. Thus, the results from the solution algorithm can be used to quantify the costs associated with meeting the nontimber management goals. Furthermore, results from such analyses should greatly assist in determining efficient levels of production for multiple forest outputs. For. Sci. 38(3):554-574.
Effects of Supply and Demand Determinants on Pulpwood Stumpage Quantity and Price in Texas
Authors: Carter Douglas R. 
Published: April 2024

Abstract
This paper presents a dynamic model of the Texas pine pulpwood stumpage market. The analysis incorporates profit maximization of the demand side with utility maximization on the supply side to analyze short-run market behavior. The model is estimated using a ridge regression form of three-stage least squares to redress the problems associated with degrading collinearity. Multipliers are then constructed to predict the short- and long-run equilibrium impacts of supply and demand determinants on pulpwood quantity and price. For. Sci. 38(3):652-660.
Spruce Budworm Defoliation and Growth Loss in Young Balsam Fir: Cohort Models of Needlefall Schedules for Spaced Trees
Authors: Fleming Richard A. , Piene Harald 
Published: April 2024

Abstract
The relationship between the age-specific rates of needlefall, q(x), and needle age, x, for cohorts of needles from young, spaced balsam fir (Abies balsamea [L.] Mill.) was described by the discrete hazard function of the Weibull model, q(x) = 1 - exp{(xs - [x + 1]s)/us}. Here u = 6.32 yr (SE = 0.122 yr), s = 3.03 (SE = 0.109), and R² = 0.982. These age specific rates increased with needle age, demonstrating a type I pattern of needlefall. Three phases of needlefall were distinguished. An "early life" phase in which the mean rates of needlefall remained under 10% per year occurred during the first 2 years of existence. Later, up to about needle age 4, the rates climbed steadily upwards with age (at 5.5% per year per year). After age 4, the rate of increase in needlefall with age increased to over 8% per year per year. This may be due to the onset of old-age or wear-out effects in the progressive deterioration of the needles with age. Use of crown level and year of observation as independent variables in addition to needle age did little to extend the explanatory power of our models. These results are consistent with the period analysis performed by Fleming and Piene (1992) on the same stands.
Because of the large year-to-year variability in age-specific rates of needlefall, fits of the Weibull's discrete hazard function to individual cohorts usually left over half the variation in the rates unexplained. This contrasted with the period analysis in which the Weibull model explained over 80% of the variation each year. Hence, despite the success of the period analysis, the large year-to-year variability drastically restricts our ability to predict age-specific rates of needlefall. Although the Weibull model may describe future needle age distributions within a given year accurately, large fluctuations in parameter values, possibly reflecting weather-caused variations or long-term cycles and trends in needlefall, can be expected. For. Sci. 38(3):678-604.
The Variability of User-Based Social Impact Standards for Wilderness Management
Authors: Williams Daniel R. , Roggenbuck Joseph W. , Patterson Michael E. , Watson Alan E. 
Published: April 2024

Abstract
A key element of wilderness management planning is prescribing standards for acceptable levels of impact or change to wilderness conditions based on input from the public. Specifically, to obtain standards for social impacts, wilderness users are surveyed to determine acceptable levels of encounters with other parties. Using a variance components model and generalizability analysis, this study examines four sources of variation in user-based social impact standards: occasion (on-site vs. mailback surveys), wilderness area, encounter context (type and location of encounter), and respondent. Data come from a survey of visitors to four wilderness areas. Results indicate that social impact standards are generalizable across wilderness areas and to a lesser degree across measurement occasions. As expected, social impact standards vary depending on the context of contact. Contrary to normative theory in sociology, standards are also highly variable across respondents. These results suggest that respondents appear to share a high level of sensitivity to encounters, but that the task of assigning a numerical standard may be too abstract or hypothetical to be meaningful. Generalizability coefficients are reported to provide guidelines to future researchers and wilderness managers for obtaining user-based standards. For. Sci. 38(4):738-756.
Evaluating the Stability of Softwood Lumber Demand Elasticity by End-Use Sector: A Stochastic Parameter Approach
Authors: Adams Darius M. , Boyd Roy , Angle John 
Published: April 2024

Abstract
Estimates of the elasticity of demand for softwood lumber are obtained from a production theoretic model disaggregated by major end-using sector. Model parameters are treated as stochastic and estimated using the Kalman filter algorithm. The analysis supports Spelter's (1985) earlier findings of a highly inelastic aggregate U.S. demand for softwood lumber and that this elasticity has declined over the period since 1950. The extent of the decline was found to be only some 25%, however, and to have occurred in a relatively uniform fashion. Lumber demand elasticities in specific end-use sectors varied widely. Significant declining elasticity trends were found only in residential upkeep and alteration and materials handling. These trends arise from both a declining share of lumber in the costs of wood-based inputs and declining elasticities of demand for the wood-based inputs themselves. At the aggregate level, the significant declining trend in elasticity derives both from changing consumption shares across end uses and from the combined movements of the component elasticity series. For Sci. 38(4):825-841.
Allocating Resources to Large Wildland Fires: A Model with Stochastic Production Rates
Authors: Mees Romain , Strauss David 
Published: April 2024

Abstract
Wildland fires that grow out of the initial attack phase are responsible for most of the damage and burned area. We model the allocation of fire suppression resources (ground crews, engines, bulldozers, and airdrops) to these large fires. The fireline at a given future time is partitioned into homogeneous segments on the basis of fuel type, available resources, risk, and other factors. Each is assigned a utility value corresponding to the importance of holding the segment. For a given resource allocation, the probability of holding the segment is modeled in terms of the (random) width of fireline built. The task is then to find the allocation that maximizes the expected total utility. With certain restrictions, it proves possible to formulate the optimization as a linear programming problem. Use of the model is demonstrated with a case study of a large fire representative of conditions on the Los Padres National Forest in southern California. One feature is that different assumptions about the uncertainty in the predictions of constructed fireline widths can lead to differences in the optimal resource allocations. Thus, if one inappropriately took the uncertainty to be zero (the deterministic case), the resulting allocation may well not be the optimal one. This illustrates the potential advantage of probabilistic modeling over the previous deterministic approach. For. Sci. 38(4):842-853
No Relationship Between Fir Decline and Air Pollution in the Bavarian Forest
Authors: Kandler Otto 
Published: April 2024

Abstract
The alleged relationship between fir decline and air pollution in the Bavarian Forest, claimed by Visser and Molenaar (1992), is due to the use of an inadequate measure of the degree of air pollution and a biased set of tree ring data. For Sci. 38(4):866-869.
Multiple-Pass Harvesting and Spatial Constraints: An Old Technique Applied to a New Problem
Authors: Nelson J. D. , Errico D. 
Published: April 2024

Abstract
A methodology for approximating and incorporating spatial harvesting constraints into forest-level, aspatial models is presented. First, operational cut block scheduling methods based on map-coloring theory are used to sample the number of passes and the percentage of area-per-pass that can be harvested without violating adjacency and exclusion period constraints for a given set of harvesting guidelines. These results are defined as spatial approximation rules, and they are subsequently used to control harvest rates within a spatial approximation model. In test cases, the multiple-pass harvesting technique used in the spatial approximation model appears to closely estimate actual cut block schedules. Two major advantages of the spatial approximation technique are: (1) the onerous task of designing and scheduling cut blocks for an entire forest is not necessary, and (2) policy analysis is enhanced because the spatial approximation rules can be quickly altered to reflect different harvesting guidelines. Model calibration and optimization of harvest timings are identified as areas requiring further research. FOR. SCI. 39(1):137-151.
Southern Pine Beetle Infestation Development: Interaction Between Pine and Hardwood Basal Areas
Authors: Showalter T. D. , Turchin P. 
Published: April 2024

Abstract
We evaluated the interactive effects of pine and hardwood basal areas on stand susceptibility to southern pine beetle during 2 yr. Low and high pine basal areas (12 vs. 25 m²/ha, respectively) and presence and absence of hardwoods (11 rs. 2 m²/ha, respectively) were represented in a 2 x 2 factorial experiment replicated in four blocks of 30-40-year-old pine stands during 1989 and 1990. Infestations were initiated by introducing bolts containing southern pine beetle pupae and callow adults from two infested trees into each experimental plot. Bolts were placed around a baited tree that provided a focus for attack.
During both years the dense, pure pine treatment showed significantly greater infestation growth than the other treatments, killing an average of 9 trees during 1990 and 6 trees for the 2 yr combined. Infestations in the other treatments killed, on average, only the baited tree. These results demonstrated experimentally that thinned stands are less susceptible to southern pine beetle and that hardwoods apparently do not increase susceptibility but may interfere with infestation growth. Implications of these results for forest management are discussed. FOR. SCI. 39(2):201-210.
Turbulence Near the Forest Floor of an Old-Growth Douglas-Fir Stand on a South-Facing Slope
Authors: Lee Xuhui , Black T. Andrew 
Published: April 2024

Abstract
This paper reports the results of the analysis of measured turbulence regimes near the forest floor in an old-growth Douglas-fir stand on a south-facing slope in northern Vancouver Island, Canada. Primary instrumentation included one eddy correlation unit, which consisted of a three-dimensional sonic anemometer, a krypton hygrometer and a fine wire thermocouple, and four home-made hot wire anemometers.
The general features of the turbulence regimes near the forest floor within this stand were similar to those observed previously in other stands with an open trunk space. The high value of the ratio of the wind speed inside the stand to that outside (0.42) suggested the existence of a secondary maximum in the stand wind profile. The wind speed near the forest floor was approximately a logarithmic function of height with an effective roughness length of 0.012 m. The average turbulence intensity was 0.86. Power spectra for the streamwise and lateral velocity components exhibited a bimodal distribution in contrast with a unimodal distribution for the spectrum of the vertical component. Near the forest floor, latent heat and sensible heat generally flowed down humidity and temperature gradients, respectively. Some unique features were also observed, namely the suppression of the vertical velocity variance by the moderate to strong temperature inversion in the daytime and the occurrence of a very small eddy diffusivity for sensible heat flux. FOR. SCI. 39(2):211-230.
Prediction Equations for Centers of Gravity and Moments of Inertia of Loblolly Pine Stems
Authors: Lynth Thomas B. , Max Timothy A. , Burkhart Harold E. , Liu Jiping 
Published: April 2024

Abstract
Adequate design of tree harvesting equipment requires reliable estimates of centers of gravity and moments of inertia for full trees and tree-length stems. Several prediction models were developed for both centers of gravity and moments of inertia based on the theory of geometric solids. These models were fitted to center of gravity and moment of inertia estimates that were derived from stem dimension and weight measurements on loblolly pine (Pinus taeda L.) trees. The models were compared, and the best prediction equations for center of gravity and moment of inertia of tree-length stems were identified. Application of standard multiple regression methods resulted in a moment of inertia prediction model with a slope parameter estimate that had a sign opposite to that indicated by a theoretical model. Ridge regression and nonlinear regression were used to fit moment of inertia prediction models having coefficient signs consistent with those predicted by the theoretical model. The parameter estimates obtained by nonlinear regression were selected since they conformed more closely to properties of the theoretical moment of inertia model. FOR. SCI 39(2):260-274.