bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Coordinate-Free Area Variance Estimator for Forest Stands with a Fuzzy Outline
Authors: Magnussen Steen 
Published: April 2024

Abstract
Digitized forest maps offer the added convenience of automated area calculation of forest stand polygons. However, the "actual" stand areas in a forest management operation may deviate from the map value due to the mapping process and the delineation procedures used to identify stand boundaries for management operations. Three sources of area variances of mapped forest stand polygons are considered: the first due to the uncertainty inherent in coordinates, a second due to the linear interpolation between points, and a third due to the basic fuzziness of the boundary. A simple coordinate-free variance estimator is introduced, and predictions made from it are compared to a standard method requiring input of all polygon coordinates. When the coordinate-free variance estimator was applied to a set of simple polygons and a set of 120 natural forest stand polygons, a generally good agreement was found between the results from the two types of estimators. The coordinate-free method is suited for planning purposes when the error components arising from the uncertainties of forest stand areas are needed. For. Sci. 42(1):76-85.
Spatial and Vertical Leaf Area Index of a Deciduous Forest Resolved Using the LAI-2000 Plant Canopy Analyzer
Authors: Strachan I. B. , McCaughey J. H. 
Published: April 2024

Abstract
The LAI-2000 Plant Canopy Analyzer (LI-COR Inc., Lincoln, Nebraska) was used to determine the spatial and vertical canopy structure of a heterogeneous deciduous forest near Chalk River, Ontario. Overstory vegetation area index (VAI) demonstrated the spatial heterogeneity that exists between points at 10 m spacing and also with direction along transects, emphasizing the need for an appropriate sampling strategy. Average (± standard deviation) VAI for the forest was determined to be 3.00 ± 0.70, which lies within 3% of an estimate made by litterfall analysis in 1989 for the same forest location. The average VAI differs from the plant area index (PAI) determined by hemispherical photography by 9%. Owing to the large standard deviation in the estimate of VAI, it was calculated that 84 samples need to be taken to be within 5% of the mean at the 95% confidence level. This number drops to 21 if the accuracy requirement is relaxed to 10%. The large number of samples can be reconciled by the speed of sampling that is possible with the LAI-2000. One-hundred-thirty-two samples were obtained in this forest during a 7 day period. Vertical measurements of VAI were made from five levels on a 25 m scaffold tower in all four cardinal directions. VAI in the top third of the canopy compared well with hemispherical photography values taken along the vertical profile. The estimates in the middle and bottom levels differ from PAI. Directional heterogeneity was shown to increase with height. VAI measured at the lowest canopy level from the tower (3.11 ± 0.34) was not significantly different from the spatial overstory average of 3.00. For. Sci. 42(2):176-181.
A Method for Integrating Risk and Attitude Toward Risk into Forest Planning
Authors: Pukkala Timo , Kangas Jyrki 
Published: April 2024

Abstract
The risk associated with decision alternatives and the attitude of the decision-maker toward risk are two important factors that should be considered in forest planning. This paper proposes an operational way of integrating both risk and attitude toward risk into tactical forest planning. Two sources of risk are considered in the proposed planning method: timber price and level of tree growth. A scenario approach is used to generate a distribution of possible outcomes for alternative forest plans. Each outcome is described by a priority index, which is computed from a priority function. The priority function is estimated by Saaty's eigenvalue technique on the basis of pairwise comparisons between the decision criteria selected by the decision-maker. Estimation of attitude toward risk is based on comparison of the importance given to the worst, the expected, and the best outcomes. The optimum plan is sought with a heuristic algorithm. In optimization, different outcomes are converted to priority indices and weighted in a manner that reflects the attitude of the decision-maker toward risk. The case study indicated that level of risk affects the choice of forest plan. In a situation involving risk, the optimum plan may be different for a risk-avoiding, a risk-neutral, and a risk-seeking decision-maker. For. Sci. 42(2):198-205.
Simulating Wildfire Containment with Realistic Tactics
Authors: Fried Jeremy S. , Fried Burton D. 
Published: April 2024

Abstract
Existing simulation models for fire protection planning rely on a containment algorithm which fails to account for the interaction between the production of containment line and a fire's capacity to spread. This paper describes a technique for simulating wildland fire containment which explicitly accounts for this interaction by extending, generalizing, and, in some cases, simplifying methods reported earlier (Anderson 1983, Albini et al. 1978, Mees 1985, Anderson 1989). Representing the containment boundary in parametric form [i.e., expressing its Cartesian (x, y) or polar (r, ) coordinates as functions of a dimensionless parameter instead of specifying y as a function of x or r as a function of ], leads to a formalism with two significant advantages: (1) it allows a free choice for the shape of the free burning fire boundary, and (2) it is appropriate for simulations of parallel (indirect) attack as well as direct head and tail attack. In general, the technique requires solution of a first-order, nonlinear, differential equation, a task easily accomplished using numerical methods. The dependence of final fire size and containment time on the line-building rate and eccentricity of the free burning fire boundary are illustrated with the special case of an expanding ellipse and constant line-building rate, for which the containment boundary can be obtained by a simple quadrature.
Our General Formulation algorithm is demonstrated with a series of simulations that span the range of likely parameters for fire spread and fireline production. Comparisons made on representative fires between predictions of the General Formulation and models currently in use indicate that current models almost always overestimate fire size, sometimes by as much as an order of magnitude. For. Sci. 42(3):267-281.
Spruce Budworm Defoliation and Growth Loss in Young Balsam Fir: Spacing Effects on Needlefall in Protected Trees
Authors: Piene Harald , Fleming Richard A. 
Published: April 2024

Abstract
Age-dependent Weibull models were used to describe precise measurements of needlefall from a pair of protected plots of young, unspaced, balsam fir (Abies balsamea [L.] Mill.). These models showed that the age-specific rates of needlefall tended to increase with needle age throughout the observed crown. Where crown level effects were evident, needle lifespans were shorter in the lower crown than in the upper crown. The influence of crown level in the unspaced plots, however, was too inconsistent to be useful as a general predictor of needlefall rates. Comparing the results with previous work on spaced sample plots showed that spacing affected many aspects of needlefall. The mean needle lifespan of 5.3 yr (SE = 0.17) on the spaced sample plots was significantly greater than the 4.7 yr (SE = 0.22) estimated for the unspaced plots. These differences were most extreme in the lower crown. Spacing also influenced the earliest phase of needlefall. For needles under 2 yr, the mean age-specific rates of fall were negligible in the spaced plots, but were about 6%/yr in the unspaced plots. Thereafter, annual increases in the age-specific rates of needlefall were similar in the spaced and unspaced plots. Spacing also affected the pattern of year-to-year variation in needlefall. There was evidence of statistically significant trends in mean needle lifespans over time in the spaced plots, but not in the unspaced plots. For. Sci. 42(3):282-289.
Landowner Objectives and Nonindustrial Private Timber Supply
Authors: Kuuluvainen Jari , Karppinen Heimo , Ovaskainen Ville 
Published: April 2024

Abstract
In this paper, nonindustrial private forest owners' objectives are empirically identified, and the link between ownership objectives and observed harvesting behavior is established by estimating a theoretically derived timber supply function. Survey data on 146 Finnish forest owners and their timber sales in 1987-1991 is used. Prior to estimation, forest owners are classified into four groups according to their ownership objectives by K-means clustering. Dummy variables indicating cluster membership are included in the supply function. According to the results, "multiobjective owners" harvest significantly more (m³/ha/yr) than the other owner groups (self-employed owners, recreationists, and investors), ceteris paribus. The results further indicate that the multiobjective owners' harvesting policy can be described as present-value maximizing while the other (single-objective) groups' harvesting behavior seems to reflect the effect of market imperfections, as assumed by the theoretical model of the study. For. Sci. 42(3):300-309.
Diel and Seasonal Patterns of Leaf Gas Exchange and Xylem Water Potentials of Different-Sized Prunus serotina Ehrh. Trees
Authors: Fredericksen T. S. , Steiner K. C. , Skelly J. M. , Joyce B. J. , Kolb T. E. , Kouterick K. B. , Ferdinand J. A. 
Published: April 2024

Abstract
Leaf gas exchange and xylem water potentials were measured in the field throughout the 1994 growing season on leaves in the upper crown of seedling, sapling, and forest canopy black cherry trees (Prunus serotina Ehrh.) in northcentral Pennsylvania. Rates of gas exchange and xylem water potentials generally decreased with increasing tree size. Rates of dark respiration also decreased with increasing tree size. Differences among tree size classes were consistent throughout the growing season for xylem water potentials, but not for leaf gas exchange measurements. In May and June, seedling net photosynthesis and stomatal conductance were approximately 2 x that of larger trees, but their values tended to be similar to or lower than those of larger trees in July and August. Averaged over the entire season, seedlings had higher leaf gas exchange rates than saplings, which had higher rates than canopy trees. Regardless of tree size, stomatal conductance and net photosynthetic rates reached a maximum near mid to late morning. Stomatal conductance and net photosynthesis decreased steadily during the afternoon for larger trees, but seedling rates remained high until late afternoon. Seedlings consistently had the highest predawn and midday xylem water potentials and leaf-to-air water vapor pressure deficits, while canopy trees had the lowest. The results of this study indicate that tree size is an important factor influencing foliar gas exchange and water relations. For. Sci. 42(3):359-365.
An Empirical Assessment of the Dimensions of Softwood Lumber Quality
Authors: Hansen Eric N. , Bush Robert J. , Fern Edward F. 
Published: April 2024

Abstract
On the basis of previous research (Garvin 1984, Parasuraman et al. 1988), an 80-item, 12-dimension model for measuring total product quality in softwood dimension lumber was developed. This model was tested using confirmatory factor analysis and buyer perception data from three segments of the softwood dimension lumber market. Test results did not support the 12-dimension model. Consequently, exploratory factor analysis was used to develop a model consisting of five dimensions: Supplier/Salesperson Characteristics, Supplier Services, Supplier Facilities, Lumber Performance, and Lumber Characteristics. This model was tested by asking softwood lumber buyers (the same ones used for original model development) to rate their suppliers on the five dimensions. On each dimension, buyers rated most-preferred suppliers higher than least-preferred suppliers, providing evidence of the model's appropriateness. For. Sci. 42(4):407-414.
Multiplication Rates In Vitro and by Stem Cuttings Propagation, and Clonal Development from Eucalyptus globulus Seedlings
Authors: Wilson P. J. 
Published: April 2024

Abstract
In developing new clones of forest trees, the first main goal is to propagate enough plantable plants for clonal field trials and a clonal archive. Models of clonal multiplication rates in Eucalyptus globulus indicate that this takes a similar time (about 56 wk) from the sowing of seed, whether multiplication is by axillary shoot culture in vitro or by stem cuttings propagation. Multiplication of unrooted shoots is relatively rapid in vitro but is largely offset by the greater time required for weaning, pricking out, and growth in the nursery. For. Sci. 42(4):415-418.
Shifts in Aboveground and Forest Floor Carbon and Nitrogen Pools After Felling and Burning in the Southern Appalachians
Authors: Clinton Barton D. , Vose James M. , Swank Wayne T. 
Published: April 2024

Abstract
Changes in aboveground and forest floor mass, carbon (C), and nitrogen (N) pools were quantified on three sites in the southern Appalachians 2 yr after felling and burning. Before felling and burning, stands were characterized by sparse overstories and dense Kalmia latifolia L. understories. Two years after burning, foliar C and N pools had reached 25% and 29% of pretreatment levels, respectively. Foliar N concentrations were not different from pretreatment values. Standing wood C and N pools were 1% and 2%, respectively, of pretreatment values. Wood N concentrations were significantly higher on two sites, likely related to differences in fire intensity. Forest floor N content 2 yr after burning was 90% of pretreatment levels, most contained in unconsumed large woody material. Forest floor mass was significantly lower in the Oi layer and unchanged in the Oe + Oa layers. Forest floor N concentrations were generally lower after treatment. The site with the least intense fire and the lowest mass loss from the forest floor had the highest forest floor, foliage, and wood N concentrations 2 yr after burning. Site recovery after felling and burning was a function of fire severity and the capacity for site-nutrient retention through plant uptake. For. Sci. 42(4):431-441.
Differences in Silvicultural Investment Under Various Types of Forest Tenure in British Columbia
Authors: Zhang Daowei , Pearse Peter H. 
Published: April 2024

Abstract
This paper presents empirical evidence on the relationship between forest tenure and investment in silviculture. Silvicultural activities and expenditures on a large number of recently logged tracts in British Columbia, under four distinct forms of tenure, are assessed using a silvicultural investment model based on the conventional theory of capital. The empirical results indicate that silvicultural investment is correlated with security of tenure, and the level of investment under the most secure form--private land--is more than 67% greater than that under the least secure form--Forest Licences. For. Sci. 42(4):442-449.
Productivity and Research and Development in Two Canadian Forest Product Industries
Authors: Mohnen Pierre , Jacques Romain , Gallant Jean-Sébastien 
Published: April 2024

Abstract
This paper examines the role of research and development (R&D) in two important sectors of the Canadian economy, its pulp and paper and wood industries. A cost of adjustment model with two quasifixed inputs (capital and R&D) and three variable inputs (labor, materials, and wood) is used to estimate the technology, the rate of return on R&D, and its contribution to total factor productivity growth in these two industries. The sample is from 1963 to 1988. R&D is found to earn a net real after-tax annual rate of return of 1.6% in the pulp and paper industry and of 7.8% in the wood industry. The contribution of R&D to total factor productivity growth is minimal. Scale remains the main determinant of total factor productivity growth. For. Sci. 42(4):487-497.
Public Acceptability Thresholds of Clearcutting to Maintain Visual Quality of Boreal Balsam Fir Landscapes
Authors: Pâquet Joséet , Bélanger Louis 
Published: April 2024

Abstract
Clearcutting transforms forest landscapes by creating important visual contrasts between cut areas and adjacent stands. The object of this study was to determine if it is possible to harvest a certain proportion of the visible landscape while maintaining a visually acceptable setting in the social and ecological context of the boreal balsam fir (Abies balsamea L. Mill.) forest of central Québec. Using an adaptation of the Scenic Beauty Estimation (SBE) method, a survey was conducted through slide presentations to 309 persons from 11 groups of forest users. Levels of acceptability for single-patch and dispersed-patch cutting strategies were established for this ecosystem. The results confirmed that an increase in the percentage of clearcut areas in the visible landscape induced a lower level of acceptability and that even a small clearcut created a visual impact. However, despite a generally unfavorable reaction to clearcuts, a certain level of landscape alteration was acceptable to the tested groups. When clearcuts were in the form of a single patch, the acceptability threshold of the user groups was reached at an average percentage of 25% of the visible landscape harvested by clearcutting. The dispersed-patch strategy reduced the negative visual impact; for 6 of the 11 groups, the acceptability threshold increased to a harvesting level of 50%. To remain visually acceptable, clearcuts must be in a subdominant position in the visible landscape. The visual impact of a clearcut is effectively mitigated when the vegetation has reached a minimum height of 4 m. For. Sci. 43(1):46-55.
Trends in Genetic and Environmental Parameters for Height, Diameter, and Volume in a Multilocation Clonal Study with Loblolly Pine
Authors: Paul A. D. , Foster G. S. , Caldwell T. , McRae J. 
Published: April 2024

Abstract
Seedlings from 30 full-sib families (contained in 2, 4 x 4 factorials) of loblolly pine (Pinus taeda L.) were cloned and planted in three test sites in Georgia. Analyses were conducted on total height at ages 1 to 5 yr in the field, dbh at age 5, and individual tree volume at age 5. Four sources of genetic control were tested: male parent, female parent, male x female parent interaction, and clone within family. Differential growth responses due to test sites were present. Significant differences were detected among male parents for only one (age 5 height) of the seven traits in only one factorial. However, variation for height among female parents was found at ages 1 to 5 in only one of the two factorials accounting for 1% to 9% of the total variation. Significant effects of clone within family were found at all ages in one factorial and at ages 1, 3, and 4 in the other factorial for height but not for dbh or individual tree volume. None of the parental sources (male, female, or male x female) were interactive with test sites except one isolated case at age 2 in one factorial. However, the clone within family source of variation interacted significantly with site for height at ages 3 to 5 in factorial 1. Differences due to male or female parent effects were somewhat lower than has been found in other similar studies, possibly due to the relatively low number of parents in both factorials and hence, sampling effects. Future genetic studies should include more parents in the mating design but with approximately the same number of cloned individuals per cross in order to provide a better test of sources of variation. Trends in genetic and environmental variances and heritabilities were examined. Additive genetic variance (VA')for tree height displayed a steady increase from age 1 to 5. Dominance genetic variance (VD') for height also increased steadily over the same age range. The relationship between VA' and VD' differed between the two factorials. In factorial 1, VA' was larger than VD' for ages 1 to 4, then VD' became larger for age 5. The reverse pattern occurred in factorial 2. Epistatic genetic variance was detected only at age 1 for height in factorial 1 and at ages 1 and 3 in factorial 2. Dominance variance equaled or exceeded additive genetic variance for dbh and individual tree volume at age 5. Narrow-sense and broad-sense heritabilities for height were low to intermediate (0.05 to 0.37) from ages 1 to 5 and were more or less stable over ages. The importance of dominance genetic variance, at least to age 5, underscores the likelihood of additional genetic gains through a clonal tree improvement and deployment program beyond the gains achieved in a seed orchard/seedling based program. For. Sci. 42(1):87-98.
New Zealand's Privatization of Forest Lands: Policy Lessons for the United States and Elsewhere?
Authors: Hall O. F. 
Published: April 2024

Abstract
Two forest policy questions are examined: 1. What particular problems in New Zealand's privatization of public forest lands (1985 to 1995) need thorough examination prior to proposing it in the United States or elsewhere? 2. What light does the New Zealand experience throw on the question of whether privatization and subdivision of forest lands is the solution to multiple use conflicts among forest land uses and users? A brief history of the origin and implementation of New Zealand's forest privatization policy is given, including the disestablishment of its national Forest Service. Two unique features of New Zealand made privatization especially appropriate there: the history of many government-operated businesses, and the great area and productivity of a very distinctive and differentiated forest type—radiata pine plantations. Nine objectives of privatization stated in New Zealand, 5 specifically on forestry, are analyzed. Six of the 9 were concluded to be successful in New Zealand. Possibilities of success in the United States are examined. As a solution for multiple-use problems, both positive and negative results of the policy are found. Finally, 6 tentative "lessons" are concluded that should be reviewed in countries where a similar policy is proposed: 1. Privatization should involve either leasing or fee simple sale of forested land primarily suited to rapid tree growth of commercially valuable species suitable for being managed for successive crops of timber at a profit, with covenants for regeneration after harvest. 2. Lands critical for recreational, aesthetic, or habitat values should remain publicly owned. 3. Lands on which re-investment of some of the income in regeneration is of questionable profitability should not be entered into the policy. 4. The policy could be successful in avoiding many but not all multiple-use conflicts for the managers. 5. In public forests retained for exclusively noncommodity uses, questions of the availability of some useful and valuable woods may require arbitration of conflicts. 6. Privatization doesn't solve the struggle to financially support park and wilderness and special wildlife habitat. For. Sci. 43(2):181-193.