bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tree Size Diversity and Economic Returns in Uneven-Aged Forest Stands
Authors: Buongiorno Joseph , Dahir Sally , Lu Hsien-Chih , Lin Ching-Rong 
Published: April 2024

Abstract
Methods are presented to predict some of the effects of management on the tree size diversity of forest stands, measured with the Shannon-Wiener index applied to diameters. The diameter distribution is an indicator of stand structure and a determinant of biological diversity. The methods, which involve linear and nonlinear programming models of managed stands, were applied to northern hardwood forests. The attendant stand growth model was calibrated and validated with remeasured plots. The results suggest that, in this specific case, a natural, undisturbed stand would reach the highest possible sustainable diversity of tree size. Any intervention would decrease that diversity. In particular, economic harvesting policies would reduce tree size diversity by 10 to 20%, depending on the length of the cutting cycle. However, economics and diversity did not necessarily conflict. With the data and model used here, lengthening the cutting cycle up to 30 yr led to higher tree size diversity, while it also increased the soil rent of a stand by decreasing the present value of the cost of re-entry. Similarly, for a given cutting cycle, the soil rent increased with tree size diversity up to about 90% of the sustainable maximum, but decreased sharply thereafter. Real internal rates of return of 2 to 4% could be earned with stands that had either mediocre or very good levels of diversity. Likewise, starting from the same initial stand state, proper choice of a cutting guide could lead to much higher levels of tree size diversity, without decreasing forest value. For. Sci. 40(1):83-103.
Spatial Autocorrelation in Growth of Undisturbed Natural Pine Stands Across Georgia
Authors: Czaplewski Raymond L. , Reich Robin M. , Bechtold William A. 
Published: April 2024

Abstract
Moran's I statistic measures the spatial autocorrelation in a random variable measured at discrete locations in space. Permutation procedures test the null hypothesis that the observed Moran's I value is no greater than that expected by chance. The spatial autocorrelation of gross basal area increment is analyzed for undisturbed, naturally regenerated stands in three Georgia forest types: loblolly, shortleaf, and slash pine. The analysis uses 0.4-ha permanent sample plots from a forest inventory that included two remeasurement intervals (1961-1972 and 1972-1982). We present a new statistic for exploratory spatial analyses, and this statistic revealed an anomalous cluster of unusually slow-growing shortleaf pine plots occurred in the mountains 100 km north of Atlanta. A regression model was used to predict gross basal area increment as a function of variables that describe local stand conditions, and no significant spatial autocorrelations existed in the regression residuals. This result suggests that the anomalous cluster of slow-growing plots can be explained by the spatial distribution of local stand conditions rather than spatial patterns of other possible causes such as air pollution, although alternative interpretations are possible. For. Sci. 40(2):314-328.
Land Attributes and Land Allocation: Nonindustrial Forest Use in the Pacific Northwest
Authors: Parks Peter J. , Murray Brian C. 
Published: April 2024

Abstract
A land allocation model quantifies the influence of timber benefits, agricultural benefits, population, and land attributes on nonindustrial forestland allocation in the Pacific Northwest. The proportion of land in forest use only gradually changes and may be unresponsive to markets for land products or market-based policy instruments such as reforestation cost subsidies. Consequently, economic responses to policies may take place within forest rotations, which could change the mix of timber and nontimber benefits from private forests in favor of timber. If joint production of timber and nontimber benefits on private lands is to be considered a policy goal, new policy instruments may be needed. For. Sci. 40(3):558-575.
The Law of One Price for U.S. Softwood Lumber: A Multivariate Cointegration Test
Authors: Jung Chulho , Doroodian Khosrow 
Published: April 2024

Abstract
The multivariate cointegration testing procedures are used to determine if there exists a single long-run equilibrium price for four softwood lumber regional markets in the United States during the period 1950-1985. The Dickey-Fuller tests reveal strong evidence for the presence of a unit root in levels of the univariate price series, but the absence of a unit root in the first-differenced series for all four U.S. regional markets. The Johansen test results support the hypothesis commonly known as the "law of one price." For. Sci. 40(4):595-600.
Causes and Remedies for Errors in International Forest Products Trade Data: Examples from the Hardwood Trade Statistics
Authors: Luppold William G. 
Published: April 2024

Abstract
The quality of data concerning international hardwood products trade declined in the 1980s because of several problems associated with the collection and processing of individual export transaction records. This note examines the source, impact, and remedies for data problems caused by data screening procedures, nonreporting, recording errors, and alternative accounting systems. Although this study focuses on the hardwood products, many of the problems discussed affect trade data for other forest products. For. Sci. 41(2):278-283.
Estimating Gopher Populations and Their Abatement in Forest Plantations
Authors: Smallwood K. Shawn , Erickson William A. 
Published: April 2024

Abstract
Indirect sampling methods for pocket gophers (Family: Geomyidae) lack adequate assessment for accuracy and efficiency. During gopher abatement trials in forest clearcuts, our new "burrow index" accounted for 95% of the gophers, while the widely used 24 hr open-hole test accounted for only 68%. Using published data, we found that mound counts and plot occupancy provided precise estimates (R² = 0.76 - 0.99) of gopher density in clearcuts. We recommend the more efficient "burrow index" for sampling gophers, and "effective depopulation" for estimating population change due to abatement, after accounting for natural population dynamics in "control" plots. A modified burrow index on strip transects can be used for measuring association of gophers with ecological variables. For. Sci. 41(2):284-296.
An Assessment of Factors Associated with Damage to Tree Crowns from the 1987 Wildfires in Northern California
Authors: Weatherspoon C. Phillip , Skinner Carl N. 
Published: April 2024

Abstract
Relationships between (1) degree of damage caused by the 1987 fires in northern California and (2) prior management activities, fuelbed characteristics, and site/stand factors were studied on the Hayfork Ranger District of the Shasta-Trinity National Forests. Postfire aerial photography was used to assess scorch and consumption of tree crowns (the selected measure of fire damage), and other data were obtained from existing records. Data were collected and analyzed separately for (1) plantations and (2) uncut and partial-cut stands. Ordinal logistic regression was the primary analytical technique used. Factors significantly related to degree of fire damage in plantations were cover of grasses, cover of forbs, elevation, site preparation method, and level of damage in the adjacent stand. Damage to uncut and partial-cut stands depended on stand treatment, primary tree species, and aspect. The variables that most strongly influenced fire damage tended to be those most directly related to management activities--site preparation method and damage in adjacent stand for plantations, and stand treatment for uncut and partial-cut stands. For. Sci. 41(3):430-451.
A Sampling Strategy to Estimate the Area and Perimeter of Irregularly Shaped Planar Regions
Authors: Gregoire Timothy G. , Valentine Harry T. 
Published: April 2024

Abstract
The length of a randomly oriented ray emanating from an interior point of a planar region can be used to unbiasedly estimate the region's area and perimeter. Estimators and corresponding variance estimators under various selection strategies are presented. For. Sci. 41(3):470-476.
Establishment, Resource Acquisition, and Early Productivity as Determined by Biomass Allocation Patterns of Three Tropical Tree Species
Authors: Haggar Jeremy P. , Ewel John J. 
Published: April 2024

Abstract
Speed of stand establishment and rate of stem biomass production after canopy closure are two important criteria in the selection of species in the expanding field of tropical reforestation. How biomass allocation patterns determine establishment and stem production was studied in 0 to 2-yr-old plantations of Cedrela odorata, Cordia alliodora, and Hyeronima alchorneoides on fertile soil in the humid Atlantic lowlands of Costa Rica. The species were evaluated by: (1) their allocation of biomass to leaves and fine roots; (2) the resource-capturing capacity of the stands as expressed in leaf area, cover, fine-root length, and root distribution; and (3) biomass accrual and aboveground productivity. All species grew very fast: average stand heights at 2 yr ranged from 4 to 6 m, and some individuals were &gt;12 m tall. Canopy closure and root-system overlap were fastest in Cordia, occurring within a year after planting. Cordia's rapid stand closure was achieved by its higher specific leaf area and specific root length, plus an architecture that distributed leaves and fine roots more widely. Maximum aboveground net primary productivities after canopy closure were 7.3, 4.9, and 3.3 g m-2d-1 for Hyeronima, Cordia, and Cedrela stands, respectively. High productivity of Hyeronima correlated with development of a high LAI coupled with a low leaf turnover rate. Cordia and Cedrela, on the other hand, had higher rates of leaf turnover, so a higher rate of leaf production was required to maintain a given leaf area; this, in turn, limited biomass allocation to production of stem biomass. Cedrela productivity was severely reduced by attacks of the stem-borer Hypsipyla grandella. Biomass allocation patterns that promoted rapid establishment of a tree stand, such as broad crowns, high specific leaf area, and high specific root length, did not lead to the highest levels of stem biomass production after canopy closure. Once stand closure is achieved, species having low rates of leaf turnover, high leaf area indices, and high density of fine roots are likely to be most productive. Fast-growing tropical tree species should be evaluated not just on initial growth but also on the stem production attained after stand closure. For. Sci. 41(4):689-708.
Hydrologic and Erosional Responses of a Granitic Watershed to Helicopter Logging and Broadcast Burning
Authors: Megahan Walter F. , King John G. , Seyedbagheri Kathleen A. 
Published: April 2024

Abstract
Forest land managers are concerned about the effects of logging and site preparation on erosion, site productivity, streamflow, and water quality. Effects of helicopter logging and prescribed burning on streamflow and sediment yields from headwater drainages in the Idaho Batholith were evaluated, using paired watersheds monitored from 1966 to 1986. In the fall of 1976, 23% of a 162 ha watershed was clearcut. All the cutting units were located on south-facing slopes. Helicopter logging was followed by broadcast burning on the cutting units. Streamflow parameters showed little change in response to the logging and burning. However, total annual sediment yields on the treated watershed increased an average of 97% in the 10 yr following logging, with the largest increases occurring in the years of highest sediment yields. Increased sediment yields did not appear to result from accelerated channel erosion; rather, about 94% was attributed to accelerated surface erosion on the cutting units, and 6% was contributed by a single mass erosion site. Accelerated erosion persisted on the cutting units throughout the study period. The accelerated surface erosion occurred primarily as a result of the prescribed burning (rather than the helicopter logging); surface erosion rates on the burned areas were about 66 times greater than those on undisturbed slopes. The accelerated rates of erosion and sedimentation have potentially serious implications for on-site productivity and downstream resources. For. Sci. 41(4):777-795.
An Economic Analysis of the Differences Between Bid Prices on Forest Service and Private Timber Sales
Authors: Munn Ian A. , Rucker Randal R. 
Published: April 2024

Abstract
Data on 220 private and 99 Forest Service sealed bid timber sales in North Carolina indicate that per acre prices are about $675 higher on the private sales. Hedonic timber price equations for Forest Service and private sales are used to decompose this price difference into (1) differences due to characteristics of the sales and (2) differences due to the valuation of those characteristics. Both components of this decomposition are found to explain a portion of the price difference. The valuation of particular tract characteristics is found to be higher on private sales. In particular, our results suggest that pine sawtimber, pine pulpwood, and hardwood pulpwood have higher market valuations on private sales. For Sci. 41(4):823-840.
The Effects of Aboveground and Belowground Competition on Understory Species Composition in a Pinus densiflora Forest
Authors: Riegel Gregg M. , Miller Richard F. , Krueger William C. 
Published: April 2024

Abstract
The objective of this research was to test the hypothesis that water and nutrients, and not light, control understory plant species composition in a Pinus ponderosa forest in northeastern Oregon. The experiment was conducted as a split-plot experimental design with a 2 x 2 factorial analysis. To assess the effects of root competition of overstory trees on understory species composition, 20 plots (4 x 4 m) were trenched approximately 1.0 m in depth, and compared to 24 nontrenched plots. To increase light levels to understory vegetation, trees were thinned from 345 to 148 trees ha-1 in half of each block (2.5 ha) during the winter and early spring of 1986. Canonical discriminant analysis indicated that light accounted for the greatest environmental resource response among the treatments. The number of species (8) that increased in cover and density was 60% greater when tree root competition was reduced in the root-reduction treatment, versus 5 when tree canopy influences were reduced in the canopy-reduction treatment. Simple correlation showed that changes in species composition were significantly (P ≤ 0.05) related to both changes in aboveground attributes (light, midday air temperature, and soil temperature) and belowground attributes (soil water potential, pH, and nitrogen). Competition for limited resources, light, water, and nutrients, does affect understory species composition as evidenced by the response of individual species to increasing availability of these resources. For. Sci. 41(4):864-889.
Inbreeding Depression in Conifers: Implications for Breeding Strategy
Authors: Williams Claire G. , Savolainen Outi 
Published: April 2024

Abstract
Use of selfing as a breeding tool for conifers is controversial; this topic is addressed with a review of genetic models, theory, and experimental results based on a wide range of plants and animals. Some supporting evidence is available from conifer studies. For most conifers, selfing will not be the best method for reducing inbreeding depression in small subpopulations or elite lines of deleterious alleles; sib- or random-mating is a better option in the early generations of conifer domestication. Possible exceptions are conifer species that have few lethal alleles. Few organisms have been studied which have more lethal equivalents than conifers, so slower rates of inbreeding than selfing are needed initially to prevent large losses to low offspring survival and adult fecundity. Inbred breeding populations will also require large numbers of replicate lines and progeny per replicate because the probability of extinction for each line is expected to be high. Like maize, few valuable lines will result from selfing in the initial generations. If inbreeding depression is based on deleterious mutations then it is hypothesized to decline with stringent selection against deleterious alleles (purging). After the initial purging phase, selfingwould be efficient. Advantages of selfing include perfect assortative mating, increased selection efficacy among lines and increased uniformity within lines. Theoretical predictions for inbreeding depression in conifers have outpaced experimentation. Operational breeding programs will not provide needed data on changes in inbreeding depression, but the inbreeding assumptions for breeding strategies must be tested experimentally. We advocate using experimental inbred populations to study direct use of inbreeding depression as a breeding method. It provides first-hand results and lends confidence to long-term population management decisions. The greatest value will be to reveal unforeseen problems, preventing irreversible mistakes. As an example, we outline a plan for a rapidly cycled experimental inbred population for Pinus taeda L. which combines early selection, rapid screening for adult fecundity, and traditional genetic testing. Inbreeding depression research is central to the success of long-term population management. It has become more powerful with integrated classical genetics-molecular approaches, accelerated breeding techniques, and computer simulation models. For. Sci. 42(1):102-117.
The Grid Packing Problem: Selecting a Harvesting Pattern in an Area with Forbidden Regions
Authors: Synder Stephanie , ReVelle Charles 
Published: April 2024

Abstract
The problem of determining the maximum value or maximum volume cutting pattern in a forested area which is divided into a regular grid is approached as a 0-1 integer programming model. Constraints are included to preclude harvests in blocks which are adjacent to one another in an effort to reduce large forest openings which can have negative environmental impacts. One form of adjacency constraints can be used to exclude the cutting of blocks which share a common edge. Other forms can prevent harvesting blocks which share an edge or point. The challenge is to write these constraints in a form that favors 0-1 solutions. The integer-friendly forms that are chosen are applied to large tracts of land in which significant areas are excluded from cutting because of habitat preservation requirements or other prohibitions. More than 100 experimental runs with hypothetical data were conducted. For. Sci. 42(1):27-34.
Pluralism by Default: Community Power in a Paper Mill Town
Authors: Beckley Thomas M. 
Published: April 2024

Abstract
Forest-dependent communities are often isolated geographically and culturally but linked politically and economically to industrial core areas. Theories of underdevelopment and resource-dependence, and theories of community power are used to explain the implications of forest-dependence for the structure of local politics in one Maine paper mill town. Three models of power, as outlined by sociologists and political scientists, suggest three possible configurations of community power structures. Historical, documentary analysis and contemporary field research demonstrate the fluidity of the power structure for the community in question. As the needs and interests of the dominant local economic force have changed over time, the community has experienced elitist, hegemonic, and pluralist regimes of power. The contemporary power structure is a pluralism by default. The withdrawal from local politics of the major economic player has created a political vacuum and the historic dependency relationship between paper mill managers and the community has created an apathetic and nonparticipative citizenry. For. Sci. 42(1):35-45.
Growth Phenology and Crown Structure of Selected Loblolly Pine Families Planted at Two Spacings
Authors: McCrady R.L. , Jokela E.J. 
Published: April 2024

Abstract
Growth phenology and crown structure of five open-pollinated loblolly pine (Pinus taeda L.) families, planted at two spacings (0.92 and 1.83 m) and grown in pure plots near Summerville, SC, were investigated using a split-plot (main plots = spacing, subplots = genotype) field design. Shoot, branch, and foliage characteristics were quantified during the fourth growing season and related to standing volume. Genotype variation in shoot and branch characteristics was generally small and nonsignificant except for differences in annual height increment (from 135 to 152 cm) and current-year branch production (from 11.1 to 14.0). Significant genotype variation in foliage amount, distribution, and longevity was associated with contrasting growth performances and stage of stand development. Foliage biomass differed by as much as 60% among genotypes (from 4.8 to 7.7 Mg ha-1), with 38% of the variation related to family differences in total height. The large range in foliage biomass was the major contributor to leaf area index differences (LAI; from 7.9 to 13.6 m² m-2), although significant genotype differences in weighted specific needle area (SNA; from 175 to 199 cm² g-1) were also a factor. Genotype variation in foliage biomass and LAI was related to the vertical distribution of foliage, and both were significantly correlated with standing volume at age 3 yr (r = 0.64 and 0.59). The best performing families (3, 7, and 49 based on progeny testing) held &gt; 60% of their total foliage biomass in the middle crown third (nonuniform distribution), whereas the poorest families (37 and 138), had &lt; 50% in the same region (more uniform distribution). Compared to the other genotypes, family 37 exhibited reduced foliage longevity, which may have contributed to its low LAI and poor growth performance. Results of this study suggest that foliage display, amount, and duration are the crown characteristics important in conferring differential family performance for loblolly pine. For. Sci. 42(1):46-57.
A Strategy for Multiproduct Stand Management with Uncertain Future Prices
Authors: Forboseh Philip F. , Brazee Richard J. , Pickens James B. 
Published: April 2024

Abstract
This paper presents a strategy for stand management with multiple series of stochastic prices. When the only decision is to reject or accept a set of prices for a clearcut, the strategy is to accept and clearcut in the current period if the revealed revenue is at least as large as the current reservation revenue. This strategy is shown to be optimal when the price process is stationary and temporarily independent with the possibility of cross-product price dependence. Simulation involving red pine yields separated into two products, pulp and sawtimber, show the reservation revenue harvest strategy is far more consistent with current management practice than previous analyses involving a single product, sawtimber, have indicated. The probability distribution of optimal rotation ages is similar to a series of exponential (also called "waitingtime") distributions with new peaks at each major ingrowth event in the multiproduct yield function. The financial implications of considering pulp and sawtimber price uncertainty simultaneously are also addressed. For. Sci. 42(1):58-66.