bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Private and Public Harvesting under Spatial and Temporal Interdependence
Authors: Koskela Erkki , Ollikainen Markku
Published: April 2024

This article extends the Hartman model to include the case where two adjacent stands may be interdependent in the provision of amenity services. We show first that the relationship between the focal and exogenous rotation age depends on the nature of their temporal interdependence, that is, on what happens to the degree of substitutability or complementarity between the stands when the rotation age of the private focal stand changes. We then apply this analysis to the determination of public rotation age in a two-stage game where the government first decides on its harvesting, and private harvesting is chosen in the second stage. Several new rules are derived for the socially optimal design of public harvesting depending on the nature of interdependence between private and public stands as well as on whether or not citizens have access to private forests for recreation. FOR. SCI. 47(4):484–496.
Forest Certification: Roots, Issues, Challenges, and Benefits
Authors: Radosevich Steven R.
Published: April 2024

Foresters have been involved in a serious debate with other members of society for at least three decades over the environmental and social consequences of continuing to manage forestlands as they have been. This debate takes many forms, ranging from simple disagreement to new laws and regulations, market boycotts, and even civil disobedience by some members of the public. Foresters and many environmental organizations alike have looked for ways to resolve these ever-present concerns about the environmental, ecological, economic, and social consequences of forest management, while providing incentives for forest landowners to change their practices. Forest certification, as a voluntary, economically driven process, may be the mechanism for resolution to eventually occur, for the debate to end.
Heritability of Ozone Sensitivity in Open-Pollinated Families of Black Cherry (Prunus serotina Ehrh.)
Authors: Lee J.C. , Steiner K.C. , Zhang J.W. , Skelly J.M.
Published: April 2024

First-year seedlings of black cherry, representing 10 open-pollinated families from wild parents, were exposed in CSTR chambers to replicated treatments of 30, 60, 90, and 120 ppb ambient ozone for a 7 hr day-1, 5 day wk-1. Stem height, occurrence of leaf senescence, and visible foliar injury expressed as adaxial stipple were measured weekly during the 10 wk duration of exposure. Basal stem diameters were measured before and after fumigation. Stipple began to occur in week 1 of the 120 ppb ozone treatment, week 2 of the 90 ppb treatment, and week 4 of the 60 ppb treatment. No stipple occurred on any seedlings exposed to 30 ppb ozone. Premature leaf senescence occurred in all treatments, but sooner and more severely at higher concentrations of ozone. Relative diameter growth rates declined as ozone concentrations increased. Families differed significantly in their response to ozone treatments in severity of adaxial stipple, but not in leaf senescence or height or diameter growth. Family heritability estimates for foliar injury, calculated by treatment and week of measurement, were generally above 0.5 in the 90 and 120 ppb ozone treatments. The relative ozone sensitivity of these 10 families under CSTR conditions corresponded well with sensitivity rankings of their 27-yr-old parents, replicated in a clonal seed orchard, and growing under ambient ozone exposures. The existence of localized, heritable variation in ozone sensitivity in wild populations has obvious implications for the use of bioindicators in forest health monitoring. For. Sci. 48(1):111–117.
Modeling Changes in Wildlife Habitat and Timber Revenues in Response to Forest Management
Authors: Marzluff John M. , Millspaugh Joshua J. , Ceder Kevin R. , Oliver Chadwick D. , Withey John , McCarter James B. , Mason C.L. , Comnick Jeffrey
Published: April 2024

Few models evaluate the effects of forest management options on wildlife habitat and incorporate temporal and spatial trends in forest growth. Moreover, existing habitat models do not explicitly consider economic trade-offs or allow for landscape level projections. To address these concerns, we linked standard wildlife habitat suitability models with habitat projections from the Landscape Management System (LMS). LMS integrates spatially explicit forest inventories with forest growth, decay, and silviculture treatment (e.g., planting, thinning, harvesting) models to compare some economic and biological impacts of forest management on wildlife habitats at spatial scales ranging from the individual forest stand to the landscape. We used LMS to quantify pileated woodpecker (Dryocopus pileatus), Cooper's hawk (Accipiter cooperi), and southern red-backed vole (Clethrionomys gapperi) habitat qualities across landscapes and to project habitat changes through time. We modeled five forest management scenarios (including no action, intensive management for timber production, moderate management and intensive management to enhance mature forest structure, and mixed management for wildlife and timber) proposed for the 566 ha Satsop Forest in western Washington. The selected wildlife species' habitats (mixture of mature conifer and deciduous forests) were maximized by simply allowing the forest to grow with no management. However, this cost an estimated $929,539/yr in lost timber revenue. Intensive thinning, replanting, and retention of large trees increased habitat for all focal species and provided $384,558/yr return from timber. Because of potential short-term reductions in habitat that occur during long-term enhancement strategies (e.g., intensive thinning) and limited ability to model understory growth dynamics, monitoring and validation of predictions would be necessary. FOR. SCI. 48(2):191–202.
Evaluation of a Winter Habitat Suitability Index Model for Elk in West-Central Alberta
Authors: Jones Paul F. , Hudson Robert J. , Farr Daniel R.
Published: April 2024

We evaluated a habitat suitability index (HSI) model developed to assess impacts of forestry on elk (Cervus elaphus) winter range in west-central Alberta. The HSI model consisted of 3 submodels that collectively utilized 14 habitat variables to represent the life requisites of food, thermal cover, and hiding cover. We assessed the performance of each submodel by determining if there was a positive correlation between a preference index (PI) and HSI classes and by determining if there was a significant difference in mean HSI for sites selected by elk versus mean HSI for available habitat sites. We used stepwise logistic regression to determine which habitat variables significantly differentiated used and available habitat sites. All 3 submodels in the original model performed poorly. Of the 20 habitat variables entered, stepwise logistic regression identified only 3 as important in differentiating elk feeding sites from available sites: tree height, stem density, and distance to unimproved access. Performance of the food submodel was improved when these 3 habitat variables and their logistic relationships were applied. Only stem density significantly differentiated elk bedding sites from available sites, but using only stem density and its logistic relationship did not improve performance of the cover submodels. Our approach to testing the model involved separating HSI scores for used and available sites, and is an alternative method to using population data. FOR. SCI. 48(2):417–425.
Combining Random and Systematic Search Heuristic Procedures for Solving Spatially Constrained Forest Management Scheduling Models
Authors: Falcão André O. , Borges José
Published: April 2024

This article analyzes three heuristics for solving forest management scheduling models encompassing both timber production and landscape structure objectives. Emphasis is on developing an efficient solution approach that may address complex temporal and spatial interactions of forest management scheduling decisions. Two random search approaches, simulated annealing and evolution programs, are compared with a new heuristic, sequential quenching and tempering, that combines random and systematic search techniques. The three heuristics were applied to four large eucalyptus forest management problems. The test forests encompassed 300 to 900 stands. The number of management alternatives ranged from 33,000 to 220,000. Model building encompassed the generation of binary decision variables for all the problems considered. In order to address economic and ecological management objectives, all the models included timber volume flow constraints, minimum and maximum clearcut opening constraints and constraints on the minimum number of old forest patches with minimum area requirements. All constraints were defined over a temporal horizon extending to thirty 1 yr periods. Results from over 1,300 test computer runs are discussed for application to these large problems. Results show that the new strategy can be compared favorably to the random search approaches. They suggest that in order to find feasible solutions to such a complex problem, random search may be combined with a systematic search component within a heuristic procedure. FOR. SCI. 48(3):608–621.
A Finite Mixture Model for Characterizing the Diameter Distributions of Mixed-Species Forest Stands
Authors: Liu Chuangmin , Zhang Lianjun , Davis Craig J. , Solomon Dale S. , Gove Jeffrey H.
Published: April 2024

A finite mixture model is used to describe the diameter distributions of mixed-species forest stands. A three-parameter Weibull function is assumed as the component probability density function in the finite mixture model. Four example plots, each with two species, are selected to demonstrate model fitting and comparison. It appears that the finite mixture model is flexible enough to fit irregular, multimodal, or highly skewed diameter distributions. Compared with traditional methods in which a single Weibull function is fit to either the whole plot or each species component separately, the finite mixture model produces much smaller root mean square error and bias, and fits the entire distribution of the plots with extreme peaks, bimodality, or heavy-tails well. In some cases, a single Weibull function fitted to individual species separately may produce more accurate estimations for the component distributions of the two species than the finite mixture model. The summation of the two independent species results, however, may not produce a better prediction for the entire plot. This study shows that the finite mixture model is a promising alternative method for modeling the diameter distribution of multispecies mixed forest stands. For. Sci. 48(4):653–661.
Density and the Growth of Even-Aged Stands
Authors: Zeide Boris
Published: April 2024

This study develops a density-driven module and combines it with conventional growth equations, making the resulting model applicable to managed stands. The relationship between the diameter increment of an average tree and density evolves from the analysis of amount of light coming to the unshaded (upper) part of the crown, distribution of foliage along the stem, proportion of light transmitted through the crown, probability of shading the lower part of the crown, and other processes. The density module contains seven parameters, all of which can be assessed from existing knowledge. One of the parameters quantifies phenotypic adaptation, which mitigates competition stress. The entire model starts and ends with basic measurable variables: number of trees per unit area and their average diameter. The growth processes are evoked only to connect the current and future values of stand variables. FOR. SCI. 48(4):743–754.
Leptographium Species: Tree Pathogens, Insect Associates, and Agents of Blue-Stain
Authors: Eckhardt Lori G.
Published: April 2024

This is an outstanding monograph of the genus Leptographium, a group of fungi that occurs predominantly in pine. Leptographium species have been associated with pine decline and mortality, primarily as associates of root feeding bark beetles and weevils that attack living trees. Several studies have shown that Leptographium plays a major role in decline syndromes both in plantations and aging forests. There are several Leptographium species which are important internationally and are becoming more important in the United States due to their obvious impact on western coniferous forests (L. wageneri) and their involvement in red pine decline (L. terebrantis and L. procerum), making this monograph a timely contribution.
Oak Forest Ecosystems: Ecology and Management for Wildlife
Authors: Harrington Constance
Published: April 2024

Oaks (Quercus spp.) are important components in many temperate forest ecosystems, and a new book that synthesizes information on their management is always of interest. The intent of this book was to bring together knowledge from a diverse group of people who study oak forests and make that information available to those interested in managing those forests in a sustainable manner for wildlife. I think the authors have done a good job in achieving their objectives.
Book Reviews: Forest Dynamics and Disturbance Regimes: Studies from Temperate Evergreen-Deciduous Forests
Authors: Parker George R.
Published: April 2024

The structure of forests in any place is largely the result of the timing and character of past disturbance events. Disturbance opens forest ecosystems for colonization of species and is essential for the long-term survival of both plant and animal species within a forested region. This book focuses on the long-term dynamics of the Lake States Region located within the states of Michigan, Wisconsin, and Minnesota in the United States. While the book is regional in its coverage, the approach used in examining disturbance factors that drive forest change could be used for any other region. The author concentrates on three main disturbance factors: fire, wind, and herbivores.
Coarse Filter Ecosystem Management in a Nonequilibrating Forest
Authors: Armstrong Glen W. , Adamowicz Wiktor L. , Beck James A. , Cumming Steven G. , Schmiegelow Fiona K.A.
Published: April 2024

The natural disturbance model of forest management is the basis of many of the sustainable forest management systems being proposed for the boreal forest of Canada. Wildfire is the dominant natural agent of disturbance in the boreal mixed-wood forest. The natural disturbance model assumes that timber harvesting systems emulating the annual area burned by natural fire, its spatial distribution, and the amount of residual material can be developed. It is further assumed that natural processes can be emulated closely enough to maintain forest biota at natural or near-natural population levels. This is a coarse filter approach to ecosystem management.

In order to emulate the natural rate of disturbance, one needs to quantify it. The annual area burned in the study area, under natural conditions, is characterized as a random draw from a lognormal distribution. A modeling system comprised of an aspatial Monte Carlo simulation model and a linear programming based forest activity scheduling model was developed. The simulation model is used to develop 200 yr forecasts of probability distributions for habitat area of five vertebrate species under a stochastic wildfire regime. These probability distributions are used to construct habitat area constraints for use in an optimization model to help quantify the trade-offs between timber values and maintenance of the range of natural variability in the forest.

The model is used to identify the trade-offs between forest harvesting, wildlife habitat, and the degree of similarity between the managed forest structure and the distribution of structures that could be generated by natural disturbance. FOR. SCI. 49(2):209–223.
Genetic Variation in Nitrogen Uptake and Growth in Mycorrhizal and Nonmycorrhizal Picea abies (L.) Karst. Seedlings
Authors: Mari Samuel , Jonsson Alena , Finlay Roger , Ericsson Tom , Kähr Monika , Eriksson Gösta
Published: April 2024

The purpose of this study was to estimate genetic variation in nitrogen uptake and growth of mycorrhizal and nonmycorrhizal seedlings from 30 open-pollinated families of Norway spruce (Picea abies), at two levels of nitrogen (N) supply. Six-week-old seedlings were transplanted into 1.7 L pots filled with pumice, and one-half of them was inoculated with the ectomycorrhizal symbiont Laccaria bicolor. A 2 × 2 factorial combination of the presence or absence of the fungus and two nitrogen concentrations (200 mg N/L and 25 mg N/L) was used during 2 wk of establishment. During the following 10 wk, no water or nutrients were supplied. At harvest (week 18) height, shoot and root dry weights, as well as the amount of nitrogen in the shoot and nitrogen acquisition capacity, were determined. There was a strong treatment effect, and most of the traits ranked in increasing order: low N, low N + Mycorrhiza, high N, high N + Mycorrhiza. With low N, plants with mycorrhiza had a shoot dry weight twice that of nonmycorrhizal plants. Significant differences among families were found for most traits in treatments without mycorrhiza, while mycorrhiza strongly reduced the number of significant family differences. The amount of nitrogen in the shoot and all biomass traits showed a significant family × mycorrhiza × nitrogen interaction. Of the two traits related to nitrogen uptake, shoot nitrogen amount showed strong genetic correlations with biomass traits in all treatments (rg within the range 0.92 to 0.99) whereas nitrogen acquisition capacity did not (rg within the range -0.53 to +0.23), which implies that the amount of nitrogen in the shoot is a better predictor of growth than nitrogen acquisition capacity. FOR. SCI. 49(2):258–267.
Nutrient Concentrations and Contents, and their Relation to Stem Growth, of Intensively Managed Pinus taeda and Pinus elliottii Stands of Different Planting Densities
Authors: Barron-Gafford Greg A. , Will Rodney E. , Colter Burkes E. , Shiver Barry , Teskey Robert O.
Published: April 2024

Foliar, stem, and fine root nitrogen (N), phosphorus (P), and potassium (K) concentrations were measured, and their contents calculated, to determine the relationship between nutrient acquisition and stem biomass increment on a stand basis in 4-yr-old pine plantations planted at different densities. The study examined stands of loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) in the lower Coastal Plain of the southeastern United States that were intensively managed (i.e., received bedded site preparation, a high level of fertilization, and nearly complete weed control). The stands were planted at densities of 740, 2, 220, and 3,700 trees ha-1 on three sites, each with a different soil type. Increases in stem biomass growth on a stand basis were not proportional to increases in stand density, indicating that competition for resources was limiting growth at the higher densities. Foliar N and P, stem wood N and K, and fine root N concentrations decreased with increased stand density. For loblolly pine, foliar N concentrations fell from 13.1 mg g-1 at 740 trees ha-1 to 10.9 mg g-1 at 3700 trees ha-1 (average of current-year and 1-yr-old foliage), the latter considered below a critical threshold concentration for maintaining high growth rates. Slash pine foliar N concentrations followed a similar pattern, decreasing from 11.2 to 9.1 mg g-1. In both species, foliar P and K concentrations remained above critical concentrations at all planting densities. Overall, foliar N concentration was negatively correlated to stem biomass increment on a stand basis (r = -0.57) whereas foliar N content of 1-yr-old foliage was positively correlated with stem biomass increment (r = 0.59). However, biomass of 1-yr-old foliage was better correlated to total stem biomass growth (r = 0.76) suggesting that amount of foliage, rather than its nutrient content, was a better estimator of growth. FOR. SCI. 49(2):291–300.
Global Forest Cover Mapping for the United Nations Food and Agriculture Organization Forest Resources Assessment 2000 Program
Authors: Zhu Zhiliang , Waller Eric
Published: April 2024

Many countries periodically produce national reports on the status and changes of forest resources, using statistical surveys and spatial mapping of remotely sensed data. At the global level, the Food and Agriculture Organization (FAO) of the United Nations has conducted a Forest Resources Assessment (FRA) program every 10 yr since 1980, producing statistics and analysis that give a global synopsis of forest resources in the world. For the year 2000 of the FRA program (FRA2000), a global forest cover map was produced to provide spatial context to the extensive survey. The forest cover map, produced at the U.S. Geological Survey (USGS) EROS Data Center (EDC), has five classes: closed forest, open or fragmented forest, other wooded land, other land cover, and water. The first two forested classes at the global scale were delineated using combinations of temporal compositing, modified mixture analysis, geographic stratification, and other classification techniques. The remaining three FAO classes were derived primarily from the USGS global land cover characteristics database (Loveland et al. 1999). Validated on the basis of existing reference data sets, the map is estimated to be 77% accurate for the first four classes (no reference data were available for water), and 86% accurate for the forest and nonforest classification. The final map will be published as an insert to the FAO FRA2000 report. FOR. SCI. 49(3):369–380.
Hyperspectral Remote Sensing of Forest Condition: Estimating Chlorophyll Content in Tolerant Hardwoods
Authors: Sampson Paul H. , Zarco-Tejada Pablo J. , Mohammed Gina H. , Miller John R. , Noland Thomas L.
Published: April 2024

To develop practical and objective measures of forest condition, the Bioindicators of Forest Sustainability Project has used a physiological, remote sensing approach that emphasizes identifying early warning measures of stress effects in forests. While stress indicators exist at the leaf level (e.g., chlorophyll fluorescence, pigment levels), developing reliable indicators at the canopy level is a challenge. Hyperspectral sensors, such as the Compact Airborne Spectrographic Imager (CASI), may be useful in remotely detecting vegetation stress effects. In this study, an inverse modeling approach demonstrated that the CASI could be used to map chlorophyll content (root mean square errors ranging from 12.6 to 13.0 mg/cm2) following different silvicultural treatments in a tolerant hardwood (sugar maple [Acer saccharum M.]) forest. This capability could be readily applied to operationally assessing forest physiological strain and in classifying forest condition based on chlorophyll content. A change analysis study was also conducted to evaluate chlorophyll estimation across seasons for a range of sites. The implications of these findings and recommendations for a prototype system to monitor forest condition are presented. FOR. SCI. 49(3):381–391.
Poverty and Employment in Forest-Dependent Counties
Authors: Berck Peter , Costello Christopher , Fortmann Louise , Hoffmann Sandra
Published: April 2024

One of the most controversial aspects of federal and state policies aimed at protecting old-growth ecosystems is the potential effect of job losses on local economic conditions. A fundamental question for historically forest-dependent areas is whether these policies will result in local economic stagnation and enduring pockets of poverty. This study uses monthly, multicounty time series data to estimate a vector autoregressive model of the experience of northern California counties during the 1980s and 1990s. It examines the long-run impact of changes in timber-related employment on other employment and participation in major federal poverty programs. It finds that employment base-multiplier effects of timber employment on other county employment are small and state economic conditions rather than local employment conditions are the principal driver behind local poverty.
Selection for Both Growth and Wood Properties in Hybrid Poplar Clones
Authors: Zhang Shu Yin , Yu Qibin , Chauret Gilles , Koubaa Ahmed
Published: April 2024

To better understand the genetic control of growth and wood properties in hybrid poplar (Populus spp.), genetic relationships of selected wood properties with growth traits were examined in a 3-yr-old clonal trial located in Windsor and St-Ours, southern Quebec, Canada. In total, 371 trees from 21 hybrid poplar clones were sampled at the two locations. Clonal effects are stronger than growth traits effects on wood density and initial moisture content. The estimated clonal repeatability for wood density (0.92) and initial moisture content (0.80) across the two sites are thus considerably higher than for dbh (0.64) and tree height (0.72). Neither wood density nor mean fiber length were found to significantly correlate with growth traits. This suggests that in the hybrid poplar clones selection for growth traits will not result in a significant reduction in the wood quality traits. Selection for stem dry fiber weight appears to be an optimal selection strategy, as it will lead to the highest genetic gain in stem dry fiber yield, or maximum fiber production while wood density is improved.
Applying Stochastic Multicriteria Acceptability Analysis to Forest Ecosystem Management with Both Cardinal and Ordinal Criteria
Authors: Kangas Jyrki , Hokkanen Joonas , Kangas Annika S. , Lahdelma Risto , Salminen Pekka
Published: April 2024

Multicriteria decision analysis is applied to ecosystem management planning in a forest landscape. Ten alternative action plans were evaluated employing five criteria. For some criteria, cardinal measures with their associated uncertainties were obtained. For other criteria, only ordinal (ranking) information was available. The Stochastic Multicriteria Acceptability Analysis with Ordinal criteria (SMAA-O) method was used, as it accommodates both cardinal and ordinal data. This is the first application of SMAA methods to forest management. SMAA-O represents inaccurate or uncertain cardinal criteria measurements by a joint probability distribution. Ordinal data is converted into stochastic cardinal data by simulating mappings between ordinal and cardinal scales that preserve the given rankings. At the same time, the unknown or partly known preferences of the decision maker are simulated by choosing weights randomly from appropriate distributions. The main results of the analysis are “acceptability indices” that describe the variety of different weights that support an alternative for a given rank. The special characteristics of SMAA-O are best utilized in problems involving uncertainty and where both cardinal and ordinal data are to be employed. It also serves well as an analysis tool in interactive planning processes, especially when criteria weights are not known or they are difficult to assess.
Relationship Between Territorial Male Golden-Winged Warblers in Managed Aspen Stands in Northern Wisconsin, USA
Authors: Roth Amber M. , Lutz Scott
Published: April 2024

We compared territorial male Golden-winged Warbler (Vermivora chrysoptera) (GWWA) density and territory placement across four size classes [(1) seedling (<2.5 cm mean diameter at breast height (dbh)), (2) small sapling (3.0–6.0 cm dbh), (3) large sapling (7.0–11.5 cm dbh), (4) pole (12.5–17.0 cm dbh)] of aspen forests (Populus spp.) in northern Wisconsin. We surveyed four stands in each size class in May-June 2000 and observed the highest male density (0.55 males/ha) in the seedling size class. Male density for size classes 2–4 combined was 0.04 males/ha. Aspen sucker density was a good predictor of male density across size classes and thus may be a good indicator of habitat quality in aspen communities. Mean GWWA territory area was 0.82 ha (n = 12) in Size Class 1, 0.54 ha (n = 6) in Size Class 4, and 0.18 ha (n = 6) for Size Classes 2 and 3 combined. We found no relationship between male density and the amount of stand edge (km/ha), and territories did not consistently include the stand edge. Because GWWA are strongly associated with aspen seedling stem densities and this aspen stand size class is suitable to GWWAs for a relatively short period of time, we believe conservation will require managing aspen forests to ensure that habitat is always available. Clearcutting aspen forest is a practical strategy to create GWWA breeding cover in the Upper Great Lakes Region. FOR. SCI. 50(2):153–161.
Juvenile Versus Mature Wood: A New Concept, Orthogonal to Corewood Versus Outerwood, with Special Reference to Pinus radiata and P. taeda
Authors: Burdon Rowland D. , Kibblewhite R. Paul , Walker John C. F. , Megraw Robert A. , Evans Robert , Cown David J.
Published: April 2024

Wood properties vary within stems of trees according to genera, species, and individuals. Such variation is largely systematic and is very pronounced in many pines, notably Pinus radiata and P. taeda. While gradual transitions predominate, there are practical needs for categorizing wood, in cutting stems to log lengths, followed by sorting and segregation for processing. Even radial segregation of wood is often possible. In such pines, there are strong, widely recognized progressions, in various wood properties, from pith to bark. Based largely on variation in density, the first few rings from the pith are widely termed juvenile wood, which intergrades outward into wood termed mature wood. Alternative terminology used for this radial progression has been from corewood into outerwood. Critical examination shows the juvenile versus mature wood terminology to be inadequate, on two counts: (1) various other wood properties, some of which can be important, show substantial axial variation at equal ring number from the pith; (2) this categorization based solely on radial variation does not fit the well-established botanical concept of maturation. However, this axial variation closely parallels the vertical variation in shoot morphology and the onset of reproduction that reflect maturation. This argues for a two-dimensional characterization of wood properties: juvenility versus maturity for the progression up the stem, and corewood versus outerwood for the radial progression from the pith to bark. FOR. SCI. 50(4):399–415.
Tree Size Distribution Functions of Four Boreal Forest Types for Biomass Mapping
Authors: Chen Wenjun
Published: April 2024

To accurately map forest biomass, which is essential for many socioeconomic and environmental studies, reliable information of tree size distribution within a stand is needed. Using measurements at 87 stands of trembling aspen (Populous tremuloides Michx.), jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana [Mill.] BSP.), and mixed forests along a 1,000-km boreal forest transect in western Canada, we investigated three methods for estimating tree size distribution: parameter prediction method for diameter-frequency distribution (PPM-Nk/N), PPM for diameter-basal area distribution (PPM-Bk/B), and parameter recovery method for diameter-frequency distribution (PRM). For diameter-frequency distribution estimation, the PPM-Nk/N and the PRM were more accurate than PPM-Bk/B. For biomass estimation, the PPM-Bk/B and the PRM were found to have mean estimation errors <3% and root mean square errors <10%, relative to the “true” values given by summation overall trees, but the PPM-Nk/N didn't perform as well. Three distribution functions (i.e., the Weibull, the Johnson's SB, and the lognormal) were used for each method but were found to make little difference in method performance. An additional test indicated that the PPM-Bk/B and the PRM performed equally well for a balsam fir (Abies balsamea [L.] Mill) stand in eastern Canada. FOR. SCI. 50(4):436–449.
Public Values for Biodiversity Conservation Policies in the Oregon Coast Range
Authors: Garber-Yonts Brian , Kerkvliet Joe , Johnson Rebecca
Published: April 2024

This study uses a choice experiment framework to estimate Oregonians' willingness to pay (WTP) for changes in levels of biodiversity protection under different conservation programs in the Oregon Coast Range. We present biodiversity policy as an amalgam of four different conservationprograms: salmon and aquatic habitat conservation, forest age-class management, endangered species protection, and large-scale conservation reserves. The results indicate substantial support for biodiversity protection, but significant differences in WTP across programs. Oregonians indicatethe highest WTP for increasing the amount of forest devoted to achieving old-growth characteristics. On average, respondents indicate an annual household WTP of $380 to increase old-growth forests from 5% to 35% of the age-class distribution. Conversely, WTP for increasingconservation reserves peaks at $45 annually to double the current level to 20% of the landscape, whereas WTP is negative for any increase over 32%. We also find resistance to any change in conservation policy, which substantially offsets WTP for increases in all four conservationprograms. FOR. SCI. 50(5):589–602.
Modeling Nesting Habitat Selection of California Spotted Owls (Strix occidentalis occidentalis) in the Central Sierra Nevada Using Standard Forest Inventory Metrics
Authors: Bond Monica L. , Seamans Mark E. , Gutiérrez R. J.
Published: April 2024

California spotted owl (Strix occidentalis occidentalis) nest sites are associated with large trees, moderate-to-high tree densities, high canopy cover, and structural complexity. Therefore, forest managers need accurate estimates of these characteristics. Standard forest inventory metrics, such as those estimated from Forest Inventory and Analysis (FIA) data, are used by silviculturists to assess forest trends and condition, and are a source of data for assessing wildlife habitat. We estimated which FIA metrics best predicted California spotted owl nesting habitat by developing a nesting-habitat model comparing owl nest stands with randomly chosen forest stands in potential nesting habitat (stands dominated by 30–60.9- and ≥61-cm diameter trees and ≥40% cover) in the central Sierra Nevada. Number of large trees (≥76.2 cm) and canopy cover were the best predictors of owl nesting habitat. We present a nesting-habitat selection model based on our analysis. FIA metrics may be useful for quantifying California spotted owl habitat in our study area, but because forest conditions are highly variable in the Sierra Nevada, our results should be tested further in other geographic regions. FOR. SCI. 50(6):773–780.
Screening European Elms for Resistance to Ophiostoma novo-ulmi
Authors: Solla Alejandro , Bohnens Jürgen , Collin Eric , Diamandis Stephanos , Franke Albrecht , Gil Luis , Burón Margarita , Santini Alberto , Mittempergher Lorenzo , Pinon Jean , Broeck An Vanden
Published: April 2024

Resistance breeding of the native elms against Dutch elm disease, caused by the fungus Ophiostoma novo-ulmi Brasier, is a major objective in Europe for the conservation of this tree species. More than 2,500 cuttings of 324 elm clones (Ulmus minor Miller, U. glabra Huds., U. laevis Pall., U. pumila L., U. minor x U. glabra, and U. minor x U. pumila) from eight European countries, planted in several randomized two-block designed plots were inoculated with various O. novo-ulmi strains. Crown wilting and dieback were recorded during the first year after inoculation. The wilting of the control trees varied among the plots, making the results difficult to compare, but analysis of variance (ANOVA) within each plot showed significant differences in disease severity among the clones tested, allowing study of the variation of the response among elm taxa. Results showed that 19 European inoculated clones recovered from O. novo-ulmi attack, giving hope for the reestablishment of native elms in countryside hedges and forests. FOR. SCI. 51(2):134–141.
Soil Arthropod Responses to Different Patch Types in a Mixed-Conifer Forest of the Sierra Nevada
Authors: Marra James L. , Edmonds Robert L.
Published: April 2024

The Teakettle Ecosystem Experiment in the southern Sierra Nevada is using thinning and prescribed fire to recreate historical stand conditions. As part of Teakettle we assessed pretreatment diversity and density of the soil arthropod community in 1998 and 2000. We determined the density and diversity of soil microarthropods among treatment plots, the influence of patch type (closed canopy, canopy gaps, Ceanothus sp., and coarse woody debris [CWD]), and established baseline pretreatment data. Mites were the dominant microinvertebrates (78%). Canopy gaps had the lowest mite density and diversity, and were more sensitive to year-to-year changes in climate (1998 was an extremely wet year for the region). Soil organic matter as represented by bulk density appeared to be most closely associated with changes in species composition among different patch types. There was substantial overlap, however, in community composition among the different patch types as represented by nonmetric multidimensional scaling (NMS) ordination. No significant differences were observed for mite species richness and density among plots assigned to future treatments. The gap data suggest that in the characteristically hot, dry summers of the southern Sierra Nevada the rate of recovery of vegetation following thinning and fire treatments may have a significant influence on the recovery rate of microarthropods, not only by providing sources of energy inputs in the form of dead organic matter, but also by moderating the microclimate of the forest floor. FOR. SCI. 51(3):255–265.
Plant Species Diversity in a Managed Forest Landscape Composed of Larix kaempferi Plantations and Abandoned Coppice Forests in Central Japan
Authors: Nagaike Takuo , Hayashi Atsuko , Kubo Masako , Abe Midori , Arai Nobumasa
Published: April 2024

To evaluate the role of each forest type and stand in an intensively managed forest landscape in terms of vascular plant species diversity, we studied a landscape composed mainly of Larix kaempferi plantations with different stand ages and secondary broad-leaved abandoned coppice forests in central Japan, which were both codominant in the study landscape. All species diversity indices were significantly higher in plantations than in secondary forests. In the detrended correspondence analysis diagram, the younger plantations were distributed far from the older plantations, and the older plantations were located close to broad-leaved secondary forests. The relative frequency of occurrence and number of weed species were both negatively correlated with stand age for plantations, while the number of species with bird-dispersed seeds was positively correlated. Therefore, these changes along the stand-age gradient for specific ecological attributes of species created the similarity in community composition found between older plantations and secondary forests. Because the relative frequency of occurrence and number of tall-tree species and the relative frequency of species with bird-dispersed seeds were significantly higher in secondary forests than in plantations, restoring these species in plantations would likely be a long process.
Total Factor Productivity Growth in the Sawmill and Wood Preservation Industry in the United States and Canada: A Comparative Study
Authors: Zhang Daowei , Nagubadi Rao V.
Published: April 2024

By using the Törnqvist-Theil index approach, we analyze trends in total factor productivity (TFP) growth in the United States and Canadian sawmill and wood preservation industries (NAICS 3211) between 1958 and 2003. The results indicate that the TFP grew at an average annual compound rate of 1.11% due to higher growth in aggregate outputs by 1.42% and a smaller growth in aggregate inputs by 0.31% in the United States. In Canada, TFP grew at a smaller average annual compound rate of 0.61% as a result of growth in aggregate outputs and inputs by 3.57% and 2.94%, respectively. Although productivity growth for production worker input was similar in both countries, large gaps in productivity growth existed for nonproduction workers, material, capital, and energy inputs. The gap in TFP growth between the two countries appears to have widened since 1987, primarily due to the differences in capital stock growth. Volatility in lumber prices after 1991 might have also played a role, as the Canadian industry could not adequately respond to changing market situations in the face of uncertainty and trade barriers on softwood lumber exports to the United States.
Calibrating a Generalized Diameter Distribution Model with Mixed Effects
Authors: Fortin Mathieu , Ung Chhun-Huor , Archambault Louis , Bégin Jean
Published: April 2024

This article proposes a mixed model approach as an alternative to the traditional parameter prediction method in diameter distribution modeling. Unthinned and thinned plots established in mixed stands were used for calibrating a generalized diameter distribution model. The model was based on a two-parameter Weibull cumulative density function (cdf). This cdf was linearized through a complementary log–log link function. Plot random effects were included to account for autocorrelation and the dependent variable, i.e., cumulative stem frequency, was assumed to follow a binomial distribution. With respect to the parameter prediction method, this mixed model approach may generate a consistent estimator with consistent and unbiased variance for the vector of parameters when the variance-covariance matrix of the error terms is properly parameterized. Moreover, the approach enables a better assessment of the different variance components. For the whole group of plots, it provides a predicted average diameter distribution. At the plot level, the random effects can be considered as a departure from this average distribution. As long as the diameter distributions of the individual plots do not exhibit major departures from unimodality, the method proposed in this study should be used to calibrate generalized diameter distribution models.
Comparison of Fuzzy and Statistical Approaches in Multicriteria Decisionmaking
Authors: Kangas Annika , Leskinen Pekka , Kangas Jyrki
Published: April 2024

Criteria used to measure ecological or social sustainability of forestry often include qualitative ones. Fuzzy additive weighting has been proposed for using qualitative data in the form of linguistic variables. It is, however, possible to formulate a linguistic problem also using statistical distributions. We compared the fuzzy and statistical approach in a linear additive weighting problem on a woodlot owned by UPM-Kymmene. The results of fuzzy additive weighting showed high uncertainty concerning the decision compared to the statistical approach. In fuzzy analysis, the best option was unclear and the risk involved in the decision seemed high, while in statistical analysis the best option was clear and the risks involved seemed negligible. The uncertainty present in the fuzzy approach did not correspond to the 95% confidence intervals, but rather to the extreme values of statistical analysis. It can be concluded that the fuzzy approach represents ignorance in the true criterion values, while the statistical approach represents variability in them. It can also be concluded that the fuzzy approach represents decisionmaking under uncertainty, while the statistical approach represents decisionmaking under risk. If probability distributions for the uncertain data can be obtained, the statistical approach is more useful. Otherwise, the fuzzy approach should be used.
Evaluation of Fumigants, EPTC Herbicide, and Paenibacillus macerans in the Production of Loblolly Pine Seedlings
Authors: Cram Michelle M. , Enebak Scott A. , Fraedrich Stephen W. , Dwinell Lew D. , Zarnoch Stanley J.
Published: April 2024

Chloropicrin fumigation, Eptam 7-E (EPTC) herbicide, and Paenibacillus macerans seed treatments were evaluated as alternatives to fumigation with methyl bromide/chloropicrin for loblolly pine (Pinus taeda L.) seedling production at three nurseries in the southern United States. A treatment of metam sodium/chloropicrin was also evaluated at one nursery. Seedling density was unaffected by fumigation and EPTC treatments at all nurseries. Seedling diameter and shoot weight were greater in some chloropicrin treatments during the first year at the southern Georgia nursery. The only measurable disease losses were caused by a nematode, Longidorus americanus, at the southern Georgia nursery. Soil-borne population densities of Pythium and Fusarium spp. did not significantly differ between methyl bromide and the other fumigant treatments at any nursery. Chloropicrin controlled nutsedge (Cyperus spp.) in the loamy sand soils at the southern Georgia nursery, but there were no differences between the control and the fumigant treatments at the Alabama nursery, and nutsedge was rarely found at the northern Georgia nursery. The herbicide EPTC had no effect on nutsedge when compared to the controls at all nurseries and the effects of the bacterial seed treatment were inconsistent among the nurseries. Chloropicrin and metam sodium/chloropicrin can be effective alternatives to methyl bromide for reducing soil-borne fungi and nematodes, but the effectiveness of chloropicrin for nutsedge control may be affected by soil type.
Estimating Air Temperature Profiles in Forest Canopy Using Empirical Models and Landsat Data
Authors: Yang Jiansheng , Wang Yeqiao , Miller David R.
Published: April 2024

The objective of this study was to characterize and predict the air-temperature profiles in forest canopy using empirical models and Landsat-7 Enhanced Thematic Mapper Plus (ETM+) thermal infrared (TIR) data. For each hour of the day, empirical models were developed using the air temperatures measured in a mixed forest in Tolland, Connecticut during the summer of 2001. Air-temperature profiles measured on eight randomly selected days over the study period were used to evaluate the models' performance. The results show high agreement between model-predicted temperatures and field observations (R2=0.96 and RMSE=0.5°C). Forest canopy-surface temperature was estimated from Landsat ETM+ TIR data and then applied on the empirical model at 10:30 to predict air temperatures below the forest canopy. Compared with field-measured air temperatures on the same day, good agreement (R2=0.80 and RMSE=0.7°C) was obtained between predicted and observed air-temperature profile in this mixed forest. This study implies that Landsat TIR data combined with empirical models have the potential to characterize and further predict the air-temperature profile in forest canopies.
A Synthesis of the Ecology of Headwater Streams and their Riparian Zones in Temperate Forests
Authors: Richardson John S. , Danehy Robert J.
Published: April 2024

Headwater streams and their riparian areas, i.e., headwater systems, differ from larger streams in a number of fundamental ways that shape their characteristic biological communities. We focus on three distinguishing characteristics of headwater systems in temperate, forested landscapes, particularly in the North American Pacific Northwest, in contrast to larger streams. Small channel size and closed canopy create a physical template of reduced light inputs, strong local microclimate gradients, higher input rates of organic matter, and low primary production. The predominance of organic matter inputs as the primary source of biologically available energy promotes detritus-based communities. Second, headwaters are either fishless or have smaller fish populations (numerically and/or size-wise), leading to reduced effects of fish predation and fewer, if any, piscivores along headwaters. A third difference is the dominant disturbance regime associated with loss of surface flow. Other disturbances include infrequent and large mass failures, e.g., channelized debris flows, but low flows are a characteristic of headwaters and not larger streams. There have been few designed comparisons of headwater systems with larger channels. Still, evidence indicates that headwaters form distinct systems contrasted with larger channels such that management should not treat them simply as big streams writ small.