bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
We compared territorial male Golden-winged Warbler (Vermivora chrysoptera) (GWWA) density and territory placement across four size classes [(1) seedling (&lt;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.