bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Harvest Strategy for Slash Pine Plantations: The Impact of Autocorrelated Prices for Multiple Products
Authors: Gong Peichen , Yin Runsheng 
Published: April 2024

Abstract
Using the management regimes of slash pine plantations in Georgia as an example, this article examines the impact of serially correlated prices for multiple outputs on harvest decision and financial performance. A stochastic dynamic programming model is formulated to derive the optimal harvest strategy numerically. While the general rule remains to harvest when the observed stumpage prices are greater than the reservation prices, our results show that there exist multiple pairs of reservation prices at each stand age, and these reservation prices cannot be reduced to a single one. This is in contrast to cases where prices are independent over time. Intensive silvicultural practices (e.g., herbicide use and fertilization) can reduce the reservation price and the variance of the financial return, but push up the mean return of a plantation project. Simulations with alternative price processes reveal that ignoring price uncertainty or price autocorrelations results in lower expected level but greater variability of the financial return and thus reduces investments by risk-averse investors. FOR. SCI. 50(1):10–19.
Efficiency of Seedlings and Rooted Cuttings for Testing and Selection in Pinus taeda
Authors: Isik Fikret , Li Bailian , Frampton John , Goldfarb Barry 
Published: April 2024

Abstract
Predicted genetic gains of polymix, cloned polymix, full-sib and cloned full-sib testing and selection options for a breeding population were estimated for Pinus taeda L. Heritabilities for volume from the clonal testing were considerably greater than the heritabilities from the seedling testing. Cloned options had higher expected genetic gains than seedling options, even after adjusting for their longer breeding cycles and higher cost of testing. This was mainly due to higher genetic gains from within-family selection of the cloned testing options. Adjusted genetic gain from within-family selection of polymix and cloned polymix were 0.27 and 0.36% per year, respectively. Increasing the number of ramets per clone did not increase the genetic gain, but gain was sensitive to the clone selection ratio within families. When the number of trees tested per family was fixed at 90 trees, all clone/ramet combinations gave greater within-family gains than the seedling option. A complementary breeding strategy consisting of polymix breeding for estimation of general combining ability and clonal selection from clonally replicated full-sib families appears to be more efficient for loblolly pine improvement than the currently used seedling-based testing system. For. Sci. 50(1):44–53.
An Assessment of Canopy Stratification and Tree Species Diversity Following Clearcutting in Central Appalachian Hardwoods
Authors: Brashears Mark Benjamin , Fajvan Mary Ann , Schuler Thomas M. 
Published: April 2024

Abstract
On high quality growing sites in West Virginia, shade intolerant tree species have increased in importance in third-generation forests following clearcutting. We investigated the effect of tree species canopy position on the Shannon-Weiner Diversity Index (H′), Pielou's evenness index (E), and species richness (S) using a chronosequence of 13 clearcuts. Two to 26 yr after clearcutting, tree species diversity significantly decreased from 2.07 to 1.83, and evenness decreased from 0.80 to 0.71 while species richness was maintained. As the number of years since harvesting increased, the importance value of oaks (Quercus L.), hickories (Carya Nutt.), American beech (Fagus grandifolia Ehrh.), sugar maple (Acer saccharum Marsh.), and black birch (Betula lenta L.) decreased while the importance of yellow-poplar (Liriodendron tulipifera L.) increased. In these mixed-species stands with stratified canopies, species importance in overstory versus understory canopy layers was the best indicator of competitive success during stem exclusion. Second-generation forests that had almost equal representation of overstory sugar maple and yellow-poplar prior to harvesting had 43% yellow-poplar and 13% sugar maple overstory importance 22–26 yr after harvest. Forty-five percent of the dominant crown class stems and 54% of the codominant class were yellow-poplar. While sugar maple was also an important (13%) overstory species overall, it had no dominant and few codominant stems and over 30% importance as overtopped trees and in the understory. As these stands progress through the stem exclusion stage, richness and measures of diversity may continue declining as yellow-poplar basal area increases. FOR. SCI. 50(1):54–64.
Tree Size and Drought Affect Ponderosa Pine Physiological Response to Thinning and Burning Treatments
Authors: Skov Kjerstin R. , Kolb Thomas E. , Wallin Kimberly F. 
Published: April 2024

Abstract
Thinning and burning treatments based on presettlement (prior to Euro-American settlement) stand conditions have been proposed for improving the vigor and growth of Pinus ponderosa. No study has examined effects of different levels of such thinning treatments on tree water, carbon, and nitrogen relations, or compared effects between postsettlement (trees established after Euro-American settlement) and presettlement (established before Euro-American settlement) trees. We investigated responses of presettlement and postsettlement trees to three levels of thinning and burning (unthinned/unburned control, light thinning/burning, heavy thinning/burning) over 2 yr that differed in precipitation in northern Arizona. Both thinning treatments consistently increased predawn water potential of both tree sizes compared with the control. Effects of thinning on leaf gas exchange varied between tree sizes and measurement times. Thinning increased net photosynthetic rate and stomatal conductance only when soil water availability was lowest, and increases were greater for postsettlement than presettlement trees. In contrast, thinning had no effect on foliar nitrogen concentration.Our results suggest greater positive effects of restoration thinning on tree water and carbon relations for postsettlement versus presettlement trees, and under drought versus nondrought conditions. Photosynthetic response to thinning in old trees may be constrained by physiological factors associated with large size such as low soil-to-leaf hydraulic conductance. FOR. SCI. 50(1):81–91.
Stand Productivity and Development in Two Mixed-Species Spacing Trials in the Central Oregon Cascades
Authors: Garber Sean M. , Maguire Douglas A. 
Published: April 2024

Abstract
Two mixed-species spacing trials were established in central Oregon to test the effects of species composition and initial spacing on stand growth, yield, and structural development. One trial was composed of Pinus contorta Dougl. ex Loud. and Pinus ponderosa Dougl. ex Laws. and the other Abies grandis (Dougl. ex D. Don) Lindl. and P. ponderosa. Spacing, species composition, and age all had large influences on standing volume and periodic annual growth. In both studies, standing volume and periodic annual increment decreased with increasing spacing. In mixed plots, the least shade tolerant species had the fastest early growth rates, while the more shade tolerant species had the slowest. Over time, initial differences in volume growth rates among plots of different species composition decreased. Relative yields in mixtures of P. contorta and P. ponderosa indicated no yield benefits. Mixtures of A. grandis and P. ponderosa, however, resulted in relative yield totals greater than one at all spacings. Spacing and species composition play an important role in stand production and development, and mixtures can yield similar if not more volume than pure stands of the higher yielding species at some spacings and stages of stand development. FOR. SCI. 50(1):92–105.
Exploring the Relationships Among Canopy Structure, Stand Productivity, and Biodiversity of Temperate Forest Ecosystems
Authors: Ishii Hiroaki T. , Tanabe Shin-ichi , Hiura Tsutom 
Published: April 2024

Abstract
Impacts of human activity on forest ecosystems are most pronounced in the temperate region. Simplification of stand structure has resulted in diminished ecosystem function and biodiversity decline, raising much debate over future management policies. Ecosystem functions and biodiversity may be enhanced by managing forests for increased structural complexity. However, processes that determine relationships among structural complexity, ecosystem functions, and biodiversity of forest ecosystems remain unclear. In this review, we present examples of studies conducted at two canopy research facilities located in different types of temperate forest to illustrate that structural complexity of forest canopies enhances stand productivity and biodiversity: (1) development of structurally complex canopies comprising various tree species enhances stand productivity by promoting complementary resource utilization among species through spatial, physiological, and temporal differentiation; and (2) development of complex canopy structure enhances biodiversity of canopy-dwelling organisms by creating a resource-rich habitat. These ecological observations stress the importance of including three-dimensional structural attributes of forest canopies in management plans and silvicultural prescriptions that aim to maintain ecosystem functions and biodiversity. FOR. SCI. 50(3):342–355.
Crown Cover Is Correlated with Relative Density, Tree Slenderness, and Tree Height in Lodgepole Pine
Authors: Rudnicki Mark , Silins Uldis , Lieffers Victor J. 
Published: April 2024

Abstract
The objective of this study was to investigate the relationship between tree height, bole slenderness, and relative density with crown shyness (crown interstitial space) in even-aged lodgepole pine. In 10 lodgepole pine stands in Alberta, Canada, ranging in height from 5.6 to 22.1 m, 9–23 triangular plots were established. A plot consisted of three trees that formed the corners of the triangle; all plots were at theoretical crown closure. Within each triangle, the percentage crown closure (% CC) was related to the mean height, slenderness coefficient (SC, tree height/diameter), and relative density (RD) of the trees that defined the triangle. Within the stands less than 12 m in height, % CC was positively correlated with RD. Within most of the stands greater than 15 m, % CC was negatively correlated to SC. Mean % CC declined with increasing stand height. Results suggest that RD is strongly related to % CC in short stands but as trees grow in height, biomechanical issues related to stem form (i.e., SC) probably play a large role in determining the amount of canopy coverage. We suggest that taller trees with high SC are more flexible, resulting in intense crown collisions, crown abrasion, and crown shyness. FOR. SCI. 50(3):356–363.
Forest and Rangeland Ecosystem Condition Indicators: Identifying National Areas of Opportunity Using Data Envelopment Analysis
Authors: Hof John , Flather Curtis , Baltic Tony , King Rudy 
Published: April 2024

Abstract
This article reports the methodology and results of a data envelopment analysis (DEA) that attempts to identify areas in the country where there is maximum potential for improving the forest and rangeland condition, based on 12 indicator variables. This analysis differs from previous DEA studies in that the primary variables are measures of human activity and indicators of forest and rangeland condition in place of the traditional economic inputs (costs) and outputs. It also involves a different (ecological) production process than traditional DEA analyses, and a statistical preanalysis is developed and applied to homogenize the large and highly diverse landscape where this ecological production process takes place for the purposes of the DEA. It is concluded that, based on this analysis, there are opportunities to improve the forest and rangeland condition without reducing the amount of human activity, but not over large areas, only for some indicators, and typically not for a large number of indicators in the same place. This means that large-scale improvements in environmental condition across many indicators may often not come about without a reduction in human activity. FOR. SCI. 50(4):473–494.
Long-Term Soil Responses to Site Preparation Burning in the Southern Appalachians
Authors: Knoepp Jennifer D. , Vose James M. , Swank Wayne T. 
Published: April 2024

Abstract
The mixed oak–pine ecosystems in the southern Appalachians are in decline because of a combination of drought and southern pine-beetle infestation. A commonly applied prescription for restoration of these degraded sites has been to fell all vegetation, allow it to dry, and conduct a site-preparation burn. However, there is little information on the mid- and long-term influences of this prescription on nutrient cycling. The fell-and-burn treatment was applied to three mixed oak–pine stands in the Nantahala National Forest in western North Carolina. Each stand had an untreated control area. Our objective was to determine the effects of this treatment on soil nutrient availability and potential nutrient loss. Exchangeable soil cations, pH, total carbon (C), and total nitrogen (N) were measured before and periodically for 5 years after treatment. Nitrogen transformations and nutrient availability in soil solution and in a stream draining one site were measured before and periodically for 3 years after burning. Exchangeable calcium and magnesium concentrations, soil pH, and N availability increased after treatment. There was no treatment effect on total soil C or N. Nitrogen mineralization rates were greater on burned versus control plots in 50% of the posttreatment measurements. This treatment increased nutrient availability and, although a significant amount of total site N was lost, there were no adverse effects on total soil nutrients or water quality. FOR. SCI. 50(4):540–550.
Simulating the Effect of Landscape Size and Age Structure on Cavity Tree Density Using a Resampling Technique
Authors: Fan Zhaofei , Lee Stephen S. , Shifley Stephen R. , Thompson III Frank R. , Larsen David R. 
Published: April 2024

Abstract
Cavity-tree density (CTD) is an important indicator of habitat quality for cavity-dependent wildlife. However, the abundance of cavities and cavity trees can vary dramatically, even among trees or stands with similar attributes. This uncertainty can make it difficult to expand stand-levelestimates of cavity abundance to large landscapes, although it is often desirable to do so. This limits the utility of CTD as a measure of habitat quality. We use a resampling method (statistical bootstrap) to construct a set of regression models to predict CTD based on landscape age structureand landscape size. The estimated regression coefficients are highly variable (in terms of the adjusted R2 and root mean square error) for landscapes &lt;100 ha, but the models perform well for larger landscapes. We test the regression models using an independent data set from theMissouri Ozark Forest Ecosystem Project (MOFEP) and find that the mean relative error (RE) when predicting CTD for landscapes between 300 and 4,000 ha is less than 10%. Both the size (in hectares) of the landscape and the stand age-class components affect RE; but RE decreases with increasinglandscape size in a consistent and quantifiable manner. For Ozark landscapes ≥100 ha, knowledge of the proportion of the area in the seedling/sapling, pole, sawtimber, and old-growth age classes can be used to readily estimate the number of cavity trees and how that number will change ifthe landscape age structure is altered. FOR. SCI. 50(5):603–609.
Sustainability of Timber Supply Considering the Risk of Wildfire
Authors: Armstrong Glen W. 
Published: April 2024

Abstract
The boreal mixedwood forest of Alberta, Canada is an important timber-producing region subject to highly variable annual disturbance by wildfire. Existing timber supply models do not adequately capture the variation in annual area burned. This article presents a procedure to evaluatethe joint effects of harvest levels and wildfire on the sustainability of timber harvest. A Monte Carlo simulation model is developed that incorporates timber harvesting, forest fires, and replanning. The output of the model consists of projected distributions of sustainable harvest levelsgenerated by a linear programming-based timber supply model in response to specified harvest volumes and randomly generated burn areas. Because of the highly variable nature of the fire regime, it is difficult or impossible to set a harvest level that is perpetually sustainable with completecertainty. An alternative definition of sustainability is developed incorporating probabilities and time. At any point in time, a harvest level is considered sustainable if the probability of the harvest level exceeding the annual allowable cut is less than an acceptable level. FOR. SCI. 50(5):626–639.
Book Reviews: Forests in a Market Economy
Authors: Zhang Daowei 
Published: April 2024

Abstract
Those of us who teach senior undergraduate and graduate level forest economics courses have often been frustrated with the fact that there is no good textbook for these courses. The publication of this book may ease some of the frustration. Moreover, as the book title implies, it can serve as a background and research guide for forest economists in studying the role of forests in a market economy.
The Two-Stage Method for Measurement Error Characterization
Authors: Canavan Sean J. , Hann David W. 
Published: April 2024

Abstract
A measurement error (ME) is a component of any study involving the use of actual measurements, but is often not recognized or is ignored. The consequences of ME on models can be severe, affecting estimates of tree and stand attributes and model parameters. Although correction methods do exist for countering the effects of ME, the use of these methods requires knowledge of the distribution of the errors. A new method for modeling error distributions, called the two-stage error distribution (TSED) method, is presented here. This method is compared with traditional methods for error modeling through an example using diameter and height ME. Comparisons between the fitted error distribution surfaces and the empirical error surface are based on a dissimilarity measure. The results indicate that the TSED method produces a much more accurate and precise characterization of the ME distribution than do traditional methods when a high percentage of errors is identical. In other cases, the TSED method works as well as the most accurate form of the traditional method. The TSED method is also expected to perform better at characterizing asymmetric distributions. It is therefore more adaptable than traditional methods and is being proposed for error modeling in the future. FOR. SCI. 50(6):743–756.
Coarse Woody Debris in Managed Central Hardwood Forests of Indiana, USA
Authors: Jenkins Michael A. , Webster Christopher R. , Parker George R. , Spetich Martin A. 
Published: April 2024

Abstract
We evaluated the volume of down deadwood (DDW) and the basal area of standing deadwood (SDW) from a chronosequence of 110 silvicultural openings and 34 mature stands (72–105 years old) across three Ecological Landtype Phases (ELTP; wet-mesic bottomlands, mesic slopes, and dry-mesic slopes) in southern Indiana, USA. The volume of DDW decreased with increasing opening age and was lower in clearcuts than in group-selection openings. Openings on mesic slopes and bottoms contained greater volumes of DDW than openings on dry-mesic slopes. Regardless of age and ELTP, openings contained low volumes of highly decayed DDW. The volume of small-diameter DDW decreased rapidly with increasing stand age across all three ELTPs. Mature stands contained low total volumes of DDW (maximum of 22.4 ± 5.1 m3 ha−1) and low volumes of both highly decayed and large-diameter DDW. Most of the dead trees in silvicultural openings were small diameter and did not contribute significantly to DDW volume. SDW basal area was very low in mature stands (maximum of 1.4 ± 0.5 m2 ha−1), suggesting that little mortality has occurred. Our results suggest that even and uneven-aged silviculture in hardwood forests have differing impacts on the volume and distribution of coarse woody debris (CWD). In addition, the mature stands that dominate forests across much of the Central Hardwood Region of the eastern United States contain relatively little CWD compared to younger and old-growth stands. FOR. SCI. 50(6):781–792.
Photosynthetic and Water Use Efficiency Responses to Diffuse Radiation by an Aspen-Dominated Northern Hardwood Forest
Authors: Rocha Adrian V. , Su Hong-Bing , Vogel Christoph S. , Schmid Hans Peter , Curtis Peter S. 
Published: April 2024

Abstract
Clouds can exert strong effects on ecosystem CO2 and water vapor fluxes and may be important determinants of terrestrial primary production. We used three years of eddy-covariance and meteorological data from an aspen-dominated northern hardwood forest in Michigan to investigate how canopy photosynthesis (P), evapotranspiration (E), and water use efficiency (WUE) responded to changes in cloud cover, or the proportion of diffuse (If) to total (It) photosynthetically active radiation (PAR). Canopy quantum efficiency (the initial slope of the P versus PAR response curve) increased with increasing cloud cover, but both midday canopy P and canopy photosynthetic potential (the asymptote of the P versus PAR response curve) were greatest under partly cloudy skies (If/It = ∼0.57). Midday canopy E decreased and midday canopy WUE increased with increasing If/It. The relationship between canopy P and cloud cover varied with soil moisture. Canopy P was insensitive to changes in soil moisture under overcast skies (If/It &gt; 0.70), whereas under clearer skies, canopy P was lower during periods of low compared to high soil moisture. These results further our understanding of cloud cover effects on canopy physiological processes and will aid in more accurate assessments of forest responses to climatic change. FOR. SCI. 50(6):793–801.
Optimum Juvenile Density, Harvesting, and Stand Structure in Even-Aged Scots Pine Stands
Authors: Hyytiäinen Kari , Tahvonen Olli , Valsta Lauri 
Published: April 2024

Abstract
The economics of timber production is studied using empirical data for various juvenile densities and a distance-independent individual-tree growth model specified for Finnish Scots pine (Pinus sylvestris [L.]) stands. Our results imply that explicit inclusion of quality effects on prices increases optimum juvenile density. In addition, quality effects make economic surplus of forestry more sensitive to variations in juvenile density. Optimum thinnings remove trees that have no prospects for high relative value growth. Optimum thinnings are selective thinnings that remove inferior-quality trees, some of the smallest trees and, contrary to conventions, those of the largest trees that fulfill the sawlog dimensions. Thinnings removing trees strictly above and/or below certain tree diameters homogenize the remaining growing stock by narrowing the diameter distribution. Homogeneous stand structure is economically favorable at final clearcutting because the stand can be clearcut promptly after the majority of trees have reached sawlog dimensions and have experienced the last high peak in value growth. FOR. SCI. 51(2):120–133.