bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Annual Inventory Designs Using Forest Inventory and Analysis Data
Authors: Arner Stanford L. , Westfall James A. , Scott Charles T. 
Published: April 2024

Abstract
Three annual inventory designs, a periodic design, and a periodic measurement with midcycle update design are compared using a population created from 14,754 remeasured Forest Inventory and Analysis plots. Two of the annual designs and the midcycle update design allow updating of plots not measured using sampling with partial replacement procedures. Comparisons are based on root mean square error and estimator bias determined for net volume (m3/hectare) and mean annual net volume change. For the annual designs, both individual year and moving average estimates are investigated. The latter are compared to both the population means of the most recent year used in the average and to population means covering the same period as the estimate. Among annual designs, a rotating panel design, in which an equal portion of the total sample is measured each year without remeasurement until the start of the next measurement cycle, produced the smallest root mean square error for estimates of mean net volume. For multiple-year comparisons, the rotating panel and periodic designs resulted in the smallest root mean square errors; for single-year comparisons, the periodic design resulted in the smallest root mean square error. For mean annual volume change, the smallest root mean square error was produced by the periodic design. Among annual designs, the rotating panel design resulted in the smallest root mean square error for multiple-year comparisons of volume change, while a design allowing annual updates of estimates using generalized least squares resulted in the smallest root mean square error for single-year comparisons. FOR. SCI. 50(2):188–203.
Improving Taper Equations of Loblolly Pine with Crown Dimensions in a Mixed-Effects Modeling Framework
Authors: Leites Laura P. , Robinson Andrew P. 
Published: April 2024

Abstract
A mixed-effects modeling framework was applied to Max and Burkhart's (1976) (MB) taper equation for loblolly pine (Pinus taeda L.). The advantages of such a strategy over ordinary least squares were: (1) more accurate specification of the correlation structure of the data and (2) the ability to assess the potentially explainable variation at the tree level. Significant relationships were established between tree-level crown dimensions and parameter estimates. The study data comprised 197 plantation-grown loblolly pine trees of 10 different ages in Uruguay. Four versions of MB were evaluated: (1) the original equation, (2) the original equation fitted with mixed effects, and two adapted versions: (3) the first included crown variables and fixed effects, (4) the second included crown variables and mixed effects. The crown variables were tree-level crown length and crown length ratio. The best of the four competing equations included both of the crown variables as well as tree-level random effects, suggesting that some linear tree-level variability may yet be explained by variables not considered in this study. Testing on an independent validation data set did not show over-fitting problems. For prediction purposes, the equations with added crown variables were more precise but not less biased. FOR. SCI. 50(2):204–212.
Importance of Foliar Nitrogen Concentration to Predict Forest Productivity in the Mid-Atlantic Region
Authors: Pan Yude , Hom John , Jenkins Jennifer , Birdsey Richard 
Published: April 2024

Abstract
To assess what difference it might make to include spatially defined estimates of foliar nitrogen in the regional application of a forest ecosystem model (PnET-II), we composed model predictions of wood production from extensive ground-based forest inventory analysis data across the Mid-Atlantic region. Spatial variation in foliar N concentration was assigned based on a correlation with mean July temperature for deciduous forests and with latitude for coniferous forests. Although the slight variation observed in foliar N in conifers had little effect on predicted wood production, large differences in N concentration in deciduous trees increased agreement with field surveys by 12–59% in individual states and by 17% across the region. The validation revealed the need to develop regional foliar N concentration equations that represent the spatial variations of N concentration in deciduous forests to improve PnET-II's predictions. FOR. SCI. 50(3):279–289.
Old-Growth Forest Canopy Structure and Its Relationship to Throughfall Interception
Authors: Nadkarni Nalini M. , Sumera Mark M. 
Published: April 2024

Abstract
Structural elements of the forest canopy such as foliage, branches, and epiphytes intercept, retain, and regulate inputs of matter and energy to the forest floor in spatially variable ways. Most studies of forest structure-function have analyzed relationships between canopy structure and the spatial distribution of inputs at the forest stand level. Few studies have focused on within-canopy spatial scales or identified the functional roles of particular structural components. Our objective was to quantitatively assess the amount of canopy structural material to a critical functional attribute: canopy interception of rainfall. We investigated forest canopy structure with a novel technique, “vertical canopy cylinder transects,” that uses access from a construction crane in an old-growth coniferous forest in Washington State. We characterized the diversity and composition of forest structural elements (tree foliage and branches by species, epiphytes by functional group) and found the majority of the foliage and epiphytes concentrated in the upper- to mid-canopy, with some vertical stratification of the epiphyte functional groups. We also quantified one aspect of forest function, the volume and variability of throughfall interception. We documented a strong relationship between the amount of structural elements and rainfall interception (R2 = 0.79). This approach of quantifying three-dimensional canopy structure at particular locations had higher predictive ability for throughfall volume than previous approaches that were not able to gain direct access to canopy components. FOR. SCI. 50(3):290–298.
Development of Canopy Structure in Pseudotsuga menziesii Forests in the Southern Washington Cascades
Authors: Van Pelt Robert , Nadkarni Nalini M. 
Published: April 2024

Abstract
We quantified stand-level structural diversity in eight stands of temperate coniferous forests that ranged in age from 50 to 950 years in the southern Washington Cascade Range. Stands were chosen based on the dominance, or former dominance in the case of the oldest stands, of Pseudotsuga menziesii. In addition, to avoid confusing patterns of structural development, only stands that had a single disturbance of origin were used. Within each stand, randomly located transects were laid out that were proportional in size to the dominant tree height. Tree heights and diameters ranged up to 90 m and 309 cm, respectively. A total of 5,737 trees among the 32 transects were mapped and measured for height, diameter, crown height, and four crown radii. The structure of the canopy in the younger stands is a simple, fairly even monolayer. This contrasts with the older stands, which have a very complex, highly diffuse canopy with extreme variability in both horizontal and vertical dimensions. The stands with the highest structural complexity were between 500 and 650 years old and retained from 17 to 76 Pseudotsuga stems/ha. Our oldest site had only one living Pseudotsuga/ha. Mean diameter of just the Pseudotsuga trees was less than 55 cm for stands less than 200 years and over 180 cm for the most complex old-growth stands. One measure of stand structural diversity, the standard deviation of dbh, ranged from less than 25 (stands less than 200 years) to values greater than 50 (most complex old-growth sites). A similar relationship exists when using the standard deviation of height. Large snags and logs important for wildlife were present only in the old-growth stands and were abundant in the most structurally diverse stands. FOR. SCI. 50(3):326–341.
Structural Phenology of the Leaf Community in the Canopy of a Liriodendron tulipifera L. Forest in Maryland, USA
Authors: Parker Geoffrey G. , Tibbs Donna J. 
Published: April 2024

Abstract
We measured the vertical dynamics of leaf area in a tall, tulip poplar (Liriodendron tulipifera)-dominated, deciduous forest on the Maryland coastal plain over three growing seasons (one intensively) using nondestructive, ground-based observations. Leaf area index (LAI) and leaf area density (LAD) were calculated by vertical level, time, and species; the time-integrated duration of leaf display (leaf area extent, LAE) was estimated by species and vertical level. In this stand LAI rises rapidly in the spring, declines slightly during the growing season, and then rapidly in the fall. In the intensively studied year, total LAI peaked at 7.1 m2m-2 LAE was 1259 m2m-2day, and the length of the canopy season (time from half-maximum LAI at leaf-out to the half-maximum at decline) was 191 days. The maximum growing season LAI, the date of leaf emergence, and the LAE differed among years, ranging 0.61 m2m-2, 14 days, and 261 m2m-2day, respectively. However, the timing of leaf fall was more consistent, ranging only 6 days. Each species differs in its height distribution, density, and timing of foliar display. In the canopy, leaf number, area, and duration are the bases of species importance; these differ substantially by species from typical importance values derived from stem-based attributes (density, basal area, biomass). FOR. SCI. 50(3):387-397.
A Walkthrough Solution to the Boundary Overlap Problem
Authors: Ducey Mark J. , Gove Jeffrey H. , Valentine Harry T. 
Published: April 2024

Abstract
Existing methods for eliminating bias due to boundary overlap suffer some disadvantages in practical use, including the need to work outside the tract, restrictions on the kinds of boundaries to which they are applicable, and the possibility of significantly increased variance as a price for unbiasedness. We propose a new walkthrough method for reducing boundary overlap bias that diminishes or eliminates the need to work outside the tract and accommodates irregular boundaries easily. Under typical conditions, the walkthrough method eliminates the boundary overlap bias associated with most objects near the border and reduces it for the remaining objects. The walkthrough method is object-centered in conception and implementation, but the measurements required are simple. The walkthrough method complements existing methods for correcting boundary overlap bias and should prove especially helpful when conditions make existing methods difficult or impossible to use. FOR. SCI. 50(4):427–435.
Forest Parameters Estimation in a European Mediterranean Landscape Using Remotely Sensed Data
Authors: Mallinis George , Koutsias Nikos , Makras Apostolos , Karteris Michael 
Published: April 2024

Abstract
Satellite remote sensing provides new possibilities and challenges to forest managers for monitoring and managing forest ecosystems. The value/use of high-resolution satellite data of Landsat Thematic Mapper (TM) to estimate tree density, basal area, basal volume, and forest biomass was investigated under an operational perspective in a spatially heterogeneous Mediterranean landscape in northern Greece. Digital classification using Fisher's linear discriminant functions produced an overall accuracy of 82%. A series of multispectral transformations were also performed, and the derivative synthetic channels were used along with the original ones as explanatory variables in the model developed. The forest stand parameters that were investigated in the study presented a similar but weak correlation with the Landsat-5 TM spectral channels. Among them, TM4 and TM7 presented the highest correlation with forest stand parameters, while the integration of the derivative synthetic channels increased the correlation coefficients and resulted in statistically significant predictive models. FOR. SCI. 50(4):450–460.
Area-Independent Sampling for Total Basal Area
Authors: Flewelling James W. , Iles Kim 
Published: April 2024

Abstract
An unbiased direct estimator of total basal area for a stand is presented; stand area need not be known. Sampling can use horizontal point samples or fixed-area plots distributed on a regular grid or randomly selected. The sample space extends beyond the stand boundary. The estimator for basal area makes no distinction between plots whose centers are interior to the stand boundary and plots whose centers are outside. Only trees within the stand boundary are tallied. For horizontal point sampling, the estimator is the product of the sample tree count, the basal area factor, and the area per grid point, with the latter being derived from grid spacing. This method avoids the complexities associated with most other estimators designed to minimize or eliminate edge bias. The proposed method may require more sample points to achieve the same level of precision as competing estimators. FOR. SCI. 50(4):512–517.
Fusion of Small-Footprint Lidar and Multispectral Data to Estimate Plot- Level Volume and Biomass in Deciduous and Pine Forests in Virginia, USA
Authors: Popescu Sorin C. , Wynne Randolph H. , Scrivani John A. 
Published: April 2024

Abstract
The principal study objective was to explore the feasibility of using small-footprint lidar data and multispectral imagery to estimate forest volume and biomass on small (0.017-ha) plots. In addition, the spatial dependency of residuals between ground-measured and lidar-estimated variables was investigated. The lidar data set was acquired over deciduous and pine stands in the southeastern United States. Individual trees were identified on the lidar-derived canopy height model by local maximum focal filtering with both square and circular windows of variable size. The size of the dynamically varying window was based on the height of the canopy and the taxonomic group as derived from coregistered multispectral optical data. Lidar-measured parameters at an individual tree level (height, crown diameter) were used with regression models and cross validation to estimate plot-level field inventory data, including volume, biomass, basal area, and diameter at breast height (dbh). Maximum R2 values for estimating biomass were 0.32 for deciduous trees (RMSE 44 Mg/ha) and 0.82 for pines (RMSE 29 Mg/ha). When estimating volume, maximum R2 values for deciduous trees were 0.39 (RMSE 52.84 m3/ha) and 0.83 for pines (RMSE 47.9 m3/ha). Calculation of Moran's I coefficient for each regression model revealed a lack of significant autocorellation of the residuals at 0.05 level. Both model fit and prediction for volume and biomass models for deciduous and pine plots indicated that the circular window shape is more appropriate to locate individual trees with lidar. Using the fused data set, lidar and optical imagery, as opposed to using lidar data alone, always improved biomass and volume estimates for pines and in some cases for deciduous plots as well. FOR. SCI. 50(4):551–565.
Modeling the Likelihood of Crown Fire Occurrence in Conifer Forest Stands
Authors: Cruz Miguel G. , Alexander Martin E. , Wakimoto Ronald H. 
Published: April 2024

Abstract
The unknowns in wildland fire phenomenology lead to a simplified empirical model approach for predicting the onset of crown fires in live coniferous forests on level terrain. Model parameterization is based on a data set (n = 71) generated from conducting outdoor experimentalfires covering a significant portion of the spectrum of burning conditions associated with the initiation of crown fires. A logistic model is developed to predict the likelihood of crown fire occurrence based on three fire environment variables, namely the 10-m open wind speed, fuel stratagap (equivalent to live crown base height in some stands), estimated moisture content of fine dead fuels, and one fire-behavior descriptor–surface fuel consumption. The model correctly predicts 85% of the cases in the data set used in its development, and the receiver operatingcharacteristic statistic is 0.94. The model is evaluated for its sensitivity to its inputs, and its behavior is compared with other models used in decision support systems to operationally predict crown fire initiation. The results of a limited test of the model against two independent experimentalfire data sets for distinctly different fuel complexes is encouraging. FOR. SCI. 50(5):640–658.
Aesthetic Impacts of Disturbances on Selected Boreal Forested Shorelines
Authors: Hunt Len M. , Haider Wolfgang 
Published: April 2024

Abstract
This article investigates the aesthetic impacts of anthropogenic and fire disturbances on forested shorelines for most coniferous forest types of the boreal forest. The novel use of the psychophysical landscape-perception approach to near-vista-view shoreline settings makes this application unique. Evaluations of aesthetic quality by laypeople show that severe fire and clearcut-logging disturbances make the forested shorelines much less attractive when compared to undisturbed sites. The analysis also provides a detailed examination of the relationships between undisturbed and logged sites by investigating the relationship between reserve width (i.e., the amount of land that separates the shoreline from logging activities) and aesthetic quality. A regression model of aesthetic evaluations demonstrates that aesthetics is positively related to undisturbed sites, to reserve width, and to the slope of the land. An interaction term of the reserve width and slope of the land is negative, which suggests that the reserve width necessary to mitigate the effects of logging on flat lands is smaller than the reserve width needed to mitigate logging on steeper lands. The model can also be used for predictive purposes such as estimating a reserve width that may be necessary to mitigate all visual effects of logging on shoreline sites. FOR. SCI. 50(5):729–738.
Book Reviews: Conserving Forest Biodiversity: A Comprehensive Multiscaled Approach
Authors: Groninger John W. 
Published: April 2024

Abstract
Landscape-level management, driven by conservation objectives, will undoubtedly continue to play a role in natural resource decisionmaking for the foreseeable future. A fundamental justification for landscape management is that reliance on designated protected areas and reserves alone is inadequate for the maintenance of forest biological diversity. According to the authors, management practices on unreserved, commodity-producing lands (referred to throughout this book as “the matrix”) will determine the success or failure of efforts to maintain forest biological conservation and forest health. This book makes the case for management at several scales to achieve these objectives within large, contiguous forest systems.
Sap Beetle Species (Coleoptera: Nitidulidae) Visiting Fresh Wounds on Healthy Oaks During Spring in Minnesota
Authors: Juzwik Jennifer , Skalbeck Thomas C. , Neuman Marc F. 
Published: April 2024

Abstract
Many species of sap beetles have been implicated as vectors of the oak wilt pathogen, (Ceratocystis fagacearum), but the species responsible for most aboveground transmission of the fungus is unknown. The abundance of adult sap beetle species inhabiting &lt;7-day-old, artificially made wounds on healthy oaks during Apr.–June of 2 years in Minnesota, and the frequencies with which viable propagules of the fungi were present on each, were determined. Sap beetles were most abundant on wounds created in May, and 1–3-day-old wounds yielded higher numbers of insects than 4–6-day-old wounds. Of the beetles collected, &gt;95% were Colopterus truncatus and Carpophilus sayi. C. fagacearum was isolated from 75% of 594 adults assayed for the fungus. The average number of viable propagules for pooled data of individuals of each species ranged from &lt;100 to 18,000. Frequencies of fungus isolation differed by days after wounding, study location, and sap beetle species. These results, when coupled with previous findings on predominant species associated with oak wilt fungi mats, support the hypothesis that Co. truncatus and Ca. sayi are the principal sap beetle species transmitting C. fagacearum from diseased to healthy oaks in Minnesota. FOR. SCI. 50(6):757–764.
Associations between Forest Fire and Mexican Spotted Owls
Authors: Jenness Jeffrey S. , Beier Paul , Ganey Joseph L. 
Published: April 2024

Abstract
In 1993, the US Fish and Wildlife Service listed the Mexican spotted owl (Strix occidentalis lucida) as threatened, in part because of the rising threat to its habitat from stand-replacing wildfires. In 1997, we surveyed 33 owl sites that, in the previous four years, had burned at various levels ranging from light controlled burns to stand-replacing fires. We compared owl occupancy and reproduction in these burned sites to 31 unburned owl sites with similar habitat and topography. Although unburned sites showed higher proportions of both occupancy and reproduction, the negative relationship observed between recent fire occurrence and owl occupancy rank was statistically weak (Test for Marginal Homogeneity, P = 0.110). Owls tended not to be present where pure pine stands (Pinus spp.) comprised a large proportion (38–85%) of burned sites, but no other factors relating to habitat or fire severity had a significant, biologically interpretable influence on occupancy rank. We suspect that relatively low-intensity ground fires, including most prescribed fires, probably have little or no short-term impact on Mexican spotted owl presence or reproduction, but we have no data on long-term effects of fire. We recommend proactive fuels-management treatments in areas not currently occupied by owls as a means of reducing fire risk in areas occupied by owls. Within areas occupied by owls, judicious treatments may be appropriate after case-by-case evaluations of potential benefits and risks within those sites. FOR. SCI. 50(6):765–772.
A Pòlya-Urn Resampling Scheme for Estimating Precision and Confidence Intervals Under One-Stage Cluster Sampling: Application to Map Classification Accuracy and Cover-Type Frequencies
Authors: Magnussen Steen , Stehman Stephen V. , Corona Piermaria , Wulder Michael A. 
Published: April 2024

Abstract
A Pòlya-urn resampling scheme (PURS) is introduced as an alternative to classical inference (CLAS) for applications related to map accuracy and estimating cover-type frequencies from land-cover maps. PURS is akin to a Bayesian bootstrap procedure for generating a predictive posterior distribution of sample estimates. PURS is a simple alternative to the complexity of deriving Taylor-series approximation (TSA) to CLAS variance estimators and reliance on asymptotic normality for construction of confidence intervals. The potential advantages of the resampling scheme are explored in simulated sampling of actual data from three 102–107-km2 large study sites. PURS root mean square errors (rmse) of six measures of classification accuracy were slightly lower than TSA to CLAS rmse. PURS estimated standard errors and coverage rates of confidence intervals (95%) for bias-corrected classified cover-type frequencies were, in most cases, superior to corresponding TSA. Yet variance estimators and confidence intervals constructed for a cover type occupying less than 5% of a study site were consistently underestimated by both methods. PURS is adaptable to a wide range of forest resource survey designs. FOR. SCI. 50(6):810–822.