bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Evaluation of Intra- and Inter-Provenance Hybrids of Loblolly Pine for Planting in Piedmont Regions of the Southern United States
Authors: Alizoti Paraskevi G. , Li Bailian , McKeand Steven E. 
Published: April 2024

Abstract
Two intra-provenance [Atlantic Coastal (C×C), Piedmont (P×P)] and two inter-provenance [Atlantic Coastal × Piedmont (C×P), Piedmont × Atlantic Coastal (P×C)] loblolly pine (Pinus taeda L.) populations, represented by 80 polycross families, were assessed for height, volume, and survival in five Piedmont regions at four years of age. The hybrid populations (C×P, P×C) were intermediate among the pure populations (C×C, P×P). Across and within regions the C×P hybrids were significantly taller and more productive in volume than the pure P×P, with performance comparable to that of C×C. The C×P hybrids exhibited stronger additive genetic control for both height and volume across and within regions, except for the two inland regions, where the P×C hybrids' genetic control for height was stronger. Stability of performance in height and volume varied among families within populations. These early results suggest that the C×P hybrids will perform better in milder Piedmont environments, while the P×C hybrids could be suitable for more inland and northern Piedmont sites. Long-term evaluation of population performance and adaptability is essential before implementing such a plan in the Piedmont.
Tree-Level Models for Predicting Lumber Volume Recovery of Black Spruce Using Selected Tree Characteristics
Authors: Liu Chuangmin , Jiang Z.H. , Zhang S.Y. 
Published: April 2024

Abstract
Four model forms (linear, polynomial, power, and exponential) and their extensions with different independent variables were studied for their predictive ability for lumber volume recovery from black spruce (Picea mariana [Mill.] B.S.P.) trees at two types of sawmills (a stud mill and a random length mill) using basic tree characteristics (dbh, tree height, and stem taper). Of the three tree characteristics, dbh was identified as having the most predictive ability for lumber volume recovery. We found that all models predicted lumber volume recovery more precisely for small-sized and medium-sized (≤23 cm) trees than for large-sized (&gt;03E23 cm) trees. In terms of the selected statistical criteria such as adjusted R2, root-mean-square error (RMSE), predicted error sum of squares (PRESS), and prediction error, the best models for predicting lumber volume recovery were considered to be the following forms for both types of sawmills: (1) the second-order polynomial function with dbh alone, (2) the polynomial function with an interaction term of squared dbh and tree height, and (3) the power function with dbh and tree height. For both types of sawmills, the three final fitted model forms accounted for over 91% of the total variation. Model validation using independent data from a stud mill indicated that by using measured tree characteristics the three model forms were able to accurately and precisely predict lumber volume recovery, especially from small- and medium-sized trees.
Historical Fire Cycles in the Canadian Rocky Mountain Parks
Authors: Wagner Charles E. Van , Finney Mark A. , Heathcott Mark 
Published: April 2024

Abstract
The subject of this article is the fire history of seven contiguous national and provincial parks in the Canadian Rocky Mountains, four to the east of the continental divide and three to the west. Seven centuries of time-since-fire data were combined and arrayed in three sets: all seven parks together, then the east-side and west-side groups separately. Fire cycles were estimated by four different methods: two of them statistical and two deterministic. Statistical evidence of distinct changes in fire regime, always toward a lower burning rate, was uncovered, with transitions in 1760 and 1940 on the east side, and in 1840 on the west side. The principal conclusions were: The seven parks as a unit supported a fire cycle of 60–70 yr for nearly five centuries before 1760. The burning rate then dropped sharply and a longer cycle of about 175 yr prevailed until 1940. Fire history in the combined large parks on the east side was similar to the above. By contrast, the smaller west-side parks group sustained a fire cycle of about 90 yr for at least five centuries before 1840; the burning rate then decreased irregularly to 2000. On the east side, the near absence of burned area after 1940 was attributed to the onset of effective fire protection. Possible prior causes of the earlier transitions on east and west sides include changes in climate or aboriginal fire practices, but this issue is left unresolved.
Bivariate Distribution Modeling with Tree Diameter and Height Data
Authors: Wang Mingliang , Rennolls Keith 
Published: April 2024

Abstract
The Logit-Logistic (LL), Johnson's SB, and the Beta (GBD) are flexible four-parameter probability distribution models in terms of the (skewness-kurtosis) region covered, and each has been used for modeling tree diameter distributions in forest stands. This article compares bivariate forms of these models in terms of their adequacy in representing empirical diameter–height distributions from 102 sample plots. Four bivariate models are compared: SBB, the natural, well-known, and much-used bivariate generalization of SB; the bivariate distributions with LL, SB, and Beta as marginals, constructed using Plackett's method (LL-2P, etc.). All models are fitted using maximum likelihood, and their goodness-of-fits are compared using minus log-likelihood (equivalent to Akaike's Information Criterion, the AIC). The performance ranking in this case study was SBB, LL-2P, GBD-2P, and SB-2P.
Incorporating Whole-Stand and Individual-Tree Models in a Stand-Table Projection System
Authors: Cao Quang V. 
Published: April 2024

Abstract
A stand table provides number of trees per unit area for each diameter class. This article presents three methods to project a current stand table into the future by predicting mortality and diameter growth for each diameter class by use of an individual-tree model. The stand table was then adjusted to produce the same total number of trees and basal area per hectare as predicted from the whole-stand model. The three methods evaluated in this study were stand table adjustment, constrained least squares (LS), and modified constrained LS. Data from the Southwide Seed Source Study of loblolly pine (Pinus taeda L.) showed that incorporating the individual-tree model helped improve the projection of stand tables, as compared to a previous approach. The three methods produced comparable results; error indices from these methods were within 5% of one another. The constrained LS method consistently provided the best fit (lowest error indices) as compared to the other methods.
Influence of Headwater Site Conditions and Riparian Buffers on Terrestrial Salamander Response to Forest Thinning
Authors: Rundio David E. , Olson Deanna H. 
Published: April 2024

Abstract
Although thinning of young, even-aged forests may accelerate the development of characteristics associated with mature forests, in the short term it may negatively affect some taxa, including terrestrial salamanders. Preexisting site conditions, including down wood, and forest management measures, such as riparian buffers, may moderate these effects, but these relationships are poorly understood. To explore whether down wood and riparian buffer widths might influence short-term responses to thinning, we sampled salamanders using ground searches before and during the first 2 years after experimental thinning at two 45- to 65-year-old headwater forest sites in western Oregon that differed in down wood volume. Prethinning distributions of terrestrial salamanders overlapped one- and two-tree height riparian buffers, and except for red-backed salamanders, overlapped very little with narrower streamside or variable-width buffers. At the site where down wood volume was low, captures of ensatina (Ensatina eschscholtzii Gray) and western red-backed salamanders (Plethodon vehiculum Cooper) both declined by 40% in thinned areas. In contrast, captures of ensatina and Oregon slender salamanders (Batrachoseps wrighti Bishop) were not significantly affected by thinning at the site where down wood volume was high. Our results suggest that site conditions, such as down wood volume, and riparian buffers may influence the effect of thinning on terrestrial salamanders, and demonstrate the tight linkage among management of aquatic, riparian, and upslope resources in headwater forests.
Mountain Pine Beetle Dispersal: The Spatial–Temporal Interaction of Infestations
Authors: Robertson Colin , Nelson Trisalyn A. , Boots Barry 
Published: April 2024

Abstract
An understanding of mountain pine beetle (Dendroctonus ponderosae Hopkins) dispersal during an outbreak is important for modeling future infestations and aiding management decisions. Data on the spatial pattern of red and green attacked trees were used to characterize the spatial–temporal nature of dispersal. Research goals were to detect evidence of dispersal based on the distance and direction between red and green attacked tree clusters, determine how dispersal changes at different stages of infestation, and to detect landscape variables influencing the observed dispersal patterns. Key variables explored were Biogeoclimatic Ecosystem Classification (BEC), topography, and the local population of susceptible hosts. Dispersal distances of 30 meters and 50 meters were consistently observed among different data subsets. Findings suggest that short-range dispersal often occurs despite an available population of susceptible hosts, and as the infestation grows in intensity, the abundance of dispersing beetles causes spot infestations to coalesce.
Evidence for Increasing Red Maple Abundance in the Eastern United States
Authors: Fei Songlin , Steiner Kim C. 
Published: April 2024

Abstract
Red maple (Acer rubrum L.) is widely believed to be increasing in abundance in eastern North America, but most evidence is anecdotal or localized. In this article we present analyses of FIA data sets designed to formally quantify changes in abundance of red maple in the eastern United States during the period of 1980 to 2005. The results indicate that recent increases in red maple abundance are almost ubiquitous on a state-by-state basis throughout the species' natural range and generally greatest in the western portions of the range. No states experienced a significant decrease in red maple abundance during this period. There is evidence that the species has naturalized into areas west of its putative pre-Columbian distribution. Red maple had an inverse “J” population structure, and density of red maple trees has increased in all diameter classes across the region. The trend of increasing red maple abundance will continue unless the circumstances that cause this phenomenon are changed.
Interactions of Elevation, Aspect, and Slope in Models of Forest Species Composition and Productivity
Authors: Stage Albert R. , Salas Christian 
Published: April 2024

Abstract
We present a linear model for the interacting effects of elevation, aspect, and slope for use in predicting forest productivity or species composition. The model formulation we propose integrates interactions of these three factors in a mathematical expression representing their combined effect in terms of a cosine function of aspect with a phase shift and amplitude that change with slope and elevation. This model allows the data to determine how the aspect effect changes with elevation and slope. Earlier articles concerning the interactions of slope, aspect, and elevation have been incomplete by either treating elevation as fixed or ignoring the possibility that aspect effect must also involve slope. The proposed set of variables is illustrated in four applications: (1) a hypothetical data set for probability of stocking by “species” having different adaptations to elevation, (2) in a discriminant function for forest/nonforest classification of data from Utah, (3) estimating mean annual increment of Utah forests, and (4) estimating the height asymptote in a mixed-model differential equation predicting Douglas-fir height growth.
Parameter Estimation of Base-Age Invariant Site Index Models: Which Data Structure to Use?
Authors: Wang Mingliang , Borders Bruce , Zhao Dehai 
Published: April 2024

Abstract
Two main approaches to estimating parameters of dominant height curves (derived by algebraic difference approach (ADA) and generalized ADA (GADA)), the dummy variable method and the difference approach (the error-in-variable (EIV) method along with ordinary least-squares (OLS) fits)are compared using second-rotation loblolly pine (Pinus taeda L.) data from a designed experiment. It was found that the EIV method consistently performed better than the dummy variable method, and the two unbiased estimation methods were not necessarily better than the biased OLS differencemethods. In general, the performance of these two approaches was similar in height prediction given site index, but in combination with site index prediction given heights, the difference methods generally performed better. The nonoverlapping forward difference data structure (III), is recommendedto fit difference models.
Rooting of Leafy Stem Cuttings of Baillonella toxisperma
Authors: Mpeck Marie Ngo , Atangana Alain 
Published: April 2024

Abstract
Rooting ability in Moabi was examined using 972 single-node leafy stem cuttings set in each of three blocks of a split-split plot experimental design in nonmist propagators. Each main plot contained three rooting media (sand, sawdust, and a 50:50 mixture of sand and sawdust), whereas three auxin types (indole-3-acetic acid [IAA], indole-3-butyric acid [IBA], and 1-naphthalene acetic acid [NAA]) and a control (alcohol) were tested at the subplot level. At the sub-subplot level, three leaf areas (25, 50, and 75 cm2) were investigated. Significant (P = 0.05) and nonsignificant substrate × hormone × leaf area interactions on rooting percentage were found at week 8 and during the rest of experiment, respectively. Significant sand versus sawdust × IBA versus IAA and NAA × quadratic components of leaf area interaction on rooting percentage was identified from week 10 to week 14 (P = 0.0462–0.038), and the highest rooting percentage (85.2 ± 7.24%) was found in 75 cm2 × IBA × sand-treated cuttings at week 14. Significant substrate × leaf area interaction on rooting percentage was observed throughout the experiment. Interacting substrate × leaf area significantly influenced the number of roots per rooted cutting at week 22. This study indicated that Moabi is amenable to vegetative propagation within 14 weeks.
An Alternative to Traditional Goodness-of-Fit Tests for Discretely Measured Continuous Data
Authors: Randolph KaDonna C. , Seaver Bill 
Published: April 2024

Abstract
Traditional goodness-of-fit tests such as the Kolmogorov-Smirnov and χ2 tests are easily applied to data of the continuous or discrete type, respectively. Occasionally, however, the case arises when continuous data are recorded into discrete categories due to an imprecise measurement system. In this instance, the traditional goodness-of-fit tests may not be wholly applicable because of an unmanageable number of ties in the data, sparse contingency tables, or both; therefore, a flexible alternative to goodness-of-fit tests for discretely measured continuous data is presented. The proposed methodology bootstraps confidence intervals for the difference between selected percentiles of the empirical distribution functions of two samples. Application of the approach is illustrated with a comparison of loblolly pine (Pinus taeda L.) tree crown density distributions at the 10th, 25th, 50th, 75th, and 90th percentiles simultaneously.
Preharvest Measurement of Marked Stands Using Airborne Laser Scanning
Authors: Peuhkurinen Jussi , Maltamo Matti , Malinen Jukka , Pitkänen Juho , Packalén Petteri 
Published: April 2024

Abstract
The customer-oriented wood procurement chain from forest to raw material user starts with a knowledge of stands available for harvesting and information on these marked stands. Despite several studies, no adequate method has been developed for obtaining preharvest measurement information to meet existing requirements. The aim here was to develop a method for the preharvest measurement of a marked stand based on single tree detection and airborne laser scanning. The trees were detected from high-density laser scanning data using automatic detection procedures, and their dbh was estimated using either local or regional models. The method was compared with actual harvester measurement of the stand and alternative methods for obtaining preharvest measurement information (systematic plot sampling, subjective inventory by compartments, and the laser canopy height distribution method). The comparisons of the methods were based on goodness-of-fit tests of diameter distributions and bucking simulations. The results indicated that the laser scanning-based single tree detection procedure has considerable advantages over other methods. The crucial point in applying the method seemed to be the choice of diameter prediction model.
Density Frontiers for Even-Aged Douglas-fir and Western Hemlock Stands in Coastal British Columbia
Authors: Montigny Louise de , Nigh Gordon 
Published: April 2024

Abstract
Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) and western hemlock (Tsuga heterophylla [Raf.] Sarg.) are the two most common and commercially important species on the coast of British Columbia, Canada. Our research focused on determining the relationship between maximum density and top height for pure stands of these species. These relationships can be used to provide a constraint on mortality functions in individual-tree growth and yield models for even-aged stands. Our data consist of density and top height from experimental plots established along the coast of British Columbia, Washington, and Oregon. These experiments yielded 2,930 observations from 628 plots. We fit stochastic frontier functions to the density/top height data. Stochastic frontier functions have a stochastic component that allows data points to lie on either side of the frontier. The fitting of the frontier functions using maximum likelihood estimation resulted in maximum density lines as an exponential function of top height for both species. The fitted model is based loosely on the −3/2 power thinning law. Our analysis shows that these relationships hold across sites with differing quality. The maximum density line is greater for western hemlock than for Douglas-fir up to a height of about 35 m, at which point they are almost the same. The higher maximum density of western hemlock is likely related to its greater shade tolerance. We used the growth-and-yield model Table Interpolation Program for Stand Yields (TIPSY) to simulate the growth of high-density stands of Douglas-fir and western hemlock. These simulations gave similar results to our fitted density frontier line.
Calcium Uptake, Partitioning, and Sinuous Growth in Douglas-Fir Seedlings
Authors: Littke Kim , Zabowski Darlene 
Published: April 2024

Abstract
Sinuosity is a growth deformation affecting Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] and other conifers. Ca, an essential nutrient in tree growth and cell development, may be deficient in these stands and could be causing sinuous growth. An experiment was conducted to test whether low Ca availability causes sinuous growth in Douglas-fir seedlings. Douglas-fir 1 + 1 seedlings were grown in a greenhouse with high to low Ca availability. After 6 months of growth, the seedlings were measured for sinuosity and separated into new-needles, new-stem, old-needles, old-stem, and roots. High Ca fertilized seedlings had greater new-needle biomass and growth than low Ca fertilized seedlings. High Ca availability also led to higher Ca concentration and content, including higher foliar membrane-associated Ca, Ca-pectate, and Ca-oxalate than low Ca seedlings. Low Ca availability had no significant effect on sinuosity. Although high Ca availability did not alleviate sinuous growth in Douglas-fir seedlings, it did lead to higher growth, foliar biomass, and membrane-associated Ca.
The Interaction between Soil Nutrients and Leaf Loss during Early Establishment in Plant Invasion
Authors: Leger Elizabeth A. , Howe Katherine M. , Gurevitch Jessica , Woo Eliza , Hickman Jonathan , Ashton Isabel W. , Lerdau Manuel 
Published: April 2024

Abstract
Nitrogen availability affects both plant growth and the preferences of herbivores. We hypothesized that an interaction between these two factors could affect the early establishment of native and exotic species differently, promoting invasion in natural systems. Taxonomically paired native and invasive species (Acer platanoides, Acer rubrum, Lonicera maackii, Diervilla lonicera, Celastrus orbiculata, Celastrus scandens, Elaeagnus umbellata, Ceanothus americanus, Ampelopsis brevipedunculata, and Vitis riparia) were grown in relatively high-resource (hardwood forests) and low-resource (pine barrens) communities on Long Island, New York, for a period of 3 months. Plants were grown in ambient and nitrogen-enhanced conditions in both communities. Nitrogen additions produced an average 12% initial increase in leaf number of all plants. By the end of the experiment, invasive species outperformed native species in nitrogen-enhanced plots in hardwood forests, where all plants experienced increased damage relative to control plots. Native species experienced higher overall amounts of damage in hardwood forests, losing, on average, 45% more leaves than exotic species, and only native species experienced a decline in growth rates (32% compared with controls). In contrast, in pine barrens, there were no differences in damage and no differences in performance between native and invasive plants. Our results suggest that unequal damage by natural enemies may play a role in determining community composition by shifting the competitive advantage to exotic species in nitrogen-enhanced environments.
Variance Reduction for Radial Line Sampling Coverage Estimators
Authors: Lynch Thomas B. 
Published: April 2024

Abstract
It may be convenient to use radial line sampling for coverage estimates in small irregularly shaped areas. Radial line samples emanate from a fixed point located in the interior of the area and would be run according to a randomly selected azimuth. Thus, radial line sampling is analogous to techniques of local stereology, which considers quantitative aspects of spatial structures in the neighborhood of a central point. Coverage estimates from radial line sampling can be based on coverage observed on several sample lines. Several variance reduction techniques commonly used in Monte Carlo integration are proposed to reduce the variance of coverage estimates based on radial line sampling: importance sampling, control variates, and antithetic variates. The success of these techniques in irregularly shaped areas depends on the assumption that total line length is correlated with length of coverage. Radial line sampling as proposed here differs somewhat from ordinary line sampling because coverage estimates are based on squared line lengths.