bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation Contracts for Forest Biodiversity: Theory and Experience from Finland
Authors: Juutinen Artti , Ollikainen Markku
Published: April 2024

We examined the Finnish biodiversity conservation pilot project, called Trading in Natural Values (TNV), using a simulated biodiversity auction model. We found, first, that the share of the most valuable old stands in the key ecological forest habitats was higher in the actual TNV program than in a simulated auction. Second, the actual bids in the TNV program were on average €400–1,200 lower per ha than the bids generated by the auction model. These findings indicate the presence of strong conservation motives among the Finnish landowners. Third, because the number of stands with high biodiversity values is limited in the study area and conservation costs are high for these stands, increasing the size of the conservation budget enrolls more stands in the program but with lower biodiversity values.
Age–Age Correlations and Early Selection for Height in a Clonal Genetic Test of Norway Spruce
Authors: Isik Kani , Kleinschmit Jochen , Steiner Wilfried
Published: April 2024

Heights of rooted cuttings from 40 clones of Norway spruce (Picea abies [L.] Karst) were measured at ages 3, 5, 8, 10, 13, and 17 from rooting at seven test environments in northern Germany. To determine the optimal age for juvenile selection for height, age-related changes in variance components, clone-mean heritability, and age–age correlations were estimated. Partitions of variance components were essentially constant after age 8. Clone-mean heritabilities were highest at age 3 (0.94) and were essentially stable after age 5. Age–age correlations were generally high between similar ages but declined as the difference between pairs of measurement ages increased. Genetic correlations were greater than corresponding phenotypic correlations but were similar in value. Trait–trait correlations between height and diameter (rG = 0.83) and height and volume (rG = 0.90) at age 17 were also high. Simple linear regressions of genetic and phenotypic age–age correlations on LAR (natural log of the ratio of younger age to older age) were significant (R2 ≥ 0.76). Predicted efficiencies of selection suggested that for a rotation age of 60 years, the optimum selection age would be as early as 13 years. Furthermore, gains per year would be increased by about 1½ times if selections were made at about age 15 rather than age 60.
The Bivariate Gompertz Diffusion Model for Tree Diameter and Height Distribution
Authors: Rupšys Petras , Petrauskas Edmundas
Published: April 2024

With this research we present a new method for describing the bivariate diameter and height distribution of trees growing in a pure, uneven-aged forest. We use a stochastic differential equation framework to derive a bivariate age-dependent probability density function of tree diameter and height when the tree diameter and height follow a bivariate stochastic Gompertz shape growth process. We also adopt the two-dimensional transition probability function methodology for growth modeling of forest stands. The bivariate stochastic Gompertz model is fit to diameter and height observations for 1,575 pine trees in the Dubrava district of Lithuania. A considerable advantage of the bivariate stochastic Gompertz growth model is that the model parameters are easily interpretable. All results are implemented in the symbolic algebra system MAPLE.
A Hedonic Approach to Value Pinus radiata Log Traits for Appearance-Grade Lumber Production
Authors: Alzamora Rosa M. , Apiolaza Luis A.
Published: April 2024

This study used a hedonic approach to estimate the economic value of radiata pine log attributes (small-end diameter, form, and internode length) for appearance-grade lumber, including molding and better, shop, and industrial finger joint. Models were also built at the tree level to investigate the effect of selection as conducted by breeders. A Chilean sawing study provided information on wood traits and log out-turn for 156 logs divided into three classes: pruned butt log, second log, and third log. The conversion return of logs, instead of log prices, was used as the measure of log economic value. The economic values of log small-end diameter were 0.33, 0.19, and 0.10 US$/mm for the first, second, and third log, respectively. Concerning form, those values were US$2.6, US$1.4, and US$0.63 for a marginal improvement of this characteristic. The value of mean internode length was 0.19 US$/cm for second unpruned logs. Values for other internode length indices are also presented in this article. Branch variables were not statistically significant to explain the log recovery value. Finally, log recovery value was found to be elastic to the changes in small-end diameter and form, but inelastic to changes in the mean internode length.
Identifying the Presence of Assessment Errors in Forest Inventory Data by Data Mining
Authors: Mäkinen Antti M. , Kangas Annika S. , Tokola Timo
Published: April 2024

All forest inventory methods are susceptible to assessment errors, and although the majority of these errors are relatively minor, some can be exceptionally large. Errors reduce data reliability and increase the probability of nonoptimal decisions in forest planning. We propose that outlier detection techniques based on data mining could be used to detect some of the assessment errors in forestry databases. We tested four outlier detection algorithms presented in previous data mining studies for detecting the errors in compartment-wise field inventory data used in forest planning and examined the relations between the outliers and assessment errors. There was a clear relation between outliers and assessment errors, but this varied somewhat among the algorithms. Compartments with large assessment errors had a higher probability of being classified as outliers. The findings suggest that outlier detection techniques based on data mining could provide a cost-efficient tool for detecting some of the largest assessment errors in inventory data and thus improve the reliability of the whole forest planning process.
Light Detection and Ranging-Based Measures of Mixed Hardwood Forest Structure
Authors: Hawbaker Todd J. , Gobakken Terje , Lesak Adrian , Trømborg Eric , Contrucci Kirk , Radeloff Volker
Published: April 2024

Light detection and ranging (LiDAR) is increasingly used to map terrain and vegetation. Data collection is expensive, but costs are reduced when multiple products are derived from each mission. We examined how well low-density leaf-off LiDAR, originally flown for terrain mapping, quantified hardwood forest structure. We measured tree density, dbh, basal area, mean tree height, Lorey's mean tree height, and sawtimber and pulpwood volume at 114 field plots. Using univariate and multivariate linear regression models, we related field data to LiDAR return heights. We compared models using all LiDAR returns and only first returns. First-return univariate models explained more variability than all-return models; however, the differences were small for multivariate models. Multiple regression models had R2 values of 65% for sawtimber and pulpwood volume, 63% for Lorey's mean tree height, 55% for mean tree height, 48% for mean dbh, 46% for basal area, and 13% for tree density. However, the standard error of the mean for predictions ranged between 1 and 4%, and this level of error is well within levels needed for broad-scale forest assessments. Our results suggest that low-density LiDAR intended for terrain mapping is valuable for broad-scale hardwood forest inventories.
Implications of Expanding Bioenergy Production from Wood in British Columbia: An Application of a Regional Wood Fiber Allocation Model
Authors: Stennes Brad K. , Niquidet Kurt , van Kooten G. Cornelis
Published: April 2024

Energy has been produced from woody biomass in British Columbia for many decades, primarily within the pulp and paper sector, using residual streams from timber processing to create heat and electricity for on-site use. More recently, there has been some stand-alone electricity production and an increase in the capacity to produce wood pellets, both using “waste” from the sawmill sector. Hence, most of the low-cost feedstock sources associated with traditional timber processing are now fully employed. Although previous studies modeled bioenergy production in isolation, we used a fiber allocation and transportation model of the British Columbia forest sector with 24 regions to demonstrate that it is necessary to consider the interaction between use of woody feedstock for pellet production and electricity generation and its traditional uses (e.g., production of pulp, oriented-strandboard, and others). We find that, despite the availability of large areas of standing mountain pine beetle-killed timber, this wood does not enter the energy mix in a dedicated salvage timber harvest to energy system. Further expansion of biofeedstock for energy is met by a combination of woody debris collected at harvesting sites and/or bidding away of fiber from existing users.
Two-Component Mixture Models for Diameter Distributions in Mixed-Species, Two-Age Cohort Stands
Authors: Podlaski Rafał
Published: April 2024

The objectives of this study were to investigate the suitability of two-component Weibull and gamma mixtures to model the dbh distribution of a mixed-species, two-age cohort stands and for age cohort determination and to compare several methods to choose initial parameter values for maximum likelihood estimation of mixture models. Investigations were carried out in near-natural, fir (Abies alba Mill.)–beech (Fagus sylvatica L.), two-age cohort stands in the Świętokrzyski National Park (Central Poland), where unusually high mortality of fir followed by its recovery and revitalization has been observed. The age cohort YG1 is composed of trees from 60 to ∼150 years of breast height age, and the age cohort YG2 is composed of trees less than 60 years of breast height age. The empirical distributions for the stands in this study were equally well fit by both the mixture Weibull and gamma models. It has been assumed that the estimated values, the weights (fractions), the means, and the standard deviations of two-component mixture models, are the predicted values of dbh statistics of age cohorts. The mean absolute relative errors used to evaluate this assumption were least for age cohort YG2 (from 14.8 to 29.6%) and largest for age cohort YG1 (from 17.7 to 45.0%). The dbh component 1 of mixture models can be identified in the stands investigated with age cohort YG2 and to a lesser degree the dbh component 2 with age cohort YG1. The multistart method for choosing initial values for the numerical procedure (a combination of the expectation-maximization algorithm with the Newton-type method) was best but also the most labor-intensive. The optimal way to estimate parameters in two-component mixtures with the Weibull or the gamma distributions is to apply min/max and 0.5/1.5/mean methods and, additionally, but only if necessary, a multistart method.
Implications of Alternative Field-Sampling Designs on Landsat-Based Mapping of Stand Age and Carbon Stocks in Oregon Forests
Authors: Duane Maureen V. , Cohen Warren B. , Campbell John L. , Hudiburg Tara , Turner David P. , Weyermann Dale L.
Published: April 2024

Empirical models relating forest attributes to remotely sensed metrics are widespread in the literature and underpin many of our efforts to map forest structure across complex landscapes. In this study we compared empirical models relating Landsat reflectance to forest age across Oregon using two alternate sets of ground data: one from a large (n ∼ 1500) systematic forest inventory and another from a smaller set of plots (n < 50) deliberately selected to represent pure conditions along predefined structural gradients. Models built with the smaller set of targeted ground data resulted in lower plot-level mapping error (root mean square error) and higher apparent explanatory power (R2) than those built with the larger, more widely distributed inventory data. However, in two of the three ecoregions considered, predictions derived from models built with the smaller ground data set displayed a bias relative to those built with the larger but noisier inventory data. A modeling exercise, wherein mapped forest age was translated into carbon, demonstrated how nonlinear ecological models can magnify these prediction biases over landscapes. From this study, it is clear that for mapping purposes, inventory data are superior to project-specific data sets if those data sets are not representative of the full region over which mapping is to be done.
Ponderosa Pine Characteristics Associated with Attack by the Roundheaded Pine Beetle
Authors: Fischer Melissa J. , Waring Kristen M. , Hofstetter Richard W. , Kolb Thomas E.
Published: April 2024

The roundheaded pine beetle (Dendroctonus adjunctus Blandford [Coleoptera: Curculionidae, Scolytinae]) is an aggressive (tree-killing) bark beetle species that attacks several species of pine. Characteristics of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) trees chosen for attack by this beetle were studied in a current outbreak in northern Arizona. We found significant differences in basal area increment, crown width, lengths of internodes, subbranches, and needles, phloem thickness, and resin composition between attacked and unattacked trees. Attacked trees had significantly lower basal area increment and internode and needle lengths but longer subbranch lengths at the top of the crown and longer crown widths. Attacked trees also had thicker phloem and contained a significantly higher percentage of α-pinene in resin, but a lower percentage of longifolene than unattacked trees. A baited tree experiment showed that attacks by the roundheaded pine beetle did not affect resin composition through time. Overall, our results suggest that host selection by the roundheaded pine beetle may not be random and that tree growth characteristics and resin composition are probably important factors in host selection.
The Effects of Irrigation and Fertilization on Specific Gravity of Loblolly Pine
Authors: Love-Myers Kimberly R. , Clark Alexander , Schimleck Laurence R. , Dougherty Phillip M. , Daniels Richard F.
Published: April 2024

The effects of two treatments, irrigation and fertilization, were examined on specific gravity (SG)-related wood properties of loblolly pine trees (Pinus taeda L.) grown in Scotland County, North Carolina. The effects on the core as a whole, on the juvenile core, on the mature core, and from year to year were all analyzed. The results indicate that fertilization significantly lowered latewood SG, overall SG, and percent latewood and did so consistently throughout the period of study. Irrigation significantly lowered earlywood SG during the phase of juvenile wood production but significantly raised latewood SG during the period of mature wood production. Significant interaction between fertilization and irrigation indicated that irrigation helped overall SG and percent latewood of fertilized trees to increase to the level of untreated trees. Therefore, this study provides evidence that although fertilization significantly affects several SG-related properties, water availability is beneficial to the fertilization process; over time, an adequate water supply may help fertilized trees to maintain SG levels similar to those of unfertilized trees.
Optimizing Inventory and Yield Data Collection for Forest Management Planning
Authors: Gilabert Horacio , McDill Marc E.
Published: April 2024

This work uses a Cost+Loss approach to estimate the optimal investment in inventory information for forest planning. A bootstrapping approach is used to simulate the impact of different inventory intensities on the quality of decisions in a linear programming harvest scheduling model. Multiple formulations of the harvest model based on varying inventory intensities are used to calculate the value of a variable labeled Loss that measures the monetary losses resulting from the use of imperfect yield information in the harvest model. The variable Loss and the cost of obtaining the inventory information are used to estimate empirical relationships between their expected value and the amount of inventory information (number of inventory plots and number of experimental plots) used in the harvest models. These two relationships are combined to give an explicit estimate of the expected Cost+Loss as a function of the inventory intensity variables. This Cost+Loss relationship is minimized to estimate optimal number of inventory plots and the optimal number of experimental plots. An example is developed with radiata pine information from southern Chile. Results for this example suggest that current practice uses too many experimental plots and too few inventory plots.
Bootstrap Evaluation of a Young Douglas-Fir Height Growth Model for the Pacific Northwest
Authors: Vaughn Nicholas R. , Turnblom Eric C. , Ritchie Martin W.
Published: April 2024

We evaluated the stability of a complex regression model developed to predict the annual height growth of young Douglas-fir. This model is highly nonlinear and is fit in an iterative manner for annual growth coefficients from data with multiple periodic remeasurement intervals. The traditional methods for such a sensitivity analysis either involve laborious math or rely on prior knowledge of parameter behavior. To achieve our goals, we incorporate a bootstrap approach to obtain estimates of the distribution of predicted height growth for any set of input variables. This allows for a sensitivity analysis with knowledge of the probability of a given outcome. The bootstrap distributions should approximate the variation we might expect from running the model on numerous independent datasets. From the variation in the model parameters, we are able to produce ranges of height growth prediction error falling under a given probability of occurrence. By evaluating these ranges under several combinations of input variables that represent extreme situations, we are able to visualize the stability of the model under each situation. Each of the four components of the model can be investigated separately, which allows us to determine which components of the model might benefit from reformulation. In this case we find that the model is less stable in extremely high site index, especially under low vegetation competition. Other than the computing time involved with the bootstrap, most of the analysis is fairly quick and easy to perform.
Total Soil Carbon in the Coarse Fraction and at Depth
Authors: Zabowski Darlene , Whitney Nicol , Gurung Janita , Hatten Jeffrey
Published: April 2024

Historically, most studies estimating soil carbon have been based almost exclusively on ≤2-mm soil particles (fine soil fraction) and generally excluded soil >2-mm (coarse soil fraction) or soil at >1-m depth. In fact, many studies have not examined soil carbon below 20 cm. This study was conducted to determine how much total soil C is underestimated by following traditional, or standard, soil sampling and analysis for both particle size fractions and depth. Seventeen soil series and one soil classified to the level of Great Group, were sampled in Alaska, Oregon, Puerto Rico, and Washington. Total soil C was quantified for the soil fine and coarse fractions, as well as for soil >1-m deep. Results of this study showed substantial soil C contained in the coarse soil fraction (<1-25%) and in soil greater than 1-m depth (3-48%). The combined exclusion of the coarse fraction and soil below 1 m could miss as much as one-half of the soil total C of a profile. These results indicate that to obtain a true value of soil total carbon, the entire soil must be sampled, including the coarse soil fraction and soil below 1 m.
Soil Carbon Change through 2 m during Forest Succession Alongside a 30-Year Agroecosystem Experiment
Authors: Devine Scott , Markewitz Daniel , Hendrix Paul , Coleman David
Published: April 2024

Forest succession (FS) and no-till (NT) agriculture are generally assumed to have a beneficial effect on surficial soil organic C (SOC) stocks compared with conventional tillage (CT) management; however, land use effects to depths >30 cm remain uncertain. In this research we compared SOC contents and composition to 2 m under CT, NT, and FS at the 30-year Horseshoe Bend agroecosystem experiment in Athens, Georgia, USA. Soils from 0 to 2 m were fractionated into particulate organic C (POC) (53-2000 μm) and fine C (<53 μm) fractions, and bulk soil δ13C signatures were determined. Soils from 0 to 28 cm were dry- and wet-sieved to estimate aggregate stability. Soil solutions were also collected at 0, 15, and 100 cm for dissolved organic C (DOC) analysis. Full-profile (0-2 m) SOC storage is 52 Mg ha−1 in CT, 60 Mg ha−1 in NT, and 62 Mg ha−1 in FS. Significant differences are limited to 0-5 cm and are linked to enhanced aggregate stability under NT and FS. Increases in subsoil POC under FS and changes in soil δ13C and C/N ratio indicate that substantial subsoil C cycling has occurred. DOC fluxes at 0 cm were significantly greater under NT (200 kg ha−1 year−1) and FS (210 kg ha−1 year−1) than under CT (80 kg ha−1 year−1). DOC fluxes at 15 cm are estimated to be 20 kg ha−1 year−1 under CT and NT and 40 kg ha−1 year−1 under FS. At 100 cm, DOC fluxes are 2 kg ha−1 year−1, regardless of land use. An increase in FS POC of 2 Mg ha−1 from 15 to 100 cm outweighs cumulative differences in DOC input to this layer, implicating deep forest rooting and bioturbation as active mechanisms in subsoil C change. Whereas differences in SOC content were concentrated near the surface, dynamic changes in C cycling extend well below the plow layer.
Carbon Inputs and Water Uptake in Deep Soils of an Eastern Amazon Forest
Authors: Davidson Eric , Lefebvre Paul A. , Brando Paulo M. , Ray David M. , Trumbore Susan E. , Solorzano Luis A. , Ferreira Joice N. , Bustamante Mercedes M. da C. , Nepstad Daniel C.
Published: April 2024

Rooting depth affects soil profiles of water uptake and carbon inputs. Here we explore the importance of deep roots in a mature tropical forest of eastern Amazonia, where a throughfall exclusion experiment was conducted to test the resilience of the forest to experimentally induced drought. We hypothesized that soil water depletion occurred below the depth previously measured by sensors in 11-m-deep soil pits and that only a small root biomass is necessary to affect water uptake and the isotopic signature of soil CO2. A noninvasive electrical profiling method demonstrated greater depletion of soil water in the 11-18 m depth increment in the exclusion plot compared with the control plot by the end of the 3rd year of the experiment. A fine root biomass of only 0.1 g/cm3 measured at 3-6 m was sufficient for soil water drawdown and for imparting an isotopic signature of modern soil 14CO2 in both plots. A soil 13CO2 profile indicated drought stress in the exclusion plot. Fine root inputs of organic C to deep soils are small with respect to the carbon dynamics of the forest, but the deep rooting habit clearly affects the ecosystem water balance and profiles of soil CO2.
Estimating Wood Volume of the Stem and Branches of Sugar Maple (Acer saccharum Marsh.) Using a Stem Profile Model with Implicit Height
Authors: Zakrzewski Wojciech T.
Published: April 2024

A taper model-based solution for estimating volume of wood in sugar maple (Acer saccharum Marsh.) in Ontario, Canada, is presented. This practical procedure, using a reformulated version of the 1999 taper model of Zakrzewski, requires measuring only dbh and produces estimates of commercial wood volume allocated in stems and (or) branches, along tree length. The suggested methodology allows tree height to be treated as an implicit variable: either unobserved or unobservable (latent). Using the dbh-based taper model, a standard height/dbh curve may be generated without height measurements. The methodology presented here may be also treated as a modeling framework for developing dbh-based biomass equations as well as for investigating spatial allocation of wood within trees, e.g., for studying the influence of the competitive environment (forest stand density) of a tree on height growth. Sample data used were measurements from 1,113 sugar maple trees from Ontario's Algonquin region.
Modeling the Effect of Midrotation Fertilization on Specific Gravity of Loblolly Pine (Pinus taeda L.)
Authors: Antony Finto , Schimleck Laurence R. , Hall Daniel B. , Clark Alexander , Daniels Richard F.
Published: April 2024

Ring specific gravity, earlywood and latewood specific gravity, and percent latewood were measured on cores collected at breast height from a thinned and fertilized midrotation loblolly pine (Pinus taeda L.) plantation in the lower Coastal Plain of North Carolina. The study was laid out in a randomized complete block design receiving four levels of nitrogen (N) fertilizer in 1984: 000 (control), 112, 224, and 336 kg/ha plus 28 kg/ha of phosphorus with each treatment. A consistent pattern of response was observed in latewood specific gravity (LWSG) after the application of different levels of fertilizer and used as a variable for modeling. The LWSG profiles of unfertilized trees followed a nonlinear relation with ring number from pith. A three-parameter asymptotic function was used to explain the LWSG profile of unfertilized trees with ring number as a covariate. Application of N reduced LWSG and was modeled using a two-parameter response function with year since fertilization as a covariate and separate parameter estimates for each fertilization level. On the basis of the model, the magnitude of maximum cumulative response was −0.025, −0.049, and −0.074 attained at 3.7, 1.9, and 0.8 years after fertilization for the 112, 224, and 336 kg/ha treatments, respectively.
Sampling Strategies for Efficient Estimation of Tree Foliage Biomass
Authors: Temesgen Hailemariam , Monleon Vicente , Weiskittel Aaron , Wilson Duncan
Published: April 2024

Conifer crowns can be highly variable both within and between trees, particularly with respect to foliage biomass and leaf area. A variety of sampling schemes have been used to estimate biomass and leaf area at the individual tree and stand scales. Rarely has the effectiveness of these sampling schemes been compared across stands or even across species. In addition, sample size estimates for achieving a certain level of precision have rarely been given. This simulation study used extensive branch and tree foliage biomass data sets for Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) and ponderosa pine (Pinus ponderosa Dougl ex. Laws.) to compare alternative sampling schemes and sample sizes. The use of auxiliary information at the estimation phase resulted in a more cost-efficient sampling scheme than when auxiliary information was used at the design phase. However, using auxiliary information at the design phase resulted in more precise estimates than using the same at the estimation phase for the same sample size. For both species, systematic sampling with ratio estimation provided the most efficient estimate of individual tree foliage biomass. In Douglas-fir, stratifying by branch type (i.e., whorl versus interwhorl) resulted in a marginal gain in precision. For Douglas-fir, on average, root mean square error decreased by 43.1% when sample size increased from 6 to 12 branches per tree, with a further decrease of 24.3% when sample size increased from 12 to 18 branches per tree. For ponderosa pine, on average, the root mean square error decreased by 44.4 and 23.9% when the sample size was increased from 6 to 12 and from 12 to 18 branches per tree, respectively. Additional work is needed to understand the appropriate sampling techniques for older conifer tree crowns and sampling multileader deciduous crowns.
Effects of Initial Spacing on Height Development of Loblolly Pine
Authors: Antón-Fernández Clara , Burkhart Harold E. , Strub Mike , Amateis Ralph L.
Published: April 2024

The relationship between dominant height and age is the base of site index, the most widely used measure of site quality. In applying the site index concept, one typically assumes that height development is not affected by stand density or thinning treatment. This assumption has been challenged by recent studies on loblolly pine. A detailed data set with initial densities ranging from 6,730 to 750 trees/ha and covering ages 1 through 25 after plantation establishment was used to study and model the effect of initial spacing on height development of loblolly pine. Dominant height was found to be dependent on initial spacing. Height-age models are proposed that take into account the effect of spacing on average and dominant height. The differences among plantation densities are evident from age 6 and are consistent to the end of the 25-year period of study. Previous studies in other conifers have reported an early advantage in terms of height growth in denser stands that tend to disappear with age, producing a crossover of the growth trajectories. No evidence of this crossover effect in height was found.
Fuel Complex Alterations Associated with Spruce Beetle-Induced Tree Mortality in Intermountain Spruce/Fir Forests
Authors: Jorgensen Carl Arik , Jenkins Michael James
Published: April 2024

Tree mortality caused during extensive outbreaks of spruce beetle (Dendroctonus rufipennis Kirby [Coleoptera: Curculionidae]) has been assumed to increase hazardous fuel loads and consequently influence fire behavior, occurrence, and effects. However, little research has been done to quantify or qualify how spruce beetle-induced tree mortality may alter fuel complexes during the course of an outbreak. The objective of our research was to determine how fuel complexes differ between stands with endemic populations of spruce beetle, stands experiencing current outbreaks, and stands with postoutbreak spruce beetle-induced tree mortality. We measured ground, surface, and aerial fuels in spruce–fir stands assigned into one of three spruce beetle condition classes: endemic, epidemic, or postepidemic. These stands were located on the Manti-LaSal and Fishlake National Forests in southcentral and southern Utah. We used analysis of variance (ANOVA) to compare mean differences in stand attributes and fuel variables between the three spruce beetle condition classes. The mean amount of down woody surface fuel (tonnes/ha) in the 100-hour size class in epidemic stands was significantly greater than that in endemic stands. Mean litter depth and amount was significantly greater in epidemic stands than in endemic and postepidemic stands. A significant increase for most estimates of live and dead herbaceous material was detected in epidemic stands and postepidemic stands compared with that in stands not affected by the spruce beetle. Likewise, significant increases in live shrub material were detected in postepidemic stands. Spruce–fir stands also had significantly less live aerial fuels after outbreaks than endemic stands.
Evaluating Tree Species Spatial Diversity Based on Neighborhood Relationships
Authors: Hui Gangying , Zhao Xiuhai , Zhao Zhonghua , von Gadow Klaus
Published: April 2024

This contribution presents a method for describing forest tree species diversity based on the analysis of tree neighborhoods. The proposed measure of tree species spatial diversity (TSS) is compared with four commonly used diversity indices using empirical and simulated data. The empirical dataset includes field observations with known tree coordinates from different forest types in China, Mongolia, Mexico, Germany, Myanmar, and South Africa. The simulated set uses 12 specifically designed patterns of spatial species mingling. The results show that the value of the TSS criterion increases with increasing tree species richness. In addition, TSS is sensitive to rare species and to variations in community structure, including species spatial isolation and spatial mingling. For these reasons, the TSS criterion is much more effective for measuring tree species diversity than the commonly used indices. It allows detailed interpretation of forest spatial diversity and of forest structural modifications after selective thinnings in multispecies forests. A particular advantage of the TSS index is the fact that its assessment, which is based on neighborhood relations, can be easily integrated in routine forest management surveys at practically no additional cost.
Modeling Crown Structure from LiDAR Data with Statistical Distributions
Authors: Cao Quang V. , Dean Thomas J.
Published: April 2024

The objective of this study was to evaluate the ability of three statistical distributions to characterize the vertical distribution of foliage mass in canopies of even-aged loblolly pine stands, based on airborne-scanning light detection and ranging (LiDAR) data. The functions were the Weibull and SB distributions and a mixture of the lognormal and Weibull distributions. Results indicated that the mixture distribution fit the LiDAR data better than the Weibull and SB distributions, according to three goodness-of-fit statistics. By switching from the lognormal for data near the tree top to the Weibull for data near the base of the crown, the mixture distribution seemed to better resemble the shape of the distribution of LiDAR returns than the Weibull alone. The mixture distribution was particularly effective for plots in which distributions of the returns were too peaked for either the Weibull or SB.
Dynamic Treatment Units in Eucalyptus Plantation
Authors: Packalén Petteri , Heinonen Tero , Pukkala Timo , Vauhkonen Jari , Maltamo Matti
Published: April 2024

The purpose of this study was to test airborne laser scanning-based forest inventory and the use of dynamic treatment units in eucalyptus plantations. Dynamic treatment units are formed by spatial optimization, which aggregates small inventory units. The hypothesis is that the use of dynamic treatment units increases yield and improves the efficiency of forest use. Forest inventory based on airborne laser scanning provides data for small units, which must be aggregated into feasible treatment units. The study area was a Eucalyptus pulpwood plantation in Brazil. Mixed-effects models were constructed for the basal area and dominant height using an area-based method. The plot-level estimates of growing stock characteristics were more accurate than those obtained for the stand level in many previous studies. The study area was divided into hexagons of 300 m2 for which the growing stock characteristics were estimated. A growth simulator was used to produce treatment schedules for the hexagons by varying the rotation length. The production potential of the planning area was examined by maximizing the growing stock volume at the end of the planning period with varying degrees of cutting area aggregation, with an even-flow cutting target for every 1-year period. The use of dynamic treatment units always increased the total volume production, i.e., the sum of harvested and ending volume. Cutting areas formed by spatial optimization often deviated from compartment boundaries.
Near-Surface Soil Carbon, Carbon/Nitrogen Ratio, and Tree Species Are Tightly Linked across Northeastern United States Watersheds
Authors: Ross Donald S. , Bailey Scott W. , Lawrence Gregory B. , Shanley James B. , Fredriksen Guinevere , Jamison Austin E. , Brousseau Patricia A.
Published: April 2024

Forest soils hold large stores of carbon, with the highest concentrations in the surface horizons. In these horizons, both the total C mass and the C/N ratio may respond more rapidly to changes in tree species than lower horizons. We measured C and C/N ratios in the Oa or A horizon from 12 watersheds at 8 established forested research sites in the northeastern United States. The dominant tree species included Acer saccharum, Betula alleghaniensis, Fagus grandifolia, Picea rubens, and Tsuga canadensis. In 710 plots, both soil C (50–530 g kg−1) and the C/N ratio (11.6–45.3) had a wide range. In all but the Cone Pond watershed, both N concentration and the C/N ratio were strongly related to C content. For these 11 watersheds, the average C/N ratio = 9.5 + 0.030 × C g kg−1 (R2 = 0.97, P < 0.001). Ratios at Cone Pond were much higher than would be predicted from this equation and charcoal was found in numerous samples, suggesting a source of recalcitrant C. Averaged by watershed, C concentration was also significantly related to C pools. The carbon concentration of the horizons sampled was negatively related to A. saccharum + B. alleghaniensis dominance and positively related to conifer + F. grandifolia dominance. The strong relationships between C, C/N ratio, and species suggest predictable patterns in C accumulation in near-surface soils.
Positive Relationship between Aboveground Carbon Stocks and Structural Diversity in Spruce-Dominated Forest Stands in New Brunswick, Canada
Authors: Wang Weifeng , Lei Xiangdong , Ma Zhihai , Kneeshaw Daniel D. , Peng Changhui
Published: April 2024

Maintaining both the structure and functionality of forest ecosystems is a primary goal of forest management. In this study, relationships between structural diversity and aboveground stand carbon (C) stocks were examined in spruce-dominated forests in New Brunswick, Canada. Tree species, size, and height diversity indices as well as a combination of these diversity indices were used to correlate aboveground C stocks. Multiple linear regressions were subsequently used to quantify the relationships between these indices and aboveground C stocks, and partial correlation analysis was also adopted to remove the effects of other explanatory variables. Results show that stand structural diversity has a significant positive effect on aboveground C stocks even though the relationship is weak overall. Positive relationships observed between the diversity indices and aboveground C stocks support the hypothesis that increased structural diversity enhances aboveground C storage capacity. This occurs because complex forest structures allow for greater light infiltration and promote a more efficient resource use by trees, leading to an increase in biomass and C production. Mixed tolerant species composition and uneven-aged stand management in conjunction with selection or partial cutting to maintain high structural diversity is therefore recommended to preserve biodiversity and C stocks in spruce-dominated forests.
Changes in the amount of nucleotide sugars in aged mouse tissues
Authors: Imae Rieko , Manya Hiroshi , Tsumoto Hiroki , Umezawa Keitaro , Miura Yuri , Endo Tamao
Published: April 2024

Aging affects tissue glycan profiles, which may alter cellular functions and increase the risk of age-related diseases. Glycans are biosynthesized by glycosyltransferases using the corresponding nucleotide sugar, and the availability of nucleotide sugars affects glycosylation efficiency. However, the effects of aging on nucleotide sugar profiles and contents are yet to be elucidated. Therefore, this study aimed to investigate the effects of aging on nucleotide sugars using a new LC-MS/MS method. Specifically, the new method was used to determine the nucleotide sugar contents of various tissues (brain, liver, heart, skeletal muscle, kidney, lung, and colon) of male C57BL/6NCr mice (7- or 26-month-old). Characteristic age-associated nucleotide sugar changes were observed in each tissue sample. Particularly, there was a significant decrease in UDP-glucuronic acid content in the kidney of aged mice and a decrease in the contents of several nucleotide sugars, including UDP-N-acetylgalactosamine, in the brain of aged mice. Additionally, there were variations in nucleotide sugar profiles among the tissues examined regardless of the age. The kidneys had the highest concentration of UDP-glucuronic acid among the seven tissues. In contrast, the skeletal muscle had the lowest concentration of total nucleotide sugars among the tissues; however, CMP-N-acetylneuraminic acid and CDP-ribitol were relatively enriched. Conclusively, these findings may contribute to the understanding of the roles of glycans in tissue aging.
The MIC distribution of dalbavancin differs between different coagulase-negative staphylococci
Authors: Svensson Sara , Hagstedt Paulina , Söderquist Bo
Published: April 2024

Background

CoNS constitute a significant part of the human microbiota of skin and mucous membranes. They can cause nosocomial infections, and have shown decreased susceptibility to several antibiotics. The few remaining treatment options include (lipo)glycopeptides such as dalbavancin. However, there is a lack of knowledge concerning whether susceptibility to lipoglycopeptides varies between different species of CoNS.

Objectives

To determine the susceptibility to dalbavancin in different species of CoNS.

Methods

We investigated 480 bacterial isolates from 10 CoNS species: Staphylococcus epidermidis, Staphylococcus capitis, Staphylococcus caprae, Staphylococcus haemolyticus, Staphylococcus lugdunensis, Staphylococcus warneri, Staphylococcus pettenkoferi, Staphylococcus hominis, Staphylococcus sciuri and Staphylococcus simulans. The isolates were randomly selected from different sources of infection, including blood isolates, as well as deep and superficial infections. Antibiotic susceptibility was tested with the gradient test method.

Results

There was a statistically significant difference (ANOVA; P < 0.0001) in the MIC distribution for dalbavancin between different CoNS species. S. sciuri was the least susceptible species, with 90% of the isolates having an MIC value for dalbavancin above the EUCAST breakpoint of 0.125 mg/L. The lowest MIC90 values were seen for S. capitis, S. simulans and S. caprae (all 0.032 mg/L).

Conclusions

This study demonstrated a difference in dalbavancin susceptibility between different CoNS species, suggesting that species-specific breakpoints for CoNS should be further investigated.
Cybersecurity trends in Cooperative, Connected and Automated Mobility
Authors: Campo O Castillo , Martínez V Gayoso , Encinas L Hernández , Muñoz A Martín , Fernández R Álvarez
Published: April 2024

Cooperative, connected and automated mobility technologies have the potential to revolutionize transportation systems and enhance safety, efficiency and sustainability. However, the increasing reliance on digital technologies also introduces new cybersecurity risks that can compromise the safety and privacy of passengers and the integrity of transportation systems. The purpose of this article is to examine the most important threats, vulnerabilities, risks and challenges related to automated mobility and to review the status of the most promising standardization initiatives on cryptography in a world where quantum computers will soon represent an actual threat.
A single arm Phase I/II trial on the combination of carboplatin, nab-paclitaxel and avastin as first-line treatment for advanced non-squamous non-small cell lung cancer (TORG1424/OLCSG1402: CARNAVAL)
Authors: Nogami Naoyuki , Kubo Toshio , Bessho Akihiro , Sakugawa Makoto , Ikeo Satoshi , Yokoyama Toshihide , Seki Nobuhiko , Ochiai Ryosuke , Fujimoto Nobukazu , Murakami Shuji , Kaira Kyoichi , Harada Toshiyuki , Kishino Daizo , Takiguchi Yuichi , Shimokawa Tsuneo , Kiura Katsuyuki , Yamashita Natsumi , Okamoto Hiroaki
Published: April 2024

Background

Bevacizumab with platinum doublet therapy including paclitaxel + carboplatin improves the survival of patients with non-squamous non-small cell lung cancer. However, in a previous trial (CA031), paclitaxel + carboplatin led to Grade > 3 neutropenia in a Japanese population. Nanoparticle albumin-bound paclitaxel exhibits an improved toxicity profile. We evaluated the safety, dosage and response rate of the nanoparticle albumin-bound paclitaxel + carboplatin + bevacizumab combination in a Japanese population.

Methods

Chemotherapy-naive patients with advanced non-squamous non-small cell lung cancer were included. The dosage schedule was established in the Phase I trial as follows: 4–6 cycles of carboplatin (area under the concentration–time curve = 6 on Day 1) + nanoparticle albumin-bound paclitaxel (100 mg/m2 on Days 1, 8 and 15) + bevacizumab (15 mg/kg on Day 1), followed by maintenance therapy (nanoparticle albumin-bound paclitaxel + bevacizumab). The response rate and presence of adverse effects were evaluated in the Phase II trial.

Results

The overall response rate was 56.5% (90% confidence interval: 44.5–68.5), and 93% of patients (43/46) showed tumor shrinkage or maintained a stable disease course. The primary endpoint was achieved. At the median follow-up duration of 42 months, the median overall survival was 18.9 (range: 10.5–32.4) months. The most frequently observed Grade ≥ 3 adverse effects were neutropenia (72%), leukopenia (50%) and anemia (30%).

Conclusions

All adverse effects were manageable and none resulted in patient death. In conclusion, the nanoparticle albumin-bound paclitaxel + carboplatin + bevacizumab combination is favorable and well tolerated in Japanese patients as first-line treatment for advanced non-squamous non-small cell lung cancer.
Alien Plant Invasions: The Story of Cogongrass in Southeastern Forests
Authors: Jose S. , Cox J. , Miller D.L. , Shilling D.G. , Merritt S.
Published: April 2024

Cogongrass (Imperata cylindrica), an alien grass listed as a federal noxious weed, has become a force to reckon with in the forestlands of the southeastern United States. Accidentally introduced in 1912 in packing material from Japan, the weed has negatively affected both natural and planted forests. Knowledge about the biology and management of cogongrass among foresters and land managers in the region is the greatest help in the fight against this alien species. An integrated management approach using all available methods is necessary to control cogongrass.
Focus on…Media Outreach: Think Locally, and You'll Make a World of Difference
Authors: Ghannam J.
Published: April 2024

Making and maintaining relationships with media representatives takes persistence and patience. It helps to know a few rules of the road.
Focus on ... Private Forest Landowners: FAQs about Conservation Easements
Authors:   none
Published: April 2024

Private forest landowners may want to consider a conservation easement to keep their land forested in perpetuity.
Perspective: Preventing Urban Sprawl while Preserving Military Readiness
Authors: Omans J.
Published: April 2024

To sustain the use of military lands for military training, and thus to prevent further development, the Marine Corps must obtain the help of private conservation groups to purchase undeveloped lands adjacent to or near military lands.
Return of the Giants: Restoring Western White Pine to the Inland Northwest
Authors: Fins L. , Byler J. , Ferguson D. , Harvey A. , Mahalovich M.F. , McDonald G. , Miller D. , Schwandt J. , Zack A.
Published: April 2024

Relatively high levels of blister rust infection in some stands of genetically improved western white pine (Pinus monticola) raised concerns that resistance may fail under field conditions. However, surveys show consistently lower infection and mortality in genetically improved white pine compared to unimproved stock. Restoring white pine by continued breeding for high levels of rust resistance, increased planting of resistant seedlings, and other silvicultural treatments are recommended to help alleviate forest health problems in Inland Northwest forests.
Focus on ... Forestry Students and Faculty: High-Tech Training: Using the Web for Photointerpretation
Authors: Befort W.
Published: April 2024

In Minnesota, students of photointerpretation can use two websites to hone their skills.
Perspective: In Search of Objectivity in Forest Auditing
Authors: Rockwell H.W. , Levesque C.A.
Published: April 2024

There is substantial controversy, and even confusion, regarding sustainable forestry audits.