bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hedonic Analysis of Hunting Lease Revenue and Landowner Willingness to Provide Fee-Access Hunting
Authors: Hussain Anwar , Munn Ian A. , Grado Stephen C. , West Ben C. , Daryl Jones W. , Jones Jeanne 
Published: April 2024

Abstract
Selling hunting access may supplement household income, yet only a small proportion of nonindustrial private (NIP) landowners in United States lease the right to hunt their land. Based on a survey of Mississippi landowners, the decision to lease hunting rights and factors influencing lease revenue per leased hectare were analyzed. The two issues were jointly modeled consistent with Heckman's sample selection model, and the lease revenue was specified in accordance with hedonic pricing theory. Empirical results showed that landowner concerns about loss of privacy, accident liability, and conflicts with personal use of land reduced the likelihood of leasing; total landownership and specific landowner characteristics increased it. With regards to factors explaining differences in lease revenue per leased hectare, bottomland hardwoods commanded a greater premium than many other land uses. In addition, lease revenue per hectare was distinctly higher where a landowner had expertise in managing a hunting lease enterprise. These findings have implications for landowners interested in managing wildlife-associated enterprises and public agencies engaged in the provision of natural resource-based recreation.
Relative Influence of the Components of Timber Harvest Strategies on Landscape Pattern
Authors: Gustafson Eric J. 
Published: April 2024

Abstract
Forest managers seek to produce healthy landscape patterns by implementing harvest strategies that are composed of multiple management components such as cutblock size, rotation length, even-aged or uneven-aged residual stand structure, conversion to plantations, and the spatial dispersion of harvest units. With use of the HARVEST model and neutral landscapes, a factorial simulation experiment was conducted to determine how each management component influenced measures of spatial pattern. There was a significant overall effect of all components on response variables defined by age class and on all but the rotation length component for response variables defined by forest type. Increasing cutblock size, rotation length, and clustering of cutblocks generally reduces measures of age class fragmentation, and increasing the use of even-aged management increases fragmentation. The response of forest type variables was consistently dominated by the component (percent plantation) that changed the abundance of a forest type. Dispersion also had a significant effect because conversions were allocated in space through the dispersion treatment. The results can be used to develop strategies to mitigate negative effects of certain silvicultural activities by showing which other components have opposite effects. Managers can better predict how specific strategy components will contribute to the cumulative landscape pattern.
Recruitment Patterns in a Mediterranean Oak Forest: A Case Study Showing the Importance of the Spatial Component
Authors: Maltez-Mouro Sara , García Luis V. , Marañón Teodoro , Freitas Helena 
Published: April 2024

Abstract
The spatial patterns of recruits in a Mediterranean forest in Southwest Portugal were examined. We aimed to investigate how several environmental and canopy variables contribute to the observed patterns, and how relevant the spatial component is in explaining the variance in the density of recruits. We took a census of every recruit of four dominant woody species (Arbutus unedo, Quercus faginea, Q. suber, and Viburnum tinus), mapping their position inside two forest plots. For a total of 309 recruits, we measured the following variables: soil moisture, slope, canopy density, herbaceous and litter ground cover, overlying species and height, and distance to the nearest adult of the same and different species. Spatial pattern analysis, principal coordinate analysis of neighbor matrices, canonical correspondence analysis, and variance partitioning were performed to detect significant deviations from complete spatial randomness and identify conspecific and interspecific patterns, characterize regeneration niches, and evaluate the importance of the spatial component. Results showed the existence of significant community structure at the recruitment stage. The distance between recruits and the nearest conspecific adult was the main explanatory variable. Light availability, soil moisture, litter accumulation, and the overlying species were also significant factors in explaining the variance in the density of recruits. The best model accounted for 37% of the overall variance in the density of recruits, and most (80%) of the explained variance corresponded to spatially structured variance. This case study shows the importance of the spatial component in understanding the forest regeneration patterns under Mediterranean conditions and will contribute to the implementation of ecologically based management actions to preserve the remaining forest fragments.
Tree-Soil Interactions Affect Production of Loblolly and Slash Pine
Authors: Dicus Christopher A. , Dean Thomas J. 
Published: April 2024

Abstract
Species-related differences in needle litter nutrient concentrations and subsequent N mineralization were examined in 17-year-old stands of loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) at a common site. Results of this common-garden study indicate that a feedback may exist between foliar litter nutrient concentration and soil N mineralization. Net N mineralization (to 30 cm) was significantly greater in loblolly pine than in slash pine stands, which was attributed to greater litter nutrient concentrations in loblolly pine. Stand volume production was also greater in loblolly pine than in slash pine and was positively correlated with N mineralization. Although lower litter nutrient concentrations may have reduced productivity of slash pine relative to loblolly pine in this study, they may serve as a mechanism to increase the relative fitness of the species by lowering the soil nutrient availability below the optimum of loblolly pine.
The Severity of Budworm-Caused Growth Reductions in Balsam Fir/Spruce Stands Varies with the Hardwood Content of Surrounding Forest Landscapes
Authors: Campbell Elizabeth M. , MacLean David A. , Bergeron Yves 
Published: April 2024

Abstract
Tree-ring data collected from balsam fir (Abies balsamea [L.] Mill.) in 31 spruce (Picea spp.)/fir-dominated stands in northern New Brunswick were used to evaluate how radial growth reductions during the last spruce budworm (Choristoneura fumiferana Clem.) outbreak (1972–1992) varied according to the hardwood content of surrounding forest landscapes, insecticide spray history and elevation. Stepwise regression analysis was used to build 12 models describing relationships between mean percent growth reduction (i.e., deviation from mean tree growth averaged over the lifespan of all trees in a stand) and the explanatory variables for years when &gt;80% of stands had growth reductions (1976–1978, 1982–1984, 1990, 1991, and 1994) and for three growth reduction periods (1972–1980, 1981–1985, and 1986–1993). The hardwood content of surrounding forest landscapes entered into all significant regression models (P &lt; 0.05), explaining 12–41% of the variance in budworm-caused growth reductions. Differences in growth reductions among stands were greatest during the initial years of the budworm outbreak (1972–1980), particularly in 1976 when mean reductions were 40% in stands with &lt;50% hardwood and content and 20% in stands in which surrounding hardwood content was &gt;50%. Relationships between variation in growth reductions among stands and elevation or insecticide spray history were weak and less consistent than with landscape hardwood content. Our findings suggest that increasing the hardwood content of forest landscapes could help to reduce the impact of outbreaks on timber supplies.
Economic and Ecological Effects of Diameter Caps: A Markov Decision Model for Douglas-Fir/Western Hemlock Forests
Authors: Zhou Mo , Buongiorno Joseph , Liang Jingjing 
Published: April 2024

Abstract
We evaluated some of the effects of not harvesting trees of 41 cm (16 in.) dbh or larger with uneven-aged management of Douglas-fir/western hemlock forests. The opportunity cost of diameter caps was measured by the difference in maximum expected net present value (NPV) or equivalent annual timber income, with or without diameter caps. For the two policies, Markov decision models were used to determine the best decision rules and their effects on the NPV, the forest area with late-seral structure, and the forest area with northern spotted owl nesting habitat structure. The opportunity cost of diameter caps was computed for 64 initial stand states defined by basal area of small, medium, or large trees of shade-intolerant species (mostly Douglas-fir) or shade-tolerant species (mostly western hemlock). The opportunity cost fell in four distinct quartiles. The 16 stand states with high basal area in large shade-intolerant and large shade-tolerant trees had the highest opportunity cost ($798–$816 ha−1year−1 or 58–76%, expected over an infinite horizon), whereas the 16 stand states with low basal area in large shade-intolerant and large shade-tolerant trees had the lowest ($59–$89 ha−1year−1 or 11–13%). The diameter caps policy increased considerably the expected area of forest with late-seral structure, over an infinite time horizon, and the expected area with spotted owl nesting habitat structure, compared with their current levels in the study region.
Modeling Containment of Large Wildfires Using Generalized Linear Mixed-Model Analysis
Authors: Finney Mark , Grenfell Isaac C. , McHugh Charles W. 
Published: April 2024

Abstract
Billions of dollars are spent annually in the United States to contain large wildland fires, but the factors contributing to suppression success remain poorly understood. We used a regression model (generalized linear mixed-model) to model containment probability of individual fires, assuming that containment was a repeated-measures problem (fixed effect) and individual fires were random effects. Changes in daily fire size from 306 fires occurring in years 2001–2005 were processed to identify intervals of high spread from those of low spread. The model was tested against independent data from 140 fires in 2006. The analysis suggested that containment was positively related to the number of consecutive days during which the fire grew little and the number of previous intervals. Containment probability was negatively related to the length of intervals during which the fire exhibited high spread and the presence of timber fuel types, but fire size was not a significant predictor. Characterization of containment probability may be a useful component of cost-benefit analysis of large fire management and planning systems.
Analysis of Holm Oak Intraspecific Competition Using Gamma Regression
Authors: Gea-Izquierdo Guillermo , Cañellas Isabel 
Published: April 2024

Abstract
Analysis of plant competition is a major issue in ecology and forestry, as it influences plant growth and plant-environment interactions. Competition is expected to be lower in the sparse tree stratum of open woodlands and agroforestry systems than in closed forests. We have analyzed competition in open woodlands of Quercus ilex in the Iberian Peninsula by studying a 10-year diameter growth increment from collected samples and from consecutive National Forest Inventories. Density was the competition index selected in all models, outperforming more complex distance-dependent indices. The models showed that competition is playing a role in growth but that the covariate most correlated with growth is age or dbh as a surrogate of age. Therefore, below-ground competition is likely to be limiting tree growth, but below-ground competition is lower in open woodlands compared with that in denser forests and thus potential growth (which is strongly linked to age) is almost expressed. Model behavior was improved when data were fitted directly using generalized linear models, which do not require transforming of the dependent variable. Our results showed that modeling growth with the gamma probability distribution resulted in better models compared with Gaussian linear models. Gamma regression offers a great potential for many forestry applications.
The Interaction among Provenances of Melaleuca leucadendra (Weeping Paperbark), Salt, and Aluminum
Authors: Nguyen Nguyen T. , Saneoka Hirofumi , Suwa Ryuichi , Fujita Kounosuke 
Published: April 2024

Abstract
The expansion in salt-affected acid sulfate soil areas induced by the rise in sea level calls for studies on plant tolerance to combined aluminum (Al) and salt (NaCl) stress. We investigated the difference in tolerance to Al and NaCl alone and in combination among 16 Melaleuca leucadendra (L.) L. provenances. Two-month-old seedlings were grown with or without 10 mM Al and/or 50 mM NaCl at pH 3.8 for 3 months. Plant growth was reduced most by combined Al and NaCl stress and then by NaCl and least by Al, and provenance variation in stress tolerance increased with an increase in the level of the stress effect. Al and NaCl enhanced each other's effects in nine provenances, but they alleviated each other's effects in two provenances. There were significant differences in plant growth among provenances in every treatment; however, positive relationships were found among Al tolerance, NaCl tolerance, and combination tolerance. Combined Al and NaCl stress greatly increased Na concentration, whereas it decreased K concentration in leaf sap. Tolerance to combination stress tended to have negative relationships with both stress-induced reduction in leaf osmotic potential and leaf K concentration among provenances, suggesting that provenance variability in tolerance to combined Al and NaCl stress is partly due to differences in the ability to limit ionic stress through an adjustment in K uptake.
Effects of Timber Prices, Ownership Objectives, and Owner Characteristics on Timber Supply
Authors: Favada Ibrahim M. , Karppinen Heimo , Kuuluvainen Jari , Mikkola Jarmo , Stavness Corinne 
Published: April 2024

Abstract
In this article, we examine factors affecting nonindustrial private timber supply using a consistent estimation method for a limited dependent variable model. The survey data, collected in 1999 from 3,051 Finnish forest owners, includes information on objectives for ownership as well as annual harvest volumes between 1994 and 1998. Ownership objectives are identified using principal component analysis, and five forest ownership objective groups are generated using K-means clustering: multiobjective owners, investors, self-employed owners, recreationists, and indifferent owners. Along with stumpage price, reforestation costs and forest and owner characteristics, including the above objective groups, are used as explanatory variables in estimating the supply equation. A consistent estimation method allowing for heteroscedasticity and non-normality is used. Statistically significant elasticity of the unconditional mean harvest with respect to timber price is 1.3. Recreationists and indifferent forest owners, ceteris paribus, harvest about 2 m3/ha/year less than multiobjective owners and self-employed owners, whereas investors and indifferent owners are more price-responsive than the other groups.
Estimation of Forest Stand Parameters from Airborne Laser Scanning Using Calibrated Plot Databases
Authors: Junttila Virpi , Kauranne Tuomo , Leppänen Vesa 
Published: April 2024

Abstract
Airborne laser scanning (also known as LiDAR) is rapidly turning into a popular method for operational forest assessment. In the course of this development, classic regression methods have been replaced by nonparametric or Bayesian methods. Accurate estimates with such methods require a large collection of several hundreds of sample plots, which is costly. We propose replacing most of these sample plots by ones collected during earlier missions in different, but similar, forests. However, using such replacement plots requires resolution of two problems. The first one is overcoming differences between different LiDAR scanners, scanning parameters, and scanning conditions, and the second one is avoiding bias due to use of alien plots. We propose a method that resolves both problems and uses only approximately 50 new plots. The method is tested for accuracy in total forest parameters and shown to provide satisfactory estimates for total forest parameters and to be robust against random variation in the selection of the few new plots.
Sediment Trapping by Streamside Management Zones of Various Widths after Forest Harvest and Site Preparation
Authors: Lakel William A. , Aust Wallace M. , Bolding M. Chad , Dolloff C. Andrew , Keyser Patrick , Feldt Robert 
Published: April 2024

Abstract
Recommended widths for streamside management zones (SMZs) for sediment protection vary. The objectives of this study were to compare the effects of SMZ widths and thinning levels on sediment moving through SMZs. Four SMZ treatments were installed within 16 harvested watersheds where intermittent streams graded into small perennial streams. Sites were clearcut, prescribed burned, and planted with loblolly pine (Pinus taeda L.). Treatments were 30.4-, 15.2-, and 7.6-m-wide SMZs without thinning and 15.2-m-wide SMZs with thinning. Three to seven treatments replicated within four blocks created a randomized incomplete block design. Erosion rates from watersheds and sediment trapping within SMZ treatments were monitored with modeling and sediment pins. A second study evaluated 24 subwatersheds within eight watersheds. Three subwatersheds were located within each watershed so sediment traps collected inputs into SMZs from harvest site-prepared areas, firelines, or at streams. SMZ treatments had no significant differences regarding sediment trapping. All SMZs widths were generally effective in trapping sediment. Within the 16 intermittent-perennial watersheds and 24 ephemeral subwatersheds, erosion to sediment delivery ratios from harvests ranged from 3 to 14%. For ephemeral stream subwatersheds, firelines adjacent to SMZs contributed 14% of total sediment. Sediment trap data collected within SMZs indicated that 97% of watershed erosion was trapped before reaching streams. In three subwatersheds, sediment penetrated SMZs due to channelized flow from failed or inadequate water controls on roads and firelines. Results support the common recommendation for SMZ widths of 15.2 m in which partial harvests may occur and emphasize the importance of implementation of best management practices for roads and firelines.
An Exploratory Study of Biomass Harvesting among Logging Firms in Virginia and North Carolina
Authors: Munsell John F. , Barrett Scott M. , Bolding M. Chad 
Published: April 2024

Abstract
Logging firms in the United States will need to harvest and transport woody biomass if national wood-based renewable energy production goals are to be achieved. Expansion of associated biomass markets could provide important revenue opportunities for logging firms and potentially alter the sector. To study biomass harvesting behavior among logging firms, a logistic regression model was developed using a backward likelihood ratio procedure and 114 Virginia and North Carolina logging firms that operate in proximity to established woody biomass markets. The sample was identified from a larger pool of firm owners who participated in a Virginia Sustainable Harvesting and Resource Professional (SHARP) Logger Program survey. Hypothesized predictors included logging operation and owner variables. Confirmatory factor analysis was used to verify the underlying structure of summated latent constructs. The model correctly classified biomass harvesting 78% of the time, exhibited acceptable fit, and contained normally distributed residual error. Significant predictors included firm mechanization, haul distance, and owner perspectives regarding job security satisfaction and attitudes about biomass harvesting. Analysis of variance and χ2 were used to test for differences between significant predictors when factored across a three-point biomass market-action variable—no market, market/no harvest, and market/harvest. The follow-on market-action evaluations included firms from the SHARP Logger Program survey that share county-level centers of operation for which at least one of the firms noted proximity to a woody biomass market. Implications for logging sector research are discussed, along with practical considerations for regions where wood-based renewable energy initiatives are on the rise.
Promotion of market-based sanitation in Ethiopia: a case study from Wolaita zone
Authors: Mamo Biruk Getachew , Novotný Josef 
Published: April 2024

Abstract
Ethiopia increased the availability of latrines notably, but the sanitation facilities rarely meet hygienic standards. Therefore, the market-based sanitation (MBS) programme has been implemented across the country for nearly a decade to expand the market and boost the demand for hygienic sanitation products and services. While it does not seem that the MBS would bring any notable change in sanitation conditions so far, its implementation challenges are not adequately understood. To address this gap, this article delves into the grassroots-level implementation of MBS in the Wolaita zone. The study relies on qualitative data gathered through interviews with various stakeholders, examining both demand- and supply-side challenges. Some issues identified were external to MBS implementation, such as high inflation and an unstable political and security situation in Ethiopia. Additionally, the study reveals that more general deficiencies of the Ethiopian health extension program, including the stress and discouragement of local change agents (health extension workers, health development army members) due to workloads and low remuneration, have adversely impacted MBS delivery. The implementation of MBS has also not effectively addressed the affordability of hygienic sanitation products. On the supply side, economic constraints and organizational inefficiencies have hindered the development of the sanitation market, preventing it from reaching a critical mass. Our research suggests that MBS alone will not suffice to improve sanitation in Ethiopia.