bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Application of a Reduced Cost Approach to Spatial Forest Planning
Authors: Pukkala Timo , Heinonen Tero , Kurttila Mikko 
Published: April 2024

Abstract
The task of forest planning is to find the best combination of treatment schedules for forest stands. With many stands and several alternatives per stand the number of possible combinations becomes very large and standard heuristics for combinatorial optimization such as simulated annealing (SA), tabu search, and genetic algorithm become slow. One way to deal with the problem of large decision space is to decompose the forest-level problem into stand-level subproblems. We developed a spatial application of the decomposing technique proposed by Hoganson and Rose. This method maximizes the reduced cost (RC) of each stand. The dual prices of forest-level constraints appear in the RC function and they tie the stand-level problems together. In our spatial application of the RC method we used a multiobjective stand-level objective function. The function included spatial objective variables, the values of which depended on adjacent stands. The dual prices of nonspatial forest-level constraints were gradually adjusted by using a variant of the subgradient method, until the set of stand-level solutions fulfilled the forest-level constraints. The method was compared with a cellular automaton and the SA heuristic in a spatial problem in two different forests. The results suggest that the spatial application of the RC method is competitive with heuristics currently used in forest planning. It was slightly superior to SA in terms of the objective function value of SA. The method is easy to use because it has few parameters.
On the Use of Statistical Tests with Non-Normally Distributed Data in Landscape Change Detection
Authors: Strimbu Bogdan , Hickey Gordon , Strimbu Vladimir , Innes John 
Published: April 2024

Abstract
Research assessing changes of the main attributes describing forested landscapes often supply contradictory findings when viewed within an unchanging socioeconomic framework (i.e., unchanging forest management policies and no human population increase). Some studies suggest forest decline, others no change, and others expansion. We used ground-measured forest inventory data from Romania to examine the evolution of the forested landscape over a 10-year period (1993–2003), during which no substantial transformations occurred in the human population or in forest management policies. Within a repeated-measures framework, a range of parametric and nonparametric statistical tests were used to evaluate forest change. Our results revealed that significant structural changes occurred at the landscape level. The changes were detected by several multivariate and nonparametric techniques. Multivariate techniques revealed that “age class,” “phyto-climatic zone,” and “ownership type” attributes had a significant influence in delineating between the 1993 and 2003 forested landscape. The univariate nonparametric tests indicated that there are factors not considered in the planning process (such as ownership or inflation) that can lead to a significant decrease of the main quantitative forest attributes (such as canopy closure or height), a decrease undetected by the corresponding parametrical statistics. Our research revealed that even when the distribution did not exhibit significant skewness, the nonparametric techniques could be more efficient than the corresponding parametric techniques by detecting significant changes of the attributes describing the forested landscape.
Public Participation GIS: A New Method for Use in National Forest Planning
Authors: Brown Gregory G. , Reed Pat 
Published: April 2024

Abstract
In this article we describe and evaluate a public participation geographic information systems (PPGIS) methodology for use in national forest planning in the United States. The Internet-based mapping method collects public landscape values and special places data for input into a national forest planning decision support system. The PPGIS method presupposes that, within their existing statutory framework, national forests should be managed for compatibility with the range of values the public holds for those lands and that inadequate understanding, modeling, and documentation of place-specific forest values can negatively affect public acceptance, viability, and the usefulness of national forest plans. In this article we 1) review previous applications of landscape value mapping methods across a variety of planning applications, 2) describe the participatory, Internet mapping method used in three studies of national forests in Arizona and Oregon in 2006 and 2007, 3) present and evaluate the results to show likely future implementation constraints, and 4) based on lessons learned, describe a recommended PPGIS protocol for national forest planning. The results from the three studies demonstrate that an Internet, participatory mapping method, although not without limitations, can be effective in measuring landscape value and special place data for use in a variety of forest planning processes. Because the protocol expands and in a sense democratizes the agency's public participation process, implementation of the PPGIS protocol across the national forest system can help restore public trust in the agency's forest planning processes and forest management decisions.
A Plotless Density Estimator Based on the Asymptotic Limit of Ordered Distance Estimation Values
Authors: Kronenfeld Barry J. 
Published: April 2024

Abstract
Estimation of tree density from point-tree distances is an attractive option for quick inventory of new sites, but estimators that are unbiased in clustered and dispersed situations have not been found. Noting that bias of an estimator derived from distances to the kth nearest neighbor from a random point tends to decrease with increasing k, a method is proposed for estimating the limit of an asymptotic function through a set of ordered distance estimators. A standard asymptotic model is derived from the limiting case of a clustered distribution. The proposed estimator is evaluated against 13 types of simulated generating processes, including random, clustered, dispersed, and mixed. Performance is compared with ordered distance estimation of the same rank and with fixed-area sampling with the same number of trees tallied. The proposed estimator consistently performs better than ordered distance estimation and nearly as well as fixed-area sampling in all but the most clustered situations. The estimator also provides information regarding the degree of clustering or dispersion.
Investments in Timberland and Softwood Timber as Parts of Portfolio Selection in the United States: A Cointegration Analysis and Capital Asset Pricing Model
Authors: Liao Xianchun , Zhang Yaoqi , Sun Changyou 
Published: April 2024

Abstract
In this article we investigated the financial performance of investments in timberland and timber and their correlations with nonforestry financial assets in the United States. Cointegration analysis and the capital asset pricing model were used to examine the long-run and short-run correlations with quarterly data from January 1992 to June 2006. The results of the cointegration analysis revealed that investment return on timberland tended to increase by 1.3% as Southern softwood stumpage price increased by 1%, indicating that a shift from pulpwood to sawtimber production might increase timber price and thus benefit timberland investment. The results also indicated that there were positive correlations between farmland return and Southern softwood stumpage price and between the stock market and timberland, indicating that treatments such as high-intensity site preparation might increase land quality and, hence, enlarge timber size and increase timber price. However, investors need to be cautious with the stock market because any change in the stock market has a potential effect on the timberland market. The results of the capital asset pricing model showed that timberland generated significant excess returns over the study period, but softwood timber did not. Timberland or softwood did not reduce systematic risk in a portfolio with stocks in the short run. In the short run, abnormal returns on timberland did occur, and timberland would be a desirable investment vehicle mixed with real estate.
Effect of the Inclusion of Mushroom Values on the Optimal Management of Even-Aged Pine Stands of Catalonia
Authors: Palahí Marc , Pukkala Timo , Bonet José Antonio , Colinas Carlos , Fischer Christine R. , Martínez de Aragón Juan R. 
Published: April 2024

Abstract
Mushrooms are an important product of the pine stands of the Central Pyrenees of Catalonia. In places where the microclimate is reasonably moist, the value of mushrooms may be clearly higher than the value of timber production. This study examines the optimal economic management for both timber and mushrooms in even-aged Scots pine and Black pine stands in Catalonia. Empirical mushroom yield models were integrated in a stand growth simulator, which was linked with an optimization algorithm to find the optimal management schedule for Pinus sylvestris and Pinus nigra stands on different sites and with different mushroom prices. The results showed that on sites where the potential mushroom yield is high, mushrooms should be taken into account in stand management. Thinning treatments, which usually are unprofitable, were included in the optimal management schedule when mushroom production was included in the analysis. Although thinnings have a negative short-term effect on mushroom yields, their long-term effect is often positive because they reduce stand density to a level that is favorable for mushrooms. At elevations that are suitable for P. sylvestris (900–1,500 m above sea level), the soil expectation value (SEV) of mushroom yields was commonly 4–10 times higher than the SEV of timber production. At somewhat lower elevations, where P. nigra dominates, the effect of mushrooms on the optimal stand management was smaller because mushroom yields are typically lower in P. nigra stands.
Long-Term Changes in Forest Productivity: A Consistent Assessment in Even-Aged Stands
Authors: Bontemps Jean-Daniel , Hervé Jean-Christophe , Dhôte Jean-François 
Published: April 2024

Abstract
The objective of the study was to provide a stand-scale assessment of long-term productivity changes in even-aged stands and to depict their chronology over the 20th century. We focused on dominant height growth as a proxy for productivity, reconstructed from stem analyses in temporary plots. Height increments from two generations of stands were compared. Stands were associated in pairs to ensure accurate control of intrinsic site fertility conditions. The historical evolution of the growth rate was estimated using a statistical modeling approach based on a mixed-effects model, with a control of both site and developmental stage effects. We placed emphasis on a model formulation that leads to a meaningful interpretation of growth rate evolution. We applied the methodology to a sample of 14 stand pairs and 84 stem analyses of common beech in northeastern France. An accelerated increase in growth rate was identified, reaching +50% over the 20th century. The trend also displayed short-term growth anomalies.
Short-Term Effects of Thinning and Burning Restoration Treatments on Avian Community Composition, Density, and Nest Survival in the Eastern Cascades Dry Forests, Washington
Authors: Gaines William , Haggard Maryellen , Begley James , Lehmkuhl John , Lyons Andrea 
Published: April 2024

Abstract
We monitored the short-term (&lt;3 years) response of land birds to restoration treatments (thin, burn, and thin-burn) in dry forests located on the eastern slope of the Cascade Range in Washington. Overall avian community composition did not change among the treatments. However, individual species responses varied with the chipping sparrow showing lower density in treatments, whereas hermit thrush, mountain chickadee, white-headed woodpecker, western bluebird, American crow, and common raven increased in treatment units. Daily survival rates of nesting guilds were similar in treated versus control stands; however, burn-only showed lower daily survival rates compared with other treatments. Additional research is needed to validate this result. Cavity-nesters (mountain chickadee, red-breasted nuthatch, and house wren) and foliage-nesters (chipping sparrow) used trees that were larger in diameter than available regardless of the treatment. Our results, in combination with other results from this study area, provide important implications for managers: (1) thin-burn treatments were effective at restoring habitat for several avian focal species; (2) spring burn treatments should be carefully designed to achieve desired restoration objectives; (3) large trees provide important habitat functions and are a key component for maintaining or restoring the viability of focal avian species; and (4) additional research is needed to better understand the effects of spring burning and the long-term effects of dry forest restoration treatments.
Response of the Photosynthesis and Antioxidant Systems to High-Temperature Stress in Euonymus japonicus Seedlings
Authors: Jin Song-Heng , Li Xue-Qin , Zheng Bing-Song , Wang Jun-Gang 
Published: April 2024

Abstract
To uncover the adaptive mechanisms of photosynthesis under high temperatures (HTs), changes in the activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco), the photosynthetic electron transport system, and antioxidant system were examined in a subtropical forest tree seedling, Euonymus japonicus. Compared with the control, the activity of rubisco and the quantum yield of photosystem (PS) II electron transport (ΦPSII) decreased in HT-treated seedlings, whereas energy-dependent quenching of chlorophyll (Chl) fluorescence (qE) increased. An analysis of the redox change of P700 and the oxygen uptake by PSI indicated that the cyclic electron transport around PSI operated at high rates in E. japonicus seedlings exposed to HT conditions. Furthermore, the levels of reactive oxygen species (ROS), the activities of superoxide dismutase, and the activities of ascorbate peroxidase were increased in HT-treated seedlings. Therefore, it is likely that an enzyme-based water-water cycle was initiated in E. japonicus seedlings in response to HT stress and that the HT-induced ROS might play an important function in HT conditions. Enhancement of cyclic electron transport around PSI and water-water cycles might help maintain a transthylakoid energy potential under HT conditions. This coordinated defense may play an important role in adaptation of E. japonicus cells to HT.
Selection Efficiency for Solid Wood Traits in Pinus taeda using Time-of-Flight Acoustic and Micro-Drill Resistance Methods
Authors: Eckard Jonathan T. , Isik Fikret , Bullock Bronson , Li Bailian , Gumpertz Marcia 
Published: April 2024

Abstract
Conventional sampling and laboratory analysis of solid wood properties to facilitate clonal screening in tree improvement programs are prohibitively time-consuming and expensive. Alternative methods—time-of-flight acoustics and micro-drilling resistance—were assessed for efficiency in screening clones for wood stiffness (modulus of elasticity [MOE]), strength (modulus of rupture [MOR]), and density. Ninety clones, consisting of 30 from each of 3 full-sib families, were screened in an 8-year-old loblolly pine (Pinus taeda L.) field test using a TreeSonic time-of-flight tool and Resistograph drill resistance tool. The same clones were sampled for wood specimens for laboratory tests of MOE, MOR, and density. TreeSonic stress wave speed measurements produced highly repeatable clonal phenotypes that facilitated efficient selection for MOE and to a lesser extent for MOR. Resistograph amplitude measurements had a strong genetic correlation with wood density and facilitated highly efficient selection for density, with correlated responses for MOR and MOE. Combining the indirect traits into a selection index improved gain for mechanical wood traits. Both tools provided high measurement rates that resulted in cost efficiencies. Indirect measurements of solid wood properties should be attractive for clonal selection programs that must screen thousands of clones under a finite budget.
Trivariate Distribution Modeling of Tree Diameter, Height, and Volume
Authors: Wang Mingliang , Upadhyay Anoop , Zhang Lianjun 
Published: April 2024

Abstract
Trivariate distribution models were constructed for tree diameter (D), height (H), and volume (V) using a normal copula (a mathematical function that joins or links marginal distribution functions to form multivariate distribution functions). The model parameters were estimated by a two-stage semiparametric method as follows: univariate distribution models were fitted separately for each tree variable, and then the copula dependency (correlation) parameters were independently estimated using empirical distribution functions to approximate the marginal models. Our results indicated that, for the available trivariate data in this study, the log-logistic (a limiting form of the logit-logistic distribution) best described both D and V distributions, whereas the logit-logistic, Johnson's SB, and Weibull marginal models provided roughly the same fitting for the H distribution. The trivariate distribution models produced satisfactory estimates of trivariate frequencies for the three variables, as well as the volume predictions from the resulting median regression models, which were comparable with commonly used volume regression models. The advantage of the normal copula method is that one can use any marginal models suitable for modeling tree diameter, height, and volume distributions separately, rather than being restricted to the SB marginal model in Johnson's SBBB system.
Synthesis of Regional Wildlife and Vegetation Field Studies to Guide Management of Standing and Down Dead Trees
Authors: Marcot Bruce G. , Ohmann Janet L. , Mellen-McLean Kim , Waddell Karen L. 
Published: April 2024

Abstract
We used novel methods for combining information from wildlife and vegetation field studies to develop guidelines for managing dead wood for wildlife and biodiversity. The DecAID Decayed Wood Advisor presents data on wildlife use of standing and down dead trees (snags and down wood) and summaries of regional vegetation plot data depicting dead wood conditions, for forests across the Pacific Northwest United States. We combined data on wildlife use by snag diameter and density and by down wood diameter and cover, across studies, using parametric techniques of meta-analysis. We calculated tolerance intervals, which represent the percentage of each species' population that uses particular sizes or amounts of snags and down wood, and rank-ordered the species into cumulative species curves. We combined data on snags and down wood from &gt; 16,000 field plots from three regional forest inventories and calculated distribution-free tolerance intervals compatible with those compiled for wildlife to facilitate integrated analysis. We illustrate our methods using an example for one vegetation condition. The statistical summaries in DecAID use a probabilistic approach, which works well in a risk analysis and management framework, rather than a deterministic approach. Our methods may prove useful to others faced with similar problems of combining information across studies in other regions or for other data types.
Population Estimation Using Partial Double Sampling
Authors: Loehle Craig 
Published: April 2024

Abstract
Detectability issues create uncertainty in field surveys of populations. Methods to overcome this problem include mark-recapture methods and double sampling. Partial double sampling involves estimating detectability, &lt;inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="carrot-p.tif"/&gt;, and using this to correct the estimate in areas sampled only once. Results of this study indicate that, if population density is not uniform across sample units, there is a tradeoff for a given sampling effort, with lower population estimation error for double sampling only a portion of the area when spatial variance and/or detectability are lower but lower error for partial double sampling when spatial variance and/or detectability are higher. Thus, whereas standard double sampling increases precision, it does not give adequate accuracy in the face of spatial variation unless the entire area can be surveyed twice, which is more expensive.
Genetic Variation of Stem Forking in Loblolly Pine
Authors: Xiong Jin S. , Isik Fikret , McKeand Steven E. , Whetten Ross W. 
Published: April 2024

Abstract
Forking defects were studied in loblolly pine (Pinus taeda L.) in 6-year-old genetic tests from the second cycle of breeding in the North Carolina State University Cooperative Tree Improvement Program. Data were available from 268 test series (each with two 6-parent half-diallel mating designs, with 12 parents, 30 crosses, and 144 progeny per cross) over six geographic regions. A subset of 123 series with average forking between 20 and 80% was used for genetic analysis. Forking differed significantly among regions, with the highest in the Upper Gulf Coastal Plain (24%) and the lowest in the Georgia-Florida Coastal Plain (12%). The individual-tree heritabilities were low (0.06), but the half-sib (0.76), narrow-sense full-sib (0.59), and broad-sense full-sib (0.71) family-mean heritabilities were moderately high. This result suggests that forking is partially under genetic control at the family level, but at the individual tree level, it is mostly determined by the environment. Genetic gain was estimated for half-sib family selection with a selection differential of 20%. Gain ranged from 12 to 23% reduction in forking across different regions. A weak unfavorable genetic correlation (0.18) was found between forking and height, suggesting that selection for growth alone will negatively affect forking in loblolly pine. A favorable genetic correlation (0.33) was found between forking and straightness.
Effects of Planting Density and Seed Source on Loblolly Pine Stands in Southeastern Oklahoma
Authors: Will Rodney , Hennessey Thomas , Lynch Thomas , Holeman Randal , Heinemann Robert 
Published: April 2024

Abstract
Since the early 1970s, loblolly pine (Pinus taeda L.) plantations have been established west of the native range of the species in the Ouachita Mountains of Oklahoma, using faster-growing seed sources from coastal North Carolina (NCC) rather than Oklahoma or Arkansas (O/A). Although the NCC sources outperform O/A sources early in stand development, it is not known how these provenances will perform later in stand development when density-dependent mortality is occurring. We tested the effects of planting density (1,075, 1,680, 2,990, and 6,725 trees ha−1) and seed source (NCC and O/A) on stand and tree attributes for 25-year-old plantations located on a droughty, mountain soil in southeastern Oklahoma. Survival decreased with increasing stand density but did not differ among sources. Average tree diameter also decreased with increasing planting density (25.5 to 15.8 cm), and, again, the pattern was consistent across provenances. Average tree heights decreased with stand density (18.6 to 16.8 m); however, the NCC seed source was taller than the O/A seed source (18.4 versus 17.0 m). This resulted in NCC stands maintaining greater stand volume than O/A stands (329 versus 301 m3 ha−1). Basal area was similar among seed sources and did not significantly differ among densities (average 49.0 m2 ha−1). These results indicate that over 25 years, the NCC seed source performed better than the regional seed source even when grown under extremely high densities and experiencing density-dependent mortality.