bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does Faustmann Rotation Apply to Fully Regulated Forests?
Authors: Tahvonen Olli , Viitala Esa-Jussi 
Published: April 2024

Abstract
Forest economics literature contains two lines of research in which the Faustmann rotation is taken to be invalid for continuous harvesting, i.e., for normal or fully regulated forests. As alternatives, a “marginal model for divisible forest capital𠇍 and a “regular profit model for timber production𠇍 have been proposed and applied. In contrast, recent forest economics has provided vast evidence that the Faustmann rotation is the long-term stationary state in rotation models with multiple age classes. In this article, we attempt to clear up this contradiction in the literature by showing that the two approaches deviating from the Faustmann approach yield the same rotation period. The deviations from the Faustmann approach are because the models are based on incorrect formulas for the value of a normal forest.
A Multilevel Approach to Individual Tree Survival Prediction
Authors: Rose Charles E. , Hall Daniel B. , Shiver Barry D. , Clutter Michael L. , Borders Bruce 
Published: April 2024

Abstract
Traditionally, modeling of permanent plot individual tree survival has not considered the multiple sources of heterogeneity and correlation that may arise due to the multilevel data structure inherent in the design (e.g., clustering of trees within a plot). Permanent plots are sampled periodically; therefore, data are interval-censored because it is only known that a tree died between two successive measurement occasions. Here, we adopt the complementary log–log (CLL) function for modeling permanent plot interval-censored individual tree survival data. The CLL function is derived directly from the likelihood function of a fully specified statistical model that accounts for interval censoring. In addition, our CLL model considers silvicultural treatment effects on survival. Our data are from young permanent plot loblolly pine plantations that have been measured annually beginning at age 1 year. Each plot was randomly assigned one of four cultural treatments:control (C), herbicide (H), fertilization (F), and herbicide and fertilization (HF). Here we extend the individual tree survival CLL model to allow for trees within a plot and plot level random effects. We demonstrate individual tree survival predictions with and without the inclusion of random effects.
Corrections for Cluster-Plot Slop
Authors: Valentine Harry T. , Ducey Mark J. , Gove Jeffrey H. , Lanz Adrian , Affleck David L.R. 
Published: April 2024

Abstract
Cluster-plot designs, including the design used by the Forest Inventory and Analysis program of the USDA Forest Service (FIA), are attended by a complicated boundary slopover problem. Slopover occurs where inclusion zones of objects of interest cross the boundary of the area of interest. The dispersed nature of inclusion zones that arise from the use of cluster plots precludes the use of most of the slopover-correction methods that apply to solitary plots. One exception is the walkthrough method, which corrects for slopover bias in radially symmetric cluster-plot designs. In this article, we provide a modification of the walkthrough method, the “walkabout method,𠇍 which is applicable to some asymmetric cluster-plot designs, such as the one used by FIA. We also present two general correction methods, the “vectorwalk method𠇍 and the “reflection method,𠇍 both of which are applicable to cluster-plot designs with satellite subplots arranged in a regular or irregular pattern. The reflection method has two sets of protocols, one that applies to radially symmetric designs and to asymmetric designs with random orientation; the other set applies to asymmetric designs with fixed orientation. Both the vectorwalk and reflection methods incorporate the walkthrough method on a subplot-by-subplot basis. All four methods correct for slopover bias for straight or curved boundaries, and where work outside the tract is impossible.
Application of the Algebraic Difference Approach for Developing Self-Referencing Specific Gravity and Biomass Equations
Authors: Jordan Lewis , Souter Ray , Parresol Bernard , Daniels Richard F. 
Published: April 2024

Abstract
Biomass estimation is critical for looking at ecosystem processes and as a measure of stand yield. The density-integral approach allows for coincident estimation of stem profile and biomass. The algebraic difference approach (ADA) permits the derivation of dynamic or nonstatic functions. In this study we applied the ADA to develop a self-referencing specific gravity function and biomass function as part of a density-integral system composed of taper, volume, specific gravity, and biomass functions. This was compared to base systems of similar equations that did not have the self-referencing parameter specifications. Systems of equations were fit using nonlinear, seemingly unrelated regressions with nonlinear cross-equation constraints to account for contemporaneous correlations in the data. Results suggest that correct volume determination is more critical than specific gravity for accurate biomass estimates. The goodness-of-fit statistics clearly show that the self-referencing system provided a better fit than the base system.
Potential of Aerial Image-Based Monoscopic and Multiview Single-Tree Forest Inventory: A Simulation Approach
Authors: Korpela Ilkka Sakari , Tokola Timo Erkki 
Published: April 2024

Abstract
Two aerial image-based estimation chains were compared for their potential in the assessment of timber resources. The two chains consisted of two- and three-dimensional image measurements followed by indirect model estimation. The effects of various errors at both the single-tree and stand levels were examined with Monte Carlo simulation. The three-dimensional multiview estimation chain with height measurements of individual trees proved less prone to random and systematic errors than the monoscopic chain. An upper limit of accuracy at the single-tree level is determined mainly by the allometric correlations. Volume estimates of single trees showed estimation accuracies (root-mean-square error, RMSE) of 15–20% and 35–40% in the multiview and monoscopic chains, respectively. This is lower than the accuracy achievable in the field, which is 6%. Image-based single-tree forest inventory is prone to systematic measurement and model errors, and in a simulation for the total effect of error sources, upper estimation accuracies (RMSE) of 15% and 30% for stand volume were computed using full mapping of the stand with the multiview and monoscopic estimation chains, respectively.
A New Type of Sample Plot that Is Particularly Useful for Sampling Small Clusters of Objects
Authors: Iles Kim , Smith Nicholas J. 
Published: April 2024

Abstract
The sampling method presented here uses a new type of plot, with surprising characteristics. Although useful in sampling any grouping of objects, it is illustrated here by correctly sampling small patches of trees remaining after harvest. Small patches are difficult to sample unbiasedly because of the “edge effect𠇍 caused by sampling with fixed or variable plots. By this we do not refer to a biological effect on trees near an edge, but to a common sampling bias that distorts the selection probabilities of those trees. Groups of objects that are small and irregular are very prone to this “edge effect bias𠇍 when using typical sampling systems. “Sector plots𠇍 will allow the user to sample the trees in a small patch, and the method can also be extended to small trees planted outside the patch after harvesting, or to solitary “dispersed𠇍 trees outside the patch but within the harvested area. The method can unbiasedly select sample trees along an irregular border. The method eliminates all bias from edge effect. It can balance the tree selection on opposite sides of the patch, and the pivot point of the plot can be arbitrarily placed by the sampler in any convenient location without introducing any bias to the selection process. This new plot shape might be described as “a constrained angle shape with variable area, randomly oriented around an arbitrary sample point, which selects objects with equal probabilities.𠇍
Developing Dynamic Site Index Curves for European Beech (Fagus sylvatica L.) in Denmark
Authors: Nord-Larsen Thomas 
Published: April 2024

Abstract
In base-age specific methodologies, assessment of base age and site index may be a problem when developing site curves from repeated measurements on permanent sample plot data. In most cases, such data will not contain measurements at any base age that is common for all the sample plots, and some sort of interpolation or even extrapolation would have to be applied to address this issue. Base-age invariant methodologies pose the desirable property of estimating the curves without prior arbitrary assumptions about values of the site indices. Presented here is the development of such base-age invariant site index curves for European beech (Fagus sylvatica L.) in Denmark, fitted to permanent sample plot data. The developed polymorphic dynamic site equations with variable asymptotes are based on the generalized algebraic difference approach, and the parameters of the model were estimated with correction for first-order serial correlation.
Analysis of Different Base Models and Methods of Site Model Derivation for Scots Pine
Authors: Cieszewski Chris J. , Zasada Michał , Strub Mike 
Published: April 2024

Abstract
Using an example of averaged growth series data of Scots pine (Pinus sylvestris L.), we examine several approaches to site-dependent height-age model derivation. We consider several renowned base models (two-dimensional equations, such as Y = f(t)) and derive from them anamorphic and polymorphic dynamic site equations (three-dimensional site-height-age models, such as Y = f(t, t 0, y 0)) of different complexities. The considered base models were selected previously as suitable for Scots pine in other studies, and are different variations of exponential and fractional functions. We compare all of the base models fit to individual site classes and the derived base-age invariant anamorphic and polymorphic dynamic site equations fit to all sites pooled together. All the fits of site equations to the pooled data from different site productivity series were based on base-age invariant stochastic regressions, in which the global model parameters that are common to all data are estimated simultaneously with the site effects unique for each site productivity series. The results show that: (1) choice of definition describing changes across site qualities may be more important than the choice of base equation defining changes over time; (2) a base model with high cost of deriving self-referencing function may sometimes be better than a base model with low cost of deriving the self-referencing function; and (3) superior base models may not produce superior anamorphic or simple polymorphic site models, but can produce superior advanced polymorphic site models, which can describe the growth patterns in data better than either anamorphic or simple polymorphic models.
Flight Periodicities, Phoresy Rates, and Levels of Pseudopityophthorus minutissimus Branch Colonization in Oak Wilt Centers
Authors: Ambourn Angie K. , Juzwik Jennifer , Eggers Jordan E. 
Published: April 2024

Abstract
Oak bark beetles, Pseudopityophthorus minutissimus and P. pruinosus, are considered important vectors of the oak wilt fungus, Ceratocystis fagacearum, in Missouri and Ohio. However, the frequency of the species’ association with diseased oaks in Minnesota and their relative importance in pathogen spread in the state are unclear. Window traps were placed in canopies of recently killed northern pin oaks to determine seasonal flight periodicities of dispersing oak bark beetles and their phoresy (pathogen presence) rates. Branch samples were collected from diseased northern pin and northern red oak canopies in May and Aug., life history data obtained, and oak bark beetles emerging from the branches assayed for the pathogen. Only P. minutissimus was found in the study areas. In 2003, peak flight of P. minutissimus in Minnesota occurred 12 May to 19 May, with 869 beetles being trapped. Dispersing beetles carried viable pathogen propagules at low frequencies (4 to 13 per 1,000) in May and June. Branches of oak wilt-killed trees were commonly colonized by the beetle. More beetles emerged from branch samples collected in May than in Aug., but none yielded C. fagacearum. These results support the hypothesis that the relative importance of P. minutissimus in the overland transmission of the pathogen in red oak species in Minnesota is minor.
Dynamic Site Model for Loblolly Pine (Pinus taeda L.) Plantations in the United States
Authors: Diéguez-Aranda Ulises , Burkhart Harold E. , Amateis Ralph L. 
Published: April 2024

Abstract
Data from a large, long-term loblolly pine (Pinus taeda L.) plantation study including 186 permanent sample plots were used to evaluate four dynamic site equations derived with the generalized algebraic difference approach (GADA). All of the equations are base-age invariant and directly estimate height and site index from any height and age. The fittings were done in one stage using the base–age invariant dummy variables method. A first-order autoregressive error structure was used to correct the serial correlation of the longitudinal data used in this study. Cieszewski’s model (Cieszewski, C.J. 2002. Comparing fixed- and variable-base–age site equations having single versus multiple asymptotes. For. Sci. 48:7–23) best described the data.
Timber Harvesting Margins in the Southern United States: A Temporal and Spatial Analysis
Authors: Sun Changyou , Zhang Daowei 
Published: April 2024

Abstract
This study focuses on the logging sector by analyzing timber harvesting margins in the southern United States between 1977 and 2001. The real growth rate of harvesting margins has been negative for pine pulpwood, while positive for pine sawtimber, hardwood pulpwood, and hardwood sawtimber. Harvesting margins for pulpwood are more stable over time and more integrated spatially when compared with those for sawtimber. There is no perfect integration in the logging sector by timber product and no individual state is found to lead the logging service market. The revealed patterns are explained in terms of changing demand for forest products and forest industry structure.
Evaluation of Selfing Effects on Western Redcedar Growth and Yield in Operational Plantations Using the Tree and Stand Simulator (TASS)
Authors: Wang Tongli , Russell John H. 
Published: April 2024

Abstract
Seed lots of western redcedar (Thuja plicata) from both wild stands and seed orchards contain a relatively large proportion of self-pollinated seeds compared to other tree species. Selfed seeds do not exhibit early inbreeding depression, and thus have the same probability of producing acceptable seedlings for field planting as outcrossed ones. However, selfed trees show, on average, about 10% reduction in 9-year height after outplanting. To evaluate the potential negative effects of selfing on productivity at harvest, growth and yield of stands comprising selfs were simulated using TASS (tree and stand simulator) with various planting sites and initial planting densities in this study. Height distributions of selfed and outcrossed individuals were also compared and modeled, which provided a solid basis for accurate TASS simulations and some inside view of selfing in this species. Our results indicate that effects of selfing are smaller on stand final productivity (8% on average) than on 9-year-young trees due to natural selection (competition) against slower-growing trees after crown closure, resulting in more selfs being purged than outcrossed trees. Using better planting sites with higher initial planting densities can substantially intensify the selection and reduce the negative effects of selfing on final productivity.
Impact of Globalization and Policy Change on United States Softwood Lumber Trade
Authors: Xiang Qing , Yin Runsheng 
Published: April 2024

Abstract
To examine the effects of global economic integration, public policy, and other factors on US softwood lumber trade, a demand and supply system for both exports and imports is estimated with panel data sets. We find that the combined impact of trading price and exchange rate before 2003 has made foreign lumber products much cheaper than those manufactured domestically. Furthermore, domestic economic conditions and production capacity strongly affect the exports and imports of both the United States and its trade partners. Also, the US federal harvest reduction policy and the Asian financial crisis influenced both export and import markets. All of these suggest the need for more integrated market analysis and strategic business thinking.
A Legal History of the Softwood Lumber Dispute (in a Nutshell)
Authors: Kennedy Kevin C. 
Published: April 2024

Abstract
In every close economic relationship, trade frictions will inevitably occur. The trade relationship between the United States and Canada is no exception. The two-decade long, Canada–U.S. softwood lumber dispute undoubtedly has been the most prominent, if not the most irritating, trade friction of all. The heart of the dispute is the different views in Canada and the United States as to what constitutes a countervailable government subsidy and the proper methodology for determining the amount of such a subsidy when one is found to exist. In the latest round in the softwood lumber dispute, Softwood Lumber IV, Canada and the United States have engaged in a series of parallel dispute settlement proceedings under North American Free Trade Agreement (NAFTA) and at the World Trade Organization. Canada insists that it has won the latest softwood lumber dispute by virtue of an Aug. 2005 decision by a NAFTA Extraordinary Challenge Committee. The United States is equally insistent that the matter remains open by virtue of the International Trade Commission (ITC)s injury determination issued in 2004. With both sides in the Softwood Lumber dispute taking a hard line, such an environment is hardly conducive to the negotiation of a mutually agreeable settlement between the parties. A negotiated resolution of a legal dispute is always better than a litigated one.
If America Had Canada's Stumpage System
Authors: Spelter Henry 
Published: April 2024

Abstract
The North American lumber market is integrated and, under normal conditions, provides unhindered access to all suppliers. North American log markets, in contrast, function on different principles: in one principle, a profit allowance for the wood processor plays a role in timber pricing, whereas in the other it is a byproduct of the give-and-take of arm's length market negotiations. Under the first system, markets are characterized by high elasticities of price transmission and, at times of market weakness, by low elasticities of product supply. Under the second system, the opposite of these benchmarks prevails. This can result in asymmetric supply responses in weak markets, to the detriment of U.S. producers. Whether this is a subsidy in the sense of conferring a direct financial contribution by the government or merely a more efficient pricing mechanism is beclouded by the dearth of market-based transactions. The challenge in the lumber dispute then is to devise a system of pricing in Canada that is more transparent in regard to the underlying valuation of timber.
Timber Sale Characteristics and Competition for Public Lands Stumpage: A Case Study from the Lake States
Authors: Leefers Larry A. , Potter-Witter Karen 
Published: April 2024

Abstract
The U.S. stumpage pricing system is often presented as a market-based approach that should be adopted by Canadian provinces. We compare four public agency stumpage pricing systems in the Lake States (Michigan, Minnesota, and Wisconsin) with many similar features, but their differences lead to diverse starting points in the stumpage pricing process. Further, comparisons between the Michigan Department of Natural Resources (MiDNR) and the USDA Forest Service indicate that there is considerably more competition for MiDNR sales. This is due to institutional differences between the agencies. We estimated hedonic pricing models for Lake States national forest and MiDNR timber sales to determine which sale and institutional characteristics influenced stumpage prices. The final models for stumpage price centered on species–product composition of sales, number of species and products, regional location, administratively set sale contract length, and sale timing, competition, and firm size. Empirical results illustrate that models within the same geographic region are not readily transferable to another ownership. This will complicate efforts for cross-border comparisons of hedonic pricing results. Importantly, the models do provide insights regarding the sign and significance of variables. We conclude that the U.S. systems are not readily adaptable to Canadian regions in which little competition exists.
Regional Stem Profile Model for Cross-Border Comparisons of Harvested Red Pine (Pinus resinosa Ait.) in Ontario and Michigan
Authors: Zakrzewski W.T. , MacFarlane D.W. 
Published: April 2024

Abstract
In recent years, considerable attention has been paid to the problem of increasing the comparability of wood valuation across different markets (e.g., stumpage prices), highlighted in the ongoing softwood lumber dispute between the United States and Canada. One major thrust is toward standardizing measurement systems across markets such that volume estimation is more consistent and versatile. As part of the Great Lakes Stem Profile Modeling Project, established to improve the local timber production process and to enable cross-border comparisons of timber volumes, here we present results of a fitting taper (stem profile) model for red pine (Pinus resinosa Ait.) growing in Michigan and Ontario, Canada. Red pine is an important commercial species in both regions. We developed a joint stem profile model that predicts individual tree volume for red pine in Michigan and Ontario with a standard deviation (SD) of error of 10%, demonstrating the feasibility of providing regionally valid stem profile models for major commercial tree species. The stem profile model was fitted as a system of simultaneous equations using a three-stage least-squares regression method. Predictions were evaluated using an equivalence test. We believe that developing statistically and legally defensible estimates of timber product volume across political borders, as exemplified by the regional stem profile model presented here, will improve communication among the trade partners, such as the United States and Canada, by reducing uncertainty created by a lack of comparable estimates.