bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Assessment of Model Errors from Four Regression Techniques
Authors: Zhang Lianjun , Gove Jeffrey H. 
Published: April 2024

Abstract
Forest modelers have attempted to account for the spatial autocorrelations among trees in growth and yield models by applying alternative regression techniques such as linear mixed models (LMM), generalized additive models (GAM), and geographically weighted regression (GWR). However, the model errors are commonly assessed using average errors across the entire study area and across tree size classes. Little attention has been paid to the spatial heterogeneity of model performance. In this study, we used local Moran coefficients to investigate the spatial distributions of the model errors from the four regression models. The results indicated that GAM improved model-fitting to the data and provided better predictions for the response variable. However, it is nonspatial in nature and, consequently, generated spatial distributions for the model errors similar to the ones from ordinary least-squares (OLS). Furthermore, OLS and GAM yielded more clusters of similar (either positive or negative) model errors, indicating that trees in some subareas were either all underestimated or all overestimated for the response variable. In contrast, LMM was able to model the spatial covariance structures in the data and obtain more accurate predictions by accounting for the effects of spatial autocorrelations through the empirical best linear unbiased predictors. GWR is a varying-coefficient modeling technique. It estimated the model coefficients locally at each tree in the example plot and resulted in more accurate predictions for the response variable. Moreover, the spatial distributions of the model errors from LMM and GWR were more desirable, with fewer clusters of dissimilar model errors than the ones derived from OLS and GAM. FOR. SCI. 51(4):334–346.
Confirmation of Oak Recruitment Failure in Indiana Old-Growth Forest: 75 Years of Data
Authors: Aldrich Preston R. , Parker George R. , Romero-Severson Jeanne , Michler Charles H. 
Published: April 2024

Abstract
We report on a long-term study of changes in the diameter distribution of red and white oaks in old-growth forest of Indiana. We expand the scope of a prior 50-year demographic study of a 20.6-ha stand by (1) extending the census period, (2) comparing diameter distributions in the large stand with those of a smaller (2.3-ha) stand, and (3) examining small-diameter ingrowth of red oaks into both stands. Oaks displayed bell-shaped or even-aged diameter distributions in 1926, suggesting a history of disturbance from timber removal, grazing, and fire. These exogenous disturbances were suppressed starting in 1917 with acquisition of the property by Purdue University. Subsequent censuses indicated considerable ingrowth of nonoak stems into both stands. Oaks that were mid-sized in 1926 gradually moved through the size classes and were replaced by younger individuals in the small stand but not in the center of the large stand. The survey of red oak saplings confirmed this pattern, revealing numerous recruits in the small stand but virtually none in the large stand. These data support the view that oaks are failing to regenerate in part due to shade-intolerance and a waning disturbance regime in the large stand interior. FOR. SCI. 51(5):406–416.
Forecasting Germany's Printing and Writing Paper Imports
Authors: Hetemäki Lauri , Mikkola Jarmo 
Published: April 2024

Abstract
Short-term forecasting of forest products demand is one of the key inputs for successful market planning in the forest sector. Currently, this field is dominated by consultants' and industry analysts' forecasts, which are often based on methods and procedures that are not well documented, or are ad hoc. This article seeks to contribute to the scarce literature on this topic by presenting results for short-term forecasts for the import demand for coated printing and writing paper in Germany. A number of univariate time series models, single equation econometric models, and multivariate systems models are estimated using quarterly data from 1991:Q1–2001:Q2, and observations from 2001:Q3–2002:Q4 are used for the out-of-sample forecast performance evaluation. Forecasts are also computed using various weighted combinations of the individual forecasting models. The results indicate that forecast accuracy increases when one moves from univariate time series models to econometric models. The best single forecasting model in terms of the root-mean-squared error criterion is a VARX model in differences. However, by optimally combining individual model forecasts, one is able to produce even more accurate forecasts. FOR. SCI. 51(5):483–497.
Soil Compaction and Forest Floor Removal Affect Early Growth and Physiology of Lodgepole Pine and Douglas-Fir in British Columbia
Authors: Kamaluddin Mohammed , Chang Scott X. , Curran Michael P. , Zwiazek Janusz J. 
Published: April 2024

Abstract
We investigated the effects of soil compaction and forest floor removal on growth and physiology of lodgepole pine (Pinus contorta ex Loud. var. latifolia Engelm.) and Douglas-fir (Pseudotsuga menziesii var. glauca [Baissn.] Franco) seedlings on a calcareous long-term soil productivity (LTSP) study site near Invermere, British Columbia. Treatments consisted of factorial combinations of soil compaction (noncompacted versus compacted) and forest floor removal (forest floor intact versus forest floor removed) as well as a remedial (rehabilitation) treatment of deep ripping following soil compaction. The experiment was not replicated at the treatment plot level, therefore no statistically based mean comparisons were made. After two growing seasons, we found that the two tree species responded differently to those treatments. Lodgepole pine height and diameter growth and unit needle-weight (dry mass per unit needle) averaged 25, 51, and 30% greater, respectively, in the rehabilitation than in the other treatments, whereas Douglas-fir responded to the rehabilitation treatment by increasing stem diameter growth by 27%, but not height growth (a change of 9%). Forest floor removal decreased height growth in lodgepole pine by 11%, but increased diameter growth in Douglas-fir by 15%. The decreases in growth for lodgepole pine in the forest floor removal treatments were accompanied by lower foliar N concentrations. Foliar N concentrations were positively correlated with rates of net photosynthesis (r = 0.69, P = 0.004) and height growth (r = 0.76, P = 0.004) in lodgepole pine, but not in Douglas-fir. Low N supply (as observed for lodgepole pine) and depletion of soil moisture as a result of forest floor removal likely played a role in shaping the growth and physiological responses of the trees in this study. FOR. SCI. 51(6):513–521.
Mismatch between Herbivore Behavior and Demographics Contributes to Scale-Dependence of Host Susceptibility in Two Pine Species
Authors: Ylioja Tiina , Slone Daniel H. , Ayres Matthew P. 
Published: April 2024

Abstract
The impacts on forests of tree-killing bark beetles can depend on the species composition of potential host trees. Host susceptibility might be an intrinsic property of tree species, or it might depend on spatial patterning of alternative host species. We compared the susceptibility of loblolly pine (Pinus taeda) and Virginia pine (P. virginiana) to southern pine beetle (Dendroctonus frontalis) at two hierarchical levels of geographic scale: within beetle infestations in heterospecific stands (extent ranging from 0.28 to 0.65 ha), and across a forest landscape (extent 72,500 ha) that was dominated by monospecific stands. In the former, beetles preferentially attacked Virginia pine (tree mortality = 65–100% in Virginia pine versus 0–66% in loblolly pine), but in the latter, loblolly stands were more susceptible than Virginia stands. This hierarchical transition in host susceptibility was predicted from knowledge of (1) a behavioral preference of beetles for attacking loblolly versus Virginia pine, (2) a negative correlation between preference and performance, and (3) a mismatch in the domain of scale between demographics and host selection by individuals. There is value for forest management in understanding the processes that can produce hierarchical transitions in ecological patterns. FOR. SCI. 51(6):522–531.
Simulating Landscape-Level Effects of Constraints to Public Forest Regeneration Harvests due to Adjacent Residential Development in Northern Wisconsin
Authors: Ward Brendan C. , Mladenoff David J. , Scheller Robert M. 
Published: April 2024

Abstract
Residential development in rural forests is currently one of the most prominent land use changes in the United States. Such development can have important effects on ecosystem processes and landscape patterns. It can also constrain forest management on public lands, influencing tree species composition and age structure at the landscape scale. We used the forest landscape simulation model LANDIS-II to analyze changes to the landscape patterns of tree species composition, age structure, windthrow disturbance, and aboveground live biomass across a range of constraints to public forest timber harvests on a northern Wisconsin landscape. Our results demonstrate that decreasing harvest area through the use of buffers reduces the dominance of early-successional species, increases the dominance of mid to later-successional species, and shifts the stand age distribution within the landscape toward older forests. These buffers increase the spatial heterogeneity of dominant species and age structure at the landscape scale, and lead to more windthrow disturbance. We believe that our study can inform policymakers, forest managers, and scientists about potential long-term landscape-level effects of interaction between residential development and forest management. FOR. SCI. 51(6):616–632.
Substitutability between US Domestic and Imported Forest Products: The Armington Approach
Authors: Gan Jianbang 
Published: April 2024

Abstract
This article estimates the Armington elasticities of substitution between US domestic and imported forest products. The results indicate that US domestic and foreign forest products are far from perfect substitutes for each other. The low substitutability calls into question the effectiveness of import restrictions that alter the relative price between domestic output and imports and the trade impact assessments that impose the law of one price. The degree of substitutability is higher in the long run than in the short run and varies across product aggregation levels. The elasticity estimates, though remaining relatively stable for most forest products, show an increase since the late 1980s for the overall forest product, implying that US domestic and imported forest products have, in general, become more substitutable over time.
Optimal Regeneration Planning for Old-Growth Forest: Addressing Scientific Uncertainty in Endangered Species Recovery through Adaptive Management
Authors: Moore Clinton T. , Conroy Michael J. 
Published: April 2024

Abstract
Stochastic and structural uncertainties about forest dynamics present challenges in the management of ephemeral habitat conditions for endangered forest species. Maintaining critical foraging and breeding habitat for the endangered red-cockaded woodpecker (Picoides borealis) requires an uninterrupted supply of old-growth forest. We constructed and optimized a dynamic forest growth model for the Piedmont National Wildlife Refuge (Georgia, USA) with the objective of perpetuating a maximum stream of old-growth forest habitat. Our model accommodates stochastic disturbances and hardwood succession rates, and uncertainty about model structure. We produced a regeneration policy that was indexed by current forest state and by current weight of evidence among alternative model forms. We used adaptive stochastic dynamic programming, which anticipates that model probabilities, as well as forest states, may change through time, with consequent evolution of the optimal decision for any given forest state. In light of considerable uncertainty about forest dynamics, we analyzed a set of competing models incorporating extreme, but plausible, parameter values. Under any of these models, forest silviculture practices currently recommended for the creation of woodpecker habitat are suboptimal. We endorse fully adaptive approaches to the management of endangered species habitats in which predictive modeling, monitoring, and assessment are tightly linked.
The Effectiveness of Different Buffer Widths for Protecting Headwater Stream Temperature in Maine
Authors: Wilkerson Ethel , Hagan John M. , Siegel Darlene , Whitman Andrew A. 
Published: April 2024

Abstract
We evaluated the effect of timber harvesting on summer water temperature in first-order headwater streams in western Maine. Fifteen streams were assigned to one of five treatments: (1) clearcutting with no stream buffer; (2) clearcutting with 11-m, partially harvested buffers, both sides; (3) clearcutting with 23-m, partially harvested buffers; (4) partial cuts with no designated buffer; and (5) unharvested controls. Over a 3-year period we measured summer water temperature hourly before and after harvesting, above and below the harvest zone. Streams without a buffer showed the greatest increase in mean weekly maximum temperatures following harvesting (1.4–4.4°C). Streams with an 11-m buffer showed minor, but not significant, increases (1.0–1.4°C). Streams with a 23-m buffer, partial-harvest treatment, and control streams showed no changes following harvest. The mean weekly maximum temperatures never exceeded the thermal stress limit for brook trout (25°C) in any treatment group. The mean daily temperature fluctuations for streams without buffers increased from 1.5°C/day to 3.8°C/day, while with 11-m buffers fluctuations increased nonsignificantly by 0.5–0.7°C/day. Water temperatures 100 m below the harvest zone in the no-buffer treatment were elevated above preharvest levels. We concluded that water temperature in small headwater streams is protected from the effects of clearcutting by an 11-m buffer (with &gt;60% canopy retention).
Fuzzy Multicriteria Approval Method and its Application to Two Forest Planning Problems
Authors: Kangas Annika , Kangas Jyrki , Laukkanen Sanna 
Published: April 2024

Abstract
Many different multicriteria decision aid methods have been used in forestry decision support. When opinions of the general public are considered, methods that are simple to understand and easy to use are required. One such method is multicriteria approval (MA). It is based on approval voting, where the voters have been replaced by criteria. In MA, alternatives are approved or rejected with respect to each voter, i.e., each criterion. In the basic version, the approval threshold is crisp and defined by the system. The varying importance of the criteria is considered using the concept of ordinal dominance. Thus, the importance order of the criteria is needed to make a recommendation. The basic MA approach favors solutions that may be mediocre with respect to all criteria. A crisp approval threshold used in MA may also lead to awkward recommendations. We propose a new method using a concept of fuzzy approval for solving these problems. The fuzzy approval also easily extends to group decision-making problems. Two forestry applications are presented, where the fuzzy version of MA is tested and compared to the results of original MA. The possibilities of using fuzzy approval in forestry decision support are discussed.
A Functional Comparison of Productivity in Even-Aged and Multiaged Stands: A Synthesis for Pinus ponderosa
Authors: O’Hara Kevin L. , Nagel Linda M. 
Published: April 2024

Abstract
The relative productivity of even-aged and uneven-aged or multiaged stands is a frequently debated topic in silviculture and forestry. Nearly all previous comparisons have been empirical growth studies, simulations of stand growth, or economic analyses based on differences in stem volume production. Both even-aged and multiaged systems are highly variable and the large number of variables and assumptions makes any comparisons difficult. In this review, a series of studies in ponderosa pine are synthesized to develop a more functional understanding of the relative stemwood productivity of these variable stand structures. Multiaged ponderosa pine stands were either as efficient or slightly more efficient at converting light energy to volume growth than even-aged stands. Even-aged stands appear to experience a higher level of mid-summer water stress than multiaged stands. This finding suggests reduced photosynthesis in even-aged stands and a possible cause for a slightly lower level of productivity in even-aged stands. However, differences in productivity are likely insignificant in comparison to the wide variations in even-aged and multiaged structures and differences caused by the operations necessary to maintain these structures. As ponderosa pine systems are primarily water-limited, these results may not apply to more light-limited systems.
Transpiration and Canopy Stomatal Conductance of 5-Year-Old Loblolly Pine in Response to Intensive Management
Authors: Samuelson Lisa J. , Stokes Thomas A. 
Published: April 2024

Abstract
The influence of weed control only (W) versus weed control plus irrigation (WI) and weed control plus irrigation and fertigation (WIF) on canopy stomatal conductance (G S) and transpiration expressed on a ground (E) and leaf area (E L) basis was examined over 1 year in 5-year-old loblolly pine (Pinus taeda L.) to determine whether increased leaf area index (L) in response to intensive silviculture resulted in regulation of G S, whole-tree hydraulic conductance per unit sapwood area (G), or the ratio of transpiring leaf area to conducting sapwood area (A L:A S) to minimize the gradient in water potential from soil to leaf (ΔΨ). Values of E were as high as 3.9 mm d−1 and increased from a total of 357 mm in the W treatment to 529 and 565 mm in the WI and WIF treatments, respectively. Values of E L did not vary with treatment and were, on average, 0.8 mm d−1 in summer and 0.4 mm d−1 in winter. Increasing management intensity increased L by as much as 76% and sapwood area up to 68%, but had no influence on ΔΨ G, G S, or leaf specific hydraulic conductance. High L values realized by intensive management resulted in regulation of A L:A S to maintain ΔΨ with increasing canopy development.
Market Performance of the Government-Controlled but Market-Based Stumpage System of Ontario
Authors: Yang Feng'e , Kant Shashi , Shahi Chander 
Published: April 2024

Abstract
The market performance of the government-controlled stumpage system of Ontario is investigated by examining the relationships between the stumpage prices and the market prices of end products (lumber, composites, and pulp) produced from standing timber, using monthly data from June 1995 to Feb. 2005. The long-run equilibrium relationship between the stumpage price and the relevant market price is tested using Johansen's multivariate co-integration approach. In addition, the Granger-causality between the stumpage price and the relevant market price is also analyzed. Test results indicate that the Ontario stumpage system is working well with respect to the stumpage prices of SPF (spruce, pine, fir) for softwood lumber and pulp, while there is a need for changes and modifications in terms of revising different parameters of the system with respect to stumpage prices of SPF for composites, and stumpage prices of red pine and white pine timber for lumber. Test results are inconclusive for the stumpage price of red pine and white pine for composites.
Consequences of Neglecting National Product Differentiation in Assessing the Impact of U.S.–Canada Softwood Lumber Disputes
Authors: Gan Jianbang 
Published: April 2024

Abstract
This study, using the Armington approach, analyzes the consequences of omitting national product differentiation on the impact assessment of U.S.–Canada softwood lumber disputes. Omitting national product differentiation is found to cause differences in the estimated impacts ranging from a 38% underestimation to a 340% overestimation under the quantity-based Canadian export tax, and from a 61.5% underestimation to a 413% overestimation under the value-based (ad valorem) U.S. import tariff. Demonstrated as an approach to alleviating the biases, a computable general equilibrium model is developed to simulate the impacts of the 1996 Softwood Lumber Agreement (SLA) and the countervailing duty (CVD) and anti-dumping duty (AD) imposed under the current round of the dispute. The SLA and the CVD and AD seem more likely to cause the redistribution of welfare than to improve the market share of U.S. domestic softwood lumber. The CVD and AD would be more beneficial to the U.S. in terms of overall welfare but causing greater distortions in both the U.S. and Canada than the SLA.
Incidence of the 1996 U.S.–Canada Softwood Lumber Agreement among Landowners, Loggers, and Lumber Manufacturers in the U.S. South
Authors: Li Yanshu , Zhang Daowei 
Published: April 2024

Abstract
A framework was developed to estimate the welfare incidence of the 1996 U.S.–Canada Softwood Lumber Agreement among producers in two-processing-stage markets—timberland owners, loggers, and lumber manufacturers—in the U.S. South. Timberland owners are the largest beneficiary whereas lumber manufacturers are the second and loggers the least. Empirically, without considering substitution effects among production inputs, timberland owners have 47.4% of total incremental producer surplus, whereas lumber manufacturers have 39.4% and loggers 13.2%. When the substitution effects are considered, timberland owners gain slightly less whereas lumber manufacturers and loggers gain slightly more.
Comparative Views of Different Stumpage Pricing Systems: Canada and the United States
Authors: Sedjo Roger A. 
Published: April 2024

Abstract
Canada and the United States have many similarities, but major differences in the ownership and tenure of forestlands. These differences generate substantial differences in the way stumpage prices are determined in the two countries. These differences, including the argument that the absence of stumpages markets results in the de facto subsidization of Canadian stumpage prices, are used to justify the host of US trade restrictions on Canadian softwood lumber imports. This article examines the differences in the tenure systems. It cites the arguments commonly given in the dispute and draws out the implications of these systems on softwood resource prices. It discusses some studies, and alternative markets systems, currently under discussion to addresses the criticisms of the Canadian system and critiques one of the major proposals.
Transaction Evidence Appraisal: Competition in British Columbia's Stumpage Markets
Authors: Niquidet Kurt , van Kooten G. Cornelis 
Published: April 2024

Abstract
As a potential resolution to the softwood lumber dispute, the US Department of Commerce recommends that administered stumpage prices in Canada be determined using information from competitive timber auctions. Previous research indicates that the degree of competition significantly influences bidding behavior. In this article, therefore, a truncated hedonic timber sale model was developed to investigate the influence of competition on stumpage markets in the interior of British Columbia. Results indicate that lower bids in several northern zones of the province are due, at least in part, to lack of competition, but that market power appears limited by spatial arbitrage. In one zone characterized by monopsony, we estimate bids are shaded below their true valuation by $12.56/m3, which approximates the calculated transportation costs ($14.90/m3) to an adjacent more competitive zone. Furthermore, the significance of the inverse mills ratio suggests that ordinary least-squares regression leads to biased estimates. Our findings have policy implications for the future development and use of transaction evidence appraisal models as a potential solution to the long-standing softwood lumber trade dispute.