bluuebunny/crossref_metadata_2025 huggingface dataset:
Duality and Faustmann: Implications for the Evaluation of Landowner Behavior
Authors: Brazee Richard J. , Amacher Gregory S.
Published: April 2024

This paper examines the behavioral consequences when landowners seek to minimize costs rather than maximize profits. We derive a cost function that is dual to the net present value function in the Faustmann Model. This cost function provides a theoretical foundation for studies that estimate forest production costs. We use comparative statics methodology to derive qualitative results for changes in selected policies and exogenous parameters. We find that the qualitative impacts under cost minimization are usually unambiguous. Qualitative impacts under profit maximization are usually ambiguous. This implies that behavioral impacts are usually easier to assess a priori, when landowners minimize costs rather than maximize profits. For. Sci. 46(1):132-138.
Relative Abundance and Species Richness of Herpetofauna in Forest Stands in Pennsylvania
Authors: Ross Brad , Fredericksen Todd , Ross Eric , Hoffman Wayne , Morrison Michael L. , Beyea Jan , Lester Michael B. , Johnson Bradley N. , Fredericksen Nell J.
Published: April 2024

The relative abundance and species richness of herpetofauna was investigated to assess the impact of recent logging operations in 47 forest stands in northeastern Pennsylvania during 1996 and 1997. Stands including nonindustrial private forestlands and public lands that have received some type of harvesting within the last 8 yr ranged from near complete overstory tree cover to complete removal of overstory cover. Stands included the two dominant forest types in the region: northern hardwood (Betula, Fagus, Prunus, Acer, and Tsuga spp.) and oak-hickory/(Quercus and Carya spp.). A total of 8,181 individuals of 26 species (12 salamander, 7 snake, 6 frog, and 1 toad species) were observed in the study stands. The relative abundance and species richness of salamanders increased significantly with increasing retention of tree basal area. Forest stands containing > 15 m²/ha live tree basal area appeared to be a threshold level for high salamander abundance. Snake species abundance and richness increased significantly with increasing removal of tree basal area. The abundance of anuran species showed no significant relationship with amount of tree basal area removal, but the relative abundance and species richness of anurans depended on the presence of water within or bordering the stands. Forest type did not change the overall response of herpetofauna community composition to forest harvesting, although salamanders were more abundant in northern hardwood stands, and snakes were more abundant in oak-hickory stands. Patterns and threshold levels of abundance and species richness of herpetofauna determined in this study may be used to maintain the abundance and richness of selected species when harvesting forest stands. For. Sci. 46(1):139-146.
Valuing a Forest as a Call Option: The Sale of Forestry Corporation of New Zealand
Authors: Hughes Warren R.
Published: April 2024

In September 1996, the New Zealand (NZ) Government sold its 100% shareholding in the Forestry Corporation of NZ (FC) to a consortium led by Fletcher Challenge Forests (FF), a publicly listed company, for NZ $2.06 billion. Option pricing methodology is used to value the forest assets that were listed in FC's 1996 Annual Report at $1.853 billion. Total net assets had a book value of $2.03 billion, about $30 million less than the selling price. Assuming a 7.5% real cost of capital and a maximum tax rate of 33%, the actual value of the forest assets realized in the sale (taken to be $1.853 billion) are at a 12.9% discount to the "fair" value of $2.128 billion derived by the option pricing approach. The advantage of this approach to forest valuation over the traditional approach (based on discounted cash flow using projected future prices over long horizons) is that only the volatility of future log prices need be estimated. The relative insensitivity of forest value to this parameter suggests less spread between bid and ask prices by forest buyers and sellers with similar costs of capital, tax rates, and so on. For. Sci. 46(1):32-39.
The Impacts of Deregulation and Privatization on Cost Efficiency in New Zealand's Forest Industry
Authors: Grebner Donald L. , Amacher Gregory S.
Published: April 2024

In this paper, we investigate whether deregulation and privatization induced changes in cost efficiency within the New Zealand wood industry. Unlike previous work, the effects of privatization, deregulation, and removal of log export bans are compared to determine which shock had the most influence on efficiency changes. Cost efficiency is measured by estimating stochastic frontier models using the recent cost function approach, which does not suffer from the endogeneity problems associated with stochastic frontier production function estimation. The results show that cost efficiency decreased after each policy reform, but deregulation was more important in this regard than privatization. This suggests that countries with comparative advantages in wood processing, who also implement deregulation or privatization, may suffer through a short-run period of lower efficiency as the economy adjusts to higher input costs in those sectors. In New Zealand's case, the adjustments most likely affecting efficiency have been investments in new technologies, where time is required to attain maximum efficiency. The results are contrary to other studies that have predicted increased efficiency as a result of privatization. For. Sci. 46(1):40-51.
Impacts of the Time Horizon for Adjacency Constraints in Harvest Scheduling
Authors: Hoganson Howard M. , Borges Jose G.
Published: April 2024

Adjacency constraints, constraints which limit the harvest timings of adjacent management units, are a challenge to address within forest management scheduling models. Four large test cases were examined to consider the need to recognize site-specific adjacency constraints over a long time horizon within a forest management scheduling model. Results suggest that the costs of adjacency constraints tend to be short-term in nature. Immediate periods tend to be influenced most because there is less lead time to prepare for the constraints. Little may be gained in planning by addressing adjacency constraints for more than a full rotation length. Adjacency constraints can likely be satisfied efficiently without having large shifts in harvest timings for most all management units. Results are consistent with an interpretation of the dual formulation of a relaxed linear programming formulation of the problem. For. Sci. 46(2):176-187.
Validation of a Forest Values Typology for Use in National Forest Planning
Authors: Brown Gregory , Reed Patrick
Published: April 2024

Public values for national forestlands are assumed to underlie preferences for actual forest use and define the context for forest planning and decision making, but the relationship between preferences and attitudes toward forest management activities and public forest values (both use and nonuse values) is not well understood. Using data from a survey of Alaskan residents in the Chugach National Forest plan revision process, the relationship between attitudes toward forest management actions and forest values is examined using a variety of statistical procedures. Key findings indicate that: (1) survey respondents were able to identify with 13 distinct forest values based on a modified forest value typology developed by Rolston and Coufal (1991), (2) no obvious latent structure of variables or constructs emerged from factor analysis of the 13 forest values indicating that the forest value typology may not be easily simplified without compromising the exclusiveness of measured forest values, (3) small, but statistically significant correlations were found between attitudes toward specific forest management practices such as logging and mining and held forest values, and (4) forest values are modestly predictive of respondent preferences for specific forest planning decisions. For. Sci. 46(2):240-247.
Tree-Growth and Understory Responses to Low-Severity Prescribed Burning in Thinned Pinus ponderosa Forests of Central Oregon
Authors: Busse Matt D. , Simon Steven A. , Riegel Gregg M.
Published: April 2024

The growth of ponderosa pine and associated understory vegetation was evaluated for a 6 yr period following spring underburning of surface fuels. Underburn and control (unburned) plots were paired at 15 replicate sites in pole-sized ponderosa pine forests of central Oregon. The burns were generally low in severity, as noted by low 0 horizon mass reduction (24%) and tree mortality (6%). A small but significant decline in basal area and volume growth rates of surviving trees was found in the 6 yr following underburning. The reduction in tree growth was related to a combination of crown length reduction, 0 horizon reduction, and site productivity. More productive stands had the highest proportional reduction in growth due to burning. By comparison, site conditions including stand density, initial basal area, elevation, parent material, and soil fertility were not related to the observed growth reduction. Understory vegetation showed a mixed response to burning. Shrub cover, dominated by Purshia tridentata, declined significantly following burning and remained well below preburn levels for the length of the study, even though one-fourth of all burned Purshia plants successfully resprouted. Total herbaceous vegetation cover and production were unaffected by burning, while species diversity increased slightly. With the exception of the decline in Purshia cover, the results indicate that low-severity prescribed burning has a relatively minor impact on tree-growth and understory response in thinned ponderosa pine stands. For. Sci. 46(2):258-268.
Predicting Daily Mean Soil Temperature from Daily Mean Air Temperature in Four Northern Hardwood Forest Stands
Authors: Brown Shannon E. , Pregitzer Kurt S. , Reed David D. , Burton Andrew J.
Published: April 2024

Soil temperature is very important in regulating ecosystem processes, yet it is often difficult and costly to measure. Most models that have endeavored to predict soil temperature have either a long time step or several complicated independent variables. Daily mean air and soil temperatures were measured from 1989-1997 in four northern hardwood sites along a 500 km latitudinal gradient in Michigan. These data were used to derive a simple method to predict daily mean soil temperature (depth of 15 cm) using the daily mean air temperature from the previous day and a cosine function of Julian date (R² = 0.93-0.96; SEM = 0.98-1.40°C). Predicted values were compared with actual recorded soil temperatures from 1997 at each of the sites, and the average difference between the observed and predicted values ranged from 0.11 to 0.39°C. Different coefficients were estimated for each of the sites; however, this general method of predicting soil temperature appears applicable to any site. Once calibrated for a given site, soil temperature may be simply estimated, thus reducing the need for extended monitoring efforts. This method also allows the reconstruction of soil temperature records beyond the monitoring period. Projecting long-term trends in soil temperature may help to further elucidate several ecosystem processes and also may provide more information on how a changing global climate will impact forest ecosystems. For. Sci. 46(2):297-301.
Perceived Ecological Risks to Water Environments from Selected Forest Industry Activities
Authors: Cavanagh Nigel , McDaniels Timothy , Axelrod Lawrence , Slovic Paul
Published: April 2024

This article examines underlying factors shaping lay perceptions, and differences between lay and expert perceptions, of the ecological risks to water environments associated with six forest industry activities. A survey was administered to 183 lay subjects in four communities within the Lower Fraser Basin of western Canada. Parts of the survey were also administered to 16 aquatic science professionals. The results show that both lay and expert respondents generally perceive that clearcut logging and effluent from pulp mills pose a high degree of risk, while selective logging poses a lesser degree of risk. Both groups believe that fertilizer use poses a risk to water quality. However, the experts viewed the construction of logging roads as posing significantly more risk to water environments, and requiring greater regulation, than did the lay respondents. Conversely, the lay respondents viewed pesticide use as posing significantly more risk to water environments, and requiring greater regulation, than did the expert respondents. Discussion about the implications of these perceptions in terms of policy issues and communication efforts complete the article. FOR. SCI. 46(3): 344–355.
Predicting Future Forestland Area: A Comparison of Econometric Approaches
Authors: Ahn SoEun , Plantinga Andrew J. , Alig Ralph J.
Published: April 2024

. Predictions of future forestland area are an important component of forest policy analyses. In this article, we test the ability of econometric land use models to accurately forecast forest area. We construct a panel data set for Alabama consisting of county and time-series observation for the period 1964 to 1992. We estimate models using restricted data sets—namely, data from early periods—and use out-of-sample values of dependent and independent variables to construct precise tests of the model's forecasting accuracy. Three model specifications are examined: ordinary least squares, dummy variables (fixed effects), and error components (random effects). We find that the dummy variables model produces more accurate forecasts at the county and state level than the other model specifications. This result is related to the ability of the dummy variables model to more completely control for cross-sectional variation in the dependent variables. This suggests that the estimated model parameters better capture the temporal relationship between forest area and economic variables. FOR. SCI. 46(3): 363–376.
Calibrating Predicted Diameter Distribution with Additional Information
Authors: Kangas Annika , Maltamo Matti
Published: April 2024

The diameter distribution of the growing stock is an essential starting point in many forest management planning problems. There are several methods for predicting the diameter distribution of a stand, varying from methods which utilize theoretical distribution functions to nonparametric methods. Usually the predicted diameter distribution is scaled so that the stem number corresponds to the measured value. However, if stem number and basal area are both known, it may be difficult to predict a distribution that gives correct estimates for both these characteristics. Such diameter distributions can be obtained using an approach adopted from sampling theory—calibration estimation. In this study, the diameter distributions of Scots pine were predicted with two different methods, the Weibull and percentile based methods, and then calibrated with additional information. The calibration reduced the RMSE of stand variables computed from the predicted distribution. FOR. SCI. 46(3): 390–396.
Centroid Method: Comparison of Simple and Complex Proxy Tree Taper Functions
Authors: Coble Dean W. , Wiant Harry V.
Published: April 2024

Cubic-meter volumes estimated from simple and complex proxy taper functions were compared to observed volumes of loblolly pine (Pinus taeda, L.) and ponderosa pine (Pinus ponderosa, Dougl. ex Laws.) trees to evaluate accuracy (bias and precision) in the centroid method. The results of this investigation showed no clear evidence that a more complex proxy taper function is more accurate than a simple function. The results also support previous studies that show accurate volumes of standing trees may be obtained using the centroid method, which requires only one upper-stem diameter measurement. FOR. SCI. 46(4):473–477.
Determination of Stand Properties in Boreal and Temperate Forests Using High-Resolution Imagery
Authors: Shugart H.H. , Bourgeau-Chavez Laura , Kasischke E.S.
Published: April 2024

The existence of a relatively long (ca. 40 yr) satellite imagery archive for examination of potential worldwide forest change motivated an inspection of the relation between forest features observable from higher resolution airborne and satellite imagery and measures of forest biomass, height, and age. Using these data, we inspected the relation between stand age, mean diameter, height, and standing aboveground biomass for forest stands located in boreal forest (near Fairbanks, Alaska) and temperate forest (near Durham, North Carolina). The features of a spatial statistic, semivariance, prove to be related to the structure, age, and biomass patterns of these forests. These initial results indicate the feasibility of using appropriately calibrated high-resolution satellite imagery to estimate and monitor aboveground carbon reserves of forests. FOR. SCI. 46(4):478–486.
An Econometric Analysis of Norwegian Sawmilling 1974–1991 Based on Mill-Level Data
Authors: Baardsen Sjur
Published: April 2024

An eight-input translog total cost function was estimated, and the estimates were used to calculate Allen and Morishima substitution elasticities, price elasticities of conditional input demands, elasticity of size, and technical change for Norwegian sawmilling at a five-digit disaggregate industry level, based on an unbalanced panel of 3,090 individual observations of sawmills over the period 1974–1991. The unusually rich source of data made it possible to analyze the production economics of sawmilling in more detail than has ever been possible before. As far as comparisons with other studies could be made, many of the Allen substitution elasticities and price elasticities of conditional input demand were in accordance with previous findings. The inputs were found to be inseparable. Therefore, frequently used overall aggregates like “materials” and “energy” are not to be recommended. Since the average sawmill had economies of size yet to be exploited, it would have been better off by increasing its size. The most effective way of doing this is to use relatively more sawlogs, electricity, capital, and the aggregate other inputs, and relatively less labor, lumber input (for planing), and the aggregate input other materials. The rate of technical change was negative for the average sawmill. FOR. SCI. 46(4):537–547.
Ideotype Development in Southern Pines: Rationale and Strategies for Overcoming Scale-Related Obstacles
Authors: Martin Timothy A. , Johnsen Kurt H. , White Timothy L.
Published: April 2024

Indirect genetic selection for early growth and disease resistance of southern pines has proven remarkably successful over the past several decades. However, several benefits could be derived for southern pine breeding programs by incorporating ideotypes, conceptual models which explicitly describe plant phenotypic characteristics that are hypothesized to produce greater yield. The potential benefits of using ideotypes include improvement in trait heritabilities and genetic correlations, higher genetic gain in diverse silvicultural environments, guidance for developing mating designs, and provision of a framework for synthesis of tree production physiology knowledge. There are numerous obstacles to the development of ideotypes for southern pines, most of them related to the difficulty of linking traits and processes that operate at small spatial and temporal scales (e.g., tree crown morphological traits or leaf net photosynthesis) with outputs that occur at large spatial and temporal scales (e.g., stand-level, rotation-age stem biomass yield). Fortunately, as we enter the 21st century, several relevant advances are converging that bode well for overcoming these obstacles. These advances relate to improvements and developments of process modeling, advances in technologies that permit measures of component processes at relevant scales, the likely future importance of intensive clonal forestry, and the movement toward large-scale genetic block plot experiments. FOR. Sci. 47(1):21–28.
Applying 3-PG, a Simple Process-Based Model Designed to Produce Practical Results, to Data from Loblolly Pine Experiments
Authors: Landsberg Joe J. , Johnsen Kurt H. , Albaugh Timothy J. , Allen H. Lee , McKeand Steven E.
Published: April 2024

3-PG is a simple process-based model that requires few parameter values and only readily available input data. We tested the structure of the model by calibrating it against loblolly pine data from the Control treatment of the SETRES experiment in Scotland County, NC, then altered the Fertility Rating to simulate the effects of fertilization. There was excellent correspondence between simulated values of stem mass and the values obtained from field measurements, and good correspondence between simulated and measured stem diameters and Leaf Area Index values. Growth efficiency values derived from the model were similar to those obtained from field data. We used the model, without further calibration, to predict tree growth in terms of stem diameter at SETRES 2, a genotype × environment interaction trial in the same locality. Simulated mean stem diameters of two provenances did not differ significantly, over 3 yr, from those observed in the Control (unfertilized) treatments, but rates of change were lower than those of fertilized provenances. We then used 3-PG to simulate fertilized stand growth for an entire rotation length, and these results corresponded to those obtained with a traditional growth and yield model. This study showed that the model can simulate accurately the behavior and responses to environmental factors of loblolly pine and that it has considerable potential value as a management tool, for scenario analysis and as a research tool. FOR. Sci. 47(1):43–51.
Analysis of Longitudinal Data from Progeny Tests: Some Multivariate Approaches
Authors: Apiolaza Luis A. , Garrick Dorian J.
Published: April 2024

Longitudinal data arise when trees are repeatedly assessed over time. The degree of genetic control of tree performance typically changes over time, creating relationships between breeding values at different ages. Longitudinal data allow modeling the changes of heritability and genetic correlation with age. This article presents a tree model (i.e., a model that explicitly includes a term for additive genetic effects of individual trees) for the analysis of longitudinal data from a multivariate perspective. The additive genetic covariance matrix for several ages can be expressed in terms of a correlation matrix pre- and post-multiplied by a diagonal matrix of standard deviations. Several models to represent this correlation matrix (unstructured, banded correlations, autoregressive, full-fit and reduced-fit random regression, repeatability, and uncorrelated) are presented, and the relationships among them explained. Kirkpatrick's alternative approach for the analysis of longitudinal data using covariance functions is described, and its similarities with the other models discussed in this article are detailed. The use of Akaike's information criterion for model selection considering likelihood and number of parameters is detailed. All models are illustrated through the analysis of weighed basic wood density (in kg/m3) at four ages (5,10,15, and 20 yr) from radiata pine increment cores. FOR. SCI. 47(2):129–140.
Species-Independent Height-Age Models for British Columbia
Authors: Nigh Gordon D.
Published: April 2024

Species-specific height-age models abound in the scientific literature. Some researchers have used Zeide's two-point system to reduce the number of models in service. However, this system requires two height-age pairs which are not always available. The purpose of this research is to develop a height-age model for British Columbia, Canada, that is independent of species. From a large database of stem analysis data, 15 plots from three coastal and seven interior species were chosen to uniformly cover the range of site index for each species. After converting the stem analysis data into height-age data, a model based on the logistic function was fit to each plot. A preliminary analysis showed that site index, geographic region (coast, interior), and shade tolerance (tolerant, intolerant) are potentially good predictors of height. These variables, along with breast height age, were incorporated into a species-independent height-age model based on the log-logistic function. An additional ten plots per species were chosen to test the model. The testing showed that the species-independent model had approximately the same accuracy as the species-specific models. Future endeavors can be directed at improving the model by incorporating more species into the analysis and including other important climatic and ecological variables. FOR. SCI. 47(2):150–157.
Relationships Between National Forest System Employee Diversity and Beliefs Regarding External Interest Groups
Authors: Halvorsen Kathleen E.
Published: April 2024

This article examines the relationship between USDA Forest Service National Forest System (NFS) employee beliefs about external interest groups and the employees' race, gender, and career path. These interest groups include environmentalists, citizen activists, the timber and mining industries, range users, tribal representatives, and recreationists. Gender, race, and career path are demonstrated to be significant factors related to NFS employee beliefs about a number of these interest groups. These results suggest that NFS employee diversification policies may have introduced into the workforce a set of employees who are less positive in their expectations of the timber industry, but more positive about environmentalists and some other key interest groups. This shift is predicted to aid the NFS in working more successfully with a wider diversity of external constituencies than in the past. For. Sci. 47(2):258–269.
Nonlinear Mixed Effects Modeling for Slash Pine Dominant Height Growth Following Intensive Silvicultural Treatments
Authors: Fang Zixing , Bailey Robert L.
Published: April 2024

A modified Richard's growth model with nonlinear mixed effects is developed for modeling slash pine (Pinus elliottii Engelm.) dominant height growth in conjunction with different silvicultural treatments. All three parameters in the model turn out to have both fixed and random individual plot or silvicultural treatments effects. Moving average correlation with 2° was identified as within-plot error structure. The advantages of the mixed effects model in prediction for new responses are demonstrated in detail by formulations and examples. The modified Richards model has a form that combines dominant height growth and site index into one model form, so the incompatibility between height growth and site index model can be avoided. The general methodologies of nonlinear mixed effects model building, such as which parameters in the model should be considered to be random and which should be purely fixed, how to determine appropriate within-plot variance covariance structure, and how to specify between-plot variation via appropriate covariate modeling, are addressed in detail. Likelihood ratio test and Akaike information criterion (AIC) are used in model performance evaluation. Some useful graphical model diagnosis tools are also presented. FOR. SCI. 47(3):287–300.
Imputation and Model-Based Updating Techniques for Annual Forest Inventories
Authors: McRoberts Ronald E.
Published: April 2024

The USDA Forest Service is developing an annual inventory system to establish the capability of producing annual estimates of timber volume and related variables. The inventory system features measurement of an annual sample of field plots with options for updating data for plots measured in previous years. One imputation and two model-based updating techniques are described and evaluated with respect to the bias and precision of their annual estimates of basal area per unit area. The evaluations indicate that simple plot-level imputation and model-based updating techniques produce adequately unbiased and precise estimates of annual mean basal area per unit area for large areas. FOR. SCI. 47(3):322–330.
Herbivory and Fire Influence White Oak (Quercus alba L.) Seedling Vigor
Authors: Adams A.S. , Rieske L.K.
Published: April 2024

We manipulated arthropod and mammalian herbivory levels on white oak seedlings using a combination of insecticide applications and fencing and employed a split-split-plot design to assess the impact of single- and multiple-year burns on seedling growth over a 2 yr period. Herbivory levels increased over time on all sites, but there was no significant difference in herbivore pressure on seedlings in single-year burned, multiple-year burned, and nonburned plots. Insecticide-treated seedlings suffered less herbivore pressure than did noninsecticide treated seedlings, and mammalian herbivory was significantly reduced by the presence of a fence. Seedling height growth, shoot elongation, diameter growth, and specific leaf mass were greatest on once-burned sites, intermediate on twice-burned sites, and least on nonburned sites. Bud expansion was the only seedling performance parameter unaffected by burn treatment. Arthropod feeding was the greater component of overall herbivory, but this herbivory did not impede seedling growth. Seedling height growth and shoot elongation were more closely linked to mammalian herbivory. These results suggest that the observed herbivory may play a negligible role, and prescribed fire may be a beneficial component of a management program designed to enhance oak regeneration. FOR. SCI. 47(3):331–337.
Phosphorus and Potassium Uptake Kinetics in Red Maple Seedlings
Authors: Kelly J.M. , Kelly J.K.
Published: April 2024

Acquisition of nutrients by tree roots generally is viewed as a complex process. Models that make use of Michaelis-Menten kinetics concepts provide a means to mechanistically simulate nutrient uptake. The objectives of this study were to provide: (1) estimates of the Michaelis-Menten parameters Imax, Km, and Cmin for P and K uptake by red maple (Acer rubrum L.) seedlings, and (2) to test the efficacy of these values in the modeling context by using the Barber-Cushman nutrient uptake model as a test vehicle. A nutrient depletion approach that used intact seedlings and transient conditions was used to define the kinetics values. These estimates were combined with literature values to provide a full parameter set for the model. Uptake of P proceeded rapidly and yielded an average Imax of 5.5E-6 μmol cm-2 s-1. Mean Km and Cmin values for P were 15.0 and 0.001 μmol mL-1, respectively. Potassium uptake was slower with a mean Imax of 3.8E-6 μmol cm-2 s-1, and the Km and Cmin values were 10.5 and 0.003 μmol mL-1, respectively. Simulated P uptake compared poorly with observed uptake (0.8 vs. 830 μmols). However, additional model runs indicated that the lack of agreement was more the result of a low estimate of soil solution P concentration than a problem with the P kinetics values. Simulated K uptake was in much better agreement with the observed value (891 vs. 1890 μmols). The Cmin values for P and K reflect an ability to continue root uptake at extremely low solution concentrations. This may contribute to the “supergeneralist” status accorded red maple. This study indicates these Imax, Km, and Cmin values can be used in the Barber-Cushman model to simulate P and K uptake by red maple. However, use of these Imax, Km, and Cmin values needs to be tempered with the understanding that several interacting factors influence uptake. This caveat is important when generic literature values provide some or all of the numbers used to initialize the model. FOR. SCI. 47(3):397–402.
Generalization of Faustmann's Formula for Stochastic Forest Growth and Prices with Markov Decision Process Models
Authors: Buongiorno Joseph
Published: April 2024

Faustmann's formula gives the land value, or the forest value of land with trees, under deterministic assumptions regarding future stand growth and prices, over an infinite horizon. Markov decision process (MDP) models generalize Faustmann's approach by recognizing that future stand states and prices are known only as probabilistic distributions. The objective function is then the expected discounted value of returns, over an infinite horizon. It gives the land or the forest value in a stochastic environment. In MDP models, the laws of motion between stand-price states are Markov chains. Faustmann's formula is a special case where the probability of movement from one state to another is equal to unity. MDP models apply whether the stand state is bare land, or any state with trees, be it even- or uneven-aged. Decisions change the transition probabilities between stand states through silvicultural interventions. Decisions that maximize land or forest value depend only on the stand-price state, independently of how it was reached. Furthermore, to each stand-price state corresponds one single best decision. The solution of the MDP gives simultaneously the best decision for each state, and the forest value (land plus trees), given the stand state and following the best policy. Numerical solutions use either successive approximation, or linear programming. Examples with deterministic and stochastic cases show in particular the convergence of the MDP model to Faustmann's formula when the future is assumed known with certainty. In this deterministic environment, Faustmann's rule is independent of the distribution of stands in the forest. FOR. SCI. 47(4):466–474.
Assessing the Priorities Using A'WOT Among Resource Management Strategies at the Finnish Forest and Park Service
Authors: Pesonen Mauno , Kurttila Mikko , Kangas Jyrki , Kajanus Miika , Heinonen Petri
Published: April 2024

We examined a hybrid method, referred to here as the A'WOT [Analytic Hierarchy Process (AHP) in SWOT analysis], for improving the usability of SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis. A commonly used decision analysis method, the Analytic Hierarchy Process (AHP), and its eigenvalue calculation framework are integrated with SWOT analysis. The connection of AHP with SWOT yields analytically determined and quantifiable priorities for the factors included in SWOT analysis. The aim in applying the hybrid method is to improve the quantitative basis of strategic planning processes. After applying the A'WOT method, decision-makers have information at their disposal about how alternative strategies are congruent with internal and external environmental factors. In a decision–making process, this information can be utilized in concert with other produced decision–support elements.

The A'WOT was used in connection with the strategic planning of natural resource management at the Finnish Forest and Park Service (FFPS). Four alternative strategies were produced during the planning process. The alternatives produced were Forestry Strategy (emphasis on sustainable economic use of forests); Recreation Strategy (emphasis on recreational use of forests and social and economic sustainability); Protection Strategy (emphasis on nature protection and ecological sustainability); and the Basic Strategy (current land allocation and forestry practice principles). Opportunities determined by the priorities of the scaling factors had the greatest weight in all the business units of the FFPS. The most important internal factors included both strengths (know–how, land, and water property ) along with a couple of weaknesses (lack of information concerning biodiversity due to insufficient planning resources, age, and development class structures of forests). FOR. SCI. 47(4):534–541.
Foreign Direct Investment, Exports and Exchange Rates: The Case of Forest Industries
Authors: Uusivuori Jussi , Laaksonen-Craig Susanna
Published: April 2024

Foreign direct investment (FDI) by forest companies has increased rapidly in the 1990s. An interesting question is to what extent FDI and traditional trade in the forest sector are substitutes or complements to each other. For example, does FDI lead to increased or decreased exports of forest products from the home country in the long run? This article explores the dynamic relationship between FDI and exports of forest industries with U.S., Finnish, and Swedish data. Both short-term and long-term interrelationships between FDI and exports are studied, as well as the short-term and long-term effects of exchange rate movements and exchange rate variation. The results show that for the U.S. forest industries, FDI and exports of forest products may have become full substitutes in the 1990s. In the case of the Finnish and Swedish forest industries, exports seem to affect negatively the investments abroad, while FDI does not affect exports in the long run. Both the FDI and exports by the U.S. forest industries are unaffected by dollar variability. In the 1980s, the strengthening value of the dollar increased the FDI by the U.S. forest industries. FOR. SCI. 47(4):577–586.
Woody Plants and Woody Plant Management: Ecology, Safety, and Environmental Impact
Authors: Miller James H.
Published: April 2024

Wise and effective woody plant management is an increasing necessity for many land uses and conservation practices, especially on forests and rangelands where native or exotic plants are affecting productivity, access, or critical habitat. Tools and approaches for managing woody plants have been under concerted development for the past 50 years, integrating mechanical, herbicidal, manual, cultural, and biocontrol techniques. This period was fraught with controversy as herbicide use increased with its consequences persistently questioned. Nevertheless, eager adopters of new tools and strategies have been managers for forestry, range, right-of-ways, wildlife, recreation, industrial sites, and more recently natural areas and preserves. Drawn to the generic title of this book, all these users would have great expectations for information to fit their many needs.
Precision of Density Estimates from Fixed-Radius Plots Compared to N-Tree Distance Sampling
Authors: Lessard V.C. , Drummer T.D. , Reed D.D.
Published: April 2024

We computed and compared the statistical properties of the estimators for the number of trees/ha (density) for fixed-radius plot and n-tree distance sampling. In forests with random spatial patterns, n-tree distance sampling density estimators are at least as precise as those of plot sampling if the fixed-radius plot size is less than the ratio of (n - 2) and the expected density, where n is the number of trees included at an n-tree location. A similar result holds for the clustered forest, where the ratio is multiplied by a factor involving a constant of heterogeneity. If the expected number of trees per plot and the plot sizes are the same for both the random and clustered spatial patterns, the variance of the plot sampling density estimator for the clustered pattern will always be greater than for that of the random spatial pattern. FOR. SCI. 48(1):1–6.
Co-integration of Timber and Financial Markets—Implications for Portfolio Selection
Authors: Heikkinen V-P.
Published: April 2024

The short-run and long-run correlations between Finnish forestry returns and financial market instruments are examined. Financial assets include the general stock market index HEX, bond rate and deposit rate. The results indicate that timber prices and bond and deposit rates are co-integrated in the long run. The study demonstrates the influence of co-integration on expected asset returns and the optimal investment portfolio. FOR. SCI. 48(1):118–128.
Effects of Management on the Composition and Structure of Northern Hardwood Forests in Upper Michigan
Authors: Crow Thomas R. , Buckley David S. , Nauertz Elizabeth A. , Zasada John C.
Published: April 2024

To improve our understanding of how management affects the composition and structure of northern hardwood forests, we compared managed with unmanaged sugar maple (Acer saccharum Marsh.) dominated forests. Unmanaged old-growth and unmanaged second-growth forests provided baselines for comparing the effects of even-aged and uneven-aged forest management on selected aspects of biological diversity. Three replications of each condition were located on the Winegar Moraine in Michigan's Upper Peninsula. Old-growth forests were multistoried, dominated by a few, large trees with well-developed crowns extending over a subcanopy stratum 10–15 m in height and an abundance of woody vegetation (mostly sugar maple seedlings) at 2–3 m. This complex stand structure contrasts with the relatively uniform structure of unmanaged second-growth forests with a closed overstory canopy and limited understory development. Forest management, both even- and uneven-aged, created forest structures that were more complex than their unmanaged second-growth baselines, yet managed forests lacked some of the structural complexity characteristic of old-growth. Managed forests had fewer large trees (stem diameter at 1.37 m > 50 cm) and considerably less basal area in dead trees when compared with old-growth. There were fewer tree species in managed forests because commercially important tree species were favored for retention and, when present, early successional species (e.g., Populus grandidentata Michx., Populus tremuloides Michx.) were harvested. A subcanopy comprised of large shrubs and small trees characteristic of old growth was absent in managed forests, but this structural element may develop with time under management. As expected, thinning the overstory and disturbing the forest floor through tree harvesting promoted understory development in managed forests. Most of the added species, however, were common in the landscape and thus added little to overall species richness. FOR. SCI.48(1):129–145.
Forest Policies and Many Governments
Authors: Amacher Gregory S.
Published: April 2024

In this article, I examine pressures on the forest stock when multiple governments, which control different policies, have distinct revenue needs and respond to different constituencies. I assume one type of government controls public forest harvesting, while other governments (typically local or lower ones) control taxes on productive firms in their constituency. Preservation of public forests provides nontimber benefits, or public goods, for consumers at both local and national levels, and these public goods values may vary across constituencies. I investigate how public goods depend on types of government coordination including revenue sharing, shared constituencies, transfers between governments, and federalism (i.e., where one government responds only to its own revenue needs and constituencies without regarding the impact on other governments' revenues or constituents). The results suggest there are several forms of government coordination that either enhance or reduce fiscal constraints imposed on governments, and these spill over onto the forest stock through policy-induced changes in harvesting. In contrast to previous work, in the forestry case reduced government coordination and fiscal federalism can actually protect forest resources and increase public goods produced from preserving forests. If governments perceive increased revenues from public harvesting, then forest exploitation is reduced by shifting fiscal responsibilities away from governments that own resources. It is also shown that pure transfers may not reduce pressures on forest stocks unless certain restrictive conditions are met, and revenue sharing can provide incentives to increase public harvesting and reduce public goods in order to support revenue collections of all governments. Forest Science 48(1):146–158.
Modeling the Joint Distribution of Tree Diameters and Heights by Bivariate Generalized Beta Distribution
Authors: Li Fasheng , Zhang Lianjun , Davis Craig J.
Published: April 2024

A bivariate generalized beta distribution (GBD-2) is fit to the joint frequency distribution of tree diameters and heights of 43 Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) plots in Idaho. The model fitting and performance are compared with the Johnson's SBB distribution using goodness-of-fit χ2 tests for the marginal distributions of diameters and heights, a bivariate goodness-of-fit test for the joint distribution of the two variables, and model predictions of tree heights and volumes. We found that the GBD-2 is more flexible and successful than the Johnson's SBB in describing both marginal and joint distributions of tree diameters and heights. On average, the relative bias (%) from the GBD-2 is three times smaller than that from the Johnson's SBB across the 43 plots when the models are used in tree volume prediction. FOR. SCI. 48(1):47–58.
Designing Compact and Contiguous Reserve Networks with a Hybrid Heuristic Algorithm
Authors: Nalle Darek J. , Arthur Jeffrey L. , Sessions John
Published: April 2024

Conflicting opinions from environmental advocates and economic interests on the best strategy for management of public lands often leaves land managers in a difficult position. Since ecosystem sustainability is in the long-term interest of each group, the establishment of nature reserves could simultaneously address both views. To promote sustainability, fragmentation of existing natural habitats should be avoided, since it is commonly recognized as being disruptive to the species adapted to these habitats. Therefore, when designing an efficient nature reserve, the compactness and contiguity of the land reserved is an essential consideration. A new formulation of the reserve selection problem is presented that explicitly addresses these issues; specifically, the model minimizes a weighted combination of compactness and contiguity measures subject to constraints on the minimal representation of each habitat class.

Motivated by the ongoing reserve efforts in the large and diverse Klamath-Siskiyou region of southwestern Oregon and northwestern California, common heuristic search techniques are implemented and results compared on various simulated test problems. From these findings a new heuristic is developed that reduces solution time and increases solution quality. When applied to the Klamath-Siskiyou region, results are promising. FOR. SCI. 48(1):59–68.