bluuebunny/crossref_metadata_2025 huggingface dataset:
Special Commentary: The Future of Digital Remote Sensing for Production Forestry Organizations
Authors: Smith James L. , Clutter Michael , Keefer Brent , Ma Zhenkui
Published: April 2024

It cannot honestly be stated that digital imagery is a standard instrument in the repertoire of the professional natural resource manager. However, we believe that the opportunity to change that situation is rapidly approaching because a nexus of technology and need has finally occurred. However, pragmatic issues remain. The key to the successful adoption of any new tool, including digital imagery, is not just having the need, but having the tool be useful, usable and available to the great mass of users, (i.e., those in the field in the case of our profession). No forester thinks twice about using an analog aerial photograph, and we need to create that same “ho-hum” status for digital imagery. FOR. SCI. 49(3):455–456.
Influence of Fusing Lidar and Multispectral Imagery on Remotely Sensed Estimates of Stand Density and Mean Tree Height in a Managed Loblolly Pine Plantation
Authors: McCombs John W. , Roberts Scott D. , Evans David L.
Published: April 2024

Stereo aerial photography has long been used to measure tree density and height photogrammetrically. Recent attempts have been made to locate and measure trees automatically in high-resolution digital imagery. This study used small-footprint lidar (1.057 µm, 1 mrad divergence, 0.67 m footprint) and high-resolution (0.61 m) multispectral (550, 675, 700, and 800 nm) data sets to estimate stem counts and tree heights in 15-yr-old loblolly pine stands. A data fusion process was used to combine the datasets. Tree identification accuracy and mean height estimation derived from the separate and fused data sets were compared against field data.

Tree identification was more accurate using spectral data (78.6% and 92.4%) than lidar data (64.7% and 87.3%) within the two planting densities, respectively. The fused dataset improved accuracy of tree identification over the single-dataset approaches (83.5% and 94.8%). Plot-level mean height of lidar-located trees provided the best estimates of mean field height (average difference = 0.15 m). Missed trees for all methods were shorter than mean field height by up to 3.03 m (fused data). These results indicate fusion of spectral and lidar data will likely improve estimates of mean tree height and stem density. Increased lidar posting density is identified as a key factor to improve tree recognition and measurement. FOR. SCI.49(3):457–466.
Public Land Management and Quality of Life in Neighboring Communities—The Chugach National Forest Planning Experience
Authors: Reed Patrick , Brown Gregory
Published: April 2024

Quality of life (QOL), by almost any definition, is important to people. We apply the concept to the relationship between rural communities and public land management. A 1999 study of residents in 12 communities neighboring the Chugach National Forest in Alaska was used during the revision of the Forest's land and resource management plan to assess the relationships between quality of life components and possible management activities being considered. Specifically, we addressed the following five questions: (1) What QOL components are most important to residents of the 14 neighboring local communities? (2) How satisfied are residents with the current status of the QOL components in their communities? (3) How do local respondent perceptions of QOL component importance compare with those of their peers nationwide? (4) If proposed forest management activities may adversely affect resident perceptions of QOL, what are the possible consequences to the communities? (5) How prepared are the communities to address any possible adverse consequences on their own? Our findings confirm that the Forest, probably not unlike other public land management units, has the ability to affect the quality of life of the communities neighboring it for better or for worse. However, the degree to which the communities' residents themselves are prepared for such change is equally significant. FOR. SCI. 49(4):479–498.
The Influence of Fire Weather and Land Use on the Fire Activity of the Lake Abitibi Area, Eastern Canada
Authors: Lefort Patrick , Gauthier Sylvie , Bergeron Yves
Published: April 2024

The fire history of two adjacent regions of the boreal forest, one characterized by logging (Ontario—510,000 ha) and the other by small scale agricultural activities (Quebec—140,000 ha), was studied before and after these regions were opened up to settlement in 1916. From a review of provincial forest fire records and the assessment of the age of fire-initiated forest stands, it appears that large but rare fires occurred during the presettlement period on both sides of the border. After 1916, due to slash and burn activities, the agricultural region (Que) had proportionally about twice the burned areas and ten times more fires than the forestry region (Ont). Despite differences in population density, road network, and land use, fire size class occurrence did not differ between landscapes over time. However, the occurrence of fires larger than 100 ha, considering three development phases (1916–1939; 1940–1969; 1970–1998), decreased in both regions from settlement to the present, particularly during the late phase (1970–1998) in the agricultural region. An analysis of fluctuations in the Canadian forest Fire Weather Index system (FWI), a rating of fire danger severity, showed major climatic stresses at the beginning of the century (1916–1924), followed by a decrease in the occurrence of extreme FWI values. Combined with the impact of climate, which affected the annual area burned and the number of large fires in both landscapes, the results suggest that the landscape fragmentation, the increase in the percentage of deciduous trees over time and/or effective fire detection by residents led to a decrease in the number of fires larger than 100 ha on the agricultural side for the late phase (1970–1998). FOR. SCI. 49(4):509–521.
Impacts of Intensive Management on Black Walnut (Juglans nigra L.) Growth and Bole Quality at Mid-Rotation
Authors: Bohanek James R. , Groninger John W.
Published: April 2024

High value hardwood species, such as black walnut (Juglans nigra L.), are increasingly planted and intensively managed in the hopes of profitably producing high quality logs. Success or failure of silvicultural practices used to establish these plantations are commonly judged on the basis of early diameter growth response. However, it is generally not known whether treatments judged to be successful when the stand is young translate into mid- and late-rotation bole quality and, ultimately, log value. This study revisits a 35-yr-old experimental black walnut plantation in south-central Illinois (black walnut site index50 = 23m), to evaluate how initial planting density, interplanting with nitrogen-fixing black alder (Alnus glutinosa [L.] Gaertn.), postestablishment weed control, and time of thinning impacted the productivity and bole quality at mid-rotation.

Postestablishment weed control conducted at age 6–7 yr did not impact walnut diameter at age 35, but incidence of frost cracks and grade defects in the butt log (lower 2.44 m) were 100% and 30% greater, respectively, on trees receiving the weed control treatment. Time of first thinning of the alder affected walnut quality in the upper log (second 2.44 m log). The higher planting density of walnut and alder reduced the number of defects by 31% in the upper log, but at the expense of stem diameter growth. At a walnut planting density of 7.9 × 7.9 m, interplanting black alder impacted neither walnut diameter growth nor bole quality. The early thinning treatment increased the number of defects on the upper log, but not the butt log. These results suggest that intensive management can have a complex and enduring impact on black walnut plantation growth and development, and elucidate the need for long-term assessment of silvicultural treatments where bole quality is an important component of stand value. For. Sci. 49(4):522–529.
A Panel Data Analysis of Nonindustrial Private Roundwood Supply with Emphasis on the Price Elasticity
Authors: Bolkesjø Torjus Folsland , Solberg Birger
Published: April 2024

This article presents an econometric analysis of the Norwegian nonindustrial private forest (NIPF) owners' short-term roundwood supply applying the conventional pooled Tobit model as well as the fixed effects (FE) Tobit model where unobserved individual heterogeneity are incorporated in the assumptions of the model. A panel consisting of 14,468 forest owners during the period 1989–1997 (except 1991) is used for the statistical testing. The results indicate that the current and lagged price, interest rate and various owner and property characteristics are relevant explanatory variables when evaluating factors affecting Norwegian NIPF owners' short-term roundwood supply. It is demonstrated that the econometric results differ quite substantially between the two models. Both the common interpretation of the results from pooled and FE models, the match to the theory of forest owner behavior, and the statistical measures suggest that panel data methods, like the FE model, are more suitable for short-run roundwood supply analysis than the conventional pooled model. Special attention is given to the price elasticity and its variability across regions and time. Based on the empirical results it is concluded that, among other factors, both the nature of the price data and the distribution of the price elasticity estimates are important to consider when comparing stumpage price elasticity estimates from different analysis. FOR. SCI. 49(4):530–538.
Clustering and Compactness in Reserve Site Selection: An Extension of the Biodiversity Management Area Selection Model
Authors: Fischer Douglas T. , Church Richard L.
Published: April 2024

Over the last 15 yr, a number of formal mathematical models and heuristics have been developed for the purpose of selecting sites for biodiversity conservation. One of these models, the Biodiversity Management Area Selection (BMAS) model (Church et al. 1996a), places a major emphasis on protecting at least a certain area for each biodiversity element. Viewed spatially, solutions from this model tend to be a combination of isolated planning units and, sometimes, small clusters. One method to identify solutions with potentially less fragmentation is to add an objective to minimize the outside perimeter of selected areas. Outside perimeter only counts those edges of a planning unit that are not shared in common with another selected planning unit in a cluster, and, therefore, compact clustering is encouraged. This article presents a new math programming model that incorporates this perimeter objective into the BMAS model. We present an application using data from the USDA Forest Service-funded Sierra Nevada Ecosystem Project (Davis et al. 1996) and show that the model can be solved optimally by off-the-shelf software. Our tests indicate that the model can produce dramatic reductions in perimeter of the reserve system (increasing clustering and compactness) at the expense of relatively small decreases in performance against area and suitability measures. FOR. SCI. 49(4): 555–565.
Maximum Likelihood Estimation for Predicting the Probability of Obtaining Variable Shortleaf Pine Regeneration Densities
Authors: Lynch Thomas B. , Nkouka Jean , Huebschmann Michael M. , Guldin James M.
Published: April 2024

A logistic equation is the basis for a model that predicts the probability of obtaining regeneration at specified densities. The density of regeneration (trees/ha) for which an estimate of probability is desired can be specified by means of independent variables in the model. When estimating parameters, the dependent variable is set to 1 if the regeneration density (trees/ha) on the plot is greater than the specified density (trees/ha), otherwise 0. Since it is desired to estimate parameters for a range of probability densities, traditional estimation techniques for logistic models cannot be used. Multiple regeneration densities require a multinomial distribution, for which maximum likelihood estimates are obtained. Counts of shortleaf pine regeneration taken 9-10 years after thinning on 182 plots established in naturally occurring shortleaf pine forests are used to estimate parameters. FOR. SCI. 49(4):577–584.
What We May Have Is a Failure to Communicate*: Labeling Environmentally Certified Forest Products
Authors: Teisl Mario F.
Published: April 2024

To develop an understanding of the performance of different eco-labels for certified forest products, we administered a mail survey to a nationally representative sample of U.S. residents. In the survey, respondents viewed different eco-labels and were asked to perform a series of tasks designed to measure the labels' communication performance. Results indicate that relatively detailed labels are more beneficial for consumers (and environmentally sensitive forest product manufacturers) than simpler eco-seals. Eco-seals are the least credible type of label and, in general, do not allow consumers an adequate basis for product differentiation. However, we also find evidence that marginal changes can significantly improve the performance of simple eco-seals. The results suggest that U.S. consumers value the environmental benefits created from more environmentally benign forestry. Thus, consumer-driven purchases could potentially support a future of environmentally benign forest management practices with less reliance on other policy alternatives. However, the results also suggest that the current state of forest product labeling, where firms can (voluntarily) label their products with simple eco-seals from a variety of certification organizations, is not the most effective labeling approach. Parties who are interested in the long-run success of these programs need to consider altering current labeling approaches.
Above- and Belowground Competition from Longleaf Pine Plantations Limits Performance of Reintroduced Herbaceous Species
Authors: Harrington Timothy B. , Dagley Christa M. , Edwards M.Boyd
Published: April 2024

Although overstory trees limit the abundance and species richness of herbaceous vegetation in longleaf pine (Pinus palustris Mill.) plantations, the responsible mechanisms are poorly understood because of confounding among limiting factors. In fall 1998, research was initiated to determine the separate effects of above- and belowground competition and needlefall from overstory pines on understory plant performance. Three 13- to 15-yr-old plantations near Aiken, SC, were thinned to 0, 25, 50, or 100% of nonthinned basal area (19.5 m2 ha-1). Combinations of trenching (to eliminate root competition) and needlefall were applied to areas within each plot, and containerized seedlings of 14 perennial herbaceous species and longleaf pine were planted within each. Overstory crown closure ranged from 0 to 81%, and soil water and available nitrogen varied consistently with pine stocking, trenching, or their combination. Cover of planted species decreased an average of 16.5 and 14.1% as a result of above- and belowground competition, respectively. Depending on species, needlefall effects were positive, negative, or negligible. Results indicate that understory restoration will be most successful when herbaceous species are established within canopy openings (0.1–0.2 ha) managed to minimize negative effects from above- and belowground competition and needlefall.
Estimating the Cost of Land Base Changes Due to Wildfire Using Shadow Prices
Authors: Armstrong Glen W. , Cumming Steven G.
Published: April 2024

Linear-programming-based timber harvest scheduling models produce shadow prices of constraints as a standard output. We present a method whereby the shadow prices of starting inventory constraints can be used to approximate the costs of land base changes, expressed in terms of the units of measure for the objective function in the timber supply model. We use this method to approximate the cost of forest fires, and compare these costs to a measure of the true cost. The approximation worked remarkably well over a large range of fire sizes, and alternative model formulations, for a study area in northeastern Alberta, Canada.
Nantucket Pine Tip Moth Development and Population Dynamics: Influence of Nitrogen Fertilization and Vegetation Control
Authors: Nowak John T. , Harrington Timothy B. , Berisford C.Wayne
Published: April 2024

It is commonly believed that Nantucket pine tip moth (Rhyacionia frustrana [Comstock]) feeding damage on loblolly pine (Pinus taeda L.) increases in relation to the intensity of silvicultural practices. Some studies have produced contrary or inconclusive data regarding this issue. This study was designed to examine the relationships between tree growth rates and tip moth development by enhancing growth with nitrogen (N) fertilizer and herbicide applications. The four treatments were N fertilizer, herbicide, herbicide+fertilizer, and untreated control. These treatments were monitored for tip moth damage levels, tip moth pupal numbers per pine shoot, insect population dynamics, and tree growth. Pine growth was significantly greater in the herbicide treatments than in the other treatments. There was a significant increase in diameter related to the fertilizer treatments, but no differences in tree height or volume were detected. Pupal weight was significantly lower in the herbicide treatment in the second year. Tip moth population fluctuations were greater in the herbicide treated plots than in the untreated control, and there were significant linear relationships between these fluctuations in the treatments versus percent parasitism, pupal weight, and diameter growth. This study shows that tip moth populations are not necessarily increased or decreased by intensive management practices, but can be less stable due to these practices.
The Importance of Place: Advances in Science and Application
Authors: Kruger Linda E. , Jakes Pamela J.
Published: April 2024

The concept of place is introduced and an orientation to place literature is provided. Following the introduction, an overview is given of the papers in this special issue of Forest Science. The papers included in this issue were presented at the 2000 International Symposium on Society and Resource Management in Bellingham, Washington.
Examining the Interaction Between Geographic Scale and Ways of Knowing in Ecosystem Management: A Case Study of Place-Based Collaborative Planning
Authors: Cheng Antony S. , Daniels Steven E.
Published: April 2024

This article examines the interaction between geographic scale and ways of knowing in the context of collaborative stakeholder participation in ecosystem analysis and management. The examination uses data from a qualitative comparative case study of two watershed councils in western Oregon. The results tentatively support the proposition that geographic scale can significantly affect individual stakeholder ways of knowing. For small-scale places, stakeholder ways of knowing tend to be particularistic and rely on diverse personal experiences and specific place features; for large-scale places, stakeholder ways of knowing tend to be aesthetic and rely primarily on recreational experiences and scientific analyses. However, the results also indicate that geographic scale combines with at least three factors to affect the development of shared ways of knowing: (1) tensions between experts and laypersons; (2) primacy of organizational representation in stakeholder interactions; and (3) discovery of common group identity based on long-term communication and shared on-the-ground experiences, such as field trips. This examination suggests that geographic scale in ecosystem management is likely an important factor affecting working relationships in a collaborative stakeholder participation process. These relationships, in turn, can affect the perceived credibility and legitimacy of outcomes.
The Politics of Place: Understanding Meaning, Common Ground, and Political Difference on the Rocky Mountain Front
Authors: Yung Laurie , Freimund Wayne A. , Belsky Jill M.
Published: April 2024

A major challenge of forest policy and management is effectively understanding different people's viewpoints on natural resource use and conservation, and how those viewpoints contribute to conflict and conflict resolution. In response to this challenge, the concept of place is gaining currency in natural resource research. The study of place promises an integrative approach to understanding people's relationships with particular areas. Realizing the potential of place research to inform forest policy and management means conceptualizing place as an arena of shared and contested meanings. A politics of place is attentive to different and potentially conflicting meanings, and how senses of place may be connected to larger political struggles. This study examines people's images, values, and interests with respect to the Rocky Mountain Front in Montana. In this case study, discourse about placenames provided a window into the politics of place. Results illustrate the ways in which place meanings are connected to people's ideas about property, conservation, and governance. Knowledge of the politics of place can inform forest policy and management and contribute to a more sophisticated understanding of natural resource conflict and the potential effectiveness of decision-making processes.
Incorporating the Natural Landscape Within an Assessment of Community Attachment
Authors: Clark Julie K. , Stein Taylor V.
Published: April 2024

An ecosystem approach to managing public natural areas requires that land planners and managers thoroughly understand the stakeholders who live within these ecosystems and are emotionally connected to the lands. Building on previous research conducted on community attachment, place attachment, and sense of place, this article explores how local stakeholders in two areas of Florida identify with and account for the natural landscape within their sense of community. To better capture the physical-natural landscape element currently unaccounted for in community attachment research, researchers explored how stakeholders identified with their communities and examined their attitudes and behaviors regarding local public natural areas. Results show the physical-natural landscape is an important part of how stakeholders identify with their community. Stakeholders who frequently visit surrounding public natural areas and identify these areas as an important part of why they live in the area are likely to identify more with the physical-natural landscape of their community than the social-cultural elements of their community. Determining how stakeholders identify with their community (natural landscape or social elements), offers public land managers a better understanding of the role the areas they manage play in local stakeholders' daily lives, and how to best communicate with those stakeholders.
Place Attachment and Context: Comparing a Park and a Trail Within
Authors: Moore Roger L. , Scott David
Published: April 2024

A number of recent studies have focused on place attachment, defined as the extent to which a person values or identifies with a particular setting. Some studies suggest that place attachment includes an emotional/symbolic “place identity” dimension and a functional “place dependence” dimension. One aspect of place attachment that has not been explored empirically is the extent to which people become attached to a specific site versus its larger setting. The main purpose of this study was to examine users' place attachment to a large metropolitan park versus their place attachment to a particular trail located within that same park. The study sample was comprised of 438 recreational users of a paved trail located in a large regional park near Cleveland, Ohio. Major findings include: (1) Frequency of use was positively related to both park and trail attachment. (2) Levels of trail attachment varied across different trail activities, but levels of park attachment did not. (3) The most powerful predictor of both park attachment and trail attachment was personal commitment to the activity that users were pursuing. (4) –Unlike previous research, factor analyses indicated that both park and trail attachment were unidimensional rather than comprised of place identity and dependence dimensions. Implications for management and research are discussed.
Basal Area Increment and Growth Efficiency as Functions of Canopy Dynamics and Stem Mechanics
Authors: Dean Thomas J.
Published: April 2024

Crown and canopy structure correlate with growth efficiency and also determine stem size and taper as described by the uniform stress principle of stem formation. A regression model was derived from this principle that expresses basal area increment in terms of the amount and vertical distribution of leaf area and change in these variables during a growth period. This model was fit to data collected from five studies analyzing various effects of cultural practices, atmospheric deposition, and stand density on the growth of loblolly pine (Pinus taeda), slash pine (P. elliottii), or lodgepole pine (P. contorta). For both southern pines, the model was fit to individual-tree data and plot totals measured on 1- to 4-yr-old trees and from 12- to 20-yr-old trees. The model was also fit to data measured on approximately 90-yr-old lodgepole pine trees in northern Utah. The model explained an average of 85% of the variation in individual-tree basal area increment and an average of 86% of variation in gross basal area increment per hectare. By comparison, leaf area alone explained an average of 54% of the variation in the increment of individual-tree stem volume and an average of 50% of the gross increment in stem volume per hectare. The value of the exponent in the model implicates stem mechanics in stem growth, and fitted exponents were all within 7% of the exponent derived from the uniform stress model. Isolines of basal area increment and basal area growth efficiency based on fitted equations indicate that increments in the product of leaf area and height to center of leaf area must increase yearly for either basal area increment or growth efficiency to be constant with age. FOR. SCI. 50(1):106–116.
Fuzzy Classification of Ecological Habitats from FIA Data
Authors: Zhang Lianjun , Liu Chuangmin , Davis Craig J. , Solomon Dale S. , Brann Thomas B. , Caldwell Lawrence E.
Published: April 2024

Fuzzy c-mean classification (FCM), multi-layer perceptron neural network (MLP), fuzzy ARTMAP, and linear discriminant analysis (LDA) were used to classify Forest Inventory and Analysis (FIA) plots into six ecological habitats in the U.S. Northeast. Among the four classifiers, both FCM and MLP produced “soft” classifications based on fuzzy membership values. In contrast, fuzzy ARTMAP and LDA generated only “hard” classifications in which a plot is assigned to the dominant habitat class, based on binary logic, without considering any coexisting classes. The error matrix and several accuracy indices were calculated to assess the classification accuracy of the methods and to test the differences among the four classifiers. The classification accuracies of FCM and MLP were 98% and 97%, respectively, for overall classification, while fuzzy ARTMAP and LDA had an overall classification accuracy of 92% and 85%, respectively. The χ2 test showed that there was no significant difference between the FCM and MLP methods in classification accuracy. But they were significantly better than both fuzzy ARTMAP and LDA methods at a significant level of α = 0.05. This study showed that the fuzzy classifiers such as FCM and MLP were preferable in the classification of ecological habitats using FIA plots, especially for the classification of ambiguous plots with mixed overstory and understory species compositions. FOR. SCI. 50(1):117–127.
Importance of Non-Stand-Replacing Fire for Development of Forest Structure in the Pacific Northwest, USA
Authors: Weisberg Peter J.
Published: April 2024

Old-growth forests have been the subject of much political concern and forestry research in the 20th century. Evidence that many old-growth stands of the western Oregon Cascade Range have experienced multiple low- to moderate-severity fires has led to the hypothesis that such fires have sustained structural complexity in certain temperate coniferous forests. Multiple regression analysis was used to assess the role of historical non-stand-replacing fire for 90 mature and old forest sites on a 450-km2 landscape of mixed-severity fire regime in western Oregon. The occurrence of non-stand-replacing fire was inferred from the relative frequency of fire scars on Pseudotsuga menziesii. Results suggest that in the central western Cascades, the occurrence of non-stand-replacing fire has favored variability in tree diameter sizes, larger trees, and a greater component of shade-tolerant tree species, after accounting for the effects of elevation, slope aspect, and stand age. However, the fire scar variable explained a relatively small percentage of the variance not explained by these effects, with partial R2 values ranging from 0.05 to 0.16. A path analysis suggested that the effects of stand age on forest structure can be partitioned into direct effects (gap dynamics and successional processes in the absence of disturbance) and indirect effects (older stands have had more time to experience non-stand-replacing fire), with the indirect effects explaining a large component of forest structural attributes that are typically associated with the old-growth seral stage. While the cumulative and long-term effects of non-stand-replacing fire in this region are likely complex, it would seem prudent to include such disturbances as a key ecosystem process, where management practices seek to emulate natural disturbance regimes or facilitate the development of old-growth forest structures. FOR. SCI. 50(2):245–258.
Book Reviews: Wildlife of Southern Forests: Habitat & Management
Authors: Miller Debbie L.
Published: April 2024

Wildlife of Southern Forests: Habitat and Management consolidates within one volume a plethora of information concerning wildlife and wildlife management in southern forests. The intended audience, land managers, will appreciate the one-stop shopping for detailed biological information coupled with practical guidelines for habitat management on a broad scale. This book succeeds in providing a complete, up-to-date overview of most areas of ecology and management important to wildlife in southern forests. Experts from universities, federal agencies, and conservation organizations of the South well qualified to write on their chosen topics author individual chapters. Most of the book is devoted to providing detailed, current information on life history traits and management strategies of individual species or suites of species.
Spatial Relationship of Biomass and Species Distribution in an Old-Growth Pseudotsuga-Tsuga Forest
Authors: Chen Jiquan , Song Bo , Rudnicki Mark , Moeur Melinda , Bible Ken , North Malcolm , Shaw Dave C. , Franklin Jerry F. , Braun Dave M.
Published: April 2024

Old-growth forests are known for their complex and variable structure and function. In a 12-ha plot (300 m × 400 m) of an old-growth Douglas-fir forest within the T. T. Munger Research Natural Area in southern Washington, we mapped and recorded live/dead condition, species, and diameter at breast height to address the following objectives: (1) to quantify the contribution of overstory species to various elements of aboveground biomass (AGB), density, and basal area, (2) to detect and delineate spatial patchiness of AGB using geostatisitcs, and (3) to explore spatial relationships between AGB patch patterns and forest structure and composition. Published biometric equations for the coniferous biome of the region were applied to compute AGB and its components of each individual stem. A program was developed to randomly locate 500 circular plots within the 12-ha plot that sampled the average biomass component of interest on a per hectare basis so that the discrete point patterns of trees were statistically transformed to continuous variables. The forest structure and composition of low, mediate, and high biomass patches were then analyzed. Biomass distribution of the six major species across the stand were clearly different and scale- dependent. The average patch size of the AGB based on semivariance analysis for Tsuga heterophylla, Abies amabilis, A. grandis, Pseudotsuga menziesii, Thuja plicata, and Taxus brevifolia were 57.3, 81.7, 37, 114.6, 38.7, and 51.8 m, respectively. High biomass patches were characterized by high proportions of T. heterophylla and T. plicata depending on spatial locations across the stand. Low AGB patches had high densities of A. amabilis and T. brevifolia. We presented several potential mechanisms for relating spatial distribution of species and biomass, including competition, invasion and extinction, disturbance, and stand dynamics. Clearly, future studies should be developed to examine the details of how each process alters the spatial patterns of tree species with sound experimental designs and long-term monitoring processes at multiple scales. FOR. SCI. 50(3):364–375.
Three-Dimensional Canopy Structure of an Old-Growth Douglas-Fir Forest
Authors: Song Bo , Chen Jiquan , Silbernagel Janet
Published: April 2024

In this study, the structurally heterogeneous canopy of a 12-ha plot in an old-growth Douglas-fir forest was analyzed using three-dimensional (3-D) canopy modeling, geographic information system (GIS), and spatial statistics. Using this approach, we were able to depict how species composition and spatial distribution affect the 3-D structure of canopies. We were also able to slice the canopy and calculate the canopy coverage at various heights, and therefore were able to calculate the cumulative canopy volume at individual crown bases. Information generated by GIS allowed us to calculate how much area canopies or canopy openings occupy. Total canopy volume (243,641 m3/ha) was dominated by western hemlocks (67.1%) and Douglas-firs (23.7%) in this plot. Western hemlocks and Douglas-firs also dominated the canopy coverage, with 65.7% and 25.5% average coverage, respectively. Average total canopy coverage was 84.3% with variations between 78.7% and 89.9% among the 12 1-ha subplots, implying that 15.7% of the stand consisted of canopy openings. Coverage of the canopy projection changed greatly from the lower to the upper canopy layers, with the maximum at about 20 m high. We also examined spatial relationships among groups of trees at different heights and at various scales using bivariate Ripley's K analysis. We found that different species of the understory layer showed different spatial relationships relative to the overstory canopy layer. Likewise the same species in the understory layer showed different spatial relationships when the overstory species differed. This approach provided a useful tool for characterizing 3-D forest canopies, and the results will be very helpful for examining leaf distribution, understory light environment, understory vegetation, and microclimate. FOR. SCI. 50(3):376–386.
Softwood Lumber Products in the United States: Substitutes, Complements, or Unrelated?
Authors: Nagubadi Rao V. , Zhang Daowei , Prestemon Jeffrey P. , Wear David N.
Published: April 2024

This study addresses an important dimension concerning the softwood lumber trade dispute between United States and Canada–substitutability among imported and domestically produced species. We employ the restricted translog subcost function approach to study this issue based on the monthly data of US softwood products consumption and prices between Jan. 1989 and July 2001. The results show that the spruce-pine-fir lumber species group, mainly imported from Canada, is largely unrelated to domestically produced treated southern yellow pine, Douglas-fir, and other species groups, but is a substitute to untreated southern yellow pine and engineered wood products. Furthermore, untreated southern yellow pine is facing more severe competition from structural panels rather than from the imported Canadian spruce-pine-fir group. FOR. SCI. 50(4):416–426.
Short-Term Forecasting Models for the Finnish Forest Sector: Lumber Exports and Sawlog Demand
Authors: Hetemäki Lauri , Hänninen Riitta , Toppinen Anne
Published: April 2024

Due to liberalization of capital and currency markets, globalization of the forest industry, and developments in information technology and logistics, the world's forest product markets have become more interrelated, and they react ever more quickly to changes in macroeconomic conditions. Thus, short-term analysis and forecasting of forest product markets have also become more important. This article explains the framework for the system of short-term forecasting of the Finnish forest sector (MESU) using a case study. We present models and forecasts for short-term changes in the lumber import demand in Germany, how this affects forecasts for Finnish lumber exports, and in turn, how these exports affect forecasts for sawlog demand in Finland. Univariate and multivariate time series models are estimated using quarterly data from 1980:1 to 1996:4, and forecasts are computed for 1997:1 to 1998:4. Results show that the MESU system can be a helpful tool for forecasting short-term changes in the Finnish forest sector. FOR. SCI. 50(4):461–472.
Relative Growth Trend as an Early Selection Parameter in a Douglas-Fir Provenance Test
Authors: Zas Rafael , Merlo Esther , Díaz Raquel , Fernández-López Josefa
Published: April 2024

Height data from 89 Douglas-fir provenances planted at seven sites in northern Spain were used to explore and discuss the utility of the relative height growth trend as an early selection parameter. Total height was measured at each site at different ages between 2 and 18 years after planting. A modification of the joint regression analysis was used to analyze and interpret the provenance × age interaction at each site. The analyses of variance showed a significant provenance × age interaction in five out of the seven sites. Most of this interaction at these sites was explained by the linear relation over years between the provenance mean height at each site and the overall site mean height. The relative growth trend was defined as the slope of these linear relations for each provenance and was considered as a temporal stability parameter. Both the high genetic variability and the biological significance of this parameter suggest its applicability in early selection. A strong linear relationship was observed between this growth parameter and the initial provenance mean height at all sites where provenance × age interaction was significant except one. This relationship indicates that the differences between provenances at an early stage will hold up and be amplified in future measurements, and then there is a relative security of early selection. One site showed no significant relation between the relative growth trend and the initial performance. At this site, rank changes among measurements are likely to be more frequent, and early selection becomes harder. The use of the relative growth trend as an early selection parameter in these sites improves the early selection efficiency. The results suggest that the relative growth trend can help in both the early selection and the evaluation of the early selection efficiency. FOR. SCI. 50(4):518–526.
A Cost-Efficient Approach to Selecting Forest Stands for Conserving Species: A Case Study from Northern Fennoscandia
Authors: Juutinen Artti , Mäntymaa Erkki , Mönkkönen Mikko , Salmi Juha
Published: April 2024

We analyze cost-efficient conservation of boreal old-growth forests using three variants of the site selection framework. In all variants, the aim is to maximize biodiversity subject to a given resource constraint. Our benchmark, an integrated site selection model, takes into account both ecological and commercial values of the stands and defines a cost-efficient solution to conservation problems. The other two models are called the ecological and the penny-pincher models. The ecological model reflects current conservation practices and is based on ecological criteria. The penny-pincher model reflects an ad hoc preservation used earlier in many countries, which leads to selection of the stands having the lowest commercial value irrespective of their ecological features. Using Finnish data on forest dwelling species and commercial values of the stands, we demonstrate that the integrated model leads to 9–19% higher conservation cost-efficiency than the other two models. We also show that the xeric forest type may be underrepresented in the current old-growth forest preservation network in this region. FOR. SCI. 50(4):527–539.
Effect of Selfing on Various Economic Traits in Pinus radiata and Some Implications for Breeding Strategy
Authors: Kumar S.
Published: April 2024

Selfed and outcrossed progenies of 41 Pinus radiata plus trees were obtained from two separate studies to evaluate the effect of inbreeding on economic traits such as diameter, bole straightness, branching, wood density, and Dothistroma infection at the selection age and at theharvest age. The possibility of using selfed families for estimation of genetic parameters and future breeding was investigated. For diameter, inbreeding depression (ID) varied between 13 and 17% at different ages across different sites. An ID of about 13% and −3.0%was obtained for straightness and wood density, respectively. For Dothistroma, the pattern of ID at different ages was not consistent across different environments. There was generally a close agreement, for all traits except diameter, between estimates of narrow-sense heritability obtainedfrom selfed and outcrossed progenies. Estimated correlations between predicted breeding values at different ages were higher for selfed families compared to outcrossed families, indicating that early selection would be more effective among selfed families than among outcrossed families. Forall traits except diameter growth, ranking of parents on selfed performance was highly correlated with outcrossed performance at the selection age. This study showed that selection on selfs (even after culling of less vigorous individuals at the nursery stage) would not be effective for diametergrowth, but it might be a reasonably good strategy for form traits, Dothistroma resistance, and wood density. FOR. SCI. 50(5):571–578.
Forest Change Detection Applying Landsat Thematic Mapper Difference Features: A Comparison of Different Classifiers in Boreal Forest Conditions
Authors: Heikkonen Jukka , Varjo Jari
Published: April 2024

This article addresses the problem of detecting forest changes via multitemporal Landsat Thematic Mapper (TM) imagery. A stand-level classification approach is selected, where, for each stand, a total of 35 statistical differences is extracted from Landsat TM images. Three forest stand-changeclasses are considered: 1) no change, 2) moderate change, and 3) considerable change. The classification results are reported by using the following classifiers: K-nearest-neighbor, Maximum Likelihood classifier with Gaussian- and Kernel-based class probability density estimation, Classificationand Regression Trees, Multilayer Perceptron (MLP) early stop committee, and the MLP with weight decay training. Two Bayesian learning methods for MLP are also used: The Evidence Framework of MacKay, and Hybrid Monte Carlo (HMC) method following Neal. The best overall correct classificationresult (88.1%) is obtained by MLP trained with HMC and the Automatic Relevance Detection approach, but the variation of the performance of the classifiers is rather small. FOR. SCI. 50(5):579–588.
Some Theory for the Application of the Moving Average Estimator in Forest Surveys
Authors: Johnson Devin S. , Williams Michael S.
Published: April 2024

The Forest Inventory and Analysis (FIA) and National Resources Inventory programs are two examples of large-scale survey programs that are in the process of moving from periodic surveys, where data for an area are collected once every 10–15 years, to annual surveys, where a smallersample of the data is collected every year. Each yearly sample can be referred to as a panel, and yearly estimates can be made with the data in each panel. With the change from periodic to annual surveys, there has been a substantial amount of discussion related to combining the data fromthe individual panels into a single estimator with an acceptably small mean square error. Numerous methods, each with certain advantages and disadvantages, have been proposed and tested. Testing with FIA data suggests that, in terms of mean square error, the equally weighted moving averageestimator is often as good as or better than other estimators when making estimates for individual counties or small groups of counties. This favorable performance is due to the relatively small sample sizes in these situations. One area of research that has not been addressed is the performanceof the moving average estimator when the sampling design deviates from its original protocol. Factors that cannot be controlled, such as weather, budgets, and politics, can alter the original sampling design. The purpose of this article is to propose and derive estimators that accommodatethese factors and give some guidelines on how to handle these situations when they occur. FOR. SCI. 50(5):672–681.
Predicting Parameters of a Weibull Function for Modeling Diameter Distribution
Authors: Cao Quang V.
Published: April 2024

The Weibull function has been widely used to characterize diameter distributions in a forest stand. Methods have been developed to predict the Weibull parameters, either directly or indirectly, from stand age, density, and dominant height. In this study, four existing methods and twonew methods of obtaining the Weibull parameters were evaluated using data from a loblolly pine (Pinus taeda L.) plantation. While both new methods performed well, one of them produced consistently better goodness-of-fit statistics than those from the existing methods. FOR. SCI. 50(5):682–685.
A Generalized Methodology for Developing Whole-Stand Survival Models
Authors: Rose Charles E. , Clutter Michael L. , Shiver Barry D. , Hall Daniel B. , Borders Bruce
Published: April 2024

A large source of variability in yield predictions is due to estimation of future surviving trees per unit area. Previous whole-stand survival modeling efforts have concentrated on modeling the empirical survival curve. Modeling hazard functions, an approach to survival analysis commonly used in fields such as medicine and sociology, can be applicable to plantation survival estimation. We offer a generalized method for deriving whole-stand survival models that are capable of modeling complex underlying hazard functions. We use our knowledge of the empirical hazard function to limit our selection to appropriate functions. Integrating selected functions results in initial condition difference equations that, when fitted to our data, provide biologically reasonable whole-stand survival predictions and adequately represent the underlying hazard function. Our method is relatively easy to implement and can model a whole-stand survival curve with a complex underlying hazard function. FOR. SCI. 50(5):686–695.