bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting Forest Attributes in Southeast Alaska Using Artificial Neural Networks
Authors: Corne Simon A. , Carver Stephen J. , Kunin William E. , Lennon Jack J. , van Hees Willem W. S. van 
Published: April 2024

Abstract
Artificial neural network (ANN) methods are used to predict forest characteristics. The data source is the Southeast Alaska (SEAK) Grid Inventory, a ground survey compiled by the USDA Forest Service at several thousand sites. The main objective of this article is to predict characteristics at unsurveyed locations between grid sites. A secondary objective is to evaluate the relative performance of different ANNs. Data from the grid sites are used to train six ANNs: multilayer perceptron, fuzzy ARTMAP, probabilistic, generalized regression, radial basis function, and learning vector quantization. A classification and regression tree method is used for comparison. Topographic variables are used to construct models: latitude and longitude coordinates, elevation, slope, and aspect. The models classify three forest characteristics: crown closure, species land cover, and tree size/structure. Models are constructed using n-fold cross-validation. Predictive accuracy is calculated using a method that accounts for the influence of misclassification as well as measuring correct classifications. The probabilistic and generalized regression networks are found to be the most accurate. The predictions of the ANN models are compared with a classification of the Tongass national forest in southeast Alaska based on the interpretation of satellite imagery and are found to be of similar accuracy. FOR. SCI. 50(2):259–276.
Book Reviews: Toward Forest Sustainability
Authors: Roberts Scott D. 
Published: April 2024

Abstract
A major issue facing forestry these days is whether forests can be actively managed while supporting diversity and maintaining their natural range of ecological processes and functions. In other words, can forests be managed sustainably? This book contains a collection of essays written by participants of a sustainable forestry roundtable held in 2002 in Marysville, Victoria, Australia. Although much of the conference focused on Australia's montane ash forests, the purpose of the book is to share the wisdom and experience of experts from countries throughout the temperate regions of the world as their countries struggle to learn how to manage forests more sustainably in the face of changing political and environmental pressures. Some of the contributors will be very familiar to readers who have followed the sustainable-forest management debates in North America, including Jerry Franklin, Michael Soulé, David Perry, and Frank Bunnell. Other contributors may not be as familiar to the North American audience, but will certainly be recognized by those who have followed the international sustainable-forestry debate. These include, among others, David Lindenmayer and Per Angelstam.
A Critical Evaluation of Fire Suppression Effects in the Boreal Forest of Ontario
Authors: Bridge S.R.J. , Miyanishi K. , Johnson E.A. 
Published: April 2024

Abstract
Although fire suppression is widely believed to have changed the “natural” fire regime in the boreal forest, empirical evidence for this effect is limited and usually involves a comparison of fire sizes, average annual area burned, and fire cycle between areas with and without fire suppression. We critically evaluate this empirical evidence and discuss problems with untested assumptions, data quality, statistical analyses, interpretations, and inferences. Furthermore, to test the hypothesis that fire suppression has changed the natural fire regime, we apply time-since-fire techniques to spatial fire data (1921–1995) for the western and eastern boreal regions of Ontario and compare temporal and spatial variation in fire cycle for areas with and without fire suppression. There is no detectable temporal change in fire cycle between 1921 and 1995 in areas with aggressive fire suppression; however, interpretation of the fire cycle in areas without aggressive fire suppression is confounded by insufficient data. Also, although the western region shows an increase in fire cycle from fully protected to less protected areas, the eastern region shows the shortest fire cycle in the most protected area. Thus, to date there is insufficient empirical evidence that fire suppression has significantly changed the fire cycle in the boreal forest of Ontario. FOR. SCI. 51(1):41–50.
Juvenile Genetic Parameters and Genotypic Stability of Pinus pinaster Ait. Open-Pollinated Families under Different Water and Nutrient Regimes
Authors: Zas Rafael , Fernández-López Josefa 
Published: April 2024

Abstract
The purpose of this study was to estimate the impact of genotype × nutrient and genotype × water availability interactions in the maritime pine (Pinus pinaster Ait.) breeding program in Galicia (northwestern Spain). Twenty-nine open-pollinated families, randomly selected in a seed orchard, were cultivated for 23 weeks in a greenhouse in a split-plot design under controlled conditions. Two water regimes (high and low water supply) combined with two nutrient regimes (high and low nutrient supply) were applied by subirrigation. Both the irrigation and the fertilization treatments had a strong effect in all the assessed traits. Heritabilities for growth and biomass traits were moderate to high (0.2–0.5) in individual treatments, especially in those treatments that led to intermediate growth. However, when analyzing all treatments together, the impact of the family × treatment interactions led to an important reduction (0.1–0.2) of the heritability estimates. The results indicated that the genotype × water and genotype × nutrient interactions may be important and could not be ignored in the Galician maritime pine breeding program. However, the study of the family ecovalence values indicated that interactions are mainly due to some interactive families (7 to 31% of families). Culling several of the female parents with high ecovalence values would result in a stable breeding population and would be enough to overcome the interaction handicap in the breeding program. FOR. SCI. 51(2):165–174.
Finding the Efficient Frontier of a Bi-Criteria, Spatially Explicit, Harvest Scheduling Problem
Authors: Sándor F. Tóth , McDill Marc E. , Rebain Stephanie 
Published: April 2024

Abstract
The effects of cost-sharing and information assistance on nonindustrial private forest owners’ investment in timber stand improvements are analyzed using a two-step estimation method. We use survey data on Finnish nonindustrial private forestland owners’ stand improvements in 1994–1998, including precommercial thinnings, cleaning of seedling stands, and restoration thinnings of juvenile stands. The investment decision is theoretically considered in a two-period model with amenity values. To allow for the joint determination of participation in the cost-sharing program and the decision to invest, a two-step estimation method is used. The predicted probability of using public subsidy from the first-step model is included in the second-step model for the probability or relative extent of stand improvements. For robust inference, quasi-maximum likelihood estimation is applied. Public subsidy, personal assistance, and forest planning expectedly increased the probability of investing. Public subsidy especially had substantial effects on the probability and extent of stand improvements. Besides overcoming the endogeneity of cost-sharing, the two-step approach showed that personal assistance also encourages stand improvements indirectly through its effect on the use of public subsidy.
The Law of One Price in the North American Softwood Lumber Markets
Authors: Shahi Chander , Kant Shashi , Yang Feng'e 
Published: April 2024

Abstract
The existence of the Law of One Price (LOP) in the North American (10 regional) markets for aggregate softwood lumber and homogeneous softwood lumber products is tested using the Johansen co-integration test and monthly price data for the Softwood Lumber Agreement (SLA) (1996–2001) period and the post-SLA (2001–2004) period. For the aggregate softwood lumber market, the LOP exists neither in the North American aggregate market nor in any combination of one regional market of Canada and all the five regional markets of the United States, nor in one regional market of the United States and all five regional markets of Canada; however, some of the regional markets are co-integrated. The regional markets of homogeneous softwood products in the two countries are co-integrated during both the SLA and post-SLA period. Further studies are essential to understand the difference between the aggregated and homogeneous softwood products market co-integration and to develop a comprehensive and comparative perspective of the Canadian and the US softwood lumber markets.
U.S.–Canada Softwood Lumber Trade: Measuring the Market and Welfare Impacts of Restrictions
Authors: Baek Jungho , Yin Runsheng 
Published: April 2024

Abstract
The U.S.–Canada softwood lumber trade dispute is the largest and most contentious one between the two countries. Using a simultaneous system of equations and a vector auto-regression model, and quarterly data for over the last two decades, this article assesses the impacts of the Memorandum of Understanding (MOU) and Softwood Lumber Agreement (SLA). We find that the MOU causes Canadian exports to drop by 8.4–9% during 1986:4–1991:3, which in turn pushes up the U.S. production by 3%. But it does not lead to higher lumber prices. The SLA does not have any significant impacts on the lumber market during 1996:2–2001:1. In addition, the price elasticities of domestic and Canadian export supply are smaller than those commonly used in evaluating the gains and losses of the U.S. restrictions, whereas such factors as exchange rates, housing starts, and log prices have played major roles in shaping the lumber markets. Combining the modest market impacts and smaller price elasticities, we obtain only moderate welfare consequences of the trade restrictions.
Bird–Habitat Relationships in Grand Fir Forests of the Blue Mountains, Oregon
Authors: Sallabanks Rex , Riggs Robert A. , Cobb Lynda E. , Dodson Steven W. 
Published: April 2024

Abstract
During the breeding seasons of 1994–1996, we sampled bird communities and habitat characteristics in grand fir (Abies grandis) forests of the Blue Mountains, northeastern Oregon, at the stand- and landscape-level with the objective of explaining variation in the composition and abundance of forest avifauna. We analyzed data from 77 forest stands that varied in size from 16 to 213 ha. Canonical correlation analysis (CANCOR) indicated that stand-level features accounted for more variance in the relative abundance of bird species than did landscape-level features (35 versus 14%, respectively). The most important stand-level features were overstory canopy cover, density of large-diameter live trees, and understory structure (especially herbs and shrubs). Important landscape features for predicting the abundance of species within a forest stand included stand isolation and the percentage of surrounding landscape within a 4-km radius that was occupied by forest cover. Using the information-theoretic approach to model selection and inference, we built models of bird–habitat relationships to forecast abundance of 24 species. Consistent with CANCOR results, species–specific habitat models were dominated by stand-level variables. Overstory cover was a significant predictor of abundance for 17 of 24 species modeled (71%). We conclude that in forests represented by our sample, management for most avian species can be usefully focused on within-stand dynamics of structure, but that efforts to forecast abundance of some species can be enhanced by integration of landscape metrics as well.
Timber Harvest Impacts on Water Yield in the Continental/Maritime Hydroclimatic Region of the United States
Authors: Hubbart Jason A. , Link Timothy E. , Gravelle John A. , Elliot William J. 
Published: April 2024

Abstract
The inland Pacific Northwest of the United States is influenced by both maritime and continental hydrometeorogical conditions. To date there are limited studies of hydrologic impacts resulting from contemporary timber harvest in this region. Streamflow data were collected since 1991 at the Mica Creek Experimental Watershed (MCEW) in northern Idaho. Treatments were designed to isolate the effects of road construction and two different harvest practices (50% clearcut, 50% partial cut). The change in water yield was assessed using linear regression and analysis of covariance (ANCOVA). Water yield increased in excess of 270 mm/yr (P &lt; 0.01) after clearcut harvesting, and by more than 140 mm/yr (P &lt; 0.01) after partial cut harvesting. Monthly and seasonal analyses revealed the largest impacts of harvest practices on water yield during the snow deposition and melt season from November through June. Dry season analyses (July through October) indicated negligible water yield increases after treatments. Estimates of evapotranspiration (ET) as the residual of the catchment water balance suggest that ET was reduced by 35% and 14% after clearcut and partial cut harvest, respectively. These results establish a base on which to develop tools for effective watershed management in the northern Idaho continental/maritime hydroclimatic region.
NetMap: A New Tool in Support of Watershed Science and Resource Management
Authors: Benda Lee , Miller Daniel , Andras Kevin , Bigelow Paul , Reeves Gordon , Michael David 
Published: April 2024

Abstract
An integrated suite of numerical models and analysis tools (NetMap) is created for three purposes: (1) Develop regional scale terrain databases in support of watershed science and resource management, (2) Automate numerous kinds of watershed analyses keying on environmental variability for diversifying resource management options, and (3) Improve tools and skills for interpreting watershed-level controls on aquatic systems, including natural disturbance. Hillslope attributes, such as erosion potential, sediment supply, road density, forest age, and fire risk are aggregated down to the channel habitat scale (20–200 m) allowing unique overlap analyses, and they are accumulated downstream in networks revealing patterns across multiple scales. Watershed attributes are aggregated up to subbasin scales (10,000 ha), allowing comparative analyses across large watersheds and landscapes. Approximately 25 automated tools address erosion risk, habitat indices, channel classification, habitat core areas, habitat diversity, and sediment and wood supply, among others. Search functions target overlaps between specific hillslope and channel conditions and between roads and landslide or debris flow potential. To facilitate its use, NetMap contains hyperlinked users' manuals and reference materials, including a library of 50 watershed parameters. NetMap provides decision support for forestry, restoration, monitoring, conservation, and regulation.
On Debris Flows, River Networks, and the Spatial Structure of Channel Morphology
Authors: Bigelow Paul E. , Benda Lee E. , Miller Daniel J. , Burnett Kelly M. 
Published: April 2024

Abstract
We evaluated the morphological effects of debris flows from headwater streams in larger, fish-bearing channels of the central Oregon Coast Range, including their influence on fans, wood recruitment, and channel morphology. Continuous channel surveys (6.4 km) were conducted in third- through fifth-order streams (drainage area &lt;10 km2 and slope &lt;7%) where debris fan effects at confluences were most evident. This basin size contains the majority of channels (67%) in the central Coast Range with gradients that are used by coho salmon (Oncorhynchus kisutch Walbaum). The close spacing between headwater tributaries susceptible to debris flows (118 m average) resulted in long continuous sections of fish-bearing streams that were bordered by debris fans (103 m average) and debris fans impinging on 54% of the total channel length surveyed. Debris flows also supplied the majority of wood (58% of pieces) to the surveyed fish-bearing channels. The highest values of large wood, boulders, and channel gradients were associated with debris fans at confluences with headwater tributaries, while deeper sediment deposits were often associated with fans but also extended up and downstream from fans. The spacing and network pattern of debris flow-prone headwater tributaries influenced the spatial structure of channel morphology and aquatic habitats leading to a high degree of physical heterogeneity and patchiness in channel environments. Our study contributes to a growing emphasis on the role of tributary confluences in structuring channel morphology and aquatic habitats in mountain drainage basins and argues for including a confluence component to stream classification and habitat typing schemes.
Stream Macroinvertebrate Community Responses as Legacies of Forest Harvest at the H.J. Andrews Experimental Forest, Oregon
Authors: Frady Charles , Johnson Sherri , Li Judy 
Published: April 2024

Abstract
To evaluate long-term effects of forest harvest, we sampled benthic and emergent macroinvertebrate communities in headwater streams through young-growth and old-growth forests in the H.J. Andrews Experimental Forest, Oregon, from June, 2003 to June, 2004. Thirty to forty years after harvest, macroinvertebrate density and richness did not differ among streams through young growth and old growth. Effects of deciduous riparian vegetation, including seasonal canopy openings and litterfall, continue to influence patterns of macroinvertebrate responses to forest harvest, as shown by higher densities of shredders in young-growth sites, the timing of emergence within basin pairs, and assemblage differences in two of the pairs of basins. The paired-basin design helped in distinguishing the specific influences of forest age from natural variability of macroinvertebrate distributions within the 5th order Lookout Creek basin. Our study suggests that understanding how macroinvertebrates respond to historical disturbances is enhanced by measures sensitive to changes in life history, such as rates of emergence, and to functional composition that reflect resource availability.
Productivity of Three Young Mixed-Species Plantations Containing N2-Fixing Acacia and Non-N2-Fixing Eucalyptus and Pinus Trees in Southeastern Australia
Authors: Forrester David I. , Bauhus Jürgen , Cowie Annette L. , Mitchell Peter A. , Brockwell John 
Published: April 2024

Abstract
Mixed species plantations have the potential to exceed the biomass production of monocultures. This study examined the productivity of three mixed species plantations in southeastern Australia. Two of these trials contained a Eucalyptus sp. (E. saligna Smith or E. nitens [Deane & Maiden] Maiden) planted with Acacia mearnsii De Wild., and the other contained Pinus radiata D. Don with A. mearnsii, A. decurrens Willd., E. benthamii Maiden & Cambage, or E. smithii R. Baker. Each trial contained both monocultures and mixtures, and was replicated three or four times. Tree diameters or heights were smaller in mixture than monocultures for some species (P. radiata diameters of 5.9 cm and 7.0 cm in 2:1 mixtures with A. mearnsii and monocultures, respectively) but tended to increase (not significantly) for other species (E. nitens diameters of 10.6 cm and 8.5 cm and A. mearnsii diameters of 9.2 cm and 8.8 cm in 1:1 mixtures and monocultures, respectively). As a result, mixtures were intermediate in aboveground biomass production between monocultures of the mixed species in each trial, or they were not significantly different from the monocultures. Competition for resources other than nitrogen (N), such as light, soil moisture, or other nutrients, appeared to balance any positive effects that might have occurred, such as through increased N availability. For example, foliar N concentrations of E. saligna were higher in mixture (23.1 mg g−1) than monoculture (17.7 mg g−1); however, this did not result in greater aboveground tree biomass. The range of different growth responses from mixing different species in this study and in other studies shows that a fundamental understanding of the underlying processes is required to enable a greater predictive capacity of the circumstances under which mixtures can be successful.
Does Monopolistic Competition Explain Intraindustry Trade of Forest Products?
Authors: Zhang Sijia , Buongiorno Joseph 
Published: April 2024

Abstract
Intraindustry trade occurs when countries import and export the same product. We found, based on Grubel-Lloyd indices, that there is substantial intraindustry trade of forest products. The explanation of intraindustry trade by the Helpman-Krugman theory of monopolistic competition implies a unit elasticity of exports with respect to production. We studied the existence of such a relationship for 11 forest industries that produce and export roundwood, sawnwood, wood-based panels, wood pulp, and paper and paperboard. The hypothesis was tested with cross-section and time-series data from 43 countries observed from 1961 to 2002. We formulated static and dynamic versions of the relationship between exports and production and estimated them with panel data methods. The best results, based on pattern of the residuals and forecasting errors, were obtained with the static and the dynamic models estimated by ordinary least squares after differencing the time series. The strongest evidence of monopolistic competition was for the pulp and paper industries: newsprint, printing and writing paper, other paper and paperboard, and chemical and semichemical woodpulp. For other forest products, although there was a statistically significant relationship between production and exports, the long-run elasticity was significantly less than unity.
Leaf Nutrient Concentrations and Timber Productivity in the Dry Sclerophyll Forests of South-East Queensland, Australia: Implications for Arboreal Marsupials
Authors: Wormington Kevin Ray , Lamb David , McCallum Hamish Ian , Moloney Damien John 
Published: April 2024

Abstract
The species richness and abundance of arboreal marsupials are positively related to the proportion of total stand basal area occupied by Corymbia citriodora ssp. variegata and tree height in South-East Queensland and have been related to nutrient availability and productivity in other parts of Australia. The objectives of this study were to assess the relationships of stand basal area occupied by C. citriodora and tree height, and the available nutrients and productivity in the dry sclerophyll forests of South-East Queensland. Leaf nutrient analysis of seven species of trees in South-East Queensland showed that the percentage by weight of phosphorus in leaves increased with the proportion of the total stand basal area of C. citriodora. This rate of increase was greater for C. citriodora than other species, indicating that C. citriodora may be more competitive on soils with greater available phosphorus. C. citriodora leaves also contained higher concentrations of nitrogen and potassium than the other tree species on multispecies sites. Timber productivity was greater at the sites where trees were taller, and tree height was positively correlated to the proportion of total stand basal area of C. citriodora and rainfall but was negatively correlated to the slope. These findings indicate that the most used habitat by arboreal marsupials in the dry sclerophyll forests of South-East Queensland (i.e., taller forests with a high proportion of the stand basal area occupied by C. citriodora) had higher concentrations of foliar nutrients and were more productive than less used habitats.