bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Site Index Solution for the Generalized Log-Logistic Height Equation
Authors: Cieszewski C.J.
Published: April 2024

The generalized log-logistic height equation computes height as a function of age and a fixed base-age site index. This equation and its modifications have been used for many applications in various regions. It is seemingly apparent that this equation is analytically insolvable for the site index; no general analytical solution to this equation is readily available. This article presents such a solution that has proven to be valid and useful with all tested parameters. This solution is based on an adaptation of the Ramanujan's (1887-1920) solution for a trinomial with real-number exponents. Ramanujan's solution is a series that in many cases can be expressed as a closed-form equation. In the present context, this series may be used for derivations of various special cases of closed-form solutions, initial-condition difference and differential equations, and for various analytical sensitivity and trend analysis, as well as for efficient site index computations. For. Sci. 46(2):291-296
The Engines of Change in Rsource-Dependent Communities
Authors: Force Jo Ellen , Machlis Gary E. , Zhang Lianjun
Published: April 2024

Social scientists have long attempted to understand change in natural resource-dependent communities. This article examines the relationship of three alternative “engines of change”: local resource production, local historical events, and broad societal trends. Regression models were used to examine the relationships between four dimensions of community social change (size, structure, cohesion, and anomie) and the alternative “engines of change” in seven resource-dependent communities in the Pacific Northwest for over 50 year time periods. Included in the group were four timber towns, as well as communities dependent upon fishing, tourism, and mining. The data suggest that broad societal trends followed by local historical events explain the largest proportion of the variation in community social change dimensions of size and structure. Local resource production has modest explanatory power when combined with the other “engines of change.” FOR. SCI. 46(3): 344–355.
Differential Effects of Rhizobacterial Strain and Dose on the Ectomycorrhizal Colonization of Loblolly Pine Seedlings
Authors: Vonderwell J.D. , Enebak S.A.
Published: April 2024

Loblolly pine seed were inoculated at sowing with one of four plant growth-promoting rhizobacteria (PGPR) strains at four different rates both in the nursery and in the greenhouse. Seedlings were harvested at 4, 8, and 12 wk after sowing in the greenhouse and at 5, 10, and 15 wk after sowing in the nursery. Ectomycorrhizae colonization, estimated as the total number ectomycorrhizal roots per seedling and averaging by gram root biomass, were not evident on any treatment at either 5 wk in the nursery or 4 wk in the greenhouse. However, by 8 wk after sowing, many treatments significantly (P < 0.0001) inhibited ectomycorrhizal root formation. Generally, increasing the rate of all bacteria applied in the greenhouse decreased ectomycorrhizal root formation. Conversely, strain LS212 at 1011 cfu resulted in an increase in ectomycorrhizal roots in the nursery. Increases in seedling root growth were also dependent on bacterial strain and rate, whereas shoot biomass was not effected. Decreases in ectomycorrhizae colonization accounted for 61% of the variation in increases in root biomass, suggesting high metabolic costs of mycorrhizal maintenance in the presence of some rhizobacteria. However, differences in shoot height and survival after outplanting could not be attributed to the mycorrhizae colonization effect. These studies demonstrate that mycorrhizae may serve as a carbon sink early in seedling development and indicate a complex interaction between soil microflora and bacterium in nursery and greenhouse settings. FOR. SCI. 46(3): 437–441.
A Review of Past Research on Dendrometers
Authors: Clark Neil A. , Wynne Randolph H. , Schmoldt Daniel.L.
Published: April 2024

The purpose of a dendrometer is to measure tree diameter. Contact and noncontact dendrometers accomplish this task by collecting different metrics, including girth or distance between tangent points on a tree stem. Many dendrometers have been developed in the last quarter century and many have been retired. This article summarizes instrument developments and application results, contains an interpretation of the results, and provides guidance for dendrometer selection. FOR. SCI. 46(4):570–576.
Potential Effect of Stand Structure on Belowground Allocation
Authors: Dean Thomas J.
Published: April 2024

Stand structure affects two key variables that affect biomass allocation to the stem: leaf area and height to the center of the crown. By translating wind forces into a bending moment, these variables generate bending stress within a stem. The uniform-stress axiom of stem formation can be used to calculate current stem mass for a given bending moment and stem allocation for changes in bending moment over a time period. Stem allocation probably affects allocation to fine roots since the stem precedes the root system on the chain of carbohydrate sinks, and total net primary production is a linear function of leaf area. This study indirectly supports this link between stand structure and belowground allocation. A regression model based on the relationship between bending moment and stem allocation explained 98% of the variation in stand-level stem production of a 12-yr-old loblolly pine (Pinus taeda L.) plantation subjected to factorial combinations of irrigation and fertilization. Further-more, relative fine-root allocation was inversely related to relative stem allocation and increases in apparent bending stress. Corresponding associations between bending stress and relative allocation between the stem and fine roots appear to exist for other species, providing additional support for the proposed link. FOR. Sci. 47(1):69–76.
Linking Growth and Yield and Process Models to Estimate Impact of Environmental Changes on Growth of Loblolly Pine
Authors: Baldwin V. Clark , Burkhart Harold E. , Westfall James A , Peterson Kelly D.
Published: April 2024

PTAEDA2 is a distance-dependent, individual tree model that simulates the growth and yield of a plantation of loblolly pine (Pinus taeda L.) on an annual basis. The MAESTRO model utilizes an array of trees in a stand to calculate and integrate the effects of biological and physical variables on the photosynthesis and respiration processes of a target tree on an hourly basis. PTAEDA2 sums the quantities for individual trees to obtain stand results; MAESTRO computes values for one tree at a time. These models were linked to provide a tool for further understanding stand, climatic, and edaphic effects on tree and forest productivity. PTAEDA2 predicts the characteristics of trees grown at a given stand density, on a given site, for a given length of time. These characteristics (outputs) are then used as direct inputs into MAESTRO which assesses the expected impact of environmental changes on tree function. The results from MAESTRO are fed back into PTAEDA2 to update future predictions by modifying the site index driver variable of the growth and yield model. An equation that predicts changes in site index as a function of net photosynthesis, age, and trees per unit area is the backbone of the dynamic linkage. The model changes required to link PTAEDA2 to MAESTRO were developed and reported earlier. This article reviews the earlier work and reports research results quantifying the relationships between net photosynthesis and the PTAEDA2 growth predictors, thus providing the basis for the MAESTRO to PTAEDA2 feedback process and integration of these two models. FOR. Sci. 47(1)77–82.
Modeling Annual Carbon Uptake for the Indigenous Forests of New Zealand
Authors: Whitehead David , Leathwick John R. , Walcroft Adrian S.
Published: April 2024

A regional estimate of annual gross carbon uptake for the indigenous forests of New Zealand is presented. Carbon uptake for forest canopies occupying 59,311 sites on a 1 km grid (25% of the total land area) is estimated daily using a leaf-level photosynthesis–stomatal conductance model with appropriate scaling procedures (Leuning et al. 1995), and a model of site water balance. For each site, estimates of monthly climate data, soil physical properties, root-zone depth, and nitrogen availability were matched from maps. Forest type was distinguished into 18 classes and values for the maximum rate of carboxylation, Vcmax0, were assigned according to the ratio of conifer to broadleaved trees and nitrogen availability. Mean annual carbon uptake across all sites was 1.5 kg m-2. Variability between sites was attributable principally to the value for Vcmax0, followed by temperature. The effects of water stress integral, air saturation deficit, and solar radiation on carbon uptake were much less. Mean radiation conversion efficiency (ratio of carbon uptake to intercepted solar radiation) was low at 0.79 kg GJ-1, consistent with low nitrogen availability. The analysis highlights the sensitivity of carbon uptake to physiological characteristics and nitrogen status and thus the need to determine values for photosynthesis parameters for trees growing in field conditions. FOR. Sci. 47(1):9–20.
Nutrient Supply and Fertilization Efficiency in Midrotation Loblolly Pine Plantations: A Modeling Analysis
Authors: Ducey Mark , Allen H. Lee
Published: April 2024

We simulated the 10 yr macronutrient budgets for 14 installations in a regionwide midrotation loblolly pine (Pinus taeda L.) fertilization study using NUTREM, a simplified model of carbon and nutrient uptake and distribution. Each installation includes 2–4 replications of N and P addition in a two-way factorial design. By approximating the constraints on nutrient use as elements in a linear programming problem, and estimating the parameters of the problem using least squares, we were able to identify baseline soil supply rates and fertilization efficiencies for N and P for each installation. Estimated N supply ranged from 47 kg ha-1 yr-1 to 103 kg ha-1 yr-1, while P supply ranged from 5.5 to 12.4 kg ha-1 yr-1. Fertilization efficiencies were extremely variable, ranging from 23% to 100% for N and 0% to 78% for P. A lower bound to the baseline supply rate was identified for K, Ca, and Mg for each site. While only three sites were P-limited, P limitation was imminent on all sites with operational doses of applied N. While the accuracy of NUTREM is limited by the availability of basic process-level data, the method suggests possibilities for predicting growth response to nutrient amendments. FOR. Sci. 47(1):96–102.
Forest Resources, Government Policy, and Investment Location Decisions of the Forest Products Industry in the Southern United States
Authors: Sun Changyou , Zhang Daowei
Published: April 2024

In this article, the results of an initial attempt to estimate the effects of state attributes on plant location and investment expenditure were presented for the forest products industry in the southern United States. A conditional logit model was used to analyze new plant births, and a time-series cross-section model to assess the total capital expenditure. Significant positive effects were found for personal income and forest inventory, and negative effects were found for population density. In the short run, tax and energy costs had negative impacts on new plant births in a state, while in the long run, stumpage price and environmental stringency had negative effects on the capital expenditure. Sensitivity of model specification was documented, and policy implications were discussed. For. Sci. 47(2):169–177.
Uncertainty, Debt, and Forest Harvesting: Faustmann Revisited
Authors: Fina Mark , Amacher Gregory S. , Sullivan Jay
Published: April 2024

Debt is a common feature of forestland ownership, yet it has not been formalized in previous work on uncertainty and forestry decision-making. We extend Faustmann-based price search models by introducing a debt obligation that landowners feel pressure to pay off in finite time. We assume a price arrival process that is more general than in previous search models and allows for multiple unknown offers each period. The motivation for paying off debt could be the high costs of searching for another price offer, costs of renegotiating or refinancing debt, increasing interest charges, or landowner preferences for eliminating debt. The decision problem and associated reservation price strategy depend on a comparison of costs and benefits of waiting to harvest. The timing of debt-payoff date is the critical feature of our model. We show that a debt-payoff date implies a certain path of reservation prices over time and ultimately affects harvesting behavior. The direction and magnitude of effect depends on forest maturity. We also investigate how the reservation price–debt payoff date relationship depends on debt in future rotations, nontimber income, amenity benefits, and single versus infinite rotations. Although these ideas, particularly the inclusion of amenities and nontimber income, are absent from the conventional price search literature, we show they have important effects on the optimal reservation price strategy when landowners feel pressure to pay off debts in finite time. FOR. SCI. 47(2):188–196.
The Effect of Nitrogen Fertilization, Rock Type, and Habitat Type on Individual Tree Mortality
Authors: Shen Guanghong , Moore James A. , Hatch Charles R.
Published: April 2024

An individual tree mortality model for nitrogen fertilized Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) stands was developed using data from permanent research plots located throughout the inland Northwest. The proposed linear logistic model included the following independent variables: a dummy variable for the two habitat types, a set of dummy variables for the five rock types, a set of dummy variables for the three N fertilizer treatments, diameter at breast height, crown ratio, and crown competition factor. The results show that N fertilization, rock type, and habitat type significantly affect individual tree mortality. The probabilities of tree mortality on fertilized plots were greater than those on control plots and increased with increasing N fertilizer application rates. Trees growing on granitic and metasedimentary rocks had lower foliar potassium concentration and exhibited greater probabilities of mortality than did those growing on other rocks. The probabilities of mortality for trees growing on sedimentary rocks were very low. Moist sites had lower soil fertility and produced higher mortality rates than dry sites. Furthermore, the N fertilization response ratio, defined as the annual mortality probability of a fertilized tree over the annual mortality probability of a unfertilized tree with identical tree and stand characteristics, was estimated based on the mortality model. The response ratios were nearly constant (about 1.4) across a range of tree diameters for all rock types with the 224 kg N treatment. The response ratios were also nearly constant (about 2.1) across a range of tree diameters for all rock types with the 448 kg N treatment. Finally, the mortality prediction model passed a validation test on independent data not used in model development. For. Sci. 47(2):203–213.
Design of Regular Landscape Fuel Treatment Patterns for Modifying Fire Growth and Behavior
Authors: Finney Mark A.
Published: April 2024

Patterns of disconnected fuel treatment patches that overlap in the heading fire spread direction are theoretically effective in changing forward fire spread rate. The analysis presented here sought to find the unit shape and pattern for a given level of treatment that has the maximum effect on forward spread rate. This occurs when the treatment units cause the fire to spread through them at the same rate as it spreads around them. Simulations suggested that these treatment patterns reduce the spread rate or fireline intensity over much of the area burned, even outside the treatment units where the fire was forced to flank. The ideal patterns are theoretically scale independent, allowing for flexible application across heterogeneous landscapes. The topology of these patterns has implications for designing landscape-level fuel treatment patterns and for understanding spatial dynamics of fuel patterns across landscapes. FOR. SCI. 47(2):219–228.
Human Demographic Trends and Landscape Level Forest Management in the Northwest Wisconsin Pine Barrens
Authors: Radeloff Volker C. , Hammer Roger B. , Voss Paul R. , Hagen Alice E. , Field Donald R. , Mladenoff David J.
Published: April 2024

The effects of landscape pattern on forest ecosystems have been a recent focus in forest science. Forest managers are increasingly considering landscape level processes in their management. Natural disturbance patterns provide one baseline for such management. What has been largely ignored is the pattern of human habitation patterns (i.e., housing), on landscapes. The objective of this study is to discuss landscape level management options for the northwest Wisconsin Pine Barrens based on both landscape ecology and the human demographics of the region. Using the 1990 U. S. Decennial Census we examined current housing density, seasonal housing unit concentration, historic housing density change and projected future housing densities. These data were related to land cover and land ownership data using a GIS. Housing density increase was particularly pronounced in the central Pine Barrens, an area where seasonal housing units are common. Lakes and streams were more abundant in areas that exhibited highest growth. Within national forest lands, 80% of the area contained no housing units. In contrast, only 12% of the area in small private land ownership contained no housing. These results are integrated with previous studies of presettlement vegetation and landscape change to discuss landscape level management suggestions for the Pine Barrens. For. Sci. 47(2):229–241.
Diameter Growth Models Using Minnesota Forest Inventory and Analysis Data
Authors: Lessard Veronica C. , McRoberts Ronald E. , Holdaway Margaret R.
Published: April 2024

The Forest Inventory and Analysis (FIA) program of the USDA Forest Service North Central Research Station (NCRS) has begun replacing the 12- to 13-yr periodic inventory cycles for the states in the North Central region with annual inventories featuring measurement of approximately 20% of all plots in each of the 11 states each year. State reports on summaries of the forest resources will be produced every 5 yr. As a method of updating information on plots not visited in the current year, NCRS is developing nonlinear, individual-tree, distance-independent annual diameter growth models for species groups. The models, formulated as the product of an average diameter growth component and a modifier component, were calibrated on Minnesota FIA data from stands that were generally undisturbed, of mixed ages and of mixed species. The dependent variable is annual diameter growth. The independent variables include crown ratio, crown class, stand basal area, stand basal area larger than the subject tree, physiographic class, and latitude and longitude of plot locations. The model predictions at both the individual-tree level and plot level have negligible bias, and the models may be easily recalibrated to include new data sets obtained from the annual inventories. For. Sci. 47(30):301–310.
Modeling and Prediction of Forest Growth Variables Based on Multilevel Nonlinear Mixed Models
Authors: Hall Daniel B. , Bailey Robert L.
Published: April 2024

In this article, we describe estimation and prediction methods for nonlinear modeling of forest growth variables that are subject to nested sources of variability. The multilevel nonlinear mixed-effects models that we consider are useful for a variety of forestry applications, but we concentrate on the problem of estimating, and making projections from, growth curves for tree height based on longitudinal data grouped by location. Wolfinger and Lin consider estimating equation approaches to fitting more general nonlinear mixed-effects models, and we adapt their zero-expansion estimating equations to the multilevel case. We develop methods of prediction based on these models that allow predictions of future height both for individual trees and for plot averages. We illustrate these methods by fitting and making predictions from a Chapman-Richards type growth model for tree height data from a loblolly pine spacing study in Putnam County, Georgia. The mean and variance of prediction errors based on our methods are examined by means of cross-validation. We provide a more complete and unified presentation of linearization-based estimation and prediction based on multilevel nonlinear mixed-effects models than has previously appeared in the forestry literature, and we argue that these models lead to substantial advantages in growth and yield prediction over traditional forestry methods. FOR. SCI. 47(3):311–321.
Effects of Gypsy Moth on Radial Growth of Deciduous Trees
Authors: Naidoo Robin , Lechowicz Martin J.
Published: April 2024

We investigated the effect of gypsy moth (Lymantria dispar L.) larval abundance on annual radial growth of preferred, intermediate, and avoided host trees: northern red oak (Quercus rubra L.), sugar maple (Acer saccharum Marsh.), and white ash (Fraxinus americana L.), respectively. Individual trees were surveyed for gypsy moth larvae from 1979 to 1992 in a chronically infested forest on a drought-prone site in southwestern Québec. Increment cores were collected from 156 oaks, 39 maples, and 39 ash, and annual radial growth indices from 1950 to 1992 were calculated for each species. Growth was corrected for the influence of climate using regression models. For red oak, the average number of gypsy moth larvae per tree explained 73% of the variance in growth not explained by climate. Sugar maple and white ash growth was not correlated with gypsy moth larval numbers. These results are consistent with gypsy moth host preferences and provide evidence that nonepidemic levels of gypsy moth larvae can have a significant negative effect on the radial growth of individual trees. For. Sci. 47(3):338–348.
The Self-Thinning Surface
Authors: Bi Huiquan
Published: April 2024

This article introduces a generalized expression of the self-thinning rule, B = KSα Nβ, where B is stand biomass per unit area, N is stand density, S is relative site index, and K, α and β are parameters. On log scales, this equation becomes a self-thinning surface that defines a density-dependent upper frontier of stand biomass over a gradient of site productivity for a given species. This equation is formulated for parameter estimation as a stochastic frontier function with two error components that have different distributional properties. As an example, maximum likelihood estimates of the self-thinning surface and its confidence envelope were shown for Pinus radiata (D. Don). Furthermore, site occupancy was estimated through one of the error components of the stochastic frontier function. The conditional response of mortality at any given site occupancy was revealed by using regression quantiles. Light mortality was associated with increases in site occupancy, while heavy mortality caused a reduction in site occupancy. Changes in the estimated site occupancy had a linear relationship with changes in log stand density. The dynamic interplay between site occupancy and mortality, together with the random external effects on the self-thinning frontier, was suggested to drive the growth trajectories of individual stands during stand growth and self-thinning. Consequently, individual stands seldom travel along their self-thinning frontiers but are more likely to converge toward them during the self-thinning phase of stand development. FOR. SCI. 47(3):361–370.
Modeling the United States Housing Sector
Authors: Montgomery Claire A.
Published: April 2024

New residential construction and improvement of existing housing account for most of the solid wood products consumption in the United States. It is important for forest policy analysts and those interested in wood products markets to understand the implications of changes in macroeconomic variables on housing markets and, hence, on wood products markets and forests. In past studies of U.S. housing markets used for long-run forest policy analysis, the time series properties of the macroeconomic data used to estimate the models were ignored. To the extent that estimation results are sensitive to those properties, the resulting model forecasts may be misleading. This study reports a structural model of the housing sector in the United States estimated using five alternative specifications to account for the time series properties of the data. Estimation results were compared, and model forecast performance was evaluated. Several stable estimation results emerged. However, further investigation is indicated for some potentially important relationships that were sensitive to model specification. FOR. SCI. 47(3):371–389.
Benefits of Forest-Owner Collaboration and Imperfect Capital Markets
Authors: Uusivuori Jussi , Kuuluvainen Jari
Published: April 2024

This article examines the effects of capital market imperfections on the optimal harvest of nonindustrial private forest owners and the potential of collaborative stand management and timber selling to counteract these effects. Monetary benefits of two-owner collaboration are derived under a binding borrowing constraint, and when borrowing and lending rates of interest differ. It is shown that collaboration offers a way to reduce the welfare loss of capital-market imperfections by permitting landowners to restore, at least partially, the separability of consumption and timber production decisions. Pooling stands enables landowners to take better advantage of the value growth of timber and to increase the profitability of their forest holdings. FOR. SCI. 47(3):428–436.
Recursive Preferences in Forest Management
Authors: Peltola Jukka , Knapp Keith C.
Published: April 2024

Expected net present value (ENPV) is a commonly used criterion in optimal forest management; however, this only applies to risk neutrality. If the owner has other risk preferences, then a utility function should be used. Expected utility is the most common way to handle stochasticity in an atemporal framework, but is problematic in intertemporal problems.Recursive preferences overcome a variety of the difficulties associated with expected utility in stochastic control problems.

Recursive preferences (RP) are applied here to forest management. The effects of risk aversion and intertemporal substitution on optimal management are weighed using this framework. Compared to ENPV, RP with empirically plausible levels of intertemporal substitution implies substantially increased harvest levels in the early years, which drastically reduces the stock growth rate. In contrast, risk aversion has little or no impact on optimal management except for an infinite elasticity of intertemporal substitution. In this instance, increasing risk aversion lowers the time to steady-state and the level of steady-state forest stocks. For. Sci. 47(4):455–465.
A Multivariate Simultaneous Prediction System for Stand Growth and Yield with Fixed and Random Effects
Authors: Fang Zixing , Bailey Robert L. , Shiver Barry D.
Published: April 2024

Forest biometricians often deal with a simultaneously interdependent model system in which common stand characteristics such as dominant height, basal area, and total volume are included. Permanent plots with some specific design are usually the main source of data for such a model system to evaluate stand growth and yield in conjunction with different silvicultural treatments or site conditions. Two basic sources of errors are very common for such data. One is within-plot error, and the other is the variation from plot to plot. Within-plot variation is usually modeled by a reasonable variance function that accounts for within-plot heteroscedasticity and correlation. The between-plot variation can be modeled by random effects that allow parameters in the model to be varied from plot to plot. The more information available on these sources of variation, the more precise the predictions of the stand characteristics for a new observation. The interdependency among the components in the system is another key to the precision of the prediction. The observed components in the system can be used to improve the prediction of the unobserved components by accounting for the contemporaneous correlation among the components. A simultaneous system containing components of a nonlinear mixed effects dominant height growth model, a log-linear basal area model, and a log-linear total volume model is developed for slash pine (Pinus elliottii Engelm.) plantations with different silvicultural treatments. Accounting for both contemporaneous correlation and random effects, we have shown the gains in the precision of the prediction of new observations that were obtained from the recommended simultaneous model system, with detailed examples for distinct situations. It has been demonstrated that dominant height is the fundamental component in the three-component system. With contemporaneous correlation and random effects for dominant height considered, including random effects in basal area and total volume model proved to be unnecessary. Between-plot variation is the main source of error for dominant height prediction, dominant height itself dominates the precision of basal area prediction, and basal area itself is the main source of error for total volume prediction. With both random effects in dominant height and contemporaneous correlations among the three components considered, the error bound (half the 95% confidence interval divided by the predicted value) of total volume prediction decreased from 52.6% to 5.8%. For. Sci. 47(4):550–562.
The Cambridge Illustrated Glossary of Botanical Terms
Authors: Jensen Edward C.
Published: April 2024

This glossary provides definitions and illustrations of over 2400 terms used to describe and classify vascular plants. The majority of terms refer to structural parts of plants visible to the naked eye or with a low power hand lens. The book is divided into two major sections: a glossary without illustrations and a set of labeled illustrations without definitions, requiring one to flip back and forth between sections for both. The illustrations are simple but effective, and all of the terms identified in the illustrations are well defined in the glossary. I found the combination to be an effective and efficient way to accomplish the authors' goals.
Habitat Requirements for the Conservation of Arboreal Marsupials in Dry Sclerophyll Forests of Southeast Queensland, Australia
Authors: Wormington Kevin Ray , Lamb David , McCallum Hamish Ian , Moloney Damien John
Published: April 2024

The habitat requirements of arboreal marsupials were investigated in the dry sclerophyll forests of southeast Queensland, Australia. Species richness and abundance of arboreal marsupials was correlated to the proportion of total stand basal area occupied by lemon-scented gum (Corymbia citriodora), the height of the tallest trees, and density of hollow-bearing trees. The first two factors suggested that the most productive forests were also the most suitable habitats for arboreal marsupials. Importantly, the number of hollow-bearing trees was a significant factor in determining species richness and abundance of arboreal marsupials in this study, with the maximum number of species reached at sites containing≥4 hollow-bearing trees/ha, and maximum abundance occurring at sites with≥6 hollow-bearing trees/ha. The proportion of C. citriodora was significant for the presence of the common brushtail possum (Trichosurus vulpecula), greater glider (Petauroides volans), and the yellow-bellied glider (Petaurus australis), while understory Acacia sp. density was important for the presence of the sugar glider (Petaurus breviceps). The yellow-bellied glider was also affected by two other variables: the density of hollow-bearing trees >50 cm diameter at breast height (dbh), and the time since the last logging. Current “Codes of Practice” regulating the density of hollow-bearing trees and silvicultural practices in state-owned timber production forests appear to provide adequate protection for arboreal marsupials, but the recently introduced increase in timber extraction rates within state forests may be detrimental to the animals. Also, protective prescriptions do not apply to the privately owned and leasehold estates, which contain the majority of the dry sclerophyll forests in southeast Queensland. FOR. SCI. 48(2):217–227.
Small Mammal Habitat Associations at Patch and Landscape Scales in Oregon
Authors: Martin Karl J. , McComb William C.
Published: April 2024

To investigate multiscale habitat associations, we examined patterns of capture rates of small mammals in thirty 250–300 ha landscapes in the central Oregon Coast Range. We compared capture rates of 14 species within ≥7 patch types to expected capture rates based on sampling effort. We used landscape level capture rates to test for associations with percent area (composition) and 8 pattern indices at the landscape scale. Capture rates of 10 of 14 small mammal species were higher in conifer and/or mixed large sawtimber patch types. At the landscape scale, capture rates of 6 of 14 species of small mammals were positively associated with the area of patch types. The pattern of patches on the landscape may influence the distribution of 5 small mammal species in this region. We conclude that some small mammals may respond to landscape pattern and/or composition, while other small mammals may not respond to either landscape pattern or composition. Our results suggest that mature forest habitat, patch richness, pattern, and composition are key landscape features that should be considered in management plans, particularly when biodiversity of forest floor mammals is a management objective. FOR. SCI. 48(2):255–264.
Response of Forest Floor Vertebrates to Riparian Hardwood Conversion Along the Bear River, Southwest Washington
Authors: MacCracken James G.
Published: April 2024

The conversion of riparian red alder (Alnus rubra) forest to conifers for salmon (Oncorhynchus spp.) habitat improvement is controversial. I monitored changes in vegetation, microclimate, and the abundance, distribution, and body condition of small mammals and amphibians during the initial stage of alder conversion. Treatments reduced alder and moss cover [mean standardized effect size (ES) = -2.38 and -1.23, respectively (P = 0.0001)], but increased shrub and forb cover [ES = 0.98 and 0.37, respectively (P = 0.0001)]. Treatment effects on microclimate were neutral to moderate (ES = 0.00 to 0.67, P = 0.2). Effects on pitfall trap capture rates of small mammals were small to moderate (ES = -0.04 to 0.51, P = 0.2) and varied by taxon, and effects on captures of amphibians were small (P = 0.2), but positive (ES = 0.05 to 0.26). Pitfall captures were influenced more by seasonal weather patterns than treatment effects on vegetation. Differences in the density of torrent salamanders (Rhyacotriton kezeri) in streams in conversion and control sites were large (ES = -1.00, P = 0.4) and moderate for giant salamanders [ Dicamptodon spp. (ES = 0.31, P = 0.4)]. Treatment effects on the mass/individual for three species of shrew were small (P = 0.2 to 0.9) and either negative or neutral (ES = -0.21 to 0.00) for juveniles and adults. Effects on the mass of western red-backed salamanders (Plethodon vehiculum) were small for adults (ES = -0.12, P = 0.6) and juveniles (ES = 0.08, P = 0.8). Treatment effect on the mass of red-legged frogs (Rana aurora) was positive ( P = 0.2) for both age classes (adult ES = 0.52, juvenile ES = 0.20). The effect of conversion on the mass of torrent salamanders was positive (adult ES = 1.00, P = 0.002; juvenile ES = 0.25, P = 0.02). Additional research should focus on confirming my results, longer term effects, and additional wildlife species. FOR. SCI. 48(2):299–308.
The Effects of Shelterwood Logging on Bird Community Composition in the Black Hills, Wyoming
Authors: Anderson Stanley H. , Crompton Bradley J.
Published: April 2024

The Black Hills of Wyoming and South Dakota are characterized by a complex history of both natural and human disturbance regimes. Historically, ponderosa pine (Pinus ponderosa) communities were characterized by frequent, cool ground fires. Intensive fire suppression and timber harvest throughout the past century have drastically altered the structure of existing forests. Today, much of the area has been harvested using shelterwood logging resulting in open even-aged stands. The goal of this study was to compare bird communities in treated (areas that have recently been harvested) and untreated (areas receiving minimal silvicultural treatment) in the past 40 yr. Of the 20 commonly observed bird species, 3 species [red-breasted nuthatch (Sitta Canadensis), brown creeper (Certhia Americana), and ovenbird (Seiurus aurocapillus)] were conspicuously less abundant in treated than in untreated stands. Eleven other species were more abundant in treated stands, while six species showed no response to treatment. Although bird species diversity and the abundance of birds were highest in treated stands, this does not imply that logging is beneficial to the entire bird community. The abundance of particular bird species may appear to have increased, but the composition of the bird community has been altered. As more of the forested areas are harvested, the bird community will shift from one with birds typical of both open pine and dense pine forest to one dominated by ground foraging species. FOR. SCI. 48(2):365–372.
Roads as Edges: Effects on Birds in Forested Landscapes
Authors: Ortega Yvette K. , Capen David E.
Published: April 2024

Numerous studies have documented that forest edges affect habitat use and reproductive success of forest birds, but few studies have considered edges created by narrow breaks in the forest canopy. We compared predation rates on artificial nests placed within forest habitat along edge transects, 10 m from unpaved roads, and along interior transects, 300 m from forest-road boundaries. Local factors, such as nest concealment, and landscape factors, such as the degree of forestation in surrounding areas, were accounted for when testing for edge effects on nest predation. We conducted fixed-radius point counts to compare relative abundance of 34 bird species on edge and interior transects. Also, seven study plots were established adjacent to unpaved roads to map the distribution of bird territories within edge areas, 0–150 m from unpaved roads, and interior areas, 150–300 m from roads. Rates of nest predation on artificial nests did not differ between edge and interior transects, but the distribution of forest birds was influenced by unpaved roads. Four of 18 forestinterior species had lower relative abundance or territory density adjacent to roads, while four of six species categorized as edge nesters had higher relative abundance on edge transects. Our results suggest that narrow openings within forested landscapes may affect habitat use but not nest predation levels, emphasizing the need to frame definitions of “edge effects” within the context of multiple ecological processes. FOR. SCI. 48(2):381–390.
Reproduction of Amphibians in Natural and Anthropogenic Temporary Pools in Managed Forests
Authors: DiMauro Danielle , Hunter Malcolm L.
Published: April 2024

Vernal-pool breeding amphibians often oviposit in anthropogenic pools formed during industrial forest-management activities, as well as in natural ephemeral pools. We quantified wood frog (Rana sylvatica) and spotted salamander (Ambystoma maculatum) reproductive effort and metamorph emergence, pool hydroperiods and environmental features, and the density of natural and anthropo-genic pools across the landscape to compare the reproductive effort and success of amphibians breeding in natural and anthropogenic pools in managed forests in Maine. Numbers of egg masses in anthropogenic and natural pools did not differ for either wood frogs (median number masses/pool = 15 and 14, respectively) or spotted salamanders (13 and 13 masses/pool). Anthropogenic pools outnumbered natural pools on survey transects by a factor of 3.7. Pool area, depth, temperature, solar exposure, and coverage of closed-canopy forest within 100 m influenced amphibian reproductive effort in temporary pools. In a year with typical breeding-season rainfall (1997), anthropogenic pools dried sooner than natural pools (median drying dates: June 17 and July 30, respectively), and extensive larval mortality occurred upon pool drying. During an unusually wet breeding season (1996), the two pool types had similar hydroperiods (median drying dates: August 17 and 28). Metamorphs emerged from natural pools later and at larger size than metamorphs emerging from anthropogenic pools. Anthropogenic pools seem to function as ecological traps for breeding wood frogs in most years, and thus they should be avoided or designed with adequate size, depth, and shading to maintain an adequate hydroperiod. FOR. SCI. 48(2):397–406.
Wildlife-Habitat Relationships in Oregon and Washington
Authors: DeGraaf Richard M.
Published: April 2024

This is a massive compilation that greatly expands on the coverage and regional themes introduced in the epochal Wildlife Habitat Relationships in Managed Forests: the Blue Mountains of Oregon and Washington (1979. J.W. Thomas, tech. coord., Pacific Northwest Forest and Range Experiment Station, USDA Forest Service, Portland, OR), Management of Wildlife and Fish Habitats in Forests of Western Oregon and Washington (1985. E.R. Brown, tech. ed., Pacific North-west Region, USDA Forest Service, Portland, OR), and Atlas of Oregon Wildlife (1997. B. Csuti, et al., Oregon State University Press, Corvallis, OR). The much-litigated natural resources management plans in the Pacific Northwest have focused attention on a few species, largely in mixed conifer forests. But the region is very diverse, and the current work covers the entire range of vegetative communities, from eastern shrubsteppe and agriculture, interior forests, westside grasslands and chaparral, to riparian, coastal, and marine environments, in addition to the more familiar mixed conifer forests.
Causes for Continuation of State Cost-Share Programs for Nonindustrial Private Forest Landowners
Authors: Mehmood Sayeed R. , Zhang Daowei
Published: April 2024

State cost-share programs for nonindustrial private forest landowners are public assistance programs in the form of direct subsidy payments. A total of 18 states have such programs. This article presents a political economy model and empirical evidences of the factors that determine their presence and continuation. A logit regression is used in the empirical analysis, and the results suggest that the importance of forestry in a state's economy and healthy state finances are significant determinants. Furthermore, there is also evidence of significant regional differences within the United States and some effects of bureaucratic intent. Irrespective of the rationales or justifications for these programs, political pressure on the forest industry made them possible, and a healthy state economy made them a reality. FOR. SCI. 48(3):471–478.
On the Optimality of a Normal Forest with Multiple Land Classes
Authors: Salo Seppo , Tahvonen Olli
Published: April 2024

We analyze a discrete time forestry model with nonlinear utility and any number of forest age and land classes. It is shown that under discounting, this model possesses a cyclical stationary state instead of an even flow of timber. The cycle length in timber flow equals the least common multiple of the rotation lengths of the various land classes. The cycle structure is dependent on the initial age-class allocation. As the discount factor approaches unity, the cyclicality in total timber harvest vanishes, but the forest age-class structure may not approach a normal forest in any land class. An aggregate even timber flow is associated with a normal forest in each land class only if there does not exist any pair of land classes with rotation periods having a common divisor greater than one. FOR. SCI. 48(3):530–542.
The Silver Lining: The Benefits of Natural Disasters
Authors: Peterson Chris J.
Published: April 2024

In this welcome and accessible volume, Seth Reice, a stream ecologist who specializes in the study of disturbance effects on community structure, explains to the informed nonspecialist how important are disturbances to the health and diversity of ecosystems. It is important to note that this book is intended to enlighten a lay audience; it is not intended strictly or even primarily for forest scientists or ecologists. And therein lies its potential value: by making the benefits of natural disasters clear to the nonspecialist, Reice communicates how, by embracing the inevitability of natural disturbances and recognizing their benefits for natural systems, we can adopt more sustainable policies, behaviors, and attitudes. I wholeheartedly applaud this goal, and believe as a whole that Reice's book is an excellent step in that direction.
Modeling Forest Dynamics with a Combined Matrix/Individual-Based Model
Authors: Picard Nicolas , Bar-Hen Avner , Franc Alain
Published: April 2024

A combined model, with a matrix component to describe the trees whose diameters are below a threshold, and an individual-based component for the trees above the threshold, is proposed. The combined model is derived from a matrix model and simulates the dynamics of a tropical rainforest in French Guiana, with a management orientation. The methodology to build a combined model starting from a matrix model is specified. The crucial point lies in three continuity conditions at the transition diameter. To establish them, both the matrix and the individual-based components are reformulated into a continuous distribution-based model, which is analytically more tractable. The combined model provides a more detailed description of the tail of the diameter distribution, which can be useful for management purposes. It also permits the separation of the dynamics of small trees, which are numerous and for which matrix coefficients can be quite precisely assessed, from the dynamics of large trees. For. Sci. 48(4):643–652.
Nutrient Use Efficiency in Three Fast-Growing Tropical Trees
Authors: Hiremath Ankila J. , Ewel John J. , Cole Thomas G.
Published: April 2024

We measured nutrient use efficiency (NPP/nutrient uptake) in three species of tropical trees, Hyeronima alchorneoides, Cedrela odorata, and Cordia alliodora. We tested the prediction that on fertile soils species with very different biomass and nutrient allocation and turnover would converge on a common value of nutrient use efficiency. Due to high soil fertility, nutrient use efficiencies of the species studied were low (95–150 and 433–962 for N and P use efficiency, respectively). Nutrient use efficiency was examined in terms of its components, nutrient productivity and the mean residence time of nutrients. Although the species converged on the same nitrogen (but not phosphorus) use efficiency, differences in nutrient productivity and nutrient residence time may confer varying abilities to deal with nitrogen limitation. A combination of high nutrient productivity and longer nutrient retention (e.g., Hyeronima) signals an ability to prosper on infertile sites, whereas high nutrient productivity in the absence of long nutrient retention (e.g., Cedrela) indicates a capacity for high productivity, but only on fertile soil. Nutrient use efficiency and its components help explain species' distributions in natural communities and can be important criteria in selecting perennial plants for human use. For. Sci. 48(4):662–672.