bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stand-Scale Correspondence in Empirical and Simulated Labile Carbohydrates in Loblolly Pine
Authors: Sampson David A. , Johnsen Kurt H. , Ludovici Kim H. , Albaugh Timothy J. , Maier Chris A. 
Published: April 2024

Abstract
As investment into intensive forestry increases, the potential trade-offs between productivity and sustainability should be scrutinized. Because of their important role in internal carbon (C) budgets, labile C pools may provide a measure of the potential ability of trees and stands to respond to stress. We modified the process model BIOMASS to examine daily C budgets of midrotation nonfertilized and fertilized loblolly pine stands. We tested whether the absolute difference between daily simulated net canopy assimilation (GPP minus maintenance respiration) and our empirical estimates of production, or daily gross carbon balance, mimics the labile carbohydrate C pool. We compared this labile pool surrogate to independent, empirical analyses of total nonstructural (starch and soluble sugars) carbohydrates from an individual whole-tree analysis scaled to the stand level.Of particular interest, the simulated daily gross C balance indicated periods of carbon deficit during the growing season that lasted from 1 to 40 days. Simulated daily net C balance was met from labile C storage during these periods. Fertilized plots had similar time-period trends as the control plots, but exhibited a twofold increase in C assimilation and use. Simulated and empirical estimates of the labile carbohydrate pools displayed similar seasonal trends, although their correspondence depended on the time of year. Simulations indicated a winter/early spring “recharge” period; concentrations peaked at ~50 and ~60 mg C g biomass-1 in control and fertilized plots, respectively, in 1995. The overall correlation between predicted and empirical estimates was low to moderate (r = 0.51). The best agreement was with the empirical data from April through June as concentrations declined; however, predicted minimum concentrations (15 and 5 mg C g biomass-1 in control and fertilized plots, respectively) were lower, and obtained earlier in the year than the empirical data (~20 mg C mg biomass-1). These analyses quantify the strong extent that loblolly pine exhibits a buffered capacity to balance the C budget when current photosynthesis occasionally cannot meet daily C requirements. Further development of our approach may lead to a tool for analyzing potential risks associated with intensive forest management. FOR. Sci. 47(1):60–68.
Influence of Two Plant Growth-Promoting Rhizobacteria on Loblolly Pine Root Respiration and IAA Activity
Authors: Vonderwell J.D. , Enebak S.A. , Samuelson L.J. 
Published: April 2024

Abstract
A clearer understanding of factors contributing to inconsistency in seedling root growth promotion among nurseries has become important to managers as the commercial use of rhizobacteria in forest nurseries increases. To address why some bacterial strains increase root growth response while others do not, two separate experiments were conducted with loblolly pine (Pinus taeda L.) seedlings. Experiment one examined growth media. Seed were sown in either a hand-mixed peat:vermiculite:perlite (2:1:1, v:v:v) potting medum or a commercial medum—Promix® (1:1 peat:vermiculite). Seed were inoculated at sowing with an equal amount of either Bacillus subtilis strain LS211, B. subtilis strain INR7, or sterile distilled water. Seedling biomass, root length, root surface area, average root diameter, and root volume were measured at 6 and 12 wk after sowing. Growth promotion was variable and dependent on media and weeks since sowing. In a second experiment, root respiration rate and total root indole-acetic acid (IAA) content were quantified at 6 and 12 wk for seedlings grown in Promix®. In experiment two, strain INR7 decreased whole root system respiration by 22% and increased root biomass and root length compared to controls at 6 wk. Bacterial strain LS211 had no effect on root respiration. Furthermore, bacterial strain INR7 produced 1.7 times the total root IAA concentration of controls at 6 wk, whereas LS211 had no effect. Although cause and effect could not be tested, these studies suggest that root growth promotion is influenced by growth media and that IAA concentrations and root respiration rates are two physiological mechanisms correlated with rhizobacterial activity and growth promotion. FOR. SCI. 47(2):197–202.
Clarification of the Mirage Method for Boundary Correction, with Possible Bias in Plot and Point Sampling
Authors: Ducey Mark J. , Gove Jeffrey H. , Ståhl Göran , Ringvall Anna 
Published: April 2024

Abstract
While the mirage method of boundary overlap correction has been shown to be unbiased, an emphasis on the case of circular inclusion zones has led to an ambiguity in its presentation in much of the literature. We present a clarification of the method and show that its incorrect application leads to bias. We further show that depending on the method of slope correction, the potential for bias extends to variable radius plot sampling. Correct application of the mirage method has implications for when plots should be reflected, and how borderline trees should be handled on the reflected plots. FOR. SCI. 47(2):242–245.
Effects of Light Regimes on the Growth of Cherrybark Oak Seedlings
Authors: Guo Yanfei , Shelton Michael G. , Lockhart Brian R. 
Published: April 2024

Abstract
Light regimes vary significantly within small forest openings, ranging from full sunlight to total shade, and they may affect the establishment and early growth of oak seedlings. We designed modified shadehouses to simulate the complex light conditions within forest openings and tested the effects of daily photosynthetically active radiation (PAR), time of direct light exposure, and the ratio of direct light to day length (direct-sunlight ratio) on height, diameter, and periodic growth of cherrybark oak (Quercus pagoda Raf.) seedlings through 2 yr. Five treatments representing the time of exposure to direct sunlight were created: NO, NOON, MORNING, AFTERNOON, and FULL. Treatments significantly affected both the height and root-collar diameter of seedlings, especially during the second growing season. The direct-sunlight ratio was linearly related to periodic height growth for the NOON treatment but not related to height growth for the other treatments. However, periodic height growth in the AFTERNOON and FULL treatments was highly correlated to mean daily PAR. Maximum periodic height growth occurred at moderate daily PAR levels. This research showed that light conditions for maximum growth of cherrybark oak seedlings change through time, with adequate shading being most favorable during the early stages of establishment. FOR. SCI. 47(2):270–277.
Tropical Deforestation, Tenure Insecurity, and Unsustainability
Authors: Barbier Edward B. , Burgess Joanne C. 
Published: April 2024

Abstract
This article explores the effects of tenure insecurity on the migrant's decision to convert tropical frontier forestland to unsustainable agriculture. We develop and extend a Faustmann model to explore the effects of insecure property rights and unsustainability on the migrant's decision to convert tropical forestland to crop production, to maintain it for long-term timber production, or to mine the forest for timber and then abandon the land. We then provide a numerical simulation of the migrant's land-use decision based on data from the Amazon to compare the returns to mahogany plantation as opposed to agricultural conversion or timber mining. Increasing insecurity of land tenure leads to a decline in the value of timber relative to agricultural production land, thus creating an incentive for forest conversion. However, when land is easily degraded and tenure insecurity is high, timber mining and land abandonment may be a particular problem. Finally, we examine the role of private and government investment in establishing and maintaining secure land tenure. Once government “arrives” at the frontier, it can encourage sustainable timber production through providing secure harvesting rights and setting an optimal concession fee. FOR. SCI. 47(4):497–509.
Forest Land Conversion Over Time: Implications for the Faustmann Formula
Authors: Burgess J.C. , Ulph D. 
Published: April 2024

Abstract
The Faustmann timber production model has been used to examine the allocation of land between alternative forest land use options. This article provides a clarification and extension of this previous work. We use the basic forest land use options model to allow for the changes in forestland use over time. First, we modify Faustmann's original assumptions to allow for a one-off change in prices or an initial allocation constraint, and examine the forest land manager's decision to switch to an alternative land use at some point in the future. Second, we look at the case where prices evolve over time and it is optimal for the forest land manager to switch between land uses on an equilibrium path. This second extension provides a new application of the Faustmann timber production model. We discuss the theoretical insights and the implications for forest conversion. FOR. SCI. 47(4):510–519.
The Effect of Positional Errors on the Accuracy of Estimates in Guided Transect Sampling
Authors: Ringvall Anna , Ståhl Göran , Lämås Tomas 
Published: April 2024

Abstract
Guided transect sampling was recently proposed as a method for sampling sparse and geographically scattered populations if auxiliary data with high spatial resolution are available prior to the inventory. In practice, a surveyor will use GPS to follow predetermined survey lines. However, the surveyor will never be able to follow the lines exactly, and thus the accuracy of estimates is likely to be affected. The aim of this article was to study the loss in accuracy of estimates in guided transect sampling due to errors in navigation. The evaluation was made through Monte-Carlo simulations in different simulated forest types. The auxiliary data were considered to be volumes of deciduous trees, and the variable of interest the abundance of an indicator species connected to deciduous trees. To describe the surveyors' movements along the survey lines, a Brownian bridge process was proposed and evaluated with field data. The results from the study indicate that errors in navigation only have a minor effect on both bias and standard errors of estimates of the population total. The bias was not higher than 2.9%, and the increase in standard error not higher than 3.2 % in any forest type. FOR. SCI. 48(1):101–110.
The Ecology of Trees in the Tropical Rain Forest
Authors: Hendrick Ronald L. 
Published: April 2024

Abstract
The primary literature describing the ecology of tropical rain forest trees is vast, yet there are relatively few summaries of their ecological traits, especially from a comparative ecology perspective. Consequently, Turner's effort to do a comparative analysis of the ecology of species from throughout the tropical rain forest is a most welcome one. His primary goal to summarize the ecology of different tropical rainforest trees has resulted in a very well written summarization of their comparative ecology (and structure). He is less complimentary of the results of his effort to find “a new synthesis of the comparative ecology of tropical trees” (p. 247) after summarizing the relevant literature, but perhaps he has done more than he suspects.
Salamander Abundance in Regenerating Forest Stands on the Monongahela National Forest, West Virginia
Authors: Duguay Jeffrey P. , Wood Petra Bohall 
Published: April 2024

Abstract
We compared the abundance of salamanders in 18 hardwood stands treated with two-age management 15 yr after harvest, clearcutting 15 yr after harvest, and mature second-growth stands in the Monongahela National Forest of West Virginia during the summers of 1995 and 1996. Salamanders were captured with pitfall traps. We sampled 47,083 trap days and captured eight species of salamanders. Abundance of salamanders, expressed as number captured per 100 trap days, was higher (P = 0.06) in the mature second-growth than two-age treatment (two-age = 0.96 ± 0.11; clearcut = 1.46 ± 0.23; mature second-growth = 2.40 ± 0.57). Abundance of redback salamanders (Plethodon cinereus) also was higher (P = 0.09) in the mature second-growth than twoage treatment (two-age = 0.76 ± 0.14; clearcut = 1.48 ± 0.34; mature second-growth = 1.84 ± 0.51). These data indicate that 15 yr after harvest, harvested stands in the Monongahela National Forest may be less favorable than mature hardwood forests for some forest salamanders. FOR. SCI. 48(2):331–335.
Temporal Patterns in Aquatic and Avian Communities Following Selective Logging in the Upper Great Lakes Region
Authors: Flaspohler David J. , FisherHuckins Casey J , Bub Brian R. , van Dusen Peter J. 
Published: April 2024

Abstract
We surveyed populations of birds, fish, and aquatic macroinvertebrates in and along riparian systems within northern and mixed-hardwood forests that varied in time since last selection logging. Thirteen headwater stream sites from the Otter River watershed in Michigan's Upper Peninsula were included in the study. We detected a significant negative correlation between a standard index of habitat quality for coldwater streams (Great Lakes Environmental Assessment Section [GLEAS]) and time since last selective logging. Brook char (Salvelinus fontinalis Mitch.) abundance was also negatively correlated with year of forest cut as was the abundance of selected aquatic macroinvertebrate orders (Ephemeroptera, Plecoptera, and Trichoptera) that are sensitive to anthropogenic disturbance. Thus, relative to more recently logged stands, stands with older cuts had higher indices of habitat quality, more brook char, and the dominant aquatic macroinvertebrates tended to be those generally associated with higher quality coldwater streams. In contrast, bird species richness was positively related to year of last selective logging. As expected, basal area was lower and ground cover was greater in more recently logged stands. Thus, bird species richness was higher in stands with less basal area (recent cuts) than in stands with more basal area (older cuts). Percent ground cover showed a strong positive correlation with bird species richness. Twelve bird species were detected only in recently logged (since 1990) stands. The results of this multitaxa study suggest that selective logging of riparian forests is associated with changes in local animal abundance and diversity, and these effects appear to persist for approximately 30 yr postharvest. FOR. SCI. 48(2):339–349.
Use of a Landbird Monitoring Database To Explore Effects of Partial-Cut Timber Harvesting
Authors: Young Jock S. , Hutto Richard L. 
Published: April 2024

Abstract
We used data from the USDA Forest Service Northern Region Landbird Monitoring Program to investigate the effects of partial-cut timber harvesting on bird abundances in conifer forests within the northern Rocky Mountains. We present point-count data from four separate years of the longterm monitoring database, which included between 467 and 907 points, depending on the year. Five bird species were significantly more abundant in uncut forest stands in at least one year, and 17 species were more abundant in partially cut stands in at least one year. Four and eight species from these two groups, respectively, showed the same differences in a short-term, control/treatment comparison conducted in the same region, and no species showed contradictory treatment effects when the two studies were compared. Provided that vegetation data are coupled with bird abundance data, and provided that enough points are visited to compensate for an uncontrolled design, these results suggest that data from long-term monitoring points can be useful not only as sources of information about long-term population trends, but as sources of information about habitat relationships and the effects of land use. FOR. SCI. 48(2):373–378.
Effects of Landscape and Local Habitat Attributes on Northern Goshawk Site Occupancy in Western Washington
Authors: Finn Sean P. , Marzluff John M. , Varland Daniel E. 
Published: April 2024

Abstract
We quantified habitat structure, composition, and configuration at three spatial scales (39 ha nest area; 177 ha post-fledging area; 1,886 ha home range) and compared vegetative conditions with measures of northern goshawk (Accipiter gentilis) site occupancy at 30 historical nest sites (those containing at least one goshawk and a large stick nest when discovered) on Washington's Olympic Peninsula. Twelve of the 30 historical sites were occupied by one or more goshawks and 8 of the 12 contained a successful breeding pair. Sites that were occupied in 1 yr tended to remain occupied throughout the 3 yr study, and breeding success was strongly and positively correlated with occupancy. Occupied historical sites tended to have a high proportion of late-seral forest [&gt;70% canopy closure of conifer species with &gt;10% of the canopy trees &gt;53 cm diameter at breast height (dbh)], reduced stand initiation cover, and reduced landscape heterogeneity at all three scales, but only the two larger scale models predicted occupancy successfully. Incorporating habitat attributes previously measured at finer (stand level) scales (canopy depth and percent shrub cover in the nest stand) improved our larger (landscape level) scale models of goshawk occupancy. Olympic Peninsula forest managers can promote goshawk occupancy, and therefore reproduction, by limiting the amount of early forest stand initiation cover (&lt;20%) and landscape contrast in the home range and by maintaining potential nest stands (≥39 ha) having deep canopies and reduced shrub cover. FOR. SCI. 47(3):427–436.
How Joint is Joint Forest Production? An Econometric Analysis of Timber Supply Conditional on Endogenous Amenity Values
Authors: Pattanayak Subhrendu K. , Murray Brian C. , Abt Robert C. 
Published: April 2024

Abstract
In search of ways to enhance and sustain the flow of services from forests, policy makers in the public and private sectors look to forest sector models to project future forest uses. A major shortcoming of these models is a timber supply specification that inadequately accounts for suppliers choosing the structure of their forest capital to self-produce nontimber amenities. This inadequate characterization of resource use, if significant, can impede the development of sound forest policy, particularly in settings where forest owners possess diverse preferences for forest amenities. In this article, we develop and estimate a timber supply model that is consistent with the idea of joint self-production of timber and nontimber amenities, such that timber supply is a function of an endogenous distribution of forest inventory that correlates to ownership and management characteristics. Using data for the U.S. South and three-stage least squares procedures, we confirm that timber and nontimber amenities are jointly produced by private forest owners. We also note that owner and management characteristics influence joint production decisions. We believe that the parameters estimated through such an integrated empirical exercise could critically improve forest sector forecasting models and the related forest policy analyses. FOR. SCI. 48(3):479–491.
Competitive Capacity of Quercus rubra L. Planted in Arkansas' Boston Mountains
Authors: Spetich Martin A. , Dey Daniel C. , Johnson Paul S. , Graney David L. 
Published: April 2024

Abstract
Results of an 11 yr study of the growth and survival of planted northern red oak (Quercus rubra L.) seedlings (2-0 bare-root) are presented. More than 4,000 seedlings were planted under shelterwood overstories that were harvested 3 yr after planting. Results are expressed as planted-tree dominance probabilities. Dominance probability is the probability that a planted tree will live to attain a favorable competitive position (i.e., at least 80% of the mean height of dominant competitors) at a specified year. We interpret the resulting probability as a measure of the competitive capacity of an individual seedling, i.e., its potential of attaining dominance in a specified environment. Based on logistic regression analysis, dominance probabilities increase with time after shelterwood overstory removal for any given environment and initial seedling characteristics. At any specified time, dominance probabilities depend on initial seedling basal diameter before planting (stem caliper 2 cm above the root collar), site quality, intensity of weed control, and shelterwood percent stocking. Dominance probabilities increase with decreasing shelterwood stocking, increasing initial stem caliper, and increasing intensity of weed control. Other factors being equal, top clipped seedlings have higher dominance probabilities than unclipped seedlings. The reciprocals of the dominance probabilities provide silviculturally useful estimates of the numbers of trees that would need to be planted to obtain, on the average, one competitively successful tree. For example, if clipped seedlings averaging 6 mm in caliper were planted where oak site index was 24 m, shelterwood stocking was 80%, and the site was given no weed control before or after planting, obtaining one competitively successful tree 11 yr after planting (8 yr after shelterwood removal) would require planting 144 seedlings. Other factors remaining the same, increasing initial caliper to 22 mm would require planting only 5 trees to obtain 1 competitively successful tree. For the same size (22 mm) and type of seedling planted on site index 18 m under a shelterwood at 40 to 60% stocking and given two weed control treatments, only 1.4 trees would need to be planted. Results emphasize the sensitivity of competitive capacity, and thus the silvicultural potential, of planted northern red oaks in the Boston Mountains of Arkansas to the joint effects of field environment and initial seedling characteristics. FOR. SCI. 48(3):504–517.
A Site Dependent Simultaneous Growth Projection Model for Pinus kesiya Plantations in Zambia and Zimbabwe
Authors: Eerikäinen Kalle 
Published: April 2024

Abstract
The aim of this study was to create a stand level yield model for Pinus kesiya (Royle × Gordon) plantations in Zambia and Zimbabwe based on the simultaneous projection model approach. The purpose was to prepare prediction models for the measurable and allometrically related stand variables which characterize the development of planted P. kesiya stands. The modeled stand characteristics are assessable in the inventories of forest plantations and are frequently employed in traditional stand yield tables and modern growth simulators. Special attention was paid to the selection of flexible nonlinear model forms that are simple and stable. Two model forms were developed: (1) a polymorphic and base age invariant site index equation, used as a growth projection model for stand dominant height, and (2) a stand volume prediction model based on Honer's single tree volume model. The projection form of the site index equation was obtained using the algebraic difference approach to solve analytically the rate parameter of the autocatalytic growth model. The simultaneous growth projection model included a model for basal area median diameter. The basal area median diameter was also used as a predictor of stand basal area. This improved the accuracy of stand basal area predictions. A model for the basal area median diameter also makes it possible to apply theoretical diameter distributions for the prediction of future stand stages. FOR. SCI. 48(3):518–529.