bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional Variation in Growth Response of Coastal Douglas-Fir to Nitrogen Fertilizer in the Pacific Northwest
Authors: Peterson C. E. , Hazard J. W. 
Published: April 2024

Abstract
Hypothesis-testing for differences in growth responses among physiographic strata, thinning levels, and fertilizer dosage levels resulted in a set of empirical models for predicting volume increment response of even-aged coastal Douglas-fir to nitrogen fertilizer. Absolute and percent responses are estimated for stands both thinned and unthinned, as a function of dosage levels and physiographic provinces. Although not "highly" significant, the physiographic factor was retained in the models for purposes of refinement. For. Sci. 36(3):625-640.
Predicting Mortality in Mixed Oak Stands Following Spring Insect Defoliation
Authors: Crow Gerald R. , Hicks Ray R. 
Published: April 2024

Abstract
Data from 141 tenth-acre plots defoliated by a complex of looper species were summarized and analyzed using discriminant analysis. We found certain variables consistently associated with the status of trees as being live or dead (species, site quality, and aspect). Mortality was more likely among species in insect-preferred food classes, on better sites, and on north or northeast aspects. Classification of dead trees was more effective than for live trees. For. Sci. 36(3):831-441.
Feedback Thinning Policies for Uneven-Aged Stand Management with Stochastic Prices
Authors: Haight Robert G. 
Published: April 2024

Abstract
This paper presents an optimization model and a numerical method for determining feedback thinning rules for uneven-aged stand management when the stumpage price forecast is a stochastic process. Periodic thinning takes place over a finite time horizon, and the objective is to maximize expected present value. The thinning rules are based on a continuous function that maps the relationship between harvest intensity and observed stand value. The parameters of the function include its slope, location, and shape. The location parameter is defined as the stand reservation value, which is the minimum stand value required for harvest. Optimal parameter values are determined using stochastic simulation. Numerical results are presented using a stage-structured model for uneven-aged stands of California white fir (Abies concolor [Gord. & Glend.] Lindl. (Iowiana [Gord.])). Stumpage price is the sum of a deterministic constant and a normally distributed random error. With these assumptions, optimal feedback thinning policies have significantly higher expected present values than do thinning policies that ignore price fluctuations. However, feedback policies have greater volatility in harvest revenue over time. Sensitivity analysis shows that the expected present value of optimal feedback management increases as the level of price risk increases. For. Sci. 36(4):1015-1031.
Growth-Competition Relationships in Young Hardwood Stands on Two Contrasting Sites in Southwestern Wisconsin
Authors: Hix David M. , Lorimer Craig G. 
Published: April 2024

Abstract
Crown-based competition measures were used to assess the relationships between growth and competition for trees in young mixed-hardwood stands on two ecosystems with contrasting site conditions. The two southwestern Wisconsin ecosystems compared were gently sloping summits with deep loessal soils and steeply sloping southwesterly backslopes with loam soils. Individual trees were sampled from variable-radius plots located in 15 stands of 4 to 42 years old. The two best predictors of height growth are the height of a tree relative to the average height of dominants and codominants, and the cross-sectional area of the exposed portion of the crown at its widest point. The data confirmed theoretical relationships between growth and light intensity for species of differing shade tolerance. However, growth rates as a function of relative height did not approach an asymptote for any species, while growth response to increasing exposed crown area was asymptotic for the tolerant species. Species' relationships differed between the two ecosystems, with maximum height growth rates being lower on the drier site. Acer saccharum was the most efficient species (highest basal area growth rate) at the higher values of exposed crown area, but larger total crown size for sugar maple was a contributing factor in such cases. For. Sci. 36(4):1032-1049.
Pathogenic Variability Among Populations of the Pinewood Nematode, Bursaphelenchus Xylophilus
Authors: Kiyohara Tomoya , Bolla R. I. 
Published: April 2024

Abstract
Virulence of populations of Bursaphelenchus spp. associated with conifers varies throughout the range of this nematode in the United States and Japan. Populations of B. xylophilus (pinewood nematode, PWN) from Japanese black and red pine in the same and distantly separated pine stands in Japan range in virulence from 0-100% and there is a tendency for the most virulent populations to be in the northernmost part of the nematode's range where establishment has been relatively recent. Virulence of PWN populations, however, does not vary within a single pine or vector insect. Isozyme patterns are similar between virulent and avirulent populations and therefore cannot be used to differentiate them. Aspartate transaminase isozyme patterns can be used to differentiate between B. xylophilus and B. mucronatus. Pathogenicity of PWN in the United States depends on the interaction of the pine species with different PWN populations, the physiological status of the infected pine, and environmental conditions. Mating and reproductive potential, virulence, DNA sequence differences determined by restriction fragment length polymorphisms, and isozyme differences are useful criteria for studying population biology and genetics of PWN, and when used together, for describing speciation of Bursaphelenchus associated with conifers. For. Sci. 36(4):1061-1076.
Pine Tip Moth, Rhyacionia spp., Response to Herbaceous Vegetation Control in an Intensively Site-Prepared Loblolly Pine Plantation
Authors: Ross Darrell W. , Berisford C. Wayne , Godbee John F. 
Published: April 2024

Abstract
Herbicide release treatments were applied to an operationally regenerated loblolly pine (Pinus taeda L.) plantation to assess the effects of vegetation control on pine tip moth (Rhyacionia spp.) damage. Treatments included banded herbicide applications (1.5-m wide bands centered over rows of seedlings) for 1 or 2 years after planting, broadcast herbicide applications (total area covered) for 1 or 2 years after planting, and an untreated check. All of the herbicide treatments significantly reduced the mount of herbaceous vegetation and improved the survival and growth of planted pines. By the end of the third growing season, pine survival in the check plots (67%) was significantly less than survival in all of the herbicide-treated plots (≥92%). Trees in herbicide-treated plots suffered more tip moth damage than trees in the check plots during the first two growing seasons after planting, but by the third growing season, damage to trees in the check plots was equal to that in the herbidde-treated plots. The method or number of herbicide applications did not have a substantial effect on tip moth infestations. Pine growth gains resulting from reduced vegetative competition were more than enough to compensate for higher tip moth damage following herbicide treatments. However, increased tip moth damage still reduced potential growth gains. Two herbicide applications did not significantly improve pine survival or growth compared to one application, but the broadcast treatments produced slightly larger trees than the banded treatments by the end of the third growing season. For. Sci. 36(4):1105-1118.
Growth and Photosynthetic Responses to a Range of Light Environments in Chinese Tallowtree and Carolina Ash Seedlings
Authors: Jones Robert H. , McLeod Kenneth W. 
Published: April 2024

Abstract
Potted seedlings of Chinese tallowtree (Sapium sebiferum [L.] Roxb.) and Carolina ash (Fraxinus caroliniana Mill.) were grown in 5%, 20%, 53%, and 100% of full sunlight. Growth and dry mass partitioning at all light levels, differences between leaf photosynthetic systems developed at 20% and 100% light, and crown profiles of net photosynthesis (PN) in 53% of full sunlight were measured. Tallowtree dry mass peaked at 100%, light while ash dry mass peaked at 53% light. Expressed as a proportion of peak dry mass within species, growth of tallowtree exceeded that of ash at all light levels except 53% of full sunlight. In all but 100% light, tallowtree partitioned more dry mass to leaves than did Carolina ash. For plants grown in 100% light, PN was highly variable with low values in some tallowtree and most ash leaves, although highest PN occurred in ash. For plants grown in 20% light, PN was closely related to photosynthetic photon flux density (PPFD), and both species had similar PN Values at any given PPFD. For plants in 53% light, maximum PN occurred at the top of the crown in tallowtree and in the middle of the crown in Carolina ash. Tallowtree seedlings are shade tolerant and yet grow rapidly in full sun. For. Sci. 36(4):851-862.
A Shelterwood Method for Regenerating Red Oak in the Southern Appalachians
Authors: Loftis David L. 
Published: April 2024

Abstract
A shelterwood method is described that provides stand conditions that enhance the growth of established red oak advance reproduction, thereby improving the chances of maintaining an oak component in the next stand. Stocking of a mature, fully stocked stand is reduced to 60%, 65%, and 70% of initial stand basal area where oak site index is 70, 80, and 90 ft, respectively. The basal area reduction is accomplished from below using herbicides, leaving the main canopy essentially intact. This level and method of treatment prevents yellow-poplar, a primary competitor of red oak, from becoming established and growing prior to the final removal cut, and it eliminates most sprout competition from shade-tolerant subcanopy species after the final removal cut. The final removal cut can be made approximately 10 years after the initial treatment. For. Sci. 36(4):917-929.
Loblolly Pine Provenance Variation in Age of Transition from Juvenile to Mature Wood Specific Gravity
Authors: Szymanski Marcella B. , Tauer C. G. 
Published: April 2024

Abstract
Regional and seed source variation were examined for the age of transition from juvenile to mature wood specific gravity in loblolly pine (Pinus taeda L.) grown in Arkansas. No regional or seed source differences were found for the age of transition or rate of change from juvenile to mature wood specific gravity with an analysis of variance "F" test. However, contrasts for groups of provenance regions defined on the basis of broad geographic characteristics showed transition ages were earlier for regions west of the Mississippi (12.0-12.3 yr) when compared to eastern regions (12.6-13.0 yr). Variation in whole core specific gravity and juvenile and mature wood core specific gravity was significant on a source and regional basis. No regional or source differences were found for percent summerwood. Specific gravity was highest in the lost pines source, followed by sources from the northwest and northeast portions of the loblolly pine range, and lowest for sources from the gulf coast and interior portions of the loblolly range. Contrasts for groups of provenance regions reflect similar results for all specific gravity traits. Percent summerwood, whole core specific gravity, and juvenile and mature wood core specific gravity had negative phenotypic correlations with transition age. Whole tree specific gravity, basal area, and percent summerwood had positive phenotypic correlations with estimated core specific gravity. For. Sci. 37(1):160-174.
Integrated Forest Planning Across Multiple Ownerships and Decision Makers
Authors: Davis Lawrence S. , Liu Gao 
Published: April 2024

Abstract
Social evaluation of public and private land-use planning of forests and rangelands is increasingly integrated across multiple land ownerships and resolved in a politicized forum of multiple decision makers. Multicriterial optimization models have limited utility for decision analysis in this environment as they must be formulated from the perspective of a single decision maker. A flexible integer programming model is demonstrated as a useful and appropriate tool to simulate and explore the collective options in a multiple ownership integrated planning (MOIP) problem. Multiple budget constraints are featured in this model as a vehicle by which resource contributions from both landowners and nonlandowners can be explicitly recognized. The hypothesis that MOIP problems define a positive sum game is supported by analyzing the data set of published national forest plan Draft Environmental Impact Statements (DEIS) for California data set. For. Sci. 37(1):200-226.
Probit Analysis of Oak Wilt Transmission Through Root Grafts in Red Oak Stands
Authors: Bruhn Johann N. , Pickens James B. , Stanfield David B. 
Published: April 2024

Abstract
In pure stands of red oak species (subgenus Erythrobalanus) in Michigan's Upper Peninsula, individual oak wilt epicenters appear to expand virtually exclusively by movement of the pathogen through root grafts between diseased and healthy trees. Containment of individual disease epicenters can be accomplished by a combination of timely separation of grafted root systems and sanitation (to prevent overland establishment of new epicenters). Disease spread models were developed by probit analysis of field data. These models predict the probability that the oak wilt fungus will spread across root grafts to a healthy (target) tree during the year alter symptoms occur in a neighboring diseased (source) tree. Movement of the fungus was best predicted by a logarithmic transformation of the quotient obtained by dividing the sum of the diameters for the potential source and target trees by the distance between these trees. Multiple-stemmed source or target trees were accurately represented by the sum of the diameters of their component stems. Soil type was found to influence the relationship, presumably through its effect on rooting habit. Oak root systems appear to extend over greater distances through soils of the deeper and more uniformly sandy Grayling series than through those of the loamier Pemene series. The specific models developed depend on site-related data, and therefore should not be applied in other areas. However, the modeling approach is of general applicability and can be used to predict root graft spread of oak wilt in other areas. For. Sci. 37(1):28-44.
Chance-Constrained and Chance-Maximizing Mathematical Programs in Renewable Resource Management
Authors: Hof John G. , Pickens James B. 
Published: April 2024

Abstract
This paper discusses a broad range of approaches to optimizing natural resource allocation in the situation where amounts of available input(s) and/or amounts of desired output(s) are random. The paper begins by reviewing, the classic approach to this class of problems, "chance-constrained programming," followed by a discussion of "joint probability chance-constrained programming," and a new alternative "total probability chance-constrained programming." The paper then develops three "chance-maximizing" counterparts. Specific formulations for executing these approaches in natural resource management problems are developed that explicitly include the cumulative probability density functions. A forestry case example demonstrates .solution procedures and shows that the different approaches can yield substantially different results. Results from different solution procedures are also compared. For. Sci. 37(1):308-325.
A Note on Carmean's Estimate of Height from Stem Analysis Data
Authors: Newberry James D. 
Published: April 2024

Abstract
Carmean (1972) presented a method for adjusting height/age data from stem analysis. This adjustment is not correct when applied to that portion of a tree bole above the highest section point. In this part of a tree bole the adjustment always underestimates tree height for a given age. A simple modification is made to Carmean's method so that it is applicable to the top section of a tree. For. Sci. 37(1):368-369.
Confidence Intervals from Single Observations in Forest Research
Authors: Valentine Harry T. , Furnival George M. , Gregoire Timothy G. 
Published: April 2024

Abstract
A procedure for constructing confidence intervals and testing hypotheses from a single trial or observation is reviewed. The procedure requires a prior, fixed estimate or guess of the outcome of an experiment or sampling. Two examples of applications are described: a confidence interval is constructed for the expected outcome of a systematic sampling of a forested tract, and a hypothesis is tested in connection with a watershed experiment. Potential misuses of the procedure also are discussed. For. Sci. 37(1):370-373.
Topographic Influences on Nitrogen Cycling within an Upland Pin Oak Ecosystem
Authors: Zak Donald R. , Hairston Anne , Grigal David F. 
Published: April 2024

Abstract
Nitrogen mineralization and nitrification were studied within an upland pin oak (Quercus ellipsoidalis E.J. Hill) forest to determine if topography could be used to understand the spatial variability of N transformations within and among individual stands. Four upland pin oak stands were used for the study, and within each stand, transects were established on northeast (45° azimuth), southeast (135° azimuth), southwest (225° azimuth), and northwest (315° azimuth) facing aspects. Nitrogen mineralization and nitrification were measured at 5-wk intervals for 1 year at top, middle, and bottom slope position along each transect using an in situ soil incubation technique. Annual rates of mineralization among the four stands ranged from 3.0 to 6.7 g N m-2 yr-1, but were not significantly influenced by aspect or slope position. Although aspect had no effect on nitrification, bottom slope positions had significantly lower (0.3 g N m-2 yr-1) nitrification rates compared to middle (1.3 g N m-2 yr-1) and top (1.4 g N m-2 yr-1 slope positions. Annual N mineralization and nitrification increased with stand age. Slope position and aspect had little influence on N cycling rates within the subtle topography of east central Minnesota; time since disturbance seems to be the most important factor influencing the variability in N dynamics among upland pin oak stands. For. Sci. 37(1):45-53.
Western Hemlock and Douglas-Fir Seedling Development with Exponential Rates of Nutrient Addition
Authors: Burgess D. 
Published: April 2024

Abstract
Ingestad's concept of controlling relative addition rate was used in growing western hemlock (Tsuga heterphylla [Raf.] Sarg.) and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings in styroblock containers under greenhouse conditions. Seedlings were fertilized for 14 weeks at different exponential rates following a 1 month pretreatment period. Based on their initial nitrogen contents, seedlings were fertilized with a complete Ingestad solution, twice weekly, at either a 1, 2, 4, or 6% per day exponentially increasing dosage, or with a constant amount each feeding (control treatment) of 0.991 mg N/seedling. Western hemlock and Douglas-fir seedlings grew fastest at the highest (6%) relative addition rate. Douglas-fir was more efficient than western hemlock at nitrogen uptake and succeeded in taking up the most nitrogen (55% of the nitrogen added) in the control treatment. Western hemlock was most efficient at nitrogen uptake in the 4% relative addition rate treatment, but still captured only 29.7% of the nitrogen added. Biomass allocation and nitrogen concentrations in seedlings of both species varied significantly with treatment, suggesting that different seedling types acclimated to different levels of nutrient stress could be produced using the concept of relative addition rate. The nitrogen concentrations of seedlings generally declined with time in the control and lowest relative addition rate treatments. For. Sci. 37(1):54-67.
A Simulation Model of the Role of Belowground Dynamics in a Florida Pine Plantation
Authors: Ewel Katherine C. , Gholz Henry L. 
Published: April 2024

Abstract
A model of a 29-yr-old slash pine (Pinus elliottii) plantation on a typical flatwoods site in north Florida evaluates the importance and magnitude of belowground processes in a forest. The model, which comprised 22 differential equations, most of them nonlinear, was parameterized with three sets of climate data and validated with measurements of soil moisture, soil CO2 evolution, root production, and root biomass.
Simulated gross primary productivity (GPP) in a year with normal rainfall was 29.5 Mg ha-1 yr-1 (C), which is consistent with measurements of GPP in a variety of north Florida sites. In the model, one-third of GPP was translocated to the roots, where more than 75% was spent on respiration. Root respiration varied little among the three simulations. Root turnover times were more variable. In the low rainfall simulation, root turnover time was 21% longer than in the other two simulations, which were nearly the same. Simulated P concentration in the soil and plant had much less effect on plant processes than soil moisture did. General agreement of transpiration rates with other studies indicated that evapotranspiration is the only major water loss in slash pine flatwoods. Simulated water-borne P losses from the site were therefore insignificant. Simulated foliage biomass varied considerably during the year, decreasing to less than haft its maximum biomass during an annual cycle in one of the simulations.
Comparison of the few sites with comparable estimates of C fixation and allocation suggests that 22%-43% of C fixed is used by roots, and that the proportion allocated to roots may be higher on nutrient-poor sites and sites with low temperatures. For. Sci. 37(1):397-438.
A Multivariate Model and Analysis of Competitive Strategy in the U.S. Hardwood Lumber Industry
Authors: Bush Robert J. , Sinclair Steven A. 
Published: April 2024

Abstract
Business-level competitive strategy in the hardwood lumber industry was modeled through the identification of strategic groups among large U.S. hardwood lumber producers. Strategy was operationalized using a measure based on the variables developed by Dess and Davis (1984). Factor and duster analyses were used to define strategic groups along the dimensions of cost leadership, focus, and differentiation. A five strategic group model was identified and examined for strategic orientation and intragroup homogeneity. Two groups had no distinctive strategic orientation that suggested a competitive advantage; one group exhibited an overall cost leadership strategy; one exhibited a differentiation strategy; and one group exhibited a dual overall cost leadership/differentiation strategy. Strategic change in the industry was predicted to be primarily toward increased differentiation. Three strategic groups indicated significant change in this direction, and one group indicated an increase along both the focus and differentiation dimensions. For. Sci. 37(2):481-499.