bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in Flood-Induced Stomatal and Photosynthetic Responses of Three Bottomland Tree Species
Authors: Pezeshki S. R. , Chambers J. L. 
Published: April 2024

Abstract
The effects of flooding on plant water status, stomatal conductance, and net photosynthesis in seedlings of three bottomland species, Fraxinus pennsylvanica Marsh., Quercus michauxii Nutt., and Taxodium distichum (L.) Rich. var. distichum were studied under controlled environmental conditions. Flooding for three weeks induced significant stomatal closure in all species. After 24 hours of flooding, stomatal conductance was reduced to 49% of the preflood level in T. distichum, 56% of the preflood level in Q. michauxii, and 53% of preflood level in F. pennsylvanica. Leaf water potential measurements indicated that water deficits did not develop as a result of flooding; therefore, stomatal closure was apparently not caused by water deficits in any of the study species. Limited photosynthesis data indicated that flooding did not substantially reduce net photosynthesis in T. distichum or F. pennsylvanica, even though partial stomatal closure was induced. Net photosynthesis was, however, substantially reduced in flooded Q. michauxii. Forest Sci. 32:914-923.
Trends in Genetic Parameters with Stand Development and Their Influence on Early Selection for Volume Growth in Loblolly Pine
Authors: Foster G. Sam 
Published: April 2024

Abstract
Analysis was conducted on data from a 15-year-old progeny test of 11 open-pollinated families of loblolly pine. Plots consisted of 49-tree blocks of single families, and measurements were taken annually for the first 8 years and at 10 and 15 years.
Three types of analysis were used to explore early selection for a more mature trait. These analyses included: age-related trends in genetic and environmental variances, juvenile-mature genetic correlations, and indirect selection.
The age-related trends varied by trait. The trends for additive genetic variance ranged from flat (survival) to exponential (total plot volume) or concave (live crown ratio). However, for all traits, additive genetic variance dipped around age 7 or 8, presumably due to intensifying competition at crown closure.
Genetic correlations between early traits (juvenile) and more mature traits (15 years) were generally high. The correlations of height or total plot volume at age 15 with juvenile traits improved rapidly from age 1 to 5. Diameter at breast height, in which there was little or no increase from ages 3 to 5, was the one exception. When correlating earlier height with height or plot volume at age 15, the pattern of correlation coefficients took a noticeable dip at ages 7 or 8.
With total plot volume at age 15 (TVOL15) as the goal of selection, response to indirect selection for height and survival at various ages was predicted. The predicted, indirect response was expressed as a ratio of response to direct selection for TVOL15 and termed relative efficiency. The relative efficiency of selection by ages 3, 4, or 5 was 81, 82, and 85%, respectively. Forest Sci. 32:944-959.
The Declining Even Flow Effect—Non Sequitur of National Forest Planning
Authors: McQuillan Alan G. 
Published: April 2024

Abstract
The traditional concept of sustained yield has evolved into the more rigid notion of even flow for timber harvest regulation on national forests. Combination of an even flow constraint with a wealth-maximizing objective function in current formulations of the forest planning model can lead to an anomaly, dubbed the declining even flow effect (DEFE), when the national forest planning process is repeated periodically as required by law. When the effect occurs, first-decade harvests fall during successive planning cycles. The cause lies in both the redefinition of the even flow constraint that occurs at successive planning cycles and the assumptions associated with a capital efficiency objective function that are violated when an even flow constraint is imposed. Forest Sci. 32:960-972.
The Role of Exchange Rates in Canadian—United States Lumber Trade
Authors: Adams Darius M. , McCarl Bruce A. , Homayounfarrokh Lalehrokh 
Published: April 2024

Abstract
The paper employs graphical analysis, simple statics and an econometric model to examine the impacts of exchange rate on consumption, production, prices, and bilateral trade flows in the Canadian-U.S. lumber market. Based on annual data for the 1950-1983 period, the econometric model is comprised of a U.S. demand relation and supply, capacity, and stumpage price relations for three U.S. regions and Canada. Analysis with the model indicates short-term elasticities with respect to exchange rate (expressed as $C/$US) of less than 0.1 for U.S. consumption, roughly -0.3 for U.S. delivered price and 0.5 for import volume. The elasticity of Canadian market share was found to be approximately 0.4. The greatest Canadian market share expansion (from roughly 20 to 27%) and rise in the U.S. dollar strength occurred during the years 1975-1979. A hypothetical simulation of this period, under the assumption of no increase in the nominal exchange rate, yielded a reduction in Canada's 1979 share to 24%, roughly a 40% reduction in market share gain. Both elasticity and simulation results indicate that exchange rate has been an important, but by no means the sole, factor in recent expansion of Canada's share in U.S. lumber markets. Forest Sci. 32:973-988.
A Logistic Model of Mortality in Thinned and Unthinned Mixed Conifer Stands of Northern Idaho
Authors: Hamilton David A. 
Published: April 2024

Abstract
Published mortality models have not always done an adequate job of predicting the probability of mortality following thinning. This paper describes a mortality model based on a series of thinned and unthinned sample plots located in northern Idaho, some of which have been measured for 70 years. Independent variables are diameter at breast height (dbh), stand basal area, annual diameter growth, relative dbh, and species. Thinning results in changes in three of these variables: the stand basal area, relative dbh, and diameter growth rate. Model performance is evaluated by considering how well the model fits the development data set, how well the model fits an independent data set, and how well the model fits biological reality. In each evaluation the selected model shows a marked improvement over the performance of the mortality model used in previous releases of the Stand Prognosis Model (Wykoff et al. 1982). The model is shown to perform well in both thinned and unthinned stands. Forest Sci. 32:989-1000.
Predicting Regeneration in the Grand Fir-Cedar-Hemlock Ecosystem of the Northern Rocky Mountains
Authors: Ferguson Dennis E. , Stage Albert R. , Boyd Raymond J. 
Published: April 2024

Abstract
Conifer establishment following regeneration treatments can be predicted in the grand fir-cedar-hemlock ecosystem of the northern Rocky Mountains. Alternative treatments can be evaluated by a model that represents regeneration establishment and early development. This model is designed to be used with the Intermountain Forest and Range Experiment Station's Prognosis Model (Stage 1973). Mathematical equations representing most harvest and site preparation methods common in the northern Rocky Mountains predict the probability of stocking, trees per acre, species composition, and tree heights between 3 to 20 years following treatment. These relations were derived from a stratified random sample of areas managed by conventional harvest and site preparation treatments. However, the analysis and modeling methods are structured to permit combinations of treatments within a stand that might differ from past practices.
A Growth and Yield Model for Thinned Stands of Yellow-Poplar
Authors: Knoebel Bruce R. , Burkhart Harold E. , Beck Donald E. 
Published: April 2024

Abstract
Simultaneous growth and yield equations were developed for predicting basal area growth and cubic-foot volume growth and yield in thinned stands of yellow-poplar. A joint loss function involving both volume and basal area was used to estimate the coefficients in the system of equations. The estimates obtained were analytically compatible, invariant for projection length, and numerically equivalent with alternative applications of the equations. Given estimates of basal area and cubic-foot volume from these equations, board-foot volumes can also be calculated.
As an adjunct to the stand-level equations, compatible stand tables were derived by solving for the parameters of the Weibull distribution from attributes predicted with the stand-level equations. This procedure for estimating the parameters of the diameter distributions of the stands before thinning gave reasonable estimates of number of trees, basal area, and cubic-foot volume per acre by diameter class. The thinning algorithm removes a proportion of the basal area from each diameter class and produces stand and stock tables after thinning from below that are consistent with those generated before thinning.
A World Model of the Demand for Paper and Paperboard
Authors: Baudin Anders , Lundberg Lars 
Published: April 2024

Abstract
The objective of this study is to develop and evaluate econometric models describing the long-term development of demand for paper products, which could be used for simulation, policy evaluation, and long-term projections, on a global scale as well as for regions and individual countries. The study is intended to cover a relatively large sample of countries on varying levels of economic development. This means, however, that the availability of data sets rather restrictive limits on the model building. The basic approach in this paper is the same as that by Buongiorno (1978). The final model chosen here for projections and simulations of demand is, however, somewhat different from Buongiorno's model. In addition, a number of alternative model specifications were explored and evaluated. For. Sci. 33(1): 185-196.
Calibration of the Hemispherical Photographic Technique to Measure Leaf Area Index Distributions in Hardwood Forests
Authors: Wang Y. S. , Miller D. R. 
Published: April 2024

Abstract
Measured distributions of leaf inclination angles and leaf azimuth angles from one stand of red maple (Acer rubrum L.) are used to modify hemispherical photograph determinations of leaf area index in two other plots of red maple as well as in the stand where structure measurements were made. LAI determinations by this technique were within 3.5% of leaf weighting measurements and 5.8% of LAI measurements by a point drop technique. This is approximately twice the accuracy of the photograph technique without calibration. For. Sci. 33(1):210-216.
Combustion Losses of Sulfur from Forest Foliage and Litter
Authors: Tiedemann A. R. 
Published: April 2024

Abstract
Sulfur (S) content of samples of ponderosa pine (Pinus ponderosa Dougl. Ex Laws.), Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), Sitka alder (Alnus sinuata [Regel] Rydb.), snowbrush ceanothus (Ceanothus velutinus [Dougl.]), and forest litter combusted in an aerated muffle furnace at 375°-575°, 575°-775°, 775°-975°, and 975°-1,175°C for 5, 30, and 60 min was compared with S content of unburned samples. Sulfur losses at 375°-575°C for 5 min ranged from 24 to 79% of S contained in unburned material. At 975°-1,175°C for 60 min, losses ranged from 61 to 92%. Results suggest that prescribed burning and wildfire could potentially cause substantial volatilization losses of S from foliage and litter. For. Sci. 33(1): 216-223.
Freeze-Crack-Related Measurements on Platanus × acerifolia Trees
Authors: Neely Dan , Himelick E. B. 
Published: April 2024

Abstract
For four consecutive winters, stem temperature, stem shrinkage, and widths of freeze cracks were measured on London plane trees, Platanus × acerifolia, in Urbana, Illinois. At temperatures below 0°C, trunk shrinkage and widths of freeze cracks were substantial and inversely correlated with temperature. Wood shrinkage was greater in trees with cracks than in trees without cracks. For. Sci. 33(1):239-244.
Long-Term Storage of Douglas-fir Pollens
Authors: Copes Donald L. 
Published: April 2024

Abstract
A test of pollen fertility after 3 years of cold storage is reported. Douglas-fir (Pseudotsuga menziesii) pollen was as fertile after 1, 2, or 3 years of storage in liquid nitrogen as was fresh pollen. Fertility of the same pollen lots decreased significantly after 1 or 2 years of storage at 0°C. For. Sci. 33(1):244-246.
Evaluation of Researchers' Decisions in Short-Rotation Forestry
Authors: Fege Anne S. 
Published: April 2024

Abstract
A survey of short-rotation forestry research from 1966-82 provided insights into the political, socioeconomic, institutional, and personal factors influencing decisions made by forestry researchers. Scientists first entered short rotation forestry research because of personal contacts with other scientists, because they considered this a "productive" research area, because funds were available, and because of the "energy crisis." They attributed their success primarily to cooperation with other scientists and potential users and to adequate financial support. These findings offer insight into the individual decisions and the economic and political factors that will shape other forestry research frontiers. For. Sci. 33(1):30-42.
Genetic Structure of Southern Pine Beetle Populations
Authors: Roberds J. H. , Hain F. P. , Nunnally L. B. 
Published: April 2024

Abstract
The pattern of geographic variation among southern pine beetle (SPB) populations of the enzootic infestations of 1978 was similar to that found among populations in the declining epizootic of 1977. Results for two Texas collections made in 1977 and 1978 indicated that these populations were genetically differentiated from each other. Allele frequencies estimated for the Arkansas and Mississippi populations provided evidence that they belonged to the more genetically uniform group of populations found outside of Texas. Two different types of population structures were found in the infestations studied in Arkansas and North Carolina. Infestations within Arkansas were slightly differentiated genetically but displayed little variation in allele frequencies among single-tree subpopulations within infestations. In the North Carolina populations, allele frequencies did not differ among infestations or among single-tree subpopulations within infestations; however, homozygosity in some single-tree subpopulations was greater than expected for random mating. Evidence for considerable two-locus linkage disequilibria was found in subpopulations of unexpanded infestations studied in North Carolina. Within subpopulations of the expanded infestations however, linkage disequilibria were less extensive. For. Sci. 33(1):52-69.
Drought Tolerance of Southwestern Oregon Douglas-Fir
Authors: White Timothy L. 
Published: April 2024

Abstract
Seedlings from two open-pollinated families of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) from each of 35 seed sources in southwestern Oregon were tested for their ability to survive simulated drought in growth room, greenhouse, and coldframe test environments. Generally, seedlings from seed sources originating from higher elevations and, to a lesser extent, from drier sites, were more drought tolerant. Seedlings from drought-tolerant sources tended to have earlier bud-set, smaller initial height, and less winter injury. The main selective force leading to earlier bud-set and smaller height growth appeared to be the colder temperature regime associated with higher elevations. Seedlings from high elevations entered dormancy sooner and were better able to survive the imposed drought. Implications for seed transfer and for breeding for drought-tolerant genotypes in southwestern Oregon are discussed. For. Sci. 33(2):283-293.
Reduction of Phellinus weirii Inoculum in Douglas-Fir Stumps by the Fumigants Chloropicrin, Vorlex, or Methylisothiocyanate
Authors: Thies Walter G. , Nelson Earl E. 
Published: April 2024

Abstract
Three dosages of chloropicrin and Vodex, with and without sealing, and one dosage of methylisothiocyanate (MIT) in capsules or open glass tubes were applied to Douglas-fir stumps to reduce Phellinus weirii (Mutt.) Gilb. inoculum. After 2 years, all fumigants had reduced the amount of inoculum, but MIT was less effective than chloropicrin or Vorlex. Neither higher levels of fumigant nor sealing the stump tops resulted in further reduction of inoculum. Inoculum in dead stumps was not further reduced by covering stumps with a plastic tarp. Presence of advanced decay did not seem to be advantageous for movement of the fumigant in stumps and roots. Assessment of inoculum survival by using either aseptic isolation techniques or observations of fungal regrowth on the cut surfaces of incubated root disks were comparable for detecting viable P. weirii in root disks from untreated stumps. As a percentage of prefumigation inoculum volume, isolations from fumigated stumps, indicated more viable P. weirii in roots (22%) than did fungal regrowth (7%). Most root disks contained viable P. weirii where residual fumigant was not detected in bioassays, whereas viable P. weirii was not found in 26 of 27 root disks where fumigant was detected. For. Sci. 33(2):316-329.
Organic Matter and Nutrients Associated with Fine Root Turnover in a White Oak Stand
Authors: Joslin J. D. , Henderson G. S. 
Published: April 2024

Abstract
Organic matter and nutrients cycled by fine root turnover were quantified in a mature white oak (Quercus alba L.) stand and compared to contributions from litterfall. The budget method, a revised version of the traditional repeated sampling method, was used to measure root turnover. The magnitude of the live and dead pools of three size classes of fine (&lt;5 mm diameter) roots were monitored bimonthly for 14 months. Decomposition rates over these intervals were also measured, while production and mortality were calculated. Litterfall was collected simultaneously, and the nutrient concentrations of the various detritus components determined. Root pools fluctuated less, and total root turnover biomass (220 g m -2 yr-1) was also less than previously noted in most other stands studied. Fine root turnover accounted for 30% of the total detritus production and 20-40% of the turnover of the five macron utrients (N, P. K, Ca, Mg) studied. Differences with previous studies suggest that there may be rather large species and/or site-related differences in the amount of energy various stands allocate for fine root maintenance. For. Sci. 33(2):330-346.
Decay Fungi and Wounding in Advance Grand and White Fir Regeneration
Authors: Aho Paul E. , Filip Gregory M. , Lombard Frances F. 
Published: April 2024

Abstract
A total of 464 living white and grand fir tree stems in 24 stands in Oregon and Washington were dissected to detect infections of hymenomycetes (decay fungi) and other microorganisms in woody tissue. Of 21,249 attempted isolations from dissected trunks, 43.2% yielded bacteria or yeasts, 38.6% were sterile, 11.0% were nonhymenomycetes, 3.1% were hymenomycetes, and 4.1% were contaminated or mixed cultures. Hymenomycetes most frequently isolated were Echinodontium tinctorium and Heterobasidion annosum, both of which caused the most discoloration and decay. Nearly 20% of all hymenomycetous isolations, particularly Hericium abietis and E. tinctorium, were from clear tissue not associated with discolored or decayed wood. More than 300 trunk wounds on 248 dissected trees were classified by size, location, age, and hymenomycetous associations. At least 45% of all trees with wounds had hymenomycetes present, of which E. tinctorium and Pholiota limonella were isolated most frequently. Discoloration caused by E. tinctorium was associated with wounds as recent as a year or as small as 56 cm2. All E. tinctorium infections that caused discoloration or decay were within 30 cm of a wound, whereas all infections within clear tissue were beyond 30 cm. These data support a hypothesis that E. tinctorium enters hosts via minute branchlet stubs, becomes dormant after the branchlet stubs occlude, and is activated by wounds in the vicinity of dormant infections. For. Sci. 33(2):347-355.
Generalized Error Structure for Forestry Yield Models
Authors: Gregorie Timothy G. 
Published: April 2024

Abstract
The combined time-series cross-sectional nature of remeasurement data from permanent forest plots is examined with an aim toward improving the precision of yield models fitted with these data. The linear model error term is regarded as an aggregation of plot, time period, and residual random effects with possibly distinct variances and correlations. Four alternative error covariance structures are posited that differ in the manner in which serial correlation, plot variance heterogeneity, and cross-plot correlations are prescribed. Yield models with the presumed error covariance specifications were fitted to a panel of 65 pure, even-aged Douglas-fir plot remeasurements, using two-stage generalized least squares and, in one case, a full maximum likelihood estimation. Ordinary least squares results were used as a basis for comparison. Comparison of the fitted models by prediction error and likelihood criteria indicate ordinary least squares nearly always performs better by the former measure, whereas one or more of the alternate specifications always have higher likelihood. For. Sci. 33(2):423-444.
Landform-Mediated Differences in Successional Pathways Among Upland Forest Ecosystems in Northwestern Lower Michigan
Authors: Host George E. , Pregitzer Kurt S. , Ramm Carl W. , Hart James B. , Cleland David T. 
Published: April 2024

Abstract
Seedling and sapling densities were compared with current overstory composition in 30 upland forest stands in northwestern Lower Michigan to study potential successional pathways. The patterns of compositional change were strongly related to topographic and edaphic differences among glacial landforms. Glaciofluvial landforms, currently dominated by oak, have relatively high densities of oak seedlings (4913 stems/ha) that seldom move into the sapling layer (10 stems/ha). Oak-dominated ecosystems on hilly ice-contact stratified drift exhibited relatively high densities of red maple saplings (48 stems/ha). Oak-dominated ecosystems on extremely well drained outwash plains exhibited sparse sapling regeneration of any species; red maple was typically absent, and oak saplings were usually in an apparent state of decline. Differences in the potential for recruitment of saplings into the overstory among these ecosystems may be attributable to differences in fire history or site-dependent effects on the competitive abilities of species. Morainal landforms, currently supporting relatively diverse northern hardwood overstories, showed little potential recruitment of any species other than sugar maple. Glacial landforms in northwestern Lower Michigan direct compositional change by influencing soil moisture and nutrient availability, and historical patterns of disturbance and species establishment. For. Sci. 33(2):445-457.
Twenty-four Years of Ponderosa Pine Growth in Relation to Canopy Leaf Area and Understory Competition
Authors: Oren R. , Waring R. H. , Stafford S. G. , Barrett J. W. 
Published: April 2024

Abstract
With data from a long-term experiment in which initial stocking of trees and understory vegetation were controlled, we tested the hypothesis that stand growth is directly correlated with the development of the forest canopy; e.g., growth is proportional to canopy leaf area. The hypothesis was generally supported. Stands of ponderosa pine without understory vegetation more rapidly developed canopy leaf area than stands with an understory. At very low leaf area indices, wood production per unit of leaf area was more efficient, particularly in stands where the understory vegetation had been removed. Once the leaf area index exceeded 2.0, however, the efficiency of wood production remained stable and was comparable for stands with and without understory vegetation. For. Sci. 33(2):538-547.