bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaling of stochastic growth and division dynamics: A comparative study of individual rod-shaped cells in the Mother Machine and SChemostat platforms
Authors: Ziegler Karl F. , Joshi Kunaal , Wright Charles S. , Roy Shaswata , Caruso Will , Biswas Rudro R. , Iyer-Biswas Srividya
Published: April 2024

Microfluidic platforms enable long-term quantification of stochastic behaviors of individual bacterial cells under precisely controlled growth conditions. Yet, quantitative comparisons of physiological parameters and cell behaviors of different microorganisms in different experimental and device modalities is not available due to experiment-specific details affecting cell physiology. To rigorously assess the effects of mechanical confinement, we designed, engineered, and performed side-by-side experiments under otherwise identical conditions in the Mother Machine (with confinement) and the SChemostat (without confinement), using the latter as the ideal comparator. We established a protocol to cultivate a suitably engineered rod-shaped mutant of Caulobacter crescentus in the Mother Machine and benchmarked the differences in stochastic growth and division dynamics with respect to the SChemostat. While the single-cell growth rate distributions are remarkably similar, the mechanically confined cells in the Mother Machine experience a substantial increase in interdivision times. However, we find that the division ratio distribution precisely compensates for this increase, which in turn reflects identical emergent simplicities governing stochastic intergenerational homeostasis of cell sizes across device and experimental configurations, provided the cell sizes are appropriately mean-rescaled in each condition. Our results provide insights into the nature of the robustness of the bacterial growth and division machinery.
pipesnake: generalized software for the assembly and analysis of phylogenomic datasets from conserved genomic loci
Authors: Brennan Ian G , Singhal Sonal , Al Bkhetan Ziad
Published: April 2024

Motivation

Phylogenetics has moved into the era of genomics, incorporating enormous volumes of data to study questions at both shallow and deep scales. With this increase in information, phylogeneticists need new tools and skills to manipulate and analyze these data. To facilitate these tasks and encourage reproducibility, the community is increasingly moving toward automated workflows.

Results

Here we present pipesnake, a phylogenomics pipeline written in Nextflow for the processing, assembly, and phylogenetic estimation of genomic data from short-read sequences. pipesnake is an easy to use and efficient software package designed for this next era in phylogenetics.

Availability and implementation

pipesnake is publicly available on GitHub at https://github.com/AusARG/pipesnake and accompanied by documentation and a wiki/tutorial.
Conversion of single-energy CT to parametric maps of dual-energy CT using convolutional neural network
Authors: Kim Sangwook , Lee Jimin , Kim Jungye , Kim Bitbyeol , Choi Chang Heon , Jung Seongmoon
Published: April 2024

Objectives

We propose a deep learning (DL) multitask learning framework using convolutional neural network for a direct conversion of single-energy CT (SECT) to 3 different parametric maps of dual-energy CT (DECT): virtual-monochromatic image (VMI), effective atomic number (EAN), and relative electron density (RED).

Methods

We propose VMI-Net for conversion of SECT to 70, 120, and 200 keV VMIs. In addition, EAN-Net and RED-Net were also developed to convert SECT to EAN and RED. We trained and validated our model using 67 patients collected between 2019 and 2020. Single-layer CT images with 120 kVp acquired by the DECT (IQon spectral CT; Philips Healthcare, Amsterdam, Netherlands) were used as input, while the VMIs, EAN, and RED acquired by the same device were used as target. The performance of the DL framework was evaluated by absolute difference (AD) and relative difference (RD).

Results

The VMI-Net converted 120 kVp SECT to the VMIs with AD of 9.02 Hounsfield Unit, and RD of 0.41% compared to the ground truth VMIs. The ADs of the converted EAN and RED were 0.29 and 0.96, respectively, while the RDs were 1.99% and 0.50% for the converted EAN and RED, respectively.

Conclusions

SECT images were directly converted to the 3 parametric maps of DECT (ie, VMIs, EAN, and RED). By using this model, one can generate the parametric information from SECT images without DECT device. Our model can help investigate the parametric information from SECT retrospectively.

Advances in knowledge

DL framework enables converting SECT to various high-quality parametric maps of DECT.
Non-pharmacological interventions to improve sleep quality and quantity for hospitalized adult patients—co-produced study with surgical patient partners: systematic review
Authors: Acharya Radhika , Blackwell Sue , Simoes Joana , Harris Benjamin , Booth Lesley , Bhangu Aneel , Glasbey James
Published: April 2024

Background

Hospitalized patients experience sleep disruption with consequential physiological and psychological effects. Surgical patients are particularly at risk due to surgical stress and postoperative pain. This systematic review aimed to identify non-pharmacological interventions for improving sleep and exploring their effects on sleep-related and clinical outcomes.

Methods

A systematic literature search was performed in accordance with PRISMA guidelines and was preregistered on the Open Science Framework (doi: 10.17605/OSF.IO/EA6BN) and last updated in November 2023. Studies that evaluated non-pharmacological interventions for hospitalized, adult patients were included. Thematic content analysis was performed to identify hypothesized mechanisms of action and modes of administration, in collaboration with a patient partner. Risk of bias assessment was performed using the Cochrane Risk Of Bias (ROB) or Risk Of Bias In Non-Randomized Studies – of Interventions (ROBINS-I) tools.

Results

A total of 59 eligible studies and data from 14 035 patients were included; 28 (47.5%) were randomized trials and 26 included surgical patients (10 trials). Thirteen unique non-pharmacological interventions were identified, 17 sleep measures and 7 linked health-related outcomes. Thematic analysis revealed two major themes for improving sleep in hospital inpatients: enhancing the sleep environment and utilizing relaxation and mindfulness techniques. Two methods of administration, self-administered and carer-administered, were identified. Environmental interventions, such as physical aids, and relaxation interventions, including aromatherapy, showed benefits to sleep measures. There was a lack of standardized sleep measurement and an overall moderate to high risk of bias across all studies.

Conclusions

This systematic review has identified several sleep interventions that are likely to benefit adult surgical patients, but there remains a lack of high-quality evidence to support their routine implementation.
Trust and State Effectiveness: The Political Economy of Compliance
Authors: Besley Timothy , Dray Sacha
Published: April 2024

This paper explores the link between trust in government, policymaking and compliance. It focuses on a specific channel whereby citizens who are convinced of the merits of a policy are more motivated to comply with it. This, in turn, reduces the government’s cost of implementing this policy and may also increase the set of feasible interventions. As a result, state effectiveness is greater when citizens trust their government. The paper discusses alternative approaches to modelling the origins of trust, especially the link to the design of political institutions. We then provide empirical evidence consistent with the model’s findings that compliance is increasing in government trust using the Integrated Values Survey and voluntary compliance during COVID-19 in the United Kingdom.
Significance of preoperative exercise oxygen desaturation in lung cancer with interstitial lung disease
Authors: Ueda Takuya , Takamochi Kazuya , Fukui Mariko , Ichikawa Tomohiro , Hattori Aritoshi , Matsunaga Takeshi , Oh Shiaki , Tomita Hisashi , Suzuki Kenji
Published: April 2024

OBJECTIVES

Evaluating the diffusing capacity for carbon monoxide (DLco) is crucial for patients with lung cancer and interstitial lung disease. However, the clinical significance of assessing exercise oxygen desaturation (EOD) remains unclear.

METHODS

We retrospectively analysed 186 consecutive patients with interstitial lung disease who underwent lobectomy for non-small-cell lung cancer. EOD was assessed using the two-flight test (TFT), with TFT positivity defined as ≥5% SpO2 reduction. We investigated the impact of EOD and predicted postoperative (ppo)%DLco on postoperative complications and prognosis.

RESULTS

A total of 106 (57%) patients were identified as TFT-positive, and 58 (31%) patients had ppo% DLco < 30%. Pulmonary complications were significantly more prevalent in TFT-positive patients than in TFT-negative patients (52% vs 19%, P < 0.001), and multivariable analysis revealed that TFT-positivity was an independent risk factor (odds ratio 3.46, 95% confidence interval 1.70–7.07, P < 0.001), whereas ppo%DLco was not (P = 0.09). In terms of long-term outcomes, both TFT positivity and ppo%DLco < 30% independently predicted overall survival. We divided the patients into 4 groups based on TFT positivity and ppo%DLco status. TFT-positive patients with ppo%DLco < 30% exhibited the significantly lowest 5-year overall survival among the 4 groups: ppo%DLco ≥ 30% and TFT-negative, 54.2%; ppo%DLco < 30% and TFT-negative, 68.8%; ppo%DLco ≥ 30% and TFT-positive, 38.1%; and ppo%DLco < 30% and TFT-positive, 16.7% (P = 0.001).

CONCLUSIONS

Incorporating EOD evaluation was useful for predicting postoperative complications and survival outcomes in patients with lung cancer and interstitial lung disease.
Hybrid noncovered open stents in repair of DeBakey type 1 acute aortic dissections
Authors: Luthra Suvitesh , Miskolczi Szabolcs , Velissaris Theodore , De Silva Ravi J , Luehr Maximilian , Kempfert Jörg , Moon Michael C
Published: April 2024

OBJECTIVES

The indications for use, evidence base and experience with the novel noncovered open hybrid surgical stents for acute type A aortic dissection repair for concurrent stabilization of the ‘downstream’ aorta remains limited. We review the evidence base and the development of these stents.

METHODS

Data were collected from Pubmed/Medline literature search to develop and review the evidence base for safety and efficacy of non-covered surgical stents. Existing guidelines for use and developments were reviewed.

RESULTS

A single randomized control trial and 4 single-centre studies were included in the review with a total worldwide experience of 241 patients. The deployment was easy and did not add significantly to the primary operation. The mortality and new stroke ranged from 6.3–18.7%. Safe and complete deployment was accomplished in 92–100%. There was no device-related reintervention. There was a significant improvement in malperfusion in over 90% of the cases with varying degrees of remodelling (60–90%) of the downstream aorta.

CONCLUSIONS

Open noncovered stent grafts represent a major technical advancement as an adjunct procedure for acute dissection repairs, e.g. hemiarch repair. It has potential for wider use by non-aortic surgeons due to simplicity of technique. Limited safety and efficacy data confirm the device to be safe, feasible and reproducible with potential for wider adoption. However, long-term trial and registry data are required before recommendations for standard use outside of high-volume experienced aortic centres.
Foliar Nutrient Composition of Juniperus osteosperma and Environmental Interactions
Authors: Bunderson Eileen D. , Weber Darrell J.
Published: April 2024

Two hundred fifty-five trees of Utah juniper (Juniperus osteosperma (Torr.) Little) were sampled from 17 pinyon-juniper sites in Utah and analyzed for foliar-mineral composition, total soluble carbohydrate, and total chlorophyll content. These foliar nutrient factors were compared to each other and related to a variety of environmental site factors including temperature, precipitation, and soil nutrient levels. Trees from each site were classified according to age and each age group was analyzed separately. Data indicate concentrations of N, P, and K in all age groups are consistent with other forest species. Concentrations of Ca varied while amounts of Na and Fe were unusually high, particularly in seedlings. Strong correlations (α = 0.01) were noted between amounts of precipitation in the research sites and variations in foliar nutrient content. Forest Sci. 32:149-156.
Measurement of Seed Vigor for Loblolly and Slash Pines
Authors: Bonner F. T.
Published: April 2024

Seed vigor test results for loblolly and slash pines were compared to germination performance data, both in the laboratory and in nursery beds. Of all laboratory vigor tests, only tetrazolium staining and leachate conductivity could be correlated with germination. Laboratory percent germination and Peak Value (a measure of germination rate) provided good vigor estimates. Derivation of these parameters from germination models based on the Weibull function was no better than obtaining them from standard germination test data with frequent counts. Leachate conductivity measurments were very promising and should be used if time constraints do not allow a germination test. Forest Sci. 32:170-178.
Response Increment: A Method to Analyze Thinning Response in Even-Aged Forests
Authors: Horne Ross , Robinson Grant , Gwalter John
Published: April 2024

A method to analyze the relationship between forest stand increment and density is described. Basal area growth response is examined by partitioning increment from ranked strata within the stand into increment which is dependent on density change and that which is not. This allows resolution of the total increment to density relationship into a number of recognizable segments. The partitioned increment to stocking relationships are found to be closely approximated by modified Weibull density and distribution functions. The method, illustrated with P. radiata D. Don data, is applicable to a wide range of even-aged forest data and can be used to improve basal area increment models. Forest Sci. 32:243-253.
Dry Weight and Nutrient Content of Fuelwood Biomass from Loblolly Pine Stands in North Louisiana
Authors: Lockaby B. G. , Adams J. C.
Published: April 2024

Three mature loblolly pine stands in north Louisiana were sampled to determine the dry weight and nutrient content of both the understory hardwoods and the pine biomass that would remain following a conventional harvest. Approximately 52 t/ha of understory hardwoods and 22 t/ha of pine residues were estimated to exist in these stands. Combined, this biomass contained 208, 16, 114, 215, and 40 kg/ha of N, P, K, Ca, and Mg. Potential removal of these quantities in a fuelwood harvest would not appear to greatly diminish soil pools of the same elements. Forest Sci. 32:3-9.
A Ratio Approach to Predicting Merchantable Yields of Unthinned Loblolly Pine Plantations
Authors: Amateis Ralph L. , Burkhart Harold E. , Burk Thomas E.
Published: April 2024

A stand-level ratio model is presented which uses the stand attributes age, site index, basal area, and number of surviving trees per acre to portion total stand yield to any desired top diameter and/or threshold dbh limit. A model is also presented which distributes the total number of trees by diameter such that the basal area is consistent with total stand basal area. Comparisons with two Weibull-based diameter distribution approaches showed the ratio approach to be a practical and satisfactory alternative. Coefficients for the equations were developed for unthinned old-field and cutover, site-prepared loblolly pine plantations. Forest Sci. 32:287-296.
Estimating and Valuing Western Pine Beetle Impacts
Authors: Liebhold Andrew M. , Berck Peter , Williams Nancy A. , Wood David L.
Published: April 2024

A tree growth and mortality model was developed to simulate timber production with and without tree mortality caused by the western pine beetle, Dendroctonus brevicomis LeConte. Stumpage value at time of harvest was discounted back to the time of mortality. A logging cost model was used to estimate revenue generated from salvaging killed trees. These values were assembled to estimate the value at risk from western pine beetle-caused tree mortality. Simulated estimates of beetle impact were affected by interest rate, time of final harvest, spatial aggregation of mortality, and distribution of mortality in relation to tree diameter and stand density. The model developed here simplified certain biological relationships. Its development highlighted the lack of quantitative data on biological factors affecting western pine beetle impact. Forest Sci. 32:325-338.
Temperature and Time in Storage Influence the Efficacy of Selected Isolates of Fungi in Commercially Produced Ectomycorrhizal Inoculum
Authors: Hung Ling-Ling L. , Molina Randy
Published: April 2024

Eight isolates of three ectomycorrhizal fungi were tested for effect of inoculum storage on mycorrhiza formation with Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. Factors tested were inoculation rate (from 1:256 to 1:4), storage temperature (2°C vs. 21°C), and storage time (up to 1 year). Initial growth chamber tests showed that fresh inocula of the three available isolates of Laccaria laccata (Scop.:Fr.) Berk. and Br. and the one isolate of Hebeloma crustuliniforme (Bull.) Quel. formed abundant mycorrhizae (>76.3 percent of the feeder roots) with container-grown Douglas-fir seedlings. However, only one of the four available isolates of Pisolithus tinctorius (Pers.) Coker and Couch was effective.

In general, fresh inocula of L. laccata and H. crustuliniforme were the most effective; their effectiveness remained high for a month of storage, then declined rapidly for a short period, then slowly to the point of no mycorrhiza formation. The effectiveness declined more rapidly with lower inoculation rates. Storage at 2°C prolonged inoculum viability for at least 2 months over that of 21°C storage. Inoculum from different fungal species or isolates within a species responded to storage temperature differently. P. tinctorius inoculum was the most sensitive: one-month storage strongly reduced its effectiveness. The difference between 2°C and 21°C storage was more obvious in H. crustuliniforme than in either isolate of L. laccata. Forest Sci. 32:534-545.
Effect of Family and Nitrogen Fertilizer on Growth and Foliar Nutrients of Douglas-fir Saplings
Authors: DeBell Dean S. , Silen Roy R. , Radwan M. A. , Mandel Nancy L.
Published: April 2024

Family x fertilizer-interactions were evaluated in a split-plot experiment involving 12 open-pollinated families of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). The fertilizer treatment was applied when trees were 12 years of age, and response was measured as cumulative volume growth during the next 4 years. Volume growth varied among families and was increased by an average of 7 percent by application of 224 kg ha-1 N as urea. Foliar concentrations of some nutrients also differed significantly (P ≤ 0.05) among families and between fertilizer treatments. The family x fertilizer interaction was not significant for any growth or foliar nutrient variable. Forest Sci. 32:643-652.
A Matrix Model of Oak-Hickory Stand Management and Valuing Forest Land
Authors: Michie B. R. , McCandless F. D.
Published: April 2024

A matrix model of oak-hickory stands is developed for analyzing the economics of naturally regenerated even-aged hardwood forests. Linear programming is used to evaluate two oak-hickory stands. The model addresses the inherent differences between the management of naturally regenerated forests with traditional plantation management. The value of liquidating a stand in one harvest is compared with liquidation in two harvests. The value of maintaining an oak-hickory stand in even-aged management forever is determined for existing stands by calculating the present value of two variable harvests plus an infinite series of identical rotations (each consisting of two harvests) thereafter. The first harvest may be either a preparation cut or a regeneration cut depending on the condition of the existing stand. A preparation cut opens the stand to encourage the establishment of natural regeneration. A regeneration cut releases the regeneration encouraged by the preparation cut. Forest Sci. 32:759-768.
Intermediate Inputs and the Estimation of Technical Change: The Lumber and Wood Products Industry
Authors: Bengston David N. , Strees Anne
Published: April 2024

Previous studies estimating the rate of technical change in the forest products industries have assumed an industry production function in which output is measured as value-added. In the value-added model, intermediate inputs—such as stumpage and energy—are not treated symmetrically with capital and labor inputs. The value-added model places unnecessary restrictions on the production process and producer behavior, and rules out changes in the forest resource and other intermediate inputs as a source of technical change. This note examines the measurement of technical change in the U.S. lumber and wood products industry by empirically comparing the value-added model of production with a gross output model that explicitly includes intermediate inputs in the production process. It is shown that the rates of technical change estimated from the two models diverge sharply. Implications for future research are discussed in a concluding section. Forest Sci. 32:1078-1085.
Evaluating Forest Vegetative Cover with Computerized Analysis of Fisheye Photographs
Authors: Chan S. S. , McCreight R. W. , Walstad J. D. , Spies T. A.
Published: April 2024

A versatile, computerized system for expediting analysis of fisheye photos of forest and shrub canopy conditions was developed and refined. The materials necessary for taking and analyzing fisheye photos are readily available and the methods easily learned. Although the equipment required (camera, fisheye lens, microcomputer, and related accessories) has a relatively high fixed cost, the efficiency and accuracy gained may justify implementing the system, particularly if large numbers of photos must be processed. Computerized fisheye photographic analysis is a practical tool for assessing and documenting forest vegetative cover and its implications for the radiation environment of understory plants. Forest Sci. 32:1085-1091.
Butt-Log Profile Equations
Authors: Bruce David
Published: April 2024

Several mathematical models were developed that describe the shape of butt logs and can be used to calculate their volumes. Three methods of developing profile equations were tested. The best method was to use the differentials of the individual terms of an unbiased volume estimator plus information about log shape to form the equation. The equation was then conditioned so that its volume estimates were compatible with the estimator. Several techniques for developing profile equations are described. Two potentially useful butt-log profile equations are derived. For. Sci. 33(1):104-115.
The Economic Efficiency of Forest Taxes
Authors: Gamponia Villamor , Mendelsohn Robert
Published: April 2024

The forest taxation literature has focused on measuring "tax burden," the present value of the difference between untaxed forest income and net after tax income. If, as many authors assume, taxes have no effect on forest management, this measure is always just the present value of the tax revenue collected. Although interesting, tax burden will often fail to measure whether one tax is more efficient than another. Excess burden, the present value of lost income from tax-induced distortions, is the appropriate measure of the relative efficiency of forest taxes. This paper measures one component of excess burden, the magnitude of the rotation age distortions caused by property and yield taxes. Collecting equivalent revenue, yield taxes actually do outperform property taxes but provide only a small quantitative advantage. For. Sci. 33(2):367-378.
Multiobjective Programming for Generating Alternatives: A Multiple-Use Planning Example
Authors: Mendoza Guillermo A. , Bare B. Bruce , Campbell Gene E.
Published: April 2024

This paper describes two related issues pertaining to the role of multiple objective programming (MOP) in complex forest planning problems. First, some implications of using inadequate MOP models in complex forest planning problems are described. Second, an alternative MOP approach--modeling to generate alternatives--is presented and illustrated using a multiple-use planning example. For. Sci. 33(2):458-468.
A Method for Estimating Log Grade Distribution in Sugar Maple
Authors: Reed David D. , Lyon Gary W. , Jones Elizabeth A.
Published: April 2024

A method is presented for estimating the distribution of gross board foot volume by log grade in sugar maple. Posterior probability expressions from linear discriminate analysis are used to estimate the expected proportion of a tree's total volume falling into each log grade class. The method is illustrated using data from sugar maple stands in northern Michigan. These results have been incorporated into a stand table projection system which takes quality development as well as biological growth into account. For. Sci. 33(2):565-569.
Determinants of Reforestation Behavior Among Southern Landowners
Authors: Royer Jack P.
Published: April 2024

Accurate models of reforestation behavior are important to projecting the nation's softwood timber supplies and deciding on appropriate public responses, if any, to encourage tree planting. Logistical regression models of the reforestation behavior of southern landowners show the probability of actively regenerating pine on cutover timberlands to be a function of market and policy influences, provided the landowners are in a financial position to consider investments, are not constrained by competing land management objectives, and are informed about reforestation opportunities. Land-owners are most sensitive to reforestation costs, cost-sharing, income limitations, and technical assistance. For. Sci. 33(3):654-667.
Jackknife and Bootstrap Estimation for Sampling with Partial Replacement
Authors: Schreuder H. T. , Li H. G. , Scott C. T.
Published: April 2024

Jackknife and bootstrap estimators and variance estimators were compared with a classical estimator and variance estimator for sampling with partial replacement (SPR) on two occasions. One hundred twenty plots were sampled at time 1. At time 2, 10, 20, or 30 plots were remeasured, and a new sample size of size 20 was also selected. The samples were drawn from three large samples of forest plots from the northeastern United States, which were treated as populations. Although variables are correlated on the two occasions (r = 0.648 - 0.891), the assumptions of linearity and homogeneity of variance are questionable.

The classical estimator is generally preferable to the jackknife and bootstrap estimators when both estimation bias and efficiency are important in SPR sampling. The jackknife variance estimator is generally preferable if variance estimation bias and confidence limit coverage rates are taken into consideration, particularly for skewed populations with small sample sizes. Generally, these jackknife variance estimates are less stable than the classical variance estimates. For. Sci. 33(3):676-689.
Water Relations and Leaf Morphology of Juniperus occidentalis in the Northern Great Basin
Authors: Miller Richard F. , Shultz Leila M.
Published: April 2024

Relationships between seasonal and diurnal leaf conductance, xylem sap potential, transpiration rates, osmotic potential, vapor pressure deficit, soil and air temperatures, soil water potential, and photosynthetic active radiation are quantified for Juniperus occidentalis Hook. Additionally, xeromorphic aspects of leaf morphology were examined with electron microscopy. Xylem sap potentials and leaf conductance ranged from -0.5 to -2.7 MPa and 0.02 to 0.13 cm s-1, respectively, during the two-year study. Leaf conductance is not clearly related to any single environmental variable, but is primarily influenced by vapor pressure deficit, photosynthetically active radiation, and factors such as soil and air temperatures, and soil water, which influence the resistance of water flow through the plant. Stomates usually closed when xylem sap potentials reached - 2.0 MPa. Stomates on mature leaves are distributed unequally on adaxial and abaxial surfaces, with none occurring on exposed surfaces. Drought avoidance mechanisms displayed by the plant were leaf morphological characteristics, low maximum leaf conductance, and reduced maximum leaf conductance under high evaporative conditions. Cold soil temperatures increased resistance of water flow through the soil-plant-atmosphere continuum. Xeromorphic leaf structure as well as seasonal osmotic adjustment provide primary mechanisms in the tolerance of Juniperus occidentalis to drought stress. For. Sci. 33(3):690-706.
Genetic Improvement Effects on Growth and Yield of Loblolly Pine Plantations
Authors: Buford Marilyn A. , Burkhart Harold E.
Published: April 2024

A series of hypotheses concerning stand dynamics and growth patterns in loblolly pine plantations of improved stock relative to plantations of unimproved stock were developed and tested. Results of these tests indicated that at the seed source and family levels: (1) the shape of the height-age curve is influenced by the site, but the level of the height-age curve is influenced by the seed source or family; (2) at the seed source and family levels, the shape of the height-diameter relationship at a given age is influenced by the site and by the initial density; and (3) the level of the height-diameter relationship is affected by the seed source or family and is directly related to the dominant height of the seed source or family at that age. Indications are that by choosing the height curve carefully, differences in development among seed sources and families on a given site can be modeled by altering the level of the height-age curve. Data from temporary plots in stands planted operationally with genetically improved stock were used to test for differences in stem quality and volume relationships as compared to comparable plots from unimproved plantations. Stem quality in the improved stands was not substantially different than in unimproved stands in the same region and of the same age range. There was no difference in stem taper or individual tree volume between improved and unimproved stock. Yield equations, based on the independent variables age, average height of dominants and codominants, and surviving number of trees, were fitted to these same plot data from operationally planted improved and unimproved stands. There were no significant differences in the yield equations, indicating that a single yield equation should suffice when the independent variables are correctly specified. For. Sci. 33(3):707-724.
The Impact of Site Value Taxation on the Optimal Time To Cut Timber when Borrowing and Lending Rates Diverge
Authors: Merz Thomas E.
Published: April 2024

The economic literature on forest taxation concludes that the timber cutting time is independent of changes in a site value tax, assuming such changes are fully capitalized into the market value of land. Adopting a continuous-time theoretical model that incorporates an imperfect capital market, it is demonstrated why empirical evidence might reject this hypothesis of "fiscal neutrality." For. Sci. 33(3):763-766.
Ozone Uptake and Effects on Transpiration, Net Photosynthesis, and Dark Respiration in Scots Pine
Authors: Skärby Lena , Troeng Erik , Boström Curt-Åke
Published: April 2024

Ozone uptake, transpiration, net photosynthesis, and dark respiration were studied in the field by using an open gas exchange system in a 20-year-old stand of Scots pine (Pinus sylvestris L.). A current shoot was treated with ozone concentrations ranging from 120 to 400 μg · m-3 during one month. During daytime there was a linear relationship between ozone concentration and ozone uptake, and the deposition rate varied between 0.05 and 0.13 cm · s-1. Ozone at the highest concentrations seemed to decrease transpiration somewhat during daytime. At night, ozone was taken up only at the highest concentration. Both transpiration and stomatal conductance increased at night when ozone concentration was 250 μg · m-3 and higher. There was no significant influence on the net photosynthetic performance during exposure to ozone. Dark respiration, however, increased throughout the experimental period, and the accumulated respiration was about 60% higher for the ozone-exposed shoot at the end of the experiment. For. Sci. 33(3):801-808.
Nitrogen Concentrations in Biomass Components of White Spruce Seedlings in Interior Alaska
Authors: Gordon Andrew M. , Van Cleve Keith
Published: April 2024

Nitrogen concentrations were determined for biomass components of white spruce (Picea glauca [Moench.] Voss) seedlings growing beneath a mature spruce stand and in adjacent cleared areas. Nitrogen concentrations were significantly higher in current needles and roots of seedlings from the clearcut areas. Nitrogen uptake into current needles of seedlings was also significantly increased by harvesting. Root/shoot data generally reflected the more abundant resources (light, water, nutrients) often found in cleared forest areas. There is a potential for using seedlings as a nutrient bioassay indicative of site nutrient regime. For. Sci. 33(4):1075-1080.
The Impact of Soil Degradation on the Expected Present Net Worth of Future Timber Harvests
Authors: Routledge R. D.
Published: April 2024

The standard Faustmann method for computing soil expectation values and economically optimal rotation times ignores potential declines in future soil productivity. In reality, common forestry practices can lead to substantial declines in soil productivity through such factors as soil compaction and nutrient losses. Adjustments to the Faustmann formulation that account for soil degradation are developed in this paper. A dynamic programming algorithm is developed, which permits the assessment of direct, long-term losses associated with destructive logging practices. Sample calculations of these losses demonstrate both the crucial impact of the discount rate and the limited role of projections for distant rotations. For. Sci. 33(4):823-834.
Estimating Genetic Parameters of Height Growth in Seven-Year Old Coastal Douglas-Fir from Disconnected Diallels
Authors: Yeh F. C. , Heaman J. C.
Published: April 2024

A disconnected diallel mating scheme was carried out on 10 sets of 6 parents each for coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco). After 7 growing seasons in 11 plantations, the total phenotypic variation in height was partitioned into portions of additive genetic effect (GCA) within sets, dominance genetic effect (SCA) within sets, interaction of plantations with additive and dominance genetic effects within sets, residual effect, and random error. The GCA effect of the parent trees within the sets was highly significant, and its variance was the most important genetic source of variation. The GCA by plantation interaction was large, and its variance was approximately 42% of the GCA variance. There were some striking rank changes among the parent trees within sets on different plantations, but such changes in the rank within the sets were confined primarily to those parents in the 18th to 82nd percentlie of the 7-year height distribution. The ranks of the top and the worst general combiners within the sets were generally consistent across the plantations. Effects owing to SCA of parent trees and SCA by plantation interaction were also significant, but their variances were small relative to the GCA variance. The heritability estimate appropriate for mass selection on 7-year height was 0.13. The results are discussed in relation to the gains to be expected from tree improvement for the species. For. Sci. 33(4):946-957.
Ontogenetic Patterns of CO2 Exchange of Quercus rubra L. Leaves During Three Flushes of Shoot Growth I. Median Flush Leaves
Authors: Hanson P. J. , Isebrands J. G. , Dickson R. E. , Dixon R. K.
Published: April 2024

Oak (Quercus) seedlings exhibit a pattern of shoot growth known to place demands on carbohydrate and nutrient reserves. This study was designed to determine ontogenetic patterns in CO2 exchange properties of red oak leaves, and to determine if individual leaf CO2 exchange rates (CER) increase in response to the assimilate demand placed on a seedling during flushing. Northern red oak (Q. rubra L.) seedlings were grown in environments favorable for multiple flushes of shoot growth. Measurements of CER on single, attached, median leaves from each flush were made over a range of photosynthetic photon flux densities on plants at nine stages of seedling development through three flushes of growth. Carbon dioxide exchange rate of red oak leaves increased during leaf development up to and beyond full leaf expansion before decreasing —an unusual pattern of photosynthesis during leaf ontogeny. Furthermore, first- and second-flush leaf CER initially decreased and then increased in conjunction with the third flush of shoot growth. These patterns indicate that red oak leaves have a capacity for CER adjustment in response to increased sink demand. For. Sci. 34(1):55-68.
Influence of Ceanothus velutinus and Associated Forbs on the Water Stress and Stemwood Production of Douglas-Fir
Authors: Petersen T. D. , Newton M. , Zedaker S. M.
Published: April 2024

Stem dimensions for two age groups of Douglas-fir growing in the central Cascade Mountains of western Oregon were related to water stress and the amount of interference from dense Ceanothus velutinus and forbs 8 years earlier. In 1978, three regimes were established in four 5-year-old and four 10-year-old stands by means of controls (no treatment) and two herbicide treatments to individual trees in each stand: a partial treatment (C. velutinus eliminated) and a complete treatment (both shrubs and forbs eliminated). In the subsequent year, soil water potential during late summer was < - 1.5 MPa at 10-, 40-, and 100-cm depths, where C. velutinus was growing with forbs. In the absence of shrubs and forbs, soil water potential at 100 cm was near field capacity throughout the 1979 growing season. Predawn stem water potential and Douglas-fir during late summer was significantly lower for trees competing with C. velutinus and forbs than for trees without competitors in the complete treatment, or for trees competing with forbs in the partial treatment, in the four 5-year-old stands and in two of the 10-year-old stands. By 1986, Douglas-fir stems were 2 to 6 cm larger in basal diameter and 1 to 2 m taller in the absence of competitors. Interference from C. velutinus and forbs had a greater effect on stem size of 5-year-old than 10-year-old trees. The correlation between growth and water stress suggests that interspecific competition for soil water during summer drought is a factor limiting stemwood production. For. Sci. 34(2):333-343.
Effects of Timber Harvest on Stream Chemistry and Dissolved Nutrient Losses in Northeast Oregon
Authors: Tiedemann Arthur R. , Quigley Thomas M. , Anderson Tom D.
Published: April 2024

Streamwater chemistry and nutrient inputs and outputs of four small (24 to 118 ha) catchments in the Blue Mountains of eastern Oregon were compared before and after timber harvest treatments. Three harvested watersheds were also compared to a control watershed. Treated watersheds included 41% clearcut in two large blocks; 17% clearcut in 0.8- to 2.4-ha patches; and selection harvest. Residues were piled and burned on the watersheds with clearcuts; on the selection harvest watershed, residues were yarded to an area off-site and burned. Chemical parameters and constitutents measured were: pH, electrical conductivity (EC), nitrate-N (NO3-N), dissolved Kjeldahl N (DKN), total dissolved PO4-P (TDP), calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K). Nitrate-N concentrations in streamflow increased in response to both clearcutting treatments. The maximum level observed (0.52 mg/l) was, however, far below the maximum allowable for drinking water standards (10 mg/l). Concentration of TDP increased significantly on the 41% clearcut watershed and small but significant increases in cation concentrations were observed with both clearcutting treatments. Outputs (kg · ha-t · yr-1) of N increased with both clearcutting treatments but losses were balanced by precipitation inputs. Cation outputs were not affected by harvest treatments. For. Sci. 34(2):344-358.
Dwarf Mistletoes on Western White Pine and Whitebark Pine in Northern California and Southern Oregon
Authors: Mathiasen Robert L. , Hawksworth Frank G.
Published: April 2024

Western white pine (Pinus monticola) is a principal host of Arceuthobium californicum in the Siskiyou Mountains of northern California and southern Oregon, and suffers extensive mortality in some stands. Whitebark pine (P. albicaulis) is a principal host and western white pine is a secondary host for A. cyanocarpum in northern California. Mortality of whitebark pine caused by this dwarf mistletoe on Mount Shasta, California, is as high as 58%. Western white pine is occasionally infected in A. tsugense-infested mountain hemlock stands in California and southern Oregon. However, no infection of western white pine occurred in A. tsugense-infested western hemlock stands in southern Oregon, indicating there are physiologically distinct races of A. tsugense parasitizing western hemlock and mountain hemlock. For. Sci. 34(2):429-440.
Measuring Foliar Flammability with the Limiting Oxygen Index Method
Authors: Mak Edwin H. T.
Published: April 2024

This paper stresses the importance of measuring flammability as a combination of ignitability, sustainability, and combustibility in quantitative terms. The Limiting Oxygen Index (LOI) method is selected and evaluated as a means to measure ignitability and sustainability. The results demonstrated that the technique can distinguish small differences in ignitability and sustainability with good precision. This can be useful for assessing the influence of foliage properties such as chemical composition on these two flammability components. The third component of flammability, combustibility, has to be measured by a different technique. For. Sci. 34(2):523-529.
Effects of Crown Expansion into Gaps on Evaluation of Disturbance Intensity in Northern Hardwood Forests
Authors: Frelich Lee E. , Martin George L.
Published: April 2024

Crown encroachment by trees surrounding newly formed gaps reduces their size, a fact that may cause error in area-based analyses of rate of gap formation and disturbance intensity. Generally, an estimate of proportional area occupied by age classes within a stand of trees can be obtained by determining the age of a selected canopy tree nearby each of randomly or uniformly located sample points. Possible methods of selecting nearby canopy trees include: (1) the nearest-tree selection method, in which the canopy tree with its stem closest to the sample point is chosen; and (2) the overhead-crown selection method, in which the canopy tree whose crown is directly above the sample point is chosen. These two methods of selecting sample trees differ greatly in their sensitivity to crown encroachment. In sugar maple stands, the nearest-tree selection method leads to better estimates of the area originally occupied by a cohort of trees. The overhead-crown selection method leads to an unbiased estimate of area currently occupied by a cohort. For. Sci. 34:(2):530-536.
On the Economic Value of Genetic Progress in Forestry
Authors: Löfgren Karl-Gustaf
Published: April 2024

This paper extends previous analyses of the economics of tree improvement by introducing a number of general theorems on the properties of the present value function as a function of biotechnological parameters. More specifically it is shown how the economic gains from the improvement can be given upper and lower bounds, which to a certain extent are expressable in entities known from current management practices.

The general theorems are derived from a model of a present value maximizing forestry firm with an initial endowment consisting of trees in different age classes, which is facing a competitive environment. However, since certain types of improvements are more easily handled at the stand level, a special section is devoted to the economics of genetic progress at the stand level.

The core results show that straightforward calculation methods often have theoretical support. An empirical application at the end of the paper also shows that the theory has practical implications. For. Sci. 34(3):708-723.
Hazard Rating Forest Sites for Pine Tip Moth, Rhyacionia spp., in the Upper Piedmont Plateau
Authors: Hood W. Michael , Hedden Roy L. , Berisford C. Wayne
Published: April 2024

Hazard rating models for pine tip moths (Rhyacionia spp.) were developed from vegetative, physiographic, and other site characteristics of loblolly pine (Pinus taeda L.) stands in the upper Piedmont of South Carolina. Results of regression models show that site preparation intensity, site index, soil calcium, and depth of the "A" horizon are the most important predictors of tip moth infestation levels. For management of loblolly pine, minimum site preparation and forest practices that favor high site quality will reduce the hazard of tip moth. The severity of tip moth damage to loblolly pine stands is inversely related to site quality and positively related to the intensity of site preparation. For. Sci. 34(4): 1083-1093.
Mathematical Analysis and Modeling of Epidemics of Rubber Tree Root Diseases: Probability of Infection of an Individual Tree
Authors: Chadoeuf J. , Joannes H. , Nandris D. , Pierrat J. C.
Published: April 2024

The spread of root diseases in rubber tree (Hevea brasiliensis) due to Rigidoporus lignosus and Phellinus noxius was investigated epidemiologically using data collected every 6 months during a 6-year survey in a plantation. The aim of the present study is to see what factors could predict whether a given tree would be infested at the following inspection. Using a qualitative regression method we expressed the probability of pathogenic attack on a tree in terms of three factors: the state of health of the surrounding trees, the method used to clear the forest prior to planting, and evolution with time. The effects of each factor were ranked, and the roles of the various classes of neighbors were established and quantified. Variability between successive inspections was small, and the method of forest clearing was important only while primary inocula in the soil were still infectious. The state of health of the immediate neighbors was most significant; more distant neighbors in the same row had some effect; interrow spread was extremely rare. This investigation dealt only with trees as individuals, and further study of the interrelationships of groups of trees is needed. For. Sci. 34(4):831-845.
Stochastic Representation of Fire Occurrence in a Wildland Fire Protection Planning Model for California
Authors: Fried J. S. , Gilless J. K.
Published: April 2024

A fire occurrence module was developed for CFES-IAM Version 2, a stochastic simulation model of initial attack on wildfires in California. The module is designed to generate annual sequences of fire start times that are consistent with local fire history. A three-stage approach was employed: (1) For each day of a simulated fire season, a random draw from a Bernoulli distribution is used to determine if any fires occur; (2) if any do occur, a random draw from a geometric multiplicity distribution determines theft number; (3) ignition times for each fire are then randomly drawn from a time of day (beta or Poisson) distribution. This approach and specific distributional forms were selected after analysis of historical fire records from California's Sierra foothills and Central Valley. Fire sequences generated with the module appear to capture historical patterns with respect to diurnal distribution, interfire times, and total number of fires per year. For. Sci. 34(4):948-959.