bluuebunny/crossref_metadata_2025 huggingface dataset:
Cretaceous chloranthoids: early prominence, extinct diversity and missing links
Authors: Friis Else Marie , Crane Peter R , Pedersen Kaj Raunsgaard , Marone Federica
Published: April 2024

Background

The Chloranthaceae comprise four extant genera (Hedyosmum, Ascarina, Chloranthus and Sarcandra), all with simple flowers. Molecular phylogenetics indicates that the Chloranthaceae diverged very early in angiosperm evolution, although how they are related to eudicots, magnoliids, monocots and Ceratophyllum is uncertain. Fossil pollen similar to that of Ascarina and Hedyosmum has long been recognized in the Early Cretaceous, but over the last four decades evidence of extinct Chloranthaceae based on other types of fossils has expanded dramatically and contributes significantly to understanding the evolution of the family.

Scope

Studies of fossils from the Cretaceous, especially mesofossils of Early Cretaceous age from Portugal and eastern North America, recognized diverse flowers, fruits, seeds, staminate inflorescences and stamens of extinct chloranthoids. These early chloranthoids include forms related to extant Hedyosmum and also to the Ascarina, Chloranthus and Sarcandra clade. In the Late Cretaceous there are several occurrences of distinctive fossil androecia related to extant Chloranthus. The rich and still expanding Cretaceous record of Chloranthaceae contrasts with a very sparse Cenozoic record, emphasizing that the four extant genera are likely to be relictual, although speciation within the genera might have occurred in relatively recent times. In this study, we describe three new genera of Early Cretaceous chloranthoids and summarize current knowledge on the extinct diversity of the group.

Conclusions

The evolutionary lineage that includes extant Chloranthaceae is diverse and abundantly represented in Early Cretaceous mesofossil floras that provide some of the earliest evidence of angiosperm reproductive structures. Extinct chloranthoids, some of which are clearly in the Chloranthaceae crown group, fill some of the morphological gaps that currently separate the extant genera, help to illuminate how some of the unusual features of extant Chloranthaceae evolved and suggest that Chloranthaceae are of disproportionate importance for a more refined understanding of ecology and phylogeny of early angiosperm diversification.
Cognitive, Sleep-Arousal, Physical, and Affective Domain Scores on the Post-Concussion Symptom Scale: Added Utility in Detecting Symptom Elevations among Student-Athletes with a Remote History of Concussion
Authors: Karr Justin E , Zuccato Brandon G , Ingram Eric O , Considine Ciaran M , Merker Bradley , Abeare Christopher A
Published: April 2024

Objective

The evaluation of self-reported symptoms is a standard component of concussion assessment and management. Clinicians typically evaluate a total symptom severity score rather than scores corresponding to specific symptom domains (i.e., cognitive, sleep-arousal, physical, and affective symptoms). This study examined (i) whether elevations in specific symptom domains would be missed when interpreting only the total symptom severity score and (ii) if a single symptom domain elevation was more common than having elevated symptoms across multiple domains.

Method

Adolescent student-athletes (N = 1,008) with concussion history (i.e., ≥6 months since last concussion) completed the Post-Concussion Symptom Scale (PCSS). The PCSS total score and cognitive, sleep-arousal, physical, and affective domain scores were calculated. To determine if symptoms were elevated, scores were compared to normative data matched on gender and pre-existing conditions, with scores considered elevated if they were ≥84th percentile. The frequency of total and domain score elevations were calculated and stratified by gender and number of prior concussions (i.e., 1 or ≥2 prior concussions).

Results

Overall, 26% of student-athletes had an elevated symptom domain score without being elevated on the total score. The most common symptom presentation was to have a single elevated symptom domain (21%), followed by two (11%), three (8%), or four elevated domains (6%).

Conclusions

Interpreting PCSS symptom domains may be beneficial in detecting student-athletes with elevated symptoms following a remote concussion. Roughly a quarter of student-athletes have domain-specific symptom elevations that would be missed by interpreting the total score alone.
Multinuclear coordination compounds constructed by bis-imidazole and azide ligands. Creation of new network structures and an M2L4 cage that includes two anions
Authors: Koike Shiori , Yamanishi Katsunori , Watanabe Kanoko , Takemoto Hiroyuki , Kondo Mitsuru
Published: April 2024

Treatment of the bis-imidazole ligand, bitb, with CuSO4·5H2O, ZnSO4·7H2O, and Co(NO3)2·6H2O in the presence of NaN3 produced [Cu2(μ-N3)2(bitb)(N3)2]n (1), [Zn(bitb)(N3)2]n (2), and [(N3)2 ⊂ Co2(bitb)4(N3)2](Me2CO)2·(H2O)4 (3). Compound 1 is a 2D coordination polymer with {Cu2(μ-N3)2}n chains in the framework. Compound 2 is a 1D coordination polymer with repetitions of the “figure-of-eight-shaped” turns. Compound 3 is an M2L4 cage compound that includes 2 N3− in the cage. Their unprecedented coordination structures are described.
Executive Summary: State-of-the-Art Review: Unintended Consequences: Risk of Opportunistic Infections Associated with Long-term Glucocorticoid Therapies in Adults
Authors: Chastain Daniel B , Spradlin Megan , Ahmad Hiba , Henao-Martínez Andrés F
Published: April 2024

Glucocorticoid-induced immunosuppression is linked to the dose, duration, and intensity, but the dose-dependent model may inaccurately predict the risk of opportunistic infections. We discuss details of glucocorticoid treatments to determine their effect on immune function and risk of opportunistic infections.
Repair of complex transposition of great arteries: What is the best technique to avoid outflow tract obstructions?
Authors: Weixler Viktoria , Gaal Julia , Murin Peter , Kramer Peter , Romanchenko Olga , Cho Mi-Young , Schmitt Katharina , Ovroutski Stanislav , Photiadis Joachim
Published: April 2024

OBJECTIVES

This study aimed to evaluate the short-/mid-term outcome of patients with complex dextro (d)-/levo (l)-transposition of the great arteries (TGA), ventricular septal defect and left ventricular outflow tract obstructions.

METHODS

A single-centre, retrospective review of all complex dextro-TGA (n = 85) and levo-TGA (n = 22) patients undergoing different surgeries [Arterial switch operation + left ventricular outflow tract obstruction-resection (ASO-R), half-turned truncal switch/Mair (HTTS), Nikaidoh and Rastelli] between May 1990 and September 2022 was performed. Groups were analysed using Kruskal–Wallis test with post hoc pairwise comparison and Kaplan–Meier time-to-event models.

RESULTS

A total of 107 patients [ASO-R (n = 20), HTTS (n = 23), Nikaidoh (n = 21), Rastelli (n = 43)] were included, with a median age of 1.0 year (0.5–2.5) and surgical repair median follow-up was 3.8 years (0.3–10.5). Groups did not differ in respect to early postoperative complications/early mortality. Five-year overall survival curves were comparable: ASO-R 78.9% (53.2–91.5), HTTS 75.3% (46.8–89.9), Nikaidoh 85% (60.4–94.9) and Rastelli 83.9% (67.5–92.5), P = 0.9. Highest rates of right ventricular outflow tract (RVOT) reinterventions [33.3% and 32.6% (P = 0.04)] and reoperations [28.6% and 32.6% (P = 0.02)] occurred after Nikaidoh and Rastelli procedures. However, overall freedom from RVOT reinterventions and RVOT reoperations at 5 years did not differ statistically significantly between the groups (ASO-R, HTTS, Nikaidoh and Rastelli): 94.4% (66.6–99.2), 69.1% (25.4–90.5), 67.8% (34–86.9), 64.4% (44.6–78.7), P = 0.2, and 90.0% (65.6–97.4), 91% (50.8–98.7), 65.3% (32.0–85.3) and 67.0% (47.4–80.6), P = 0.3.

CONCLUSIONS

Surgical repair of complex dextro-/levo-TGA can be performed with satisfying early/mid-term survival. RVOT reinterventions/reoperations were frequent, with highest rates after Nikaidoh and Rastelli procedures. Left ventricular outflow tract obstruction reoperations were rare with zero events after Nikaidoh and HTTS procedures.
Identifying Woodland Owner Characteristics Associated with Timber Management
Authors: Greene John L. , Blatner Keith A.
Published: April 2024

Discriminant analysis of 47 variables from a questionnaire mailed to 3,200 randomly selected woodland owners in Arkansas yielded models for the combined Ozark-Ouachita and Coastal Plain regions of the state that were nearly 80 percent successful in differentiating between timber managers and nonmanagers. Simpler field-use models, developed from a subset of 17 variables that can be determined prior to contacting an owner, averaged over 70 percent successful in classifying owners. Contact with a forester, the owner being a farmer, and the owner being well-educated were associated with timber management in models for both regions, as were variables related to large woodland size and some nontimber objectives of ownership. Forest Sci. 32:135-146.
Merchantability of Loblolly Pine—An Application of Nonlinear Regression with a Discrete Dependent Variable
Authors: Strub Mike R. , Green Edwin J. , Burkhart Harold E. , Pirie Walter R.
Published: April 2024

A model to predict the probability of merchantability for an individual loblolly pine tree is developed. The model would be a useful addition to diameter distribution-based yield models. As the dependent variable is discrete and bounded by [0, 1], the model is constrained to yield predictions in this interval. Graphical techniques were used to screen potential independent variables, and maximum likelihood was used to estimate the model parameters. Forest Sci. 32:254-261.
The Scenic Beauty Temporal Distribution Method: An Attempt to Make Scenic Beauty Assessments Compatible with Forest Planning Efforts
Authors: Hull R. Bruce , Buhyoff Gregory J.
Published: April 2024

A method was developed which simulates and evaluates scenic beauty through time with the intent of providing useful information for forest management and planning efforts. It is argued that temporal based scenic information is essential given the dynamic nature of forest management and planning. Temporal distributions of scenic beauty, which represent the level of scenic beauty at each year during the planning horizon, were simulated in order to evaluate the scenic impacts of proposed management actions. Four general loblolly pine stand management practices (unthinned natural, unthinned planted, lightly thinned planted, and heavily thinned planted) were compared with respect to their impacts on scenic beauty. Overall, natural stands were of highest scenic quality followed by unthinned planted and heavily thinned planted stands, which were not significantly different from one another. The lightly thinned stands were least scenic. These findings are consistent with results of past research. Also examined were the scenic impacts of management actions such as rotation age and initial density. In general, decreasing stand density increases scenic beauty, less productive sites have more scenic beauty, and increasing stand age increases scenic beauty. Information about initial stand conditions was found highly predictive of how scenic beauty temporal distributions perform over a 50-year horizon. It was concluded that the scenic beauty temporal distribution method provides managerially relevant information and has the potential to be a useful forest management decision-making tool. Forest Sci. 32:271-286.
Soil Nutrient Flux: A Component of Nutrient Cycling in Temperate Forest Ecosystems
Authors: Peterson David L. , Hammer R. David
Published: April 2024

Extractable nutrient levels in a floodplain forest soil varied significantly over the course of a year. Temporal variation in nutrient pools expressed as the ratio range/mean was in the following order: NH4-N > NO3-N » extractable P > exchangeable K > exchangeable Mg > exchangeable Ca. Lowest concentrations occurred during the summer months for all nutrients except NO3-N. The magnitude of this variation exceeded the size of several other nutrient fluxes within the ecosystem, which indicated that the soil system was a dynamic component of the floodplain forest ecosystem. Considerable evidence from diverse soil and vegetation types suggests that temporal variation in soil nutrient levels is a feature common to most temperate forest ecosystems. Forest Sci. 32:318-324.
Input/Output Models and Forest Resource Constraints: A Comment
Authors: Vincent Jeffrey R.
Published: April 2024

Input/output (I/O) analysis has been used to study regional impacts of timber supply increases. Two types of I/O models exist, the conventional demand-driven model and the more obscure supply-driven model. Contrary to a suggestion by Schallau and Maki (1983), results of these two models cannot be compared to gain useful information about different types (endogenous or exogenous) of public timber supply changes. This is demonstrated by a simple example in which a timber supply increase of the same type (that is, endogenous or exogenous) is used to drive each model. Quite different results are obtained, due to the diametrically opposed assumptions of the two models. When comparing endogenous and exogenous changes, analysts should make an ex ante choice between the two models, not use them both; some guidelines for making this choice are suggested. Forest Sci. 32:397-401.
Volume Growth Estimation From Permanent Horizontal Points
Authors: Van Deusen Paul C. , Dell Tommy R. , Thomas Charles E.
Published: April 2024

Net change in volume (V) from time 1 to time 2 can be attributed to the components of ingrowth (I), survivor growth (S), mortality (M), and cut (C) (Beers 1962) as follows: V2 - V1 = I + S - M - C. Traditional point sampling methods for estimating the right-side growth components often lead to an inequality with the left-side estimate of net change. This paper shows concisely why this occurs. A new estimator for survivor growth is developed which ensures equality between estimates of net change and the components thereof. Forest Sci. 32:415-422.
Taxonomic Implications of Monoterpene Compounds of Blue and Engelmann Spruces
Authors: Schaefer Peter R. , Hanover James W.
Published: April 2024

The monoterpenes of cortical oleoresin collected from mature blue and Engelmann spruce have significant diagnostic potential in taxonomic studies of these species, while seedling cortical monoterpenes appear to be less useful.

Cortical monoterpene compounds were analyzed in 38 blue and 13 Engelmann spruce in the Scotch Creek drainage in southwestern Colorado, and in their 6-months-old progeny. The objective was to explore the utility of monoterpenes in studying natural hybridization between the two species. Twenty-two compounds were detected in the cortical oleoresin of mature trees, twelve of which were identified. Species differences were generally quantitative, with most statistically significant. Blue spruce oleoresin contained higher levels of tricyclene, alpha-pinene, camphene, and bornyl acetate, while Engelmann spruce oleoresin contained higher levels of beta-pinene, 3-carene, terpinolene, and several unknown compounds. Monoterpene content of seedlings differed appreciably from that of mature parents. The large increase in beta-pinene in Engelmann spruce seedlings was the most striking. A discriminant function analysis of mature tree data distinguished between blue and Engelmann spruce with no misclassifications. Forest Sci. 32:725-734.
Height-Diameter Relationships at Age 15 in Loblolly Pine Seed Sources
Authors: Buford M. A.
Published: April 2024

Data from nine locations not thinned by age 15 of the loblolly phase of the Southwide Pine Seed Source Study were analyzed to determine the effect of seed source on the shape and level of the height-diameter curves. Seed source affected the shape of the height-diameter curve at only one of the nine locations. Six of the nine locations showed a seed source effect on the level of the height-diameter regression. Seed source differences in height-diameter relationships can be integrated into growth and yield models by modifying the level of the height-diameter curve to reflect dominant height without altering the basic shape of the curve for a given site. Suggestions for further study are given. Forest Sci. 32:812-818.
Clonal and Annual Variation in Cone Production in Loblolly Pine Seed Orchards
Authors: Byram T. D. , Lowe W. J. , McGriff J. A.
Published: April 2024

Monitoring two loblolly pine (Pinus taeda L.) orchards for several years indicated that cone production was under moderate genetic control (broad-sense heritability estimates of 0.35 and 0.40). Early in the life of these orchards a few clones contributed most of the cone crop. This percentage was reduced as the orchards matured until approximately 60% of the clones were required to produce 90% of the cone crop. Even then, clones frequently changed rank from year to year. There was no relationship between a clone's cone production in a seed orchard and its performance in progeny tests. Forest Sci. 32:1067–1073.
Market Value of Timber When Some Offerings Are Not Sold: Implications for Appraisal and Demand Analysis
Authors: Huang F. Mey , Buongiorno J.
Published: April 2024

A model of market value was developed for tracts of timber sold at auction for a minimum appraised value, when a substantial number of the tracts offered do not receive a bid. In this model, market value is a function of the characteristics of the timber and of market conditions, but market value is observed and equal to the high bid only if it is greater than the appraised value. This tobit model leads to the probability of selling a tract of given characteristics, conditional on a certain appraised value. Symmetrically, the model yields the appraised value that ensures a certain probability of selling. The expected high bid, conditional or unconditional on the occurrence of a sale, can also be computed. When this is done for all tracts offered and for various probability targets, a schedule of expected volume sold against expected price is obtained that corresponds to the aggregate demand for timber from the forest of interest. The model was estimated by maximum likelihood with data from the Chequamegon National Forest (WI) from 1976 to 1980. Variables influencing market value were: volume and quality of timber, hauling distance, hardwood lumber price, and whether the sale was a salvage operation. The corresponding parameters were used to predict the effect of setting appraised values that would have sold 95, 75, or 65% of the tracts offered for sale on the Chequamegon in 1981 and 1982. The results led to an estimate of the price elasticity of the demand for timber from that forest of -1.56. Forest Sci. 32:845-854.
A Test of Six Methods for Estimating True Heights from Stem Analysis Data
Authors: Dyer Michael E. , Bailey Robert L.
Published: April 2024

Six published or proposed methods of estimating the height corresponding to a given age with sectioned-tree stem analysis data were compared using actual heights at known ages for 28 loblolly pine trees. The most accurate was Carmean's (1972) method, which assumes that height growth is constant for each year contained within a bolt and that each crosscut occurs in the middle of a year's growth. Methods proposed by Lenhart (1972) and by Newberry (1978) were less accurate but probably acceptable. These three methods produce data that, when used to fit a nonlinear height-age model with Richards' (1959) equation, gave more than 80% overlap in the asymptotic 95% confidence intervals of the parameter estimates. Resulting height-age curves were nearly coincident for these three methods. For. Sci. 33(1):3-13.
Cost Sharing in Multiple Use Forestry: A Game Theoretic Approach
Authors: Rideout Doug , Hof John
Published: April 2024

Game theory is applied to the problem of joint cost allocation in forest management. The theory is used to define bounds (limits) to cost allocations. These traditional bounds are further defined in the context of potentially relevant benefit information to arrive at "benefit-included" bounds. These benefit-included bounds are consistent with both game theory and the early water resources principles that were based on cost separability. The traditional bounds and the benefit-included bounds are applied to a multipurpose forestry case study. The application is facilitated using the "nucleolus" cost allocation technique. The nucleolus provides a unique allocation that does not breach the bounds. The previously obscure calculation procedure of the nucleolus is clarified by example. For. Sci. 33(1):81-88.
Chaparral Conversion to Increase Streamflow in Arizona: Sequential Treatments Extend Duration of Nitrate Loss to Stream Water
Authors: Davis Edwin A.
Published: April 2024

Converting an Arizona chaparral watershed to grass cover in two stages by means of herbicide treatments increased stream flow and the concentration of nitrate ions in the stream water. Nitrate rose to remarkably high concentrations (83 ppm) and was exported from the watershed in extraordinary amounts (up to 143 kg/ha/yr) in comparison with a control watershed (1.0 kg/ha/yr). Abnormal concentrations of nitrate in streamflow persisted for more years from the two-stage treated watershed than from a companion watershed converted in one stage. Monthly mean weighted nitrate concentrations fluctuated in an annual cyclic pattern that closely corresponded with major rainfall events and the annual stream discharge cycle, which peaked during the winter rainy season. A possible consequence of such large releases of nitrate ions into stream water is eutrophication of downstream watercourses and reservoirs. In planning for chaparral conversions to enhance water yield, forage production, and wildlife habitat, consideration should be given to the nitrate-release phenomenon associated with conversion to reduce possible adverse environmental impacts. For. Sci. 33(1):89-103.
Early Genetic Evaluation of Open-Pollinated Douglas-Fir Families
Authors: Riitters Kurt H. , Perry David A.
Published: April 2024

In a test of early genetic evaluation of the growth potential of 14 families of open-pollinated Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), measures of growth and phenology of seedlings grown in a coldframe were correlated with height of saplings in evaluation plantations at 9, 12, and 15 years. Fifteen-year height was most strongly correlated with measures of seedling budset (r = -0.57), height (r = 0.54), and branchiness (r = -0.53). Seedling growth and phenology values generally were poorly correlated with seed weight; however, seedling-sapling correlations were related to seedling-seed weight correlations. Seedling-sapling correlations improved with sapling age from 9 to 15 years. For. Sci. 33(2):577-582.
The Quantitative Description of Cable Yarder Settings—Parameters for the Triangular Setting with Apical Landing
Authors: Greulich Francis E.
Published: April 2024

The design and operation of an economically efficient timber harvesting system requires the effective characterization of the individual setting. Two contributions are made toward this objective. First, closed-form solutions for several well-established parameters of turn location, including average yarding distance and average yarding slope, are derived for triangular settings on uniform slope with an apical landing. These derivations are greatly facilitated by a new expected value formulation. Second, the new concept of an effective external boundary is presented with one possible definition of its measure for any setting. Closed-form solutions are then obtained for the effective external boundary and the average external yarding distance on any triangular setting with an apical landing. For. Sci. 33(3):603-616.
A Procedure to Evaluate Sampling Schemes for Improving Already Calibrated Models
Authors: Gertner George
Published: April 2024

A Bayesian procedure is presented for evaluating potential sampling schemes to update previously calibrated models. Consideration can be given to biological restrictions on the range measurement interval of variables. The criterion used to evaluate the schemes is the mean variance of prediction in the response region where the model will be used. Two examples of sampling schemes for improving existing forest growth models are assessed. For. Sci. 33(3):632-643.
Economic Harvesting of Uneven-Aged Northern Hardwood Stands Under Risk: A Markovian Decision Model
Authors: Kaya Ismail , Buongiorno Joseph
Published: April 2024

A method is presented to determine economic harvesting policies for northern hardwood stands, taking into account uncertain stand growth and prices. The method used a transition matrix giving the probability of a stand and market state in five years, given the current stand and market state. Stand states were defined by the basal area of trees in three timber sizes. Market states were defined by timber price levels. The transition probabilities were computed by simulation, using a stochastic model of northern hardwoods and the probability distribution of prices in Wisconsin. A method of successive approximations was used to find the harvesting policy that would maximize the expected net discounted value of returns from a stand over an infinite horizon. The solution also gave the expected stand value, including land. The best management policy prescribed a specific harvest for each possible stand and market state. A sensitivity analysis was done of the effects of changes in discount rate, fixed costs, and transition probabilities on the best policy and the expected cutting cycle. For. Sci. 33(4):889-907.
Ecological Implications of Loblolly Pine Regeneration for Small Mammal Communities
Authors: Mengak Michael T. , Guynn David C. , Van Lear David H.
Published: April 2024

Loblolly stands regenerated by the seed tree method (natural regeneration) and loblolly plantations were compared for differences in habitat and small mammal populations. Measurements were taken on 20 habitat variables that characterized the understory vegetation and gross habitat structure of each stand. Small mammals were collected by removal trapping during 1984 and 1985. Capture rates, expressed as the number of animals caught per 100 trap nights (TN), were higher in natural stands than in plantations overall and in 4 of 5 trap sessions. However, differences were not significant. The logarithm of capture rate was linearly related to age with a negative slope for each regeneration method, but was not statistically different between methods. Animal capture rates were correlated with habitat variables that declined with age. Changes in the trophic structure of the small mammal community are discussed. When sites are prepared by chopping and burning, small mammal populations respond similarly for both natural and artificial regeneration methods. For. Sci. 35(2):503-514.
Expert Opinion Estimation of Fireline Production Rates
Authors: Fried Jeremy S. , Gilless J. Keith
Published: April 2024

An expert opinion survey of wildland firefighters (engine captains, handcrew bosses, and dozer operators) was used to obtain estimates of fireline production rates for use in stochastic simulations of initial attack on wildland fires. The survey design was inspired by the probabilistic PERT/CPM technique of expressing the time required to complete a given activity as a beta distribution. This design proved intelligible to firefighters, cost-effective, and caused minimal disruption of normal firefighting activities. The survey produced useable information quickly. Comparisons of the results with production rates reported in prior studies indicate that the latter are quite optimistic. Production rates appear to be strongly influenced by variations in topography and vegetation that could not be easily categorized on a statewide basis. Other researchers may find this estimation technique to be of value for quantifying a stochastic production process, especially one not readily amenable to direct measurement.
A Signal Detection Framework to Evaluate Models of Tree Mortality Following Fire Damage
Authors: Saveland James M. , Neuenschwander Leon F.
Published: April 2024

Signal detection theory provides an appropriate framework to evaluate the performance of various individual tree mortality models. Receiver operating characteristic (ROC) curves show the tradeoffs that are possible by varying the decision criteria, show predictive performance with respect to chance, and show the difference between various models. Two ROC curves were generated to predict ponderosa pine mortality following fall prescribed fires in northern Idaho. One ROC curve was developed from rules of thumb using percent crown scorch. A second ROC curve was developed from a logistic mortality model using diameter at breast height and scorch height. Overall, percent crown scorch is a better predictor of mortality than scorch height, and thus should be used to plan and conduct salvage operations in ponderosa pine following a fire. Because of the difficulties involved in predicting percent crown scorch before a fire, the logistic model based on scorch height can be used to plan understory prescribed fires. For. Sci. 36(1):66-76.
Frequency Distribution and Heritability of First-Order Lateral Roots in Loblolly Pine Seedlings
Authors: Kormanik Paul P. , Ruehle John L. , Muse H. David
Published: April 2024

Frequency distributions and heritability of first-order lateral roots (FOLR) were computed for seedling progeny of loblolly pine mother trees in different years in a nursery. Seeds were from 12 mother trees the first year and from 25 different mother trees the second year. The theoretical frequency distribution of FOLR in these loblolly pine seedlings was best appropriated by a truncated normal distribution for untransformed FOLR >0. Family mean heritability estimates (h²) for the 12 and 25 half-sib seedlots were (0.769 ± 0.17 and 0.766 ± 0.11) and combined data produced an h² of 0.767 ± 0.09. Seedlings were also stratified into four FOLR categories: 0-3, 4-5, 6-7, and ≥8. The aboveground dimensions of seedlings in the 0-3 category were consistently and significantly smaller than in the other three grades for all families. Seedlings in this category represented 39% of all seedlings tested over 2 years. In four families 57% of the progeny were in this lowest FOLR category, while in four other families only 25% of the seedlings were in this category. All measured seedling parameters increased significantly from the smallest to the largest FOLR category. These data suggest that mother trees could be selected for FOLR development by some standard nursery procedure. For. Sci. 36(3):802-814.
In Vitro Propagation of the Endangered Virginia Roundleaf Birch (Betula uber [Ashe] Fern.) Using Dormant Buds
Authors: Vijayakumar N. K. , Feret Peter P. , Sharik Terry L.
Published: April 2024

Dormant buds collected from greenhouse and field-grown trees of Betula uber (Ashe) Fern., the endangered Virginia round-leaf birch, were used for micropropagation. A nutrient medium containing the mineral salts of Murashige and Skoog (1962) supplemented with organic nutrients and growth regulators supported bud break, elongation, and limited multiplication. Shoots were 2-3 cm in height with 3-4 leaves in four weeks. They developed roots in vivo in 4-6 weeks in peat pellets under high humidity conditions with 16 h photoperiod at a temperature of 20°C. For. Sci. 36(3):842-846.
A Basal Area Increment Model for Individual Conifers in the Northern Rocky Mountains
Authors: Wykoff William R.
Published: April 2024

A basal area increment model is developed and evaluated for individual trees of 11 conifer species. This distance-independent model is applicable over much of the northern Rockies, an extensive region where stands have considerable variation in species composition, age structure, and past management. The model represents the diverse ecological requirements of the various species and responds appropriately across the observed range of predictor variables. Furthermore, it is well behaved even when used for conditions found in the region but not represented in the large calibration data set (44,086 trees). In addition, it possesses desirable statistical properties such as homogeneous residual variance, minimal multicollinearity, and linear parameters. The model is validated against independent data from two sources: a research study of young managed stands (2,881 trees) and a collection of long-term permanent research plots (6,594 trees). Predictions for small suppressed trees from the permanent plots are generally too large, but there are no significant relationships between residuals and other predictor variables in either data set. An unusual feature of the model is the intentional omission of site index and age, which is motivated by the large number of irregular stands in the region. Validation tests using the permanent research plots indicate, however, that residuals are not correlated with site index and age. Furthermore, long-term projections of stand attributes are unbiased. For. Sci. 36(4):1077-1104.
Estimating Limiting Foliar Biomass in Conifer Plantations from Allometric Relationships and Self-Thinning Behavior
Authors: Blake John , Somers Greg , Ruark Greg
Published: April 2024

The ability of forest stands to sustain increasing amounts of foliage biomass is related in a positive manner to both aboveground woody biomass and to site productivity. Knowledge of the limit to sustainable foliar biomass at a given level of photosynthetically active radiation and under minimum environmental stress would have important implications for modeling primary forest productivity. Theoretical analysis and limited experimental data collected on even-aged plant populations that are undergoing self-thinning indicate that total stand foliar biomass should achieve a nearly constant value for a given species and site. Average diameter-plant density relations for various conifers species coupled with available foliage mass-stem diameter equations were used to approximate the maximum amount of foliage which could be sustained. Sources of bias and effects due to changes in specific leaf area are evaluated. The maximum foliage biomass calculated in this manner was subject to positive bias, but estimates at low densities correspond to values obtained empirically for mature stands growing under very favorable environmental conditions. Calculated estimates suggest that maximum sustainable foliage biomass increases slightly with decreasing plant density along the self-thinning line, in contrast to expectations. The magnitude of the increase depends upon the relative value of the self-thinning exponent compared to the exponent of the allometric equation. Changes in light distribution in relation to crown architecture, particularly crown depth and foliage clustering, may account for this effect. For. Sci. 37(1):296-307.
A Hierarchical Approach to Forest Planning
Authors: Weintraub Andrés , Cholaky Alejandro
Published: April 2024

We present a hierarchical approach for large-scale forest planning. It is based on solving an aggregate problem, which is of moderate size, at higher levels of derision. The results obtained lead to land allocations and input-output targets for the different zones of the forest. At a lower level of decision, based on the land allocation and input-output targets, each zone is modeled in a detailed way. These problems are again of moderate size. Consistency between the two levels of derision is preserved. The economic and algorithmic implications of this methodology approach are discussed. A test case is presented to show the feasibility of this approach. For. Sci 37(2):439-460.
Prediction Bias and Response Surface Curvature
Authors: Gertner George
Published: April 2024

Many functions used for forestry applications have response surfaces that have curvature. Depending on the degree of curvature, predictions made with these functions can be biased when the inputs to these functions have unbiased random errors. An approximation is presented for calculating the bias in prediction when there are unbiased but random errors in the inputs of the function. Examples of some fairly simple functions used in forestry are shown to provide highly biased predictions in typical applications. For. Sci. 37(3):755-765.
Genetic Parameter Estimates for Greenhouse Traits of Slash Pine Artificially Inoculated with Fusiform Rust Fungus
Authors: de Souza S. M. , White T. L. , Hodge G. R. , Schmidt R. A.
Published: April 2024

Six-week-old greenhouse-grown seedlings of 100 open-pollinated slash pine families were artificially inoculated with fusiform rest fungus in three testing periods at the USDA Forest Service Resistance Screening Center. SIX months after inoculation, seedlings were scored for symptoms of rest infection. Genetic parameters (heritabilities, genetic correlations and family x test interactions) were estimated for 16 traits. Eleven traits appear highly promising for inclusion into a selection index to predict breeding values for rest resistance in the field. For these 11 traits, family x test interaction was not important, family heritabilities were high (>0.78), and differences among the four groups of families were minor for family variance, variance of family means, and heritability estimates. The other five traits had measurable amounts of family x test interaction and lower heritability estimates (<0.70). For. Sci. 37(3):836-848.
Root Damage by the Conifer Swift Moth: A Mortality Factor in Montane Red Spruce Regeneration
Authors: Grehan J. R. , Paricer B. L. , Wagner D. L. , Rosovsky J. , Aleong J.
Published: April 2024

Red spruce seedlings potted with Korscheltellus gracilis (Lepidoptera: Hepialidae) larvae exhibited characteristic feeding damage, including localized removal of bark and cambium, and root girdling. Seedling damage resulted in a significant increase in needle dieback, and reductions in growth, root area, and root weight. A survey of population density and montane distribution of larvae and adults at Whiteface Mountain (New York) and Mount Moosilauke (New Hampshire) revealed significantly higher numbers at elevations of 900-1100 m compared to 500 m, 700 m, and 1300 m. Larval densities reached a maximum mean of 38/m² on Mount Moosilauke and 11/m² on Whiteface Mountain, with higher densities recorded from the windward slopes. The potential ecological significance of K. gracilis is discussed in relation to the problem of red spruce decline. For. Sci. 38(3):611-622.
Approximate Srivastava Estimation in Forestry
Authors: Ouyang Z. , Schreuder H. T.
Published: April 2024

Srivastava estimation formalizes the introduction of additional prior and posterior information in sampling to increase efficiency in estimation. An unbiased new estimator is given for Poisson sampling which is approximately as efficient as the standard slightly biased estimator without using any additional information.

The increased efficiency possible with this method or approximations to it are illustrated for Poisson sampling and point-Poisson sampling using simulations. Srivastava estimation may be applicable in many forest inventory situations. Besides efficiency, the seriousness of estimation bias and reliability of variance estimators need to be considered in all applications. FOR. SCI. 39(2):309-320.
Thirty-Seven Year Performance of Loblolly Pine Seed Sources in Eastern Maryland
Authors: Schmidtling R. C. , Froelich R. C.
Published: April 2024

Nine loblolly pine seed sources from The Southwide Southern Pine Seed Source Study were planted on the eastern shore of Maryland. After 20 yr, the local Maryland source had the highest yield, and the southernmost source, from Livingston Parish, LA, the lowest yield. At age 37, the Texas and Arkansas sources had the highest volumes and Maryland and Livingston Parish the lowest. The Maryland source had good height, but above-average mortality and small diameters. Texas and Arkansas sources, originating from areas where droughts are common, were below average in height at age 37, but yield was best because of better survival. These sources appear to be more tolerant of competition and less damaged by beetles after prolonged drought. Better regulation of stand density was needed to optimize yields of all seed sources. For. Sci. 39(4):706-721.
Do Fire Sizes Differ Between Southern California and Baja California?
Authors: Chou Yue Hong , Minnich Richard A. , Dezzani Raymond J.
Published: April 2024

This paper examines the methods employed in a previous study by Strauss et al. (1989) in which the authors suggested that the degrees of size inequality of large fires are much the same in southern California and Baja California, Mexico. We found that both the graphical method and the curve-fitting method employed in that study are inappropriate for comparing fire-size frequency distributions. Our examination of fire histories using the analysis of variance and the contingency table analysis indicates a significant difference in fire-size frequency between these regions. The result implies that spatial strategies of wildfire management must be established to minimize the potential of unnatural sizes and that management strategies should be focused on effective preventive treatments. For. Sci. 39(4):835-844.
Further Studies of Root Decomposition Following Harvest of a Northern Hardwoods Forest
Authors: Fahey Timothy J. , Arthur Mary A.
Published: April 2024

An earlier study of decomposition and nutrient release of root systems following harvest of a northern hardwoods forest ecosystem indicated uncertainties with regard to (1) possible experimental effects on decay of fine and woody roots and (2) patterns of woody root decay and nutrient release in the first several years of decay. Results of this study suggested that most fine roots in the forest floor died early in the first growing season after forest harvest, releasing much of their tissue K. In contrast, mineral soil roots either died much more slowly or were not effectively leached of K during most of the first summer. Rates of release of C and N from fine roots were similar, suggesting that previous studies using mesh bags bad either overestimated N release or underestimated C mineralization, or both. Earlier estimates of total N released from fine roots of northern hardwoods in the first 2 yr after harvest probably were too high. Rates of decay of large woody roots of northern hardwoods were high, with 45%-63% dry weight loss in 4 yr as measured with tethered roots, but this method probably overestimated decay by exposing cut ends to decay organisms. High variation in decay rates was associated especially with the site of incubation, as all the roots (independent of species and size class) incubated in a particular location decayed at about the same rate. For. Sci. 40(4):618-629.
Needlefall Returns and Resorption Rates of Nutrients in Young Intensively Managed Slash and Loblolly Pine Stands
Authors: Dalla-Tea Fernando , Jokela Eric J.
Published: April 2024

Annual needlefall (NF) returns and resorption rates of nutrients in 6-yr-old slash (Pinus elliottii Engelm. var. elliotti,) and loblolly (p. taeda L.) pine stands were investigated using a 2 x 2 x 2 factorial experiment (species, annual fertilization, sustained competition control) in north central Florida. Compared with the reference (untreated), the combination treatment (annual fertilizer plus competition control) increased NF N returns about 6.3-fold (from 2.5 to 15.8 kg ha-1) for slash pine and 13.3-fold (from 1.5 to 19.9 kg ha-1) for loblolly pine. Similar treatment effects were found for P, with recycling rates for loblolly pine greater than for slash pine. Absolute resorption rates of N (from 4.7 to 19.9 kg ha-1 for slash pine; 2.5 to 21.1 kg ha-1 for loblolly pine) and P (from 0.5 to 1.9 kg ha-1 for slash pine; 0.2 to 2.4 kg ha-1 for loblolly pine) increased for both species as management intensity increased (i.e., cultural treatments; reference vs. fertilizer plus competition control). However, specific resorption rates of N and P were lowest for fertilizer treatments. When averaged over all cultural treatments, slash pine resorbed more N (62 vs. 57%) and P (62 vs. 51%) than loblolly pine; approximately 26% of the annual P requirements for slash pine were met by reabsorption compared with 13% for loblolly pine. Nutrient pool size within the plant (uptake) and annual nutrient demands for growth were dominant factors influencing the nature and extent of N and P resorption for both pine species. For. Sci. 40(4):650-662.
Time Trends of Predicted Breeding Values in Selected Crosses of Coastal Douglas-fir in British Columbia: A Methodological Study
Authors: Magnussen S. , Yanchuk A. D.
Published: April 2024

Analytical techniques for estimating time trends and projections of breeding values from sparse data, unbalanced mating designs, and irregular assessments periods are presented and discussed. Time trends (ages 4 to 23) in genetic parameters of tree heights in 14-18 full-sib Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) crosses among six male trees from Coastal B.C. and six female trees from Washington and Oregon planted on four test sites on Vancouver Island were examined, and tentative projections of genetic gains were made. Annual height estimates were derived by fitting splines to height measures at ages 4, 7, 12, 18, and 23 yr. Genetic variances were derived from direct computations of covariances among all possible half-sib combinations; a method deemed superior to the conventional factorial analysis. Irregular fluctuations in genetic parameter estimates vanished after minor adjustments (<1.5%) of variance-covariance matrices with negative eigenvalues. Sites effects were highly significant (P < 0.001), but site-to-site correlations for pair-cross means were all nonsignificant (P > 0.10). Additive genetic control of height growth was weak to moderate (h² ≈ 0.1, but generally increasing with age). The best genetic discrimination was observed on the more productive sites. A stable ranking of full-sib family means was reached at age 7 yr on one site versus age 18 for the other sites. Trends in breeding values were described with a mixed linear autoregressive time series model from which 10-yr projections were made. Projections took into consideration both the error structure surrounding the breeding values and the errors of the parameter estimates in the time series model. Selection of the best parent out of six for breeding and deployment on a single site type would generate an expected gain of about 2-5% in height growth between ages 4 and 23 yr. For. Sci. 40(4):663-685.
Spatial Characteristics of Diameter and Total Height in Juvenile Loblolly Pine (Pinus taeda L.) Plantations
Authors: Liu Jiping , Burkhart Harold E.
Published: April 2024

The spatial characteristics of diameter at breast height and total height were analyzed using data collected from a set of spacing trials planted with loblolly pines. These spacing trials were established at four locations in the Piedmont and Coastal Plain regions of Virginia and North Carolina in 1983. Trend surface analysis was employed to separate the systematic microsite variation from the variation incurred by intertree competition, and a simulation study was carried out to derive an empirical distribution for Moran statistics calculated from regression residuals. At the seedling period of stand development, the systematic environmental gradients had a dominant impact on the spatial patterns of dbh and total height; however, the impact of environmental gradients diminished as stands developed. Intertree competition was evident in the autocorrelation measures, i.e., Moran and Geary indices, which declined with increased density and with stand age. Moran index was statistically significant when competition was severe. Confounding of intertree competition and microsite variation effects made the spatial patterns of observation very complicated and difficult to describe mathematically. Autocorrelation was predominantly positive with total height, but mostly insignificant or negative with dbh in the juvenile period of loblolly pine stands, which suggests that total height is less sensitive to competition. For. Sci. 40(4):774-786.