bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Compatible Estimators for Survivor Growth and Ingrowth from Remeasured Horizontal Point Samples
Authors: Roesch Francis A. , Green Edwin J. , Scott Charles T. 
Published: April 2024

Abstract
Forest volume growth between two measurements is often decomposed into the components of survivor growth (S), ingrowth (I), mortality (M), and cut (C) (for example, Beers 1962 or Van Deusen et al. 1986). Net change between volumes at times 1 and 2 (V2 - V1) is then represented by the equation V2 - V1 = S + I - M - C. Two new compatible pairs of estimators for S and I in this equation are presented for use with the usual estimators of V2 and V1 from permanent horizontal point samples. In addition, a new estimator for V1 (V1**) is presented, which takes advantage of the data from time 2. These estimators are evaluated along with previously existing estimators over a range of sample sizes. In all but the smallest of inventories, one of the new estimators of S (S**) will provide better estimates of survivor growth in more cases than any previously developed estimator of S. S** is shown to be compatible with V1** and the Purdue estimators of ingrowth, while empirical evidence is presented to support earlier contentions that the Purdue estimator is the best possible estimator of ingrowth from point samples. Recommendations are given based upon the presence or absence of a compatibility requirement and willingness to change the estimate of volume at time 1. For. Sci. 35(2):281-293.
Predicting Wood Production by Canopy Trees in Forest Communities in the Western Great Smoky Mountains
Authors: Callaway Ragan M. , Clebsch Edward E. C. , White Peter S. 
Published: April 2024

Abstract
A sequence of multivariate techniques (after Golden 1981) including hierarchial classification, detrended correspondence analysis, and multiple discriminant analysis was used to classify forest types in the Great Smoky Mountains National Park. Multiple regressions were used to develop predictive equations for canopy tree productivity (periodic bole volume increment) from environmental variables and measurements of tree growth. An index of topographic shape was constructed to quantify the effects of landform on forest distribution and productivity.
The topographic index "protection" was the most important variable for predicting forest productivity. Elevation was the most important variable determining vegetation distribution with protection the second. Predictability of forest productivity from environmental factors was lower on older logged and farmed sites than on undisturbed sites. For. Sci. 35(2):338-348.
Effects of Costs, Demand, and Labor Productivity on the Prices of Forest Products in the United States, 1958-1984
Authors: Buongiorno Joseph , Lu Hsien-Chih 
Published: April 2024

Abstract
The objective of this study was to investigate the reasons for changes in the prices of forest products. To do this, a mark-up model of price formation was proposed. It linked yearly price changes to changes in variable costs and changes in demand. This model was estimated with annual data on prices, variable costs, and inventory-output ratios, from 1958 to 1984. Four solidwood industries and three pulp and paper industries of the United States were studied. The results showed that, depending on the industry, the theory explained 83 to 98% of the variation in annual price changes. Rises and declines of variable costs had symmetric effects on prices, except for pulp mills, the most concentrated industry, in which downward-price inflexibility was apparent. Decomposition analysis showed that over the interval 1958-1984, the rise in variable costs explained most of the rise in product prices. Further decomposition indicated that within variable costs, increases in material costs led to increases in prices that were much higher than those due to labor costs. Finally, in no industry did the increase in labor productivity between 1958 and 1984 compensate for the rise in the wage rate, so that increases in wages also contributed to the general inflation in forest product prices. To improve their competitiveness, the forest products industries should strive to control material costs and increase their labor productivity. For. Sci. 35(2):349-363.
Development and Evaluation of an Expert System for Diagnosing Pest Damage of Red Pine in Wisconsin
Authors: Schmoldt Daniel L. , Martin George L. 
Published: April 2024

Abstract
An expert system for diagnosing pest damage of red pine stands in Wisconsin, PREDICT, runs on IBM or compatible microcomputers and is designed to be useful for field foresters with no advanced training in forest pathology or entomology. PREDICT recognizes 28 damaging agents including species of mammals, insects, and pathogens, as well as two types of abiotic damage.
Two separate development tools (EXSYS and INSIGHT2 +) were used. Each employs a role-based method for representing knowledge, which was obtained from the literature and from human experts in the fields of forest pathology and entomology. The pest-inference rule blocks, for each damaging agent, are based on the abduction model of diagnosis and include rules for eliminating a pest from further consideration, diagnosing a pest as certain, and compiling evidence in favor of a pest. Both development tools employ a backward-chaining control strategy; however, it was necessary to modify this approach by designing a special block of rules to approximate the mixed strategy used by the human experts. A logic and completeness rule block was also constructed to deduce facts omitted by the user and to minimize the need for questioning.
Input to PREDICT is obtained from pest damage reports containing specific information about stand/site conditions, tree symptoms, and signs. Diagnoses from PREDICT take the form of a list of one or more possible agents with corresponding confidence values. Actual and hypothetical test cases were used to refine the knowledge base, then a separate set of 20 actual cases was used as a basis for testing and evaluating the completed system. It was necessary to develop special procedures for refining and evaluating the system to accommodate the often vague and uncertain nature of pest damage information.
Two versions of PREDICT (developed with the EXSYS and INSIGHT2 + tools, respectively) were evaluated and compared with three recognized experts and two field foresters. No significant differences were found between the performances of PREDICT and the experts; however, PREDICT performed significantly better than the two foresters, even though they both have training and experience in forest pest diagnosis. It was concluded that PREDICT is able to improve the diagnoses of field foresters to a level comparable with recognized experts. For Sci. 35(2):364-387.
Determinants of Log-To-Lumber Conversion Efficiency: A Washington Case Study
Authors: Cardellichio Peter A. 
Published: April 2024

Abstract
Log-to-lumber conversion efficiency is modeled using pooled cross-section and time-series data for individual sawmills. The analysis incorporates economic variables, technological characteristics of sawmills, and timber characteristics. To exploit optimally the panel structure of the database, fixed effects and error components models are estimated, along with the ordinary least squares model. The elasticity of substitution between sawlogs and other inputs used in manufacturing lumber is small, but statistically significant. However, the data are not adequate to rule out the conclusion that lumber production is a fixed proportions production process because relative prices may be correlated with exogenous technological change. Mill size, mill vintage, headrig type, and log diameter also are key factors that influence log use. However, once a sawmill is in place, there is a large unsystematic component to its recovery performance. For. Sci. 35(2):437-452.
The Generation and Fate of Road-Surface Sediment in Forested Watersheds in Southwestern Washington
Authors: Bilby Robert E. , Sullivan Kathleen , Duncan Stanley H. 
Published: April 2024

Abstract
Studies conducted in southwestern Washington, examining the generation of sediment on gravel road surfaces, its transport to small streams and its fate after entering flowing waters, are reviewed. The amount of sediment produced on an hourly basis from a road segment was related to traffic rate. Accumulated material flushed rapidly from the road surface with precipitation, leading to a decrease in sediment concentration in the ditch with time during a storm. Depth of road ballast and type of surfacing material also influenced sediment generation. The majority of the sediment produced by these roads was finer than 0.004 mm. Steeper roads produced a higher proportion of coarser particles. Approximately 34% of surveyed road drainage points entered streams, mainly first- or second-order channels. Thus, the delivery of road sediment to larger streams often depended on its transport through these smaller channels. Small streams temporarily retained a high proportion of road sediment input to them. Coarser particles were retained at a higher rate than finer material. Due to the fine particle size of road sediment delivered to streams, little effect of this material on the composition of streambed gravel could be discerned. The results of these studies provide guidelines for management of those roads where sediment has the highest potential to impact aquatic resources. For. Sci 35(2):453-468.
Spatial and Temporal Variability of Foliar Nutrient Levels in Fraser Fir Christmas Trees
Authors: Hockman Joseph N. , Burger James A. , Smith David Wm. 
Published: April 2024

Abstract
The variation of Fraser fir (Abies fraseri [Pursh] Poir.) foliar nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) levels within plantations, the tree crown, and season of the year was studied. Extensive variation in nutrient concentrations existed. The data show that use of foliar nutrient levels for diagnosing nutrient sufficiency without regard to this variation could cause erroneous fertilization prescriptions. Recommended foliar sampling technique consists of sampling current-year's tissue from 2- or 3-yr-old south-facing branches in October. For. Sci 35(2): 632-639.
Height-Age Trends from an Arkansas Seed Source Study
Authors: Sprinz Peter T. , Talbert Cheryl B. , Strub Mike R. 
Published: April 2024

Abstract
An analysis of average and dominant height, and height growth indicated the geographic origin of planted loblolly pine significantly affected height development through 29 years in Arkansas. For average and dominant height, sources west of the Mississippi were shorter than eastern sources at all ages; coastal Carolina and Virginia sources were taller than local sources from Arkansas, northern Louisiana, east Texas, and Oklahoma at all ages. The interior sources from northern Mississippi, Alabama, Georgia, and piedmont Carolina were shorter than the coastal sources initially, but became similar by age 25. It was also determined that region rankings for dominant height remained fairly consistent with age, but the relative magnitudes of difference among regions decreased with age. Region rankings for average and dominant heights were similar, but the relative differences in magnitude were greater for average height than for dominant height. A flexible height-age model suggested that while dominant height maximized at a common level, the shape of development varied to that asymptote with seed source. Lastly, it was found that region differences existed in the shape and level of height growth over time. Eastern origin material showed the greatest height growth initially, but the western origin stands had attained the same height growth rate by age 20. For. Sci. 35(3):677-691.
Stockability: A Major Factor in Productivity Differences between Pinus Taeda Plantations in Hawaii and the Southeastern United States
Authors: DeBell Dean S. , Harms William R. , Whitesell Craig D. 
Published: April 2024

Abstract
Basal area and volume production in loblolly pine spacing trials in Hawaii were nearly double the average production in research plantings in the Southeastern United States. The higher productivity in Hawaii was associated, to some extent, with site index and more rapid growth of individual trees. Competition-related mortality, however, was considerably lower in Hawaii, despite the fact that trees were larger. Consequently, limiting density and mortality threshold boundary lines were much higher. Such differences in stockability (or maximum mean tree size-stand density relationships) accounted for most of the differences in productivity. Forest managers and scientists should pay more attention to possible differences in stockability in the quest for productivity improvement. For. Sci. 35(3):708-719.
Design Efficiencies with Planned and Unplanned Unbalance for Estimating Heritability in Forestry
Authors: McCutchan Barbara G. , Namkoong Gene , Giesbrecht Francis G. 
Published: April 2024

Abstract
Design efficiencies are evaluated for the estimation of heritability in unbalanced designs using Modified Maximum Likelihood estimation. Assuming knowledge of the variance components, the variance of the estimate of heritability is calculated. The effects of block size, plot size, family size, variance of family size, and total number of observations on design efficiency are examined across the range of heritability and under 100%, 90%, 80%, and 60% survival. The implications of each of these design factors are discussed. There is no uniformly best design for estimating heritability; the most efficient design is a function of the heritability. For. Sci. 35(3):801-815.
Influence of Disease Management Strategies on the Production of White Spruce in a Forest Tree Nursery
Authors: Enebak S. A. , Palmer M. A. , Blanchette R. A. 
Published: April 2024

Abstract
In a Wisconsin forest tree nursery dazomet, captan, thiram, captan-thiram combination, or silica sand did not reduce populations of three soilborne fungi. Preemergence mortality was greatest in nontreated plots, (56%) and least in plots treated with dazomet (46%). Nontreated plots had the most post-emergence damping off, (15%) and silica sand the least (3%). Rhizoctonia solani (AG-1) was isolated from 52% of damped-off seedlings collected while Pythium spp., Fusarium spp. and Cylindrocladium spp. were recovered from 24%, 23%, and 1% of the seedlings, respectively. Seedling mortality from May 18 to September 23, 1986, ranged from 28% in the dazomet plots to 61% in nontreated plots. At the end of the first growing season, plots treated with dazomet had significantly more seedlings than any other treatment. The incidence of stunted seedlings was greatest in plots treated with dazomet and least when seed was covered with silica sand. Silica sand or thiram treatments produced seedlings with the greatest total dry weights. For. Sci. 35(4):1006-1013.
A Model to Predict the Moisture Content of Reindeer Lichen
Authors: Péch Gy. 
Published: April 2024

Abstract
The Fine Fuel Moisture Code (FFMC) of the Canadian Forest Fire Weather Index System is modified to apply to the top layers of reindeer lichen (Cladina rangiferina [L.] Nyl.). While the basic assumption for FFMC, i.e., exponential drying in constant weather influenced by relative humidity, air temperature, and wind, is retained in the calculation of the reindeer lichen moisture code, actual drying in the model is accelerated by isolation. The equilibrium moisture content (E) of sun-exposed reindeer lichen is 3-4% lower than that for shaded fuels. Rainfall causes a more rapid rise of moisture content in reindeer lichen than in FFMC, and the change is proportional to the initial (Mo) and saturation (Ms) moisture contents of the lichen, and the amount of rain (R). The model postulates that after rain the moisture content of the lichen (Mr) is: Mr = Mo + [a(Ms - Mo)/(a + Mo)][1 - e -b(Ms-Mo)R;] Comparison of experimental measurements with calculated values suggests that the model represents moisture content in the top 3-4 cm layer of reindeer lichen. For. Sci. 35(4): 1014-1028.
Endemic and Epidemic Populations of Southern Pine Beetle: Implications of the Two-Phase Model for Forest Managers
Authors: Mawby W. D. , Hain F. P. , Doggett C. A. 
Published: April 2024

Abstract
Typical of many Dendroctonus species, the southern pine beetle (D. frontalis Zimmerman) exhibits dramatic fluctuations in population levels. Using field observations of beetle damage, this study empirically demonstrates that a two-phase model described for mountain pine beetle (D. ponderosae Hopkins) is appropriate for southern pine beetle at each of five hierarchical levels: the tree, the local infestation, the county, the state, and the region. The model has three points that represent a stable low-level (endemic) phase maintained by host-tree-defensive capabilities, a transient high-level (epidemic) phase determined by the availability of host material, and a threshold between the two phases. The threshold depends on local environmental and biotic factors and is a rarely observed phenomenon. Implications of these results for southern pine beetle management and control are discussed. The necessity for establishing and maintaining control programs during the endemic phase is stressed. For. Sci. 35(4): 1075-1087.
Red Spruce Rhizosphere Dynamics: Spatial Distribution of Aluminum and Zinc in the Near-Root Soil Zone
Authors: Smith William H. , Pooley H. 
Published: April 2024

Abstract
Red spruce roots, associated with mature, healthy trees occupying canopy positions, were located in three 8.5 m² forest floor plots at 250 m elevation in the Hubbard Brook Experimental Forest, White Mountain National Forest, New Hampshire. Roots, 0.25-1.0 cm diam, were severed, and cut ends were placed in soil in plastic bags. In 14 months, new roots developed behind cut ends and were cultured in wooden trays containing screened forest floor material. Forest floor concentrations of aluminum, calcium, chlorine, iron, lead, and zinc were established. Trays containing roots were supplied with a distilled water treatment or with distilled water containing chloride salts of aluminum, lead or zinc sufficient to increase substrate cation concentration by 500 ppm. Eight weeks following treatment, roots (largely ectomycorrhizal, diam 0.4-1.0 mm) with associated rhizosphere soil were harvested by impregnating specimens in agar and freezing in liquid nitrogen. Cross sections of root-rhizosphere soil samples were freeze dried and examined with a scanning electron microscope and energy dispersive x-ray spectrometer. Gradients of element concentrations were established along transects from root interiors (cortex) through the inner and outer rhizosphere zones (2 mm from root) and in bulk soil (devoid of roots). The pH of rhizosphere soil was approximately 0.5 unit less than bulk soil. Aluminum concentrations exhibited a strongly descending gradient from bulk soil through the rhizosphere to the root. Estimated concentrations ranged from 1000 ppm within 200μ of the root to 10 X this amount in soil beyond 2000μ. Calcium distribution, without aluminum amendment, was relatively constant through the rhizosphere, but with aluminum amendment, calcium exhibited a sharply decreasing gradient near the root. In the unamended treatment, the Al:Ca ratio dropped from 7 to 0.2 across the rhizosphere. Chlorine was constant in the rhizosphere but exhibited pronounced accumulation inside the root. Iron counts were variable in the rhizosphere, but on average suggested constant concentrations across the rhizosphere. Zinc concentrations were marginally detectable and exhibited slight accumulation in cortex tissue. Aluminum uptake appeared to be strongly mediated by rhizosphere processes. Solubility, and more importantly exchangeability, of aluminum may be enhanced in the rhizosphere by lowered pH; greater availability of low molecular weight organic ligands, or some other unique chemical characteristic of the rhizosphere. Judgments made concerning potential uptake of aluminum from bulk soil characteristics of forest soils, without consideration of rhizosphere dynamics, could lead to improper conclusions. For. Sci. 35(4):1114-1124.
A Tree-Ring Reconstruction of Western Spruce Budworm History in the Southern Rocky Mountains
Authors: Swetnam Thomas W. , Lynch Ann M. 
Published: April 2024

Abstract
Tree-ring width chronologies from ten mixed-conifer stands in the Colorado Front Range and New Mexico Sangre de Cristo Mountains were used to reconstruct the timing, duration, and radial growth impacts of past outbreaks of western spruce budworm (Choristoneura occidentalis Freeman). At least nine outbreaks were identified in the stands from 1700 to 1983. Severity and timing of outbreaks was highly variable. The average duration of reduced growth periods caused by budworms was 12.9 years and ranged from 5 to 26 years. The average interval between initial years of successive outbreaks was 34.9 years and ranged from 14 to 58 years. The average maximum and periodic radial growth reductions were 50% and 21.7%, respectively. There was a relatively long period of reduced budworm activity in the first few decades of the twentieth century, and since that time outbreaks have been markedly more synchronous among the sampled stands. It is hypothesized that the increased synchroneity of outbreaks in the latter half of the twentieth century is due to changes in age structure and species composition following harvesting and fire suppression in the late nineteenth and early twentieth centuries. For. Sci. 35(4):962-986.
A Variable-Form Taper Function for Pinus Oocarpa Schiede in Central Honduras
Authors: Perez D. N. , Burkhart H. E. , Stiff C. T. 
Published: April 2024

Abstract
A variable-form taper equation was developed for Pinus oocarpa Schiede in central Honduras. The model predicts tree profile as a function of total height, diameter at breast height, and relative height with a continuous function using a changing exponent to compensate for the form of different tree sections. The proposed five parameter model predicts underbark diameters with a standard error of 1.4 cm. The point where the taper curve changes from neiloid to paraboloid form, the inflection point, was assumed to occur at 25% of total height. For the data used, no changes in the predictive ability of the model were observed with different locations of the inflection point. For. Sci. 36(1):186-191.
Classification Model to Predict Fraser Fir Christmas Tree Grade
Authors: Hockman J. N. , Burger J. A. , Smith D. Wm. 
Published: April 2024

Abstract
Objective measures of Christmas tree grade that would better quantify tree responses to cultural treatments were sought. Fraser fir Christmas tree attributes in a 3-year-old plantation were measured and correlated with conventional three-class grade categories, and a discriminate classification model was developed to test the predictability of grade based on tree attributes. Tree attributes best correlated with grade were basal diameter, terminal leader length and total bud and lateral bud frequencies on the terminal leader. Grade prediction based on five easily measured growth attributes produced a discriminate classification success rate of 72%. For. Sci. 36(1):45-53.
A Stochastic Restrictions Regression Model Approach to Volume Equation Estimation
Authors: Meng C. H. , Tang S. Z. , Burk T. E. 
Published: April 2024

Abstract
The stochastic restrictions regression estimator is suggested as a means of combining auxiliary information with standard regression applied to a data set. A derivation of the estimator is given, and the estimator is compared to other estimators that use auxiliary information and other regression approaches that have previously been applied in forestry. A test statistic for determining whether the auxiliary information is unbiased is presented along with a table of critical values. Approximate confidence interval procedures are obtained, and consistent means of estimating nuisance parameters are given. Finally, an example is provided to illustrate calculations. For. Sci. 36(1):54-65.