bluuebunny/crossref_metadata_2025 huggingface dataset:
Note on Log Sort Yard Location Problems
Authors: Broad L. R.
Published: April 2024

Sort yards placed either at forest locations or at locations between forest and utilization sites may be used to sort logs into log types that are more consistent with their final form of utilization. This sorting procedure has the potential to increase returns from log scales. A formulation of the inherent location problem as a Mixed Integer Linear Program (MILP) is presented. For. Sci. 35(2):640-645.
Spatial Stochastic Modeling of Growth and Forest Resource Evaluation
Authors: Samra J. S. , Gill H. S. , Bhatia V. K.
Published: April 2024

Possibilities of spatial interpolations by the unbiased and minimum variance technique of kriging for mapping forest inventories have been examined. Observations recorded on the height of Dharek (Melia azedarach Linn.) planted in a sodic soil at 3 x 6 m spacing were used as test data. Coefficient of variation (CV) in the tree height was 28%, 30%, and 27% after 1, 2, and 3 years of growth as compared to 6% 1 month after the sapling establishment. The heterogeneity was modeled as intrinsic random fields of geostatistics after removing the deterministic component nonparametrically. Tree height varied both as a function of direction in the field (anisotropy) as well as lag distance. Depending on the age, 70 to 77% of the heterogeneity was structured in the NW-SE direction. Since modeling could be validated very precisely, interpolation (kriging) of the values at locations between the sampled sites for the inventory mapping has been recommended. Error variance of the kriging estimator (jackknifing) was 9% of the general mean. Suitability of this technique for forest resource evaluation from the samples taken on the ground or on the remotely sensed devices has been indicated. For Sci. 35(3):663-676.
Substitution in Demand Between Sawnwood and Other Wood Products in Norway
Authors: Baudin Anders , Solberg Birger
Published: April 2024

A combined factor and consumer demand logit model for analyzing the substitution between sawnwood, particleboard, fiberboard, and gypsumboard was estimated for four industrial sectors in Norway. The causes of substitution are discussed. It is found that they are not uniform over the sectors. For instance, in the building and construction sector, labor costs dominated while in the furniture sector, price differentials between sawnwood and particleboard were most important. Sectoral substitution analyses are used to make projections of sawnwood demand, by applying a multisector macroeconomic model for Norway. For. Sci. 35(3):692-707.
Long-Term Effects of Fertilization on Stem Form, Growth Relations, and Yield Estimates of Slash Pine
Authors: Jokela E. J. , Harding R. B. , Nowak C. A.
Published: April 2024

The long-term effects of time-of-planting phosphorus (P) fertilization on stem form were evaluated in a 25-year-old slash pine plantation in north Florida. Cylindrical form factor (CFF), relative taper curves, the constant-stress principle of stem formation, and individual tree volume and biomass estimation equations were compared among treatments. Significant differences in CFF and taper existed between control and fertilized trees. Treatment-induced changes in crown size and accelerated tree and stand development may be responsible for these differences. Although statistically significant, alteration of stem form by fertilization was of minor importance relative to the accurate estimation of stand volume and weight. The cost and effort necessary to develop treatment-specific equations for quantifying fertilizer responses for slash pine on P-deficient sites appears unwarranted. For. Sci. 35(3):832-842.
Cumulative Employment Effects on Northern California's Wood Products Industries from National Forest Timber Harvests
Authors: Sullivan Jay , Gilless J. Keith
Published: April 2024

Econometric models of labor demand are used to examine the relationship between timber harvest levels and employment in the logging and sawmill industries of northern California. Evidence is found to reject the hypothesis of a linear relationship, implying that timber harvests have cumulative effects across national forests. Questions raised about current national forest planning include the accuracy of estimated employment impacts and the appropriateness of developing land management plans independently for adjacent national forests. For. Sci. 35(3):00-00.
Comparing Basal Area Growth Rates in Repeated Inventories: Simpson's Paradox in Forestry
Authors: Thomas Charles E. , Parresol Bernard R.
Published: April 2024

Recent analyses of radial growth rates in southern commercial forests have shown that current rates are lower than past rates when compared diameter class by diameter class. These results have been interpreted as an indication that the growth rate of the forest is declining. In this paper, growth rates of forest populations in Alabama are studied. Basal area growth (a function of both radius and radial growth squared) by diameter classes is examined for plantation and natural stands. Basal area growth and population distributions for the 1962-1972 and 1972-1982 measurement periods are presented. Also, significance of Simpson's paradox in these analyses is discussed. Basal area growth proves to be consistent with changes that have occurred in tree frequency in diameter classes, i.e., stand structure. In Alabama's natural stands, basal area growth is shown to be relatively constant over the most recent inventories, while it has increased in plantations. Simple comparison of radial growth would be misleading. For. Sci. 35(4): 1029-1039.
Field Performance of Ponderosa, Scots, and Austrian Pines with Pisolithus tinctorius Ectomycorrhizae in Prairie Soils
Authors: Riffle Jerry W.
Published: April 2024

Pinus ponderosa, P. sylvestris, and P. nigra seedlings, with Pisolithus tinctorius (Pt) ectomycorrhizae formed with standard or industrially produced pure culture inoculum, were planted on prairie soils in south-central and southeastern Nebraska, or in central Kansas. Survival and growth of the seedlings were evaluated annually over a 5-year period. Seedlings also were examined for presence of Pt and naturally occurring ectomycorrhizae. Pt remained viable on inoculated trees in each of three plantings during the 5-year period, but ectomycorrhizae formed with this symbiont did not improve survival and growth of the three pine species when compared to noninoculated control trees that had become ectomycorrhizal with naturally occurring symbionts. Factors (high soil pH and other fungi) contributing to the lack of growth response under field conditions for trees with Pt ectomycorrhizae are discussed. For. Sci. 35(4):935-945.
Air-Conducting Porosity in Slash Pine Roots from Saturated Soils
Authors: Fisher H. M. , Stone E. L.
Published: April 2024

On many sites, slash pine taproot systems extend into zones of perennially saturated, anoxic soil. Tap and sinker roots, submerged for weeks or months by periodic rising of the water table, appear to be undamaged by anoxia. On such sites, green wood of large-diameter sinkers and a taproot had unusually high air contents (48% to 69% of green volume), a consequence of low wood substance and low moisture volumes. Green root sections conducted air longitudinally when small pressures (0.06 to 0.98 kPa) were applied at one end. Mass air flow through root wood increased linearly with the pressure applied and was approximately proportional to root cross-sectional area. Since sinker roots taper, root length influenced mass flow by affecting both pressure gradient and the conducting cross-section. Using Darcy's Law, mass air flow through each root was characterized by K, an air-permeability factor, which incorporates the unique anatomic or morphologic features of each root section. The average K for the population of green sinker and taproot sections was 68.6 cm² kPa-1 min-1, which is the same magnitude of Darcy K estimates reported for mass air flow through dried pine stem wood. The findings suggest that vertical roots simultaneously conduct water up from, and air down to, submerged distal ends of the root system. The large gas-filled volume in wood likely serves as a pool for diffusive gas exchange between the atmosphere and 02-depleted tissues. For. Sci. 36(1):18-33.
Growth and Biomass Partitioning of Northern Red Oak and Yellow-Poplar Seedlings: Effects of Shading and Grass Root Competition
Authors: Kolb T. E. , Steiner K. C.
Published: April 2024

Seedling growth of northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.) were compared under conditions of grass root competition (Poa pratensis L.) and shading. Each species was grown from seed for 2 years in each of four environments: (1) 100% sun/no grass, (2) 100% sun/grass, (3) 37% sun/no grass, and (4) 37% sun/grass. Leaf, stem, and root biomass and projected surface areas of leaves and roots were measured by destructive harvests in each year. Growth allocation to organs was compared among environments by coefficients of the allometric equation Y = aXb. Total seedling biomass of oak was greater than yellow-poplar in all environments and harvests because of an initial growth advantage from larger seed reserves. However, biomass relative growth rate of yellow-poplar was greater than oak in all environments. Grass root competition reduced biomass of both species, but more for yellow-poplar than for oak. In the absence of grass, shading reduced biomass of both species, especially yellow-poplar, while shading in the presence of grass resulted in a nonsignificant increase in biomass of both species. In all environments, shoot-root ratio and partitioning of leaf and root biomass to surface area for yellow-poplar was greater than oak. In response to competition for soil resources, both species increased biomass partitioning to the root at the expense of the shoot. In response to shading, yellow-poplar increased leaf area proportion, while oak did not. Thinner leaves and a more fibrous root system were more important in explaining yellow-poplar's higher relative growth rate under conditions of shading and root competition compared to oak than differences in shoot-root weight ratio or plasticity in biomass partitioning. For. Sci. 36 (1):34-44.
Effects of Pollen Source on Loblolly Pine Resistance to Cronartium Quercuum f. sp. Fusiforme
Authors: Snow G. A. , Matthews F. R. , Nance W. L. , Foster G. S.
Published: April 2024

Pine seedlings from control-pollinated and wind-pollinated seeds of nine loblolly (Pinus taeda L.) pine trees were inoculated with Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme in separate experiments at Gulfport, Mississippi, and Athens, Georgia. A factorial mating design was used in which nine female parent trees were crossed with six other loblolly trees (males). The male and female parents were chosen to represent a range of resistance to the pathogen. Results at the two laboratories were similar in that the percentage of trees galled for pine families was highly correlated. Resistant parents, either male or female, usually produced resistant progeny, and susceptible parents usually produced susceptible progeny. There were notable exceptions, as one female parent produced highly resistant progeny when crossed with three of the males, but crosses of this female with the other males, including a cross with pollen carried by the wind, were highly susceptible. Gall form, a variable derived from gall length divided by gall diameter, gave an equal or better determination of female rust susceptibility than the percent-galled variables for certain crosses in the Gulfport experiment. Development of round galls appears to be an indication of tolerance to the disease and may be a useful trait for resistance work. The advantage of using control-pollinated progeny instead of wind-pollinated progeny to detect trees that can be crossed to produce highly resistant progeny was demonstrated. The avoidance of errors that can be introduced by using unknown male parents was strongly implied by the dramatic effects of resistant and susceptible males. For. Sci. 36(2):304-312.
Some Novel Statistical Analyses Relevant to the Reported Growth Decline of Pine Species in the Southeast
Authors: Warren William G.
Published: April 2024

Existing statistical methodology has been adapted to give additional insight into the data on pine-growth reduction in the Southeast as presented by Sheffield et al. (1985). Specifically the generation of confidence intervals for the percentage growth reduction is illustrated. The probability integral transformation and cumulative sum techniques are employed as a meta-analytic approach to testing the significance of the growth reduction. While these methods are suggested as a means of obtaining a quantitative overview of these particular data, the potential for wider application exists. It is also shown how the observed pattern of reduction and most, if not all, of its magnitude can be explained by a simple conceptual model for hardwood competition. Verification of this approach is, however, not possible with the data as provided by Sheffield et al. For. Sci 36(2):448-463.
Multicriteria Nonlinear Programming for Optimal Spatial Allocation of Stands
Authors: Roise Joseph P.
Published: April 2024

The forest planning problem is formulated using stand level variables for each management unit. It is shown that harvests can be spatially allocated to stands to meet nonadjacency requirements by using a nonlinear programming formulation. A penalty function form of the mathematical program is used to find solutions. This study represents a first attempt at a possibly robust technique. It appears to be applicable to small forest areas. For larger forest areas containing many stands (>200) the method is predicted to converge too slowly for practical use. The considerable conflict between achieving optimal present net value of the forest and meeting nonadjacency requirements is illustrated for example cases. For. Sci. 36(3):487-501.
A Sampling Strategy for Estimating Past Crown Recession on Temporary Growth Plots
Authors: Maguire Douglas A. , Hann David W.
Published: April 2024

Seven alternative sampling strategies for estimating past crown recession on temporary plots were compared using known 5-yr recession rates reconstructed on permanent plots. Actual past crown recession was established on 28 Douglas-fir trees by application of a branch mortality dating technique to all branches in 10-15 whorls below present crown base. Seven sampling schemes were then chosen to sample only two or four whorls per tree. Proposed estimators for each scheme were applied to compute past crown recession for each tree over various 5-yr intervals. Simple linear regressions of estimated on actual recession demonstrated that several of the sampling strategies produced an intercept and slope not significantly different (P < 0.01) from zero and one, respectively, and hence were satisfactory for estimating past 5-yr crown recession on these plots. Extension of this technique by tailoring sampling strategies to specific site conditions is discussed. For. Sci. 36(3):549-563.
Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Response to Water and Nutrient Status of Loblolly Pine
Authors: Ross Darrell W. , Berisford C. Wayne
Published: April 2024

Loblolly pine (Pinus taeda L.) seedlings were grown in a greenhouse under conditions of variable water and nutrient availability and then exposed to natural populations of the Nantucket pine tip moth (Rhyacionia frustrana [Comstock]). Seedling growth was directly related to water and nutrient availability. Tip moth oviposition was highest on the most vigorous seedlings, even after accounting for differences in seedling size among treatments. The ratios of mean number of pupae per seedling to mean number of eggs per seedling for each treatment indicated percent tip moth survival may have been lower on vigorous seedlings than on stressed seedlings, but differences may have been due to factors other than the suitability of seedlings as larval food. Larger numbers of heavier pupae developed on vigorous seedlings than on stressed seedlings. Pupal weights were directly related to total nitrogen concentration and inversely related to total phenolic and condensed tannin concentrations of pine shoot tissues. Total phenolic and condensed tannin concentrations were inversely related to seedling growth. These results suggest that tip moth populations will increase rapidly following silvicultural treatments that increase water and nutrients available to young loblolly pines. For. Sci. 36(3):719-733.
Allocation Patterns of Carbon and Minerals in Juvenile and Small-Adult Juniperus occidentalis
Authors: Miller P. M. , Eddleman L. E. , Kramer S.
Published: April 2024

Allocation patterns in juvenile and small-adult western juniper (Juniperus occidentalis Hook. subsp. occidentalis) were studied to understand how a successful, invasive, native species balances the allocation of resources between above-ground tissue to optimize photosynthetic capacity, and below-ground tissue to maintain itself in a semi-arid environment. Above- and below-ground biomass, gross heat of combustion, concentrations of macro- and micronutrient elements, and construction costs were measured on seven trees with 100% juvenile foliage (juveniles) and seven with both juvenile and adult foliage (small-adults) from a site in central Oregon. Adult foliage had the highest heat of combustion, nitrogen concentrations, and construction cost. Allocation patterns indicated a larger investment in resources to above-ground than below-ground tissue in both juvenile and small-adult J. occidentalis. The proportions by weight of nutrient elements in juniper foliage were 1.3 to 29 times higher that the optimal proportions required for maximum growth of Pinus sylvestris. The relatively high nutrient status of J. occidentalis may indicate that additional root biomass is not required to balance the activity and relative growth rate of above-ground tissue. Assuming that unrecovered fine roots were a similar percentage of total root dry mass and that sampling errors were similar between studies, J. occidentalis had high root:shoot ratios when compared with other conifer species from more mesic habitats and Larrea tridentata from more xeric habitats. Compared with similar-aged species for which data are available, juvenile and small adult J. occidentalis allocate larger proportions of dry mass to foliage, to optimize photosynthetic capacity, and to roots, to optimize water and nutrient acquisition; the larger allocation to foliage and roots was accomplished through reduction of allocation to branch/trunk. For. Sci. 36(3):734-747.
Nutrient Leaching of a Loblolly Pine Forest Floor by Simulated Rainfall I. Intensity Effects
Authors: Schreiber J. D. , Duffy P. D. , McDowell L. L.
Published: April 2024

Material from the L(Oi) and F (Oe) horizons was collected from the floor of a loblolly pine (Pinus taeda L.) plantation and subjected separately and in combination to 25.4 mm of simulated rain at 6.1, 25.4, and 98.8 mm · h-1 using a multiple-intensity rainfall simulator. Leachate (rainfall that flowed through the floor materials), sampled at intervals during each simulated storm, was analyzed for PO4-P, NO3-N, NH4-N, and total organic carbon (TOC) concentrations. Generally, the concentration and amount of nutrients in the leachate were greater at the lower rainfall intensities. In the leachate within each storm the concentration increased rapidly to a maximum and then decreased to a nearly constant value for each intensity, horizon, and nutrient. After reaching a maximum concentration, the function C = aTb best described the relationship of concentration (C) with time (T); however, the function C = aebQ best described the relationship of concentration with cumulative leachate volume (Q). Of the total nutrient stored in the combined L and F horizons, a single storm leached ≤0.23% of the N as NH4-N and NO3-N, ≤0.15% of C as TOC, and up to 2.0% of the P as PO4-P. Results provide greater insight to nutrient cycling, provide input to chemical transport models, and make implications about management practices that change the forest floor. For. Sci. 36(3):765-776.
The Gain in Efficiency in πps Sampling over Poisson Sampling
Authors: Schreuder H. T.
Published: April 2024

A ratio is derived for the relative efficiency of mean-of-ratio estimation for πps sampling without replacement relative to Poisson sampling, assuming the model for which πps sampling with this estimator is optimum. This efficiency ratio is R = 1 + 1/ne where ne = the expected sample size in Poisson sampling and the sample size used in pps sampling. πps sampling from the cumulated x-values, a replacement sampling scheme, is compared to Poisson sampling in a simulation study using four sets of three populations, where two populations in each set are realizations of the optimal linear model for πps sampling with the Horvitz-Thompson estimator, and the third is an actual data set. The derived ratio is a good indicator of the gain in efficiency of πps sampling relative to Poission sampling. This is confirmed by simulation results from some populations. For. Sci. 36(4):1146-1152.
Cost Effectiveness from Regional Optimization in the USDA Forest Service
Authors: Hof John G. , Baltic Tony J.
Published: April 2024

This paper addresses the potential for improving cost effectiveness in the National Forest System through large-scale optimization. It is shown theoretically why allocations of output targets and budgets across National Forests should be expected to be inefficient in the absence of large-scale optimization analysis. And, conservative estimates of the potential for cost savings from large-scale optimization are developed using a multilevel optimization model. These estimates indicate that the output levels in the current "preferred alternatives" in Forest Service land management planning could be achieved for at least 1 to 11% less cost if outputs and budgets were allocated more efficiently across forests. For. Sci. 36(4):939-954.
Effects of Annual Fertilization and Sustained Weed Control on Dry Matter Partitioning, Leaf Area, and Growth Efficiency of Juvenile Loblolly and Slash Pine
Authors: Colbert S. R. , Jokela E. J. , Neary D. G.
Published: April 2024

Productivity and stand development of juvenile loblolly (Pinus taeda L.) and slash pine (P. elliottii Engelm. var. elliottii) were investigated using a 2 x 2 x 2 factorial experiment (species, fertilization, weed control) in north-central Florida. After four growing seasons, annual fertilization and complete weed control produced similar levels of response, increasing aboveground biomass 700% for loblolly pine and 300% for slash pine. The combined treatment improved total dry matter production 1600% (from 1.9 to 32.2 Mg ha-1) for loblolly pine and 450% (from 4.3 to 23.6 Mg ha-1) for slash pine. Equally large treatment-associated increases (up to 1210%) in all-sided leaf area index were measured. Cultural treatments increased the proportional allocations of dry matter to stem wood, stem bark, and branches for both species, a consequence of accelerated stand development. Regardless of treatment, dry matter partitioning to bole (stem wood and stem bark) tissues was greater for slash than loblolly pine (58 vs. 44%), whereas the opposite was true for the crown (foliage and branches) components (42 vs. 57%). Bole production per unit leaf area (growth efficiency) improved with increasing intensity of cultural treatments and was significantly greater for slash than loblolly pine. Results indicate that the potential to increase southern pine productivity on Lower Coastal Plain flatwoods sites is large, and that soil-plant nutrient availability is an important limiting factor. For. Sci 36(4):995-1014.
Estimating Annual Increment Response to Forest Fertilization: A Comparison of Methods by Uniformity Trials
Authors: Monness Erik
Published: April 2024

Several estimators of annual basal area increment response to forest fertilization are compared using mean square error. Estimates of mean square error are obtained through uniformity trials. The unadjusted response estimator, that is, the annual basal area increment difference between the treated and the control plots, has an annual root mean square error of approximately 0.1 m²/ha. The other estimators use pretreatment increment difference to improve the response estimate. The easily calculated constant and ratio estimators are satisfactory, with root mean square errors of approximately 0.04 m²/ha initially, rising to about 0.1 m²/ha about 20 years after the pretreatment period. Estimators using time series, covariance, or regression adjustment do not improve upon this. The data has its origin from a broad set of fertilization field trials on Pinus sylvestris L. and Picea abies L. Karst. in the southeast of Norway. For. Sci. 37(1):123-135.
Compatible Basal Area and Number of Trees Estimators from Remeasured Horizontal Point Samples
Authors: Roesch Francis A. , Green Edwin J. , Scott Charles T.
Published: April 2024

Compatible groups of estimators for total value at time 1 (V1), survivor growth (S), and ingrowth (I) for use with permanent horizontal point samples are evaluated for the special cases of estimating the change in both the number of trees and basal area. Caveats which should be observed before any one compatible grouping of estimators is chosen for a particular application are given. For. Sci. 37(1):136-145.
Comparative Study of the Aerial Structure of Five Shrubs of Mediterranean Shrublands
Authors: Papió C. , Trabaud L.
Published: April 2024

Each year hundreds of thousands of hectares of forests and shrublands are destroyed by wildfires in countries of the western part of the Mediterranean Basin (France, Italy, Spain). Structural canopy components influencing flammability and fire behavior were studied for five Mediterranean shrub species. For each species, total fuel loading, available fuel loading, and vertical distribution of different fuel particles [leaves, twigs of different diameter classes (alive or dead) and stratas] were estimated in a 30-yr-old shrubland. Live to dead fuel ratio, size distribution, and porosity were calculated and compared. The results revealed three groups of species with regard to the fire hazard they present. They are, from the lowest to the highest hazard: (1) Cistus salvifolius, Pistacia lentiscus, and Rosmarinus officinalis with low fuel loadings, (2) Phillyrea angustifolia with high fuel loadings and the highest porosity, and (3) Genista scorpius having the highest fine fuel loading and dead material values. For. Sci. 37(1):146-159.
Trunk and Root Sprouting on Residual Trees After Thinning a Quercus chrysolepis Stand
Authors: Paysen Timothy E. , Narog Marcia G. , Tissell Robert G. , Lardner Melody A.
Published: April 2024

Canyon live oak (Quercus chrysolepis Liebm.) showed sprouting patterns on root and trunk zones following forest thinning. Root sprouting was heaviest on north and east (downhill) sides of residual trees; bole sprouts were concentrated on the south and west (uphill). Root and bole sprouting appeared to be responding to different stimuli, or responding differently to the same kind of stimulus. Thinning affected sprout growth, but not sprout numbers. Sprouting responses were at the tree level rather than the thinning treatment level. Unexpected sprouting occurred in uncut control plots. Light, temperature, or mechanical activity may have affected sprouting on trees in the thinned plots. A better understanding of factors affecting sprout physiology in this species is required in order to fully explain sprouting responses following stand thinning. For. Sci. 37(1): 17-27.
Biomathematical Growth Equations for Natural Longleaf Pine Stands
Authors: Somers Greg L. , Farrar Robert M.
Published: April 2024

Simultaneous stand level basal area projection and survival prediction equations with useful extrapolative properties are derived from assumptions that reflect many of the currently accepted concepts about stand development. Both equations are modifications of the Chapman-Richard's growth curve which has parameters for the asymptote and the annual rate of growth towards the asymptote. The original form is modified by defining the asymptote and annual growth rate as functions of changing stand conditions. For basal area projection the asymptote is a function of number of trees which approaches zero as density declines. The rate of approach to the asymptote is a function of growth in average dominant and codominant trees and change in average stand age. The survival equation is a reverse Chapman-Richard's curve that approaches zero over time. The asymptotic value is a decreasing function of basal area in accordance with the self-thinning rule. Additional terms controlling the rate of movement away from the asymptote are a minimum mortality rate for low density stands and ingrowth of new trees into the smallest diameter class for young stands with vigorous basal area growth. Nonlinear three-stage least squares procedures are used to simultaneously fit both equations to a natural longleaf pine (Pinus palustris Mill.) permanent plot data set. Predictions are verified using cross-validation procedures, and long-range extrapolations are demonstrated and discussed. For. Sci. 37(1):227-244.
The Effect of Nontimber Taxes on the Harvest Timing—The Case of Private Nonindustrial Forest Owners: A Note
Authors: Ollikainen Markku
Published: April 2024

The paper focuses on how lump sum, exogenous labor income and capital income taxes influence timber supply in a two-period model, when future timber price is uncertain. First, the usual comparative static results are derived. Second, the relative effects of taxes on the timber supply are studied, on the assumption that government keeps the tax revenue constant. It will be established that the entire taxation system, i.e., even nontimber taxes, affect timber supply. Moreover, the supply effects of government tax policy depend crucially on capital market conditions. Under perfect capital markets a switch from lump sum tax towards labor income tax has no effect on supply, and on the other hand, a tax switch toward capital income tax (increased interest payment deductability) decreases timber supply. Under credit rationing the sign of the former switch depends on the relative magnitudes of labor income during the first and second period, and the latter increases timber supply. For. Sci. 37(1):356-363.
Carryover Effects of Acid Rain and Ozone on the Physiology of Multiple Flushes of Loblolly Pine Seedlings
Authors: Sasek Thomas W. , Richardson Curtis J. , Fendick Edward A. , Bevington Stephen R. , Kress Lance W.
Published: April 2024

The effects of acid rain and ozone exposure on loblolly pine (Pinus taeda L.) seedlings in the Piedmont of North Carolina were assessed over two exposure seasons (1987-1988). Direct effects and carryover effects of long-term exposure on the photosynthetic potential and photopigment concentrations of different needle age-classes were studied. Three half-sib families were grown in open-top field chambers and exposed to two acid rain treatments (pH 5.3 or 3.3) and five ozone exposures delivered in proportion to ambient concentrations (0.5x to 3.0x ambient) in a complete factorial design.

Ozone significantly affected photosynthesis but there were no statistically significant effects of add rain nor any ozone x acid rain interactions. In 1987, photosynthesis of the 1987 first-flush progressively diverged among the ozone treatments except between charcoal-filtered (CF ≈ 0.5x ambient) and nonfiltered air (NF). At the end of the first season, photosynthesis was reduced 24% at 1.5x compared to CF and more than 80% at 2.25x and 3.0x. Chlorophyll and carotenoid concentrations were similarly reduced at elevated ozone exposures. In 1988, photosynthesis of the 1987 first-flush in the elevated ozone treatments remained lower. Early in the second season, the 1988 first-flush had a 25% to 50% lower photosynthetic potential at 2.25x and 3.0x compared to CF. This carryover effect on the photosynthetic potential before significant cumulative exposure was progressively smaller in the later 1988 flushes. In the late season flushes in the highest ozone treatments, photosynthesis was significantly higher than in the lower ozone treatments. For. Sci. 37(4):1078-1098.
Increased Site Fertility and Litter Decomposition Rate in High-Pollution Sites in the San Bernardino Mountains
Authors: Fenn Mark
Published: April 2024

Some possible factors causing enhanced litter decomposition in high-pollution sites in the San Bernardino Mountains of southern California were investigated. Nitrogen concentration of soil, as well as foliage and litter of ponderosa pine (Pinus ponderosa Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) were greater in high-pollution plots than in moderate- or low-pollution plots. Nitrogen concentration of soil, foliage, and litter of ponderosa pine (ozone-sensitive), and of the ozone-tolerant spedes, sugar pine (Pinus lambertiana Dougl.) and incense cedar (Calocedrus decurrens [Torr.] Florin.), were all higher at a higher pollution site than at a moderate-pollution site. The rate of litter decomposition for all three species was also greater at the high-pollution site. Results suggest that the primary factor causing enhanced decomposition of L-layer litter in high-pollution plots is greater site fertility, leading to the production of foliage and litter that is higher in N than litter from moderate- or low-pollution plots.

Although foliage of ponderosa pine trees exhibiting symptoms of severe ozone damage in high-pollution plots abscissed 2-4 years earlier than foliage of trees in low-pollution plots, retranslocation of N and P prior to needle abscission was not inhibited in high-pollution plots. Higher N levels in litter in the high-pollution plots does not appear to be due to reduced retranslocation of N from senescing foliage. Litter from ponderosa pine trees with severe symptoms of ozone damage (chlorotic mottle) decomposed at the same rate as litter from adjacent trees with no visible chlorotic mottle.

Treating ponderosa and Jeffrey pine litter from four plots with 2, 20, or 200 mM NH4NO3 significantly increased the rate of litter decomposition at one or more N concentrations in three of the four plots. Total CO2 generated by the decomposing litter during a 15 or 17 day period tended to increase with N amendment, but was significantly increased only with litter from the dogwood plot treated with 200 mM NH4NO3. In some areas in the San Bernardino Mountains, chronic N deposition may stimulate litter decomposition by: (1) increasing site fertility, leading to higher concentrations of N in foliage and litter, and (2) accumulation of N onto litter and plant canopies, which stimulates litter decomposition upon wetting. For. Sci. 37(4):1163-1181.
The Effects of Stand Structure After Thinning on the Growth of an Allegheny Hardwood Stand
Authors: Marqus David A. , Ernst Richard L.
Published: April 2024

A 50-year-old Allegheny hardwood stand in which the crown canopy had stratified into distinct species groups was thinned to 60% relative density leaving dramatically different stand structures and species composition. Treatments included combined thinning, thin from middle, thin from above, thin from below, and unthinned control. Individual tree growth was stimulated most by thinnings that created openings in the main crown canopy and still retained adequate numbers of the larger stems of the faster growing species. Thinning from below, which removed primarily noncommerdal saplings and small poles of the shade-tolerant species, did not affect diameter growth of the larger stems. Total stand growth in basal area and volume was dramatically reduced by thinning from above, which removed nearly all of the larger stems and faster growing species. Treatments that reduced growing stock in the largest size classes, where most of the stand value is concentrated, had a detrimental effect on future timber values. Best individual tree growth, and best stand growth in basal area, cubic volume, board volume, and dollar value occurred in the combined thin treatment. Future yields after any thinning can be viewed as the net effect of reduction in the amount of growing-stock capital and increases in residual tree growth resulting from reduced competition. Recommendations for appropriate types of thinning and timing of the first thinning in stands such as this are provided. For. Sci. 37(4):1182-1200.
A Note on the Optimal Rotation Period in a Synchronized Normal Forest
Authors: Hultkrantz Lars
Published: April 2024

This note compares three alternative rules for choosing the optimal age for cutting trees. The first is the Faustmann-Pressler-Ohlin rule, the second is a rule for the "divisible capital" forest that has been proposed by Oderwald and Duerr, and the third is a rule for a synchronized "normal" forest, i.e., in a case where there is a steady-state constraint. A few comments on the relevance of the latter rule are given. For. Sci. 37(4):1201-1206.
Soils, Seed-Zone Maps, and Physiography: Guidelines for Seed Transfer of Douglas-Fir in Southwestern Oregon
Authors: Campbell Robert K.
Published: April 2024

One procedure for guiding seed transfer is to partition the species habitat into zones within which there is little genetic variation from location to location. This report compares soil types and the existing regional seed zones as bases for classifying geographic genetic variation into zones. The data used were genotypic values of 135 Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees from 80 locations in a 15,000 km² area in southwestern Oregon. Genotypic values were estimated by measuring traits expressing phenology and growth potential of 2-year seedlings in a common-garden experiment. Neither the soils model nor the seed-zones model satisfactorily classified geographic genetic variation (significant lack of fit). When physiographic variables (latitude, longitude, elevation, etc.) were added to the models, the added variables accounted for 16% to 23% of the total variation among locations. Gradients of genetic variation therefore exist within soil types and present seed zones. These gradients reflect the overall gradients of geographic variation with latitude, longitude, and elevation that occur in the region. The results suggest that zones constructed from a physiographic model may explain more of the genetic variation in southwestern Oregon than do either soils or seed-zones models. For. Sci. 37(4):973-986.
Predicting Radiation Attenuation in Stands of Douglas-Fir
Authors: Smith N. J.
Published: April 2024

Forty-one fixed-area plots established in even-aged second-growth Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands were sampled for plot average attenuation of photosynthetically active radiation. Light transmission was modeled as a function of Curtis' relative density and a surrogate for the coeffident of variation of diameter at breast height (dbh). This surrogate, Dratio, was defined as: (Dmax-Dmin)/Dq where Dq is quadratic mean diameter, Dmax is the dbh of the maximum dbh tree, and Dmin is the dbh of the minimum dbh tree in a plot. Dratio helped account for variation in light attenuation associated with different stocking levels for a given relative density. Curtis' relative density and Dratio are easily computed and accurately measured during routine cruising of stands and can be extracted from most stand growth models. The results are applicable to fiat or south-facing slopes within the Vancouver Island dry variant of the Coastal Western Hemlock (CWHal) subzone including second-growth stand habitat of potential importance for the winter range and survival of black-tailed deer (Odocoileus hemionus columbianus Richardson) during severe winters. Results were validated from 27 independent plots. For. Sci. 37(5):1213-1223.
Measuring the Efficiency of Forest Management
Authors: Kao Chiang , Yang Yong Chi
Published: April 2024

In managing forests, the relative efficiency of management accomplishments should be evaluated to obtain a guideline for future planning. However, to evaluate whether a multiple-use forest is efficiently managed is very difficult bemuse many outputs do not have market values. In this paper a model based on the principle of Pareto optimality is introduced for measuring the efficiency of forest management. The model is of a linear fractional program which can be converted to a linear program. The aggregate efficiency of a management unit can be separated into technical and scale efficiency to enable the manager to identify the sources of inefficiency. From the dual formulation of the linear program, the inefficient inputs and outputs can also be identified together with the amounts by which they can be improved. As an illustration, the model is applied to measuring the management efficiency of the 13 districts of the National forests of Taiwan, Republic of China. Surprisingly, the results perfectly explain a current proposal of the Taiwan Forestry Bureau. For. Sci. 37(5):1239-1252.
Amyloglucosidase and α-Amylase Enzymes for Determining Starch Concentration in Ponderosa Pine Root Tissue
Authors: Omi Steven K. , Rose Robin
Published: April 2024

Purified combinations of α-amylase and amyloglucosidase were compared with combinations direct from the supplier to determine their relative precision in estimating starch concentration in root tissue of ponderosa pine (Pinus ponderosa Laws.). For two of the combinations, estimates of starch by an enzymatic digest method were nearly identical, suggesting that an insignificant amount of contaminants was present in the unpurified enzyme combination. The third combination tended to yield slightly lower values of starch, yet was still similar in precision to the other two. We concluded that the purity of purchased enzymes was sufficient for use in the enzyme digest method. For. Sci. 37(5):1479-1483.
Seedling Responses of Five Species of Western Conifers to Simulated Ambient Sulfur Dioxide Exposures
Authors: Leininger Theodor D. , Miller Paul R. , Schilling Susan L. , Dunn Paul H.
Published: April 2024

Seedlings of ponderosa pine, Douglas-fir, white fir, Engelmann spruce, and subalpine fir were exposed continuously to charcoal-filtered (CF) air or one of three levels of a simulated ambient exposure typical of SO2 pollution near smelters in the western United States. Seedlings were exposed during winter-spring experiments for 60 days to hourly means of 17, 38, and 54 ppb in 1988 and 35, 57, and 99 ppb in 1989. Sensitivities of species to SO2 were determined from height growth, diameter growth, root, stem, and needle weights, and from foliar injury.

Ponderosa pine in all SO2 treatments in 1989 had decreased diameter growth and decreased needle weights compared with those in CF air. In 1989, average diameter growth of Douglas-fir in all SO2 treatments was less than those in CF air. Diameter growth and needle weights of ponderosa pine were correlated in all SO2 treatments and CF air. Diameter growth and needle weights of Douglas-fir were correlated in all SO2 treatments. Tip necrosis of needles occurred on a larger proportion of seedlings of all species in high SO2 than on those in CF air. Ponderosa pine and Douglas-fir were about equally sensitive to SO2 and both were more sensitive than white fir. White fir was more sensitive to SO2 than Engelmann spruce and subalpine fir which were equally unresponsive to SO2. For. Sci. 37(6):1538-1549.
Predicting Duff and Woody Fuel Consumption in Northern Idaho Prescribed Fires
Authors: Brown James K. , Reinhardt Elizabeth D. , Fischer William C.
Published: April 2024

Experimental burns were conducted on 36 plots in mixed conifer logging slash in northern Idaho to investigate consumption of duff and woody fuel. Fires were conducted in spring and fall, in YUM (yarded unmerchantable material) and non-YUM dearcuts and seed-tree cuts. Preburn duff depth averaged 3.8 cm and consisted of a shallow layer of decomposing litter, averaging 2 cm, interspersed with deep pockets of rotten wood averaging 13 cm. Preburn total woody fuel quantities ranged from 63 to 193 t/ha. Regression relationships between fuel consumption and fuel characteristics were developed. Duff depth reduction was related to preburn duff depth and to a lesser extent, duff moisture content. Percent duff consumption and mineral soil exposure were related negatively to duff moisture and positively to large fuel (diameter > 7.6 cm) diameter reduction. Diameter reduction of large fuel pieces was positively related to preburn diameter and negatively related to measured moisture content. Consumption of rotten material was greater than that of sound material. These relationships were compared to other empirical fuel consumption models and a theoretical model in predicting our fuel consumption. The relationships presented here can be used to predict duff and woody fuel consumption from prescribed burning in logging slash in the mixed conifer type of the northern Rocky Mountains. For. Sci. 37(6):1550-1566.
Evaluating Forest Management Investments: The Capital Asset Pricing Model and the Income Growth Model
Authors: Wagner John E. , Rideout Douglas B.
Published: April 2024

This article combines an Income Growth Model (IGM) with a nominal and real Capital Asset Pricing Model (CAPM) to evaluate two alternative management regimes using a simulation of two fully regulated Pacific Northwest ponderosa pine (Pinus ponderosa) plantations. The IGM can be used to estimate the cost of capital for nonpublicly traded firms. The IGM was used to estimate a real cost of capital to value the land and timber inventory of the forestry assets. The simulation highlights five findings: (1) the results, both nominal and real, showed that a thinning investment did not reduce financial variability as measured by the beta index of the CAPM; (2) the beta indices indicate the returns to the forestry assets examined were insensitive to nominal or real changes in returns of the market portfolio; (3) a majority of the total variability of the two forestry asset's returns is diversifiable; (4) the forestry assets examined were identified as inferior inflation hedges; and (5) there was no statistical difference between the nominal and real beta indices of the forestry assets examined. Ex post data (particularly market proxy data) cannot prove that the nonthinning regime is ex ante more financially sound, although these results suggest strongly that it is. For. Sci. 37(6):1591-1604.
Evaluation of a Stochastic Diameter Growth Model for Mountain Ash
Authors: Johnson S. E. , Ferguson I. S. , Rong-wei Li
Published: April 2024

A stationary Markov model of diameter growth in mountain ash (Eucalyptus regnans F. Muell.) was evaluated using remeasurement data collected over an 18-year period in a spacing trial located in south-central Victoria, Australia. The assumptions of Markovity and Stationarity central to this approach were tested using χ² statistics not previously employed in this context, The Stationarity assumption was found to be violated in this analysis, leading to the conclusion that alternative time and density dependent models should be pursued for this species. For. Sci. 37(6):1671-1681.
Estimating Log Volume Using the Centroid Position
Authors: Wiant H. V. , Wood G. B. , Furnival G. M.
Published: April 2024

In 8 of 15 comparisons by tree species (6 Australian and 9 American), log volumes were estimated with more precision when the interlog position for measuring cross-sectional area was located at the midvolume (centroid) position rather than the midlength (Newton) position. It is concluded that the centroid of a tree or log defines a position of special significance for estimating volume. A formula is developed for estimating log volume based on measurements of log length and diameter at both ends of the log and at any intermediate position. For. Sci. 38(1):187-191.