bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating Annual Increment Response to Forest Fertilization: A Comparison of Methods by Uniformity Trials
Authors: Monness Erik 
Published: April 2024

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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 &gt; 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

Abstract
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

Abstract
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.