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Sample records for sawlogs

  1. Softwood sawlog secondary transport travel speed prediction for the ...

    African Journals Online (AJOL)

    The objective of this study was to develop a predictive model for travel speed of softwood sawlog timber transport (STT) vehicles over a range of forest and provincial roads of varying condition for the South African forestry industry. Data was accumulated from both the Eastern Cape/KwaZulu-Natal and Mpumalanga forest ...

  2. Productivity and Cost of Integrated Harvesting of Wood Chips and Sawlogs in Stand Conversion Operations

    Directory of Open Access Journals (Sweden)

    Hunter Harrill

    2012-01-01

    Full Text Available This study evaluated the operational performance and cost of an integrated harvesting system that harvested sawlogs and biomass (i.e., energy wood chips in stand conversion clearcut operations. Douglas-fir (Pseudotsuga menziesii trees were processed into sawlogs while whole trees of tanoak (Lithocarpus densiflorus, and sub-merchantable materials (small-diameter trees, tops and limbs were fed directly into a chipper to produce biomass for energy production. A standard time study method was used to determine productivity and costs. Over 26 working days, the integrated system produced 1,316 bone-dry metric tonnes (BDTs of sawlogs, and 5,415.89 BDT of chips, with an average moisture content of 43.2%. Using the joint products allocation costing method, the costs of the integrated system were $29.87/BDT for biomass and $4.26/BDT for sawlogs. Chipping utilization was as low as 41%, directly affecting production and cost of chipping operation. Single-lane, dirt, spur roads were the most costly road type to transport whole trees to a centralized processing site: transportation costs for biomass and sawlogs were increased by $0.08/BDT and $0.02/BDT, respectively, for every 50 meter increase in traveling distance. Diesel fuel price could raise total system cost for each product by $0.78/BDT and $0.08/BDT for each $0.10/liter increase.

  3. Barge loading facilities in conjunction with wood chipping and sawlog mill, Tennessee River Mile 145. 9R: Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    1990-08-01

    The purpose of this Environmental Assessment (EA) is to evaluate the environmental consequences of approving, denying, or adopting reasonable alternatives to a request for barge loading facilities. These facilities would serve a proposed wood chipping and sawlog products operation at Tennessee River Mile (TRM) 145.9, right descending bank, (Kentucky Lake), in Perry County, Tennessee. The site is located between Short Creek and Peters Landing. The applicant is Southeastern Forest Products, L.P. (SFP), Box 73, Linden, Tennessee and the proposed facilities would be constructed on or adjacent to company owned land. Portions of the barge terminal would be constructed on land over which flood easement rights are held by the United States of America and administered by the Tennessee Valley Authority (TVA). The US Army Corps of Engineers (CE) and TVA have regulatory control over the proposed barge terminal facilities since the action would involve construction in the Tennessee River which is a navigable water of the United States. The wood chipping and sawlog products facilities proposed on the upland property are not regulated by the CE or TVA. On the basis of the analysis which follows, it has been determined that a modified proposal (as described herein) would not significantly affect the quality of the human environment, and does not require the preparation of an environmental impact statement. 8 refs.

  4. Effects of Harvesting Systems and Bole Moisture Loss on Weight Scaling of Douglas-Fir Sawlogs (Pseudotsuga Menziesii var. glauca Franco

    Directory of Open Access Journals (Sweden)

    Jarred D. Saralecos

    2014-09-01

    Full Text Available Characterizing the moisture loss from felled trees is essential for determining weight-to-volume (W-V relationships in softwood sawlogs. Several factors affect moisture loss, but research to quantify the effects of bole size and harvest method is limited. This study was designed to test whether bole size, harvest method, environmental factors, and the associated changes in stem moisture content of felled Douglas-fir (Pseudotsuga menziesii var. glauca Franco affected the weight-to-volume relationship of sawlogs. Thirty trees in three size classes (12.7–25.4 cm, 25.5–38.1 cm, 38.2–50.8 cm were felled and treated with one of two harvesting processing methods. Moisture content was sampled every two days for four weeks. Results showed 6% greater moisture loss in the crowns of stems that retained limbs after felling compared to stems with limbs removed after harvesting. Additionally, moisture loss rate increased as stem size decreased. The smallest size class lost 58% moisture content compared to 34% in the largest size class throughout the study duration. These stem moisture content changes showed a 17% reduction in average sawlog weight within the largest size class, shifting current W-V relationships from 2.33 tons m−3 to 1.94 tons m−3 during the third seasonal quarter for northern Idaho Douglas-fir and potentially altering relationships year-round.

  5. Sawlog grades for eastern white pine

    Science.gov (United States)

    Myron D. Ostrander; Robert L. Brisbin; Robert L. Brisbin

    1971-01-01

    In 1957, the USDA Forest Service Log Grade Committee recommended a service-wide action program in log- and tree-grade research. Approval of the program in 1958 resulted in the establishment of five species-oriented timber-quality research projects covering several groups of commercially important timber species. The eastern softwood timber-quality project was activated...

  6. Sawtimber by Prescription - The Sudden Sawlog Story Through Age 33

    Science.gov (United States)

    J.D. Burton

    1982-01-01

    Presents total and net yield, standing volume, volume harvested, and natural mortality, in cubic feet i.b. to a 3-inch top d.i.b., and in board feet Int. ¼ to an 8-inch and to a 6-inch top, together with dbh distribution at various ages.

  7. Long- and short-term changes in nutrient availability following commercial sawlog harvest via cable logging

    Science.gov (United States)

    Jennifer Knoepp; Wayne Swank; Bruce L. Haines

    2014-01-01

    Soil nutrient availability often limits forest productivity and soils have considerable variation in their ability to supply nutrients. Most southern Appalachian forests are minimally managed with no fertilizer inputs or routine thinning regime. Nutrient availability is regulated by atmospheric inputs and the internal cycling of nutrients through such processes as...

  8. Effect of logging wounds on diameter growth of sawlog-size Appalachian hardwood crop trees

    Science.gov (United States)

    Neil I. Lamson; H. Clay Smith; H. Clay Smith

    1988-01-01

    In previously thinned, even-aged Appalachian hardwood stands, 5-year diameter growth of 102 wounded and 102 unwounded codominant crop trees were compared. A wounded crop tre was defined as one with at least one exposed sapwood logging wound at least 100 inch2 in size. An unwounded crop tree of the same species and size was selected near each of the 102 wounded trees....

  9. Comparison of mechanized systems for thinning Ponderosa pine and mixed conifer stands

    Science.gov (United States)

    Bruce R. Hartsough; Joseph F. McNeel; Thomas A. Durston; Bryce J. Stokes

    1994-01-01

    We studied three systems for thinning pine plantations and naturally-regenerated stands on the Stanislaus National Forest, California. All three produced small sawlogs and fuel chips. The whole tree system consisted of a feller buncher, skidder, stroke processor, loader and chipper. The cut-to-length system included a harvester, forwarder, loader and chipper. A hybrid...

  10. Variation in strength, stiffness and related wood properties in young ...

    African Journals Online (AJOL)

    The objective of this study was to examine the variation in and intercorrelation among wood properties determining the suitability of 16- to 20-year-old South African-grown Pinus patula trees for structural timber. A total of 1 112 sawn boards from 340 logs, 170 trees and 17 different compartments were examined. Sawlogs ...

  11. Yield and ultrasonic modulus of elasticity of red maple veneer

    Science.gov (United States)

    Robert J. Ross; Steven Verhey; John R. Erickson; John W. Forsman; Brian K. Brashaw; Crystal L. Pilon; Xiping Wang

    2004-01-01

    The purpose of the study was to assess the potential for using red maple sawlogs to manufacture laminated veneer lumber (LVL). The primary objective was to determine the yield of ultrasonically graded veneer from red maple logs. A sample of 48 logs was obtained from six Eastern and Lake States in the United States. The logs were visually graded and shipped to a plywood...

  12. A form of two-phase sampling utilizing regression analysis

    Science.gov (United States)

    Michael A. Fiery; John R. Brooks

    2007-01-01

    A two-phase sampling technique was introduced and tested on several horizontal point sampling inventories of hardwood tracts located in northern West Virginia and western Maryland. In this sampling procedure species and dbh are recorded for all “in-trees” on all sample points. Sawlog merchantable height was recorded on a subsample of intensively measured (second phase...

  13. Utilizing hardwood logging residue: a case study in the Appalachians

    Science.gov (United States)

    E. Paul Craft

    1976-01-01

    An Appalachian hardwood timber stand that contained 6,700 board feet per acre of sawtimber was harvested by clearcutting. After the merchantable sawlogs were removed, this stand contained 69.3 tons per acre of green wood residue. Thirty-three and one-third tons of residue were from tops of merchantable sawtimber; 36 tons were from residual trees. Treetop residue...

  14. Adventitious shoot regeneration and rooting of Prunus serotina in vitro cultures

    Science.gov (United States)

    Ana Carolina Espinosa; Paula M. Pijut; Charles H. Michler

    2006-01-01

    A complete regeneration protocol was developed for Prunus serotina Ehrh., an important hardwood species for timber and sawlog production in the central and eastern United States. Nodal sections were cultures on Murashige and Skoog (MS) medium supplemented with 4.44 µM 6-benzylaminopurine (BA), 0.49 µM indole-3-butyric acid (IBA),...

  15. Anomalous dark growth rings in black cherry

    Science.gov (United States)

    Robert P. Long; David W. Trimpey; Michael C. Wiemann; Susan L. Stout

    2012-01-01

    Anomalous dark growth rings have been observed in black cherry (Prunus serotina) sawlogs from northwestern Pennsylvania making the logs unsuitable for veneer products. Thirty-six cross sections with dark rings, each traceable to one of ten stands, were obtained from a local mill and sections were dated and annual ring widths were measured. One or...

  16. Small-diameter timber utilization in Wisconsin: a case study of four counties

    Science.gov (United States)

    Scott A. Bowe; Matthew S. Bumgardner

    2006-01-01

    The state of Wisconsin has numerous forest ownership types. These include national, state, and county forests, as well as privately owned industrial and nonindustrial forests. In addition to sawlog markets, portions of the state also have substantial pulpwood markets associated with paper and panel mills. Combined, these attributes make Wisconsin a good location for...

  17. Joint production and substitution in timber supply: a panel data analysis

    Science.gov (United States)

    Torjus F Bolkesjo; Joseph Buongiorno; Birger Solberg

    2010-01-01

    Supply equations for sawlog and pulpwood were developed with a panel of data from 102 Norwegian municipalities, observed from 1980 to 2000. Static and dynamic models were estimated by cross-section, time-series andpanel data methods. A static model estimated by first differencing gavethe best overall results in terms of theoretical expectations, pattern ofresiduals,...

  18. Geographic information system-based spatial analysis of sawmill wood procurement

    Science.gov (United States)

    Nathaniel M. Anderson; Rene H. Germain; Eddie Bevilacqua

    2011-01-01

    In the sawmill sector of the forest products industry, the clustering of mills and wide variation in forest stocking and ownership result in sawlog markets that are complex and spatially differentiated. Despite the inherent spatial attributes of markets for stumpage and logs, few studies have used geospatial methods to examine wood procurement in detail across...

  19. Integrated harvesting for conventional log and energy wood ...

    African Journals Online (AJOL)

    In the integrated energy wood harvesting plot, 37 m3 ha−1 of energy wood was extracted in addition to the sawlog and pulp log volumes. Extracting the additional energy wood reduced the productivity of the forwarder and increased the cost of extraction (AU$2.7 m−3) compared with the control plot (AU$2.2 m−3).

  20. Characteristics of factory-grade hardwood logs delivered to Appalachian sawmills

    Science.gov (United States)

    Curtis D. Goho; Paul S. Wysor; Paul S. Wysor

    1970-01-01

    Until now, information about the characteristics of sawlogs delivered to Appalachian sawmills has been generally unavailable. We know what the standing timber is like, from forest-survey data. But this paper covers a different spectrum: the frequency distributions-by size, grade, volume, and species group-of factory-grade logs actually harvested and delivered to the...

  1. Effects of forest management on soil carbon: results of some long-term resampling studies

    Science.gov (United States)

    D.W. Johnson; Jennifer D. Knoepp; Wayne T. Swank; J. Shan; L.A. Morris; David H. D.H. van Lear; P.R. Kapeluck

    2002-01-01

    The effects of harvest intensity (sawlog, SAW; whole tree, WTH; and complete tree, CTH) on biomass and soil carbon (C) were studied in four forested sites in the Southeastern United States: (mixed deciduous forests at Oak Ridge, TN and Coweeta, NC; Pinus taeda at Clemson, SC; and P. eliottii at Bradford, FL). In general, harvesting had no lasting...

  2. Coast redwood live crown and sapwood

    Science.gov (United States)

    John-Pascal Berrill; Jesse L. Deffress; Jessica M. Engle

    2012-01-01

    Understanding crown rise and sapwood taper will help meet management objectives such as producing long branch-free boles for clear wood and old-growth restoration, or producing sawlogs with a high proportion of heartwood. Coast redwood (Sequoia sempervirens) tree crown ratio data were collected 20 years after partial harvesting in a 65-year-old second growth stand....

  3. Assessing the lumber manufacturing sector in western Washington

    Science.gov (United States)

    Jean M. Daniels

    2010-01-01

    The production structure of the lumber manufacturing sector in western Washington was investigated using a translog cost function with capital. labor, and sawlog inputs. Analyses were performed with a panel data set of biennial observations from 1972 to 2002 on a cross section of 16 western Washington counties. Production structure was examined using Allen and...

  4. The effect of planting density on the wood quality of South African ...

    African Journals Online (AJOL)

    This paper presents the results of a wood property and sawn board quality study performed on disc samples and sawlogs taken from a 23-year-old Eucalyptus grandis Nelder 1a spacing trial at J.D.M. Keet plantation near Tzaneen. Ten trees from each of four markedly different planting densities were chosen to provide ...

  5. Highlights from wood for structural and architectural purposes

    Science.gov (United States)

    C.W. Boyd; P. Koch; H.B. McKean; C.R. Morschauser; S.B. Preston; F.F. Wangaard

    1977-01-01

    In 1970 the softwood and hardwood forests of the United States yielded 193 million tons (OD basis) of sawlogs, veneer logs, pulpwood, miscellaneous industrial wood, and fuel wood. By 1965, demand for such wood will likely be in the range from 248 to 260 million tons, while supply should be about 260 million tons. By the year 2000, demand will probably be in the range...

  6. PREDICTION AND ANALYSIS OF SLOVAKIAN TIMBER TRADE ON GLOBAL MARKET CONDITIONS

    Directory of Open Access Journals (Sweden)

    Miloš Gejdoš

    2017-11-01

    Full Text Available In Slovakian forestry the main source of finance is the wood sale. The main aim of this paper is to evaluate the assortments supply structure (quality management, prices development for the coniferous sawlogs and to set the future prediction of this development in new global market conditions, which are affected mainly by the global climate changes. Price changes were analysed for the period of the years from 2000 to March 2016 for the spruce and fir sawlogs. Data about the volume supply of raw-wood assortments in Slovakia for years 2005-2014 were collected from “Green Reports“ published by the Ministry of Agriculture and Rural Development of the Slovak Republic. From the influence factors in the studied period, the biggest impact was assigned to the global economic crisis. The prediction captures the further decline of prices of raw-wood assortments. In the second half of the year 2016 the price of sawlogs decreased by € 4 per 1 m3. Local impacts, the structure of wood processors and specific trade area in Slovakia affected substantially the structure of assortments on Market. There is also some space for a better evaluation of harvested wood.

  7. Trends in economic scarcity of U. S. timber commodities. Forest Service Resource Bulletin

    Energy Technology Data Exchange (ETDEWEB)

    Skog, K.; Risbrudt, C.

    1982-04-01

    Scarcity of natural resources has been of concern to industrial societies since Malthus developed his theory of population growth and resource use in the late 18th century. Barnett and Morse, in 1963, tested the widely held premise that natural resource commodities are becoming more economically scarce. They concluded that of all major natural resource commodities-agricultural, mineral, and timber-only timber commodities were increasing in economic scarcity. In particular, sawlogs have shown consistent increases in economic scarcity since the late 1800's. Data were prepared for the Barnett and Morse study by Potter and Christy and subsequently updated by Potter and Christy and subsequently updated by Manthy to 1973. This paper extends and expands these data series on timber commodities. Specifically, information will be presented on one indicator of economic scarcity-trends in real prices (prices deflated by the general producer price index).

  8. Commercial Thinning to Meet Wood Production Objectives and Develop Structural Heterogeneity: A Case Study in the Spruce-Fir Forest, Quebec, Canada

    Directory of Open Access Journals (Sweden)

    Martin-Michel Gauthier

    2015-02-01

    Full Text Available We evaluated the effectiveness of commercial thinning mainly from below (CT; 0, 26%, 32% and 40% merchantable basal area removals in meeting wood production demands and developing structural heterogeneity in a balsam fir (Abies balsamea (L. Mill and spruce (Picea spp. stand. After 10 years, 32%–40% removals showed a 12%–18% increase in mean diameter and 27%–38% increase in gross merchantable volume (GMV per tree compared to the unthinned control. At the stand level, all thinning treatments generated as much cumulative GMV (harvested volume + GMV after 10 years and gross sawlog volume per hectare as the unthinned control. As for stand structure, eight out of nine thinned experimental units showed increased structural heterogeneity after 10 years, i.e., irregular, positively-skewed diameter distribution with an elongated right tail toward larger trees. The diameter distribution in the unthinned control became more symmetric, unimodal and regular over time, with fewer saplings than at the beginning of the experiment and lower density of larger trees compared to CT. Regeneration density and stocking were abundant in all treatments, largely dominated by balsam fir. Results indicate that thinning can be used to meet wood production objectives and help develop structural heterogeneity in this forest.

  9. Young children’s learning of relational categories:multiple comparisons and their cognitive constraints

    Directory of Open Access Journals (Sweden)

    Jean-Pierre eThibaut

    2015-05-01

    Full Text Available Relational categories are notoriously difficult to learn because they are not defined by intrinsic stable properties. We studied the impact of comparisons on relational concept learning with a novel word learning task in 42-month-old children. Capitalizing on Gentner et al. (2011, two, three or four pairs of stimuli were introduced with a novel relational word. In a given trial, the set of pairs was composed of either close or far pairs (e.g., close pair: knife1-watermelon, knife2-orange, knife3-slice of bread and knife4-meat; far pair: ax-evergreen tree, saw-log, cutter-cardboard and knife-slice of bread, for the cutter for relation. Close pairs (2 vs. 3 vs. 4 pairs led to random generalizations whereas comparisons with far pairs gave the expected relational generalization. The 3 pair case gave the best results. It is argued that far pairs promote deeper comparisons than close pairs. As shown by a control experiment, this was the case only when far pairs display well known associations.

  10. Acoustic-Based Non-Destructive Estimation of Wood Quality Attributes within Standing Red Pine Trees

    Directory of Open Access Journals (Sweden)

    Peter F. Newton

    2017-10-01

    Full Text Available The relationship between acoustic velocity (vd and the dynamic modulus of elasticity (me, wood density (wd, microfibril angle, tracheid wall thickness (wt,, radial and tangential diameters, fibre coarseness (co and specific surface area (sa, within standing red pine (Pinus resinosa Ait. trees, was investigated. The data acquisition phase involved 3 basic steps: (1 random selection of 54 sample trees from 2 intensively-managed 80-year-old plantations in central Canada; (2 attainment of cardinal-based vd measurements transecting the breast-height position on each sample tree; and (3 felling, sectioning and obtaining cross-sectional samples from the first 5.3 m sawlog from which Silviscan-based area-weighted mean attribute estimates were determined. The data analysis phase consisted of applying graphical and correlation analyses to specify regression models for each of the 8 attribute-acoustic velocity relationships. Results indicated that viable relationships were obtained for me, wd, wt, co and sa based on a set of statistical measures: goodness-of-fit (42%, 14%, 45%, 27% and 43% of the variability explained, respectively, lack-of-fit (unbiasedness and predictive precision (±12%, ±8%, ±7%, ±8% and ±6% error tolerance intervals, respectively. Non-destructive approaches for estimating the prerequisite wd value when deploying the analytical framework were also empirically evaluated. Collectively, the proposed approach and associated results provide the foundation for the development of a comprehensive and precise end-product segregation strategy for use in red pine management.

  11. Evaluating Double Entry Logging for Forest Residue Recovery in Southwestern Oregon.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Lawrence F.; Craig, Linda S.; Buscaglia, Phillip

    1985-09-01

    The objective of this research was to compare actual cost and production between conventional logging practices and double entry methods for residue removal in old-growth fir and pine of southwest Oregon using an actual timber sale, to determine and report benefits of the double entry concept to the study cooperators, any uncontrolled variables in the study which could influence the results, and how the order of yarding influences the results; and to compute the cost of logging with the double-entry method, the cost and quantity of the residue removed, and the cost of delivering the fuel to a theoretical cogeneration plant 14 miles from the timber sale. As a result of the study it might be concluded that situations where double entry appears to be cost effective would be those which have a large variation in piece size, require YUM yarding to a 6'' by 8' or smaller size piece, are on steep terrain, and have an understory with many small unmerchantable logs and residue mixed with the large overstory trees. A similar study in the intermountain region by Leonard Johnson of the University of Idaho found that a 29% increased sawlog recovery was accompanied by a 63% increased gross return per acre and a 58% increased cost per acre. The added cost of double entry did not offset all traditional costs of slash disposal. However, if slash disposal requires yarding of residues, the cost per acre is reduced by the double entry method. Johnson made similar findings of the need to determine most optimum terrain and tree species for the method and to improve the yarder and various loading options. 6 refs., 13 figs., 23 tabs.

  12. Long-term development of nursing mixtures of Sitka spruce and larch species in an experiment in northern Scotland

    Directory of Open Access Journals (Sweden)

    William L. Mason

    2014-12-01

    Full Text Available Aim of the study: An experiment was established in 1966 to compare the growth and development of 50: 50 mixtures of Sitka spruce (Picea sitchensis with either Japanese larch (Larix kaempferi or tamarack (L. laricina with that found in pure plots of Sitka spruce. The site was one of moderate nitrogen availability where the presence of heather (Calluna vulgaris could be expected to limit the growth ofSitka spruce.Area of the study: North-east Scotland.Material and methods: There were different patterns of spruce growth in the pure plots and in the mixtures, with faster spruce growth in mixture in the years approaching and immediately following canopy closure (i.e. ages 15-25. Foliage analysis suggested that this was linked with improved nitrogen status of spruce trees in the mixed compared to the pure plots.Main results: At years 20 and 25 there were significant differences in height, diameter, and basal area between treatments, with the largest basal area being found in the Japanese larch/Sitka spruce mixtures, indicative of overyielding in the mixed plots. However, when the experiment was clearfelled at 41 years of age, all treatments had self-thinned to produce spruce dominated stands of similar height with only an occasional larch tree surviving in plots that were originally 50:50 mixtures.Research highlights: There were no differences between treatments in basal area, harvested volume or sawlog outturn after 41 years. These results can be interpreted as showing facilitation between the larch and the spruce during the establishment phase followed by competition for light once canopy closure had occurred.Keywords: Mixed stand dynamics; facilitation; nitrogen status; product outturn.

  13. Accounting for density reduction and structural loss in standing dead trees: Implications for forest biomass and carbon stock estimates in the United States.

    Science.gov (United States)

    Domke, Grant M; Woodall, Christopher W; Smith, James E

    2011-11-24

    Standing dead trees are one component of forest ecosystem dead wood carbon (C) pools, whose national stock is estimated by the U.S. as required by the United Nations Framework Convention on Climate Change. Historically, standing dead tree C has been estimated as a function of live tree growing stock volume in the U.S.'s National Greenhouse Gas Inventory. Initiated in 1998, the USDA Forest Service's Forest Inventory and Analysis program (responsible for compiling the Nation's forest C estimates) began consistent nationwide sampling of standing dead trees, which may now supplant previous purely model-based approaches to standing dead biomass and C stock estimation. A substantial hurdle to estimating standing dead tree biomass and C attributes is that traditional estimation procedures are based on merchantability paradigms that may not reflect density reductions or structural loss due to decomposition common in standing dead trees. The goal of this study was to incorporate standing dead tree adjustments into the current estimation procedures and assess how biomass and C stocks change at multiple spatial scales. Accounting for decay and structural loss in standing dead trees significantly decreased tree- and plot-level C stock estimates (and subsequent C stocks) by decay class and tree component. At a regional scale, incorporating adjustment factors decreased standing dead quaking aspen biomass estimates by almost 50 percent in the Lake States and Douglas-fir estimates by more than 36 percent in the Pacific Northwest. Substantial overestimates of standing dead tree biomass and C stocks occur when one does not account for density reductions or structural loss. Forest inventory estimation procedures that are descended from merchantability standards may need to be revised toward a more holistic approach to determining standing dead tree biomass and C attributes (i.e., attributes of tree biomass outside of sawlog portions). Incorporating density reductions and structural

  14. Análise da rentabilidade econômica dos reflorestamentos com essências nativas brasileiras: o caso do Estado de São Paulo Economic profitability analysis of reforestation with native trees: the state of São Paulo's case

    Directory of Open Access Journals (Sweden)

    José Arimatéia Rabelo Machado

    2002-01-01

    Full Text Available No presente trabalho, analisou-se a rentabilidade econômica dos reflorestamentos com essências nativas brasileiras destinados à produção de toras, considerando como caso em estudo o Estado de São Paulo. Na revisão de literatura, constatou-se que poucos são os trabalhos publicados a respeito do reflorestamento com essências nativas e com um longo período de observação. Dentre esses trabalhos, destacou-se um, no qual os autores recomendaram três espécies florestais como viáveis para reflorestamentos comerciais: Centrolobium tomentosum (araruva, Balfourodendron riedelianum (pau-marfim e Araucaria angustifolia (pinheiro-brasileiro. Após recuperar as informações técnicas dos experimentos com essas essências nativas, realizou-se a análise de rentabilidade econômica de possíveis projetos, em condições deterministas e de risco. Concluiu-se que, do ponto de vista privado, os projetos de reflorestamento com essas essências nativas são viáveis economicamente. Diante desse cenário, sugerem-se novas linhas de pesquisa técnica capazes de gerar resultados que assegurem maior confiabilidade e ampliação na rentabilidade dos projetos de reflorestamento com essências nativas brasileiras.This paper analyzes the economic profitability of native-tree reforestation for the production of sawlogs. The projects evaluated are experimental rather than commercial and are located in the Brazilian state of São Paulo. These experimental plots were reforested with the native tree species Centrolobium tomentosum ("araruva", Balforodendron riedelianum ("pau-marfim" and Araucaria angustifolia ("pinheiro-brasileiro", recommended for their economic value by a previous evaluation of long-term native-tree reforestation. Economic profitability analyses were made under both deterministic and risk conditions using data from the reforestation experiments. It was found that all the experiments would be profitable. This paper concludes with the suggestion

  15. Accounting for density reduction and structural loss in standing dead trees: Implications for forest biomass and carbon stock estimates in the United States

    Directory of Open Access Journals (Sweden)

    Domke Grant M

    2011-11-01

    Full Text Available Abstract Background Standing dead trees are one component of forest ecosystem dead wood carbon (C pools, whose national stock is estimated by the U.S. as required by the United Nations Framework Convention on Climate Change. Historically, standing dead tree C has been estimated as a function of live tree growing stock volume in the U.S.'s National Greenhouse Gas Inventory. Initiated in 1998, the USDA Forest Service's Forest Inventory and Analysis program (responsible for compiling the Nation's forest C estimates began consistent nationwide sampling of standing dead trees, which may now supplant previous purely model-based approaches to standing dead biomass and C stock estimation. A substantial hurdle to estimating standing dead tree biomass and C attributes is that traditional estimation procedures are based on merchantability paradigms that may not reflect density reductions or structural loss due to decomposition common in standing dead trees. The goal of this study was to incorporate standing dead tree adjustments into the current estimation procedures and assess how biomass and C stocks change at multiple spatial scales. Results Accounting for decay and structural loss in standing dead trees significantly decreased tree- and plot-level C stock estimates (and subsequent C stocks by decay class and tree component. At a regional scale, incorporating adjustment factors decreased standing dead quaking aspen biomass estimates by almost 50 percent in the Lake States and Douglas-fir estimates by more than 36 percent in the Pacific Northwest. Conclusions Substantial overestimates of standing dead tree biomass and C stocks occur when one does not account for density reductions or structural loss. Forest inventory estimation procedures that are descended from merchantability standards may need to be revised toward a more holistic approach to determining standing dead tree biomass and C attributes (i.e., attributes of tree biomass outside of sawlog

  16. Historical land-use changes and potential effects on stream disturbance in the Ozark Plateaus, Missouri

    Science.gov (United States)

    Jacobson, Robert B.; Primm, Alexander T.

    1997-01-01

    Land-use changes have been blamed for creating disturbance in the morphology of streams in the Ozark Plateaus, Missouri (hereafter referred to as the "Ozarks"). Historical evidence and stratigraphic observations document that streams have been aggraded by substantial quantities of gravel beginning sometime at or near the time of European settlement of the Ozarks. Before European settlement, streams were depositing a mixed sediment load of gravel bedload and silty overbank sediment. Observations of early explorers conspicuously lack descriptions of extensive gravel bars; observations of geologists working during the middle to late 1800's before significant landuse disturbance, however, include descriptions of large quantities of gravel in stream banks and beds.The first change in land cover as settlement progressed from the early 1800's to approximately 1880 was replacement of valley-bottom forest with cultivated fields and pastures. At the same time, suppression of wildfires in the uplands caused an increase of woodland with woody understory at the expense of grassland and oak savannah. Valley-bottom clearing probably initiated some direct disturbance of stream channels, but fire suppression would have decreased runoff and sediment yield from uplands.Beginning sometime from 1870 to 1880 and continuing until 1920, commercial timber companies began large operations in the Ozarks to harvest shortleaf pine for sawlogs and oak for railroad ties. Selective cutting of large timber, use of livestock for skidding logs from the forest, and avoidance of the steeper slopes minimized the effect of this phase of logging on runoff and sediment supply of uplands and valley-side slopes. Continued decreases in the erosional resistance of valley bottoms through clearing and road building and the incidence of extreme regional floods from 1895 to 1915 probably caused initiation of moderate stream disturbance. This hypothesis is supported by historical and oral-historical observations