Sample records for sawlogs

  1. The Value Versus Volume Yield Problem for Live-Sawn Hardwood Sawlogs (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman


    The potential conflict between value and volume maximization in sawing hardwood sawlogs by the live sawing method was analyzed. Twenty-four digitally described red oak sawlogs were sawn at the log orientation of highest value yield. Five opening face sawlines were iteratively placed in the sawlog a 1/4-inch intervals and lumber grades, volumes, and values from...

  2. 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 ...

  3. Merchantable sawlog and bole-length equations for the Northeastern United States (United States)

    Daniel A. Yaussy; Martin E. Dale; Martin E. Dale


    A modified Richards growth model is used to develop species-specific coefficients for equations estimating the merchantable sawlog and bole lengths of trees from 25 species groups common to the Northeastern United States. These regression coefficients have been incorporated into the growth-and-yield simulation software, NE-TWIGS.

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

    Energy Technology Data Exchange (ETDEWEB)


    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.

  5. 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


    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.

  6. Sawlog sizes: a comparison in two Appalachian areas (United States)

    Curtis D. Goho; A. Jeff Martin


    Frequency distributions of log diameter and length were prepared for eight Appalachian hardwood species. Data obtained in Ohio, Kentucky, and Tennessee, were compared with information collected previously from West Virginia and New England. With the exception of red oak, significant regional differences were found.

  7. Influence of Lumber Volume Maximization in Sawing Hardwood Sawlogs (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman


    The Best Opening Face (BOF) technology for volume maximization during sawing has been rapidly adopted by softwood sawmills. Application of this technology in hardwood sawmills has been limited because of their emphasis on sawing for the highest possible grade of lumber. The reason for this emphasis is that there is a relatively large difference in price between the...

  8. Adjusting Quality index Log Values to Represent Local and Regional Commercial Sawlog Product Values (United States)

    Orris D. McCauley; Joseph J. Mendel; Joseph J. Mendel


    The primary purpose of this paper is not only to report the results of a comparative analysis as to how well the Q.I. method predicts log product values when compared to commercial sawmill log output values, but also to develop a methodology which will facilitate the comparison and provide the adjustments needed by the sawmill operator.

  9. Impacts of changing hardwood lumber consumption and price on stumpage and sawlog prices in Ohio (United States)

    William Luppold; Matthew Bumgardner; T. Eric. McConnell


    In the early 2000s, increasing US furniture imports preceded declining US hardwood lumber demand and price. In the summer of 2002, however, hardwood lumber prices started to increase as demand by construction industries increased. By the mid-2000s, hardwood lumber prices hit all-time highs. Lumber prices hit all-time highs for red oak (Quercus spp...

  10. Influence of Lumber Volume Maximization on Value in Sawing Hardwood Sawlogs (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman


    Research based on applying volume-maximizing sawing solutions to idealized hardwood log forms has shown that average lumber yield can be increased by 6 percent. It is possible, however, that a lumber volume-maximizing solution may result in a decrease in lumber grade and a net reduction in total value of sawn lumber. The objective of this study was to determine the...

  11. Crown releasing of red maple poles to shorten high-quality sawlog rotations (United States)

    Gayne G. Erdmann; Ralph M., Jr. Peterson; Robert R. Orberg


    The effects of six crown-release treatments on growth and bole quality development of 54-year-old dominant, codominant, and intermediate red maples (Acer rubrum L.) were evaluated on a good red maple site (site index = 19.3 mat 50 years) in upper Michigan. Results showed that crown release stimulated the growth of dominants, codominants, and strong...

  12. Effect of logging wounds on diameter growth of sawlog-size Appalachian hardwood crop trees (United States)

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


    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....

  13. Appalachian hardwood stump sprouts are potential sawlog crop trees. Research note NE-299. [Oak, maple, linden, cherry trees

    Energy Technology Data Exchange (ETDEWEB)

    Lanson, N.I.


    Dbh and height of 8- and 12-year-old coppice shoots and the number of live shoots were recorded for 736 stumps at least 12 inches in diameter of Liriodendron tulipifera, Prunus serotina, Quercus rubra, Acer rubrum, and Tilia americana in north-central West Virgina. Of the 8-year-old shoots, T. americana had the greatest number of live stems/stump (16.8) and the greatest number of potential crop trees (dominant or co-dominant shoots attached to the stump not more than 6 inches above the ground), averaging 2.5 stems/stump. The average numbers of potential crop trees/stump were similar at 8 and 12 year. At 12 years, at least 88% of stumps of each species had at least one stem of groundline origin with no forks below 25 feet were 84% for L. tulipifera, 59% for Q rubra, 73% for A. rubrum, and 65% for P. Serotina.

  14. The effect of curve sawing two-sided cants from small diameter hardwood sawlogs on lumber and pallet part yields (United States)

    Peter Hamner; Marshall S. White; Philip A. Araman


    Curve sawing is a primary log breakdown process that incorporates gang-saw technology to allow two-sided cants from logs with sweep to be cut parallel to the log surface or log axis. Since curve-sawn logs with sweep are cut along the grain, the potential for producing high quality straight-grain lumber and cants increases, and strength, stiffness, and dimensional...

  15. Economics of Coharvesting Smallwood by Chainsaw and Skidder for Crop Tree Management in Missouri (United States)

    Peter Becker; E.M.(Ted) Bilek; Terry Cunningham; Michael Bill; Marty Calvert; Jason Jensen; Michael Norris; Terry Thompson


    Forest improvement harvests using individual-tree and group selection were conducted in four oak or oak-hickory stands in the Missouri Ozarks with conventional equipment (chainsaw and skidder). Volumes (and revenues) for different timber classes (sawlogs and smallwood from topwood and small trees) and hours of machine use were recorded to calculate production rates....

  16. Predicting logging residues: an interim equation for Appalachian oak sawtimber (United States)

    A. Jeff Martin


    An equation, using dbh, dbh², bole length, and sawlog height to predict the cubic-foot volume of logging residue per tree, was developed from data collected on 36 mixed oaks in southwestern Virginia. The equation produced reliable results for small sawtimber trees, but additional research is needed for other species, sites, and utilization practices.

  17. Oklahoma forest industries, 1978 (United States)

    Victor A. Rudis; J. Greg Jones


    Oklahoma supplied 73 million cu ft of roundwood to forest industries in 1978, an increase of 13 percent since 1972, and 35 percent since 1975 (fig. 1). Pine made up four-fifths of the total. Sawlogs and pulpwood were the major products, accounting for 81 percent of the roundwood produced. Veneer logs accounted for 8 percent and the remainder was mostly posts.

  18. Impact of Early Pruning and Thinning on Lumber Grade Yield From Loblolly Pine (United States)

    Alexander Clark; Mike Strub; Larry R. Anderson; H. Gwynne Lloyd; Richard F. Daniels; James H. Scarborough


    The Sudden Sawlog Study was established in 1954 near Crossett, AR, in a 9-year-old loblolly pine plantation to test the hypothesis that loblolly plantations can produce sawtimber in 30 years. To stimulate diameter and height growth and clear wood production, study plots were heavily thinned, trees pruned to 33 feet by age 24 years, under-story mowed, and growth of...

  19. The development of reforestation options for dryland farmland in ...

    African Journals Online (AJOL)

    This zone is beset with land degradation problems, such as salinity and wind erosion, and there has been considerable effort in the last three decades to develop reforestation options to stabilise the landscapes. Traditional forestry approaches using pulp wood or sawlog production in this zone have been limited by ...

  20. Yield and ultrasonic modulus of elasticity of red maple veneer (United States)

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


    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...

  1. Analyzing Investments in Thin-Kerf Saws (United States)

    Philip H. Steele; Philip A. Araman


    The rising cost of hardwood sawlogs has increasd sawmill managers' interest in considering the installation of thin-kerf sawing machines in their sawmills. Replacement of circular headrigs by band headrigs and/or reducing resaw kerfs are the available options. Equipment replacement or modification to achieve thin-kerf sawing will require an investment. Sawmill...

  2. Cradle-to-gate life cycle impacts of redwood forest resource harvesting in northern California (United States)

    Han-Sup Han; Elaine Oneil; Richard D. Bergman; Ivan L. Eastin; Leonard R. Johnson


    The first life cycle impact assessment for redwood (Sequoia sempervirens) forest management activities (i.e. a cradle-to-sawmill gate input) including the growing, harvesting, and hauling of redwood sawlogs to a sawmill was completed. In the stump-to-truck timber harvesting analysis, primary transport activities such as skidding and yarding consumed...

  3. Imports and exports of roundwood in the upper Midwestern United States. Chapter 2. (United States)

    Charles H. Perry; Mark D. Nelson; Ronald J. Piva


    Industrial roundwood is the raw material produced from harvested trees that is used to manufacture a wide range of wood products. Roundwood is harvested from the forest and is transported to primary manufacturing facilities to be processed into primary and secondary wood products. Roundwood includes sawlogs that are processed into...

  4. Coast redwood live crown and sapwood (United States)

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


    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....

  5. Geographic information system-based spatial analysis of sawmill wood procurement (United States)

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


    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...

  6. Ultrafast CT scanning of an oak log for internal defects (United States)

    Francis G. Wagner; Fred W. Taylor; Douglas S. Ladd; Charles W. McMillin; Fredrick L. Roder


    Detecting internal defects in sawlogs and veneer logs with computerized tomographic (CT) scanning is possible, but has been impractical due to the long scanning time required. This research investigated a new scanner able to acquire 34 cross-sectional log scans per second. This scanning rate translates to a linear log feed rate of 85 feet (25.91 m) per minute at one...

  7. 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 ...

  8. Michigan timber industry: An assessment of timber product output and use, 1990. Forest Service resource bulletin

    International Nuclear Information System (INIS)

    Hackett, R.L.; Pilon, J.


    The bulletin discusses recent Michigan forest industry trends and reports the results of a detailed study of forest industry, industrial roundwood production, and associated primary mill wood and bark residue in Michigan in 1990. Such detailed information is necessary for intelligent planning and decisionmaking in wood procurement, forest resource management, and forest industry development. Likewise, researchers need current forest industry and industrial roundwood information for planning projects. All board foot data in the report have been converted to International 1/4 inch scale by applying a multiplier of 1.08 to all saw-log volume reported in Scribner Decimal C scale by sawmills, a multiplier of 1.04 to all veneer log volume reported in Scribner Decimal C scale by veneer mills, a multiplier of 1.38 to all saw-log volume reported in Doyle scale by sawmills, and a multiplier of 1.14 to all veneer log volume reported in Doyle scale by veneer mills

  9. Flexural properties of laminated veneer lumber manufactured from ultrasonically rated red maple veneer : a pilot study. (United States)

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


    The study described in this report was conducted to examine the flexural properties of laminated veneer lumber (LVL) manufactured from red maple veneer. Ultrasonically rated veneer, which was peeled from low value red maple saw-logs, was fabricated into 1/2-in.-(1.3-cm-) and 2-in.-(5-cm-) thick LVL billets. The flexural properties of the billets and of corresponding...

  10. Three diameter-limit cuttings in West Virginia hardwoods a 5-year report (United States)

    Russell J. Hutnik


    Mine timbers are a basic need of West Virginia's giant coal industry. The annual requirement of sawed mine timbers is roughly 250 million board feet. The mines also use a large volume of wood in rough form for props and lagging. Yet, compared to sawlogs and veneer logs, these mine timbers are low-value products. This means that they must be produced at low cost....

  11. Beech wood export and import trends in Serbia

    Directory of Open Access Journals (Sweden)

    Ranković Nenad


    Full Text Available By the establishment and analysis of the model of beech wood export and export trends in Serbia (by quantity and value, for the period 1988-2002 the regularities of the changes of their magnitude in time were defined. On this basis, the relations of import and export trends were analyzed. Based on the study elements, the potentials of beech sawlog and beech sawnwood export, as well as the potential economic effects, were pointed out.


    Directory of Open Access Journals (Sweden)

    Miloš Gejdoš


    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.

  13. Global warming response options in Brazil's forest sector: comparison of project-level costs and benefits

    International Nuclear Information System (INIS)

    Fearnside, P.M.


    A project-level assessment of monetary and carbon costs and benefits for five classes of global warming response options in the forest sector is attempted for typical Brazilian conditions. Options considered are: silvicultural plantations (for pulp, charcoal and sawlogs), sustainable timber management and reduction of deforestation. Comparison of pulpwood and sawlog plantations with the vegetation characteristic of deforested areas indicates of modest carbon benefit. Plantations for charcoal can produce a substantial carbon benefit through fossil fuel substitution, but much of this calculated benefit disappears if discount rates greater than zero are applied to carbon. Sustainable timber management, when compared with existing forest, represents a net carbon loss, accumulation of carbon in wood products being insufficient to compensate for biomass reduction over a 100 year time scale. Reduction of deforestation has great potential as a global warming response option, its per-hectare carbon benefits being approximately four times that of silvicultural plantation establishment for pulp and sawlogs over a 100 year period. The costs of reducing deforestation are difficult to assess, however, due to the importance of government policy changes such as removal of land speculation and land tenure establishment as motives for clearing. Although these changes would not cost money and would have tremendous carbon and other benefits, they have not yet occurred. (Author)

  14. Productivity and cost of harvesting a stemwood biomass product from integrated cut-to-length harvest operations in Australian Pinus radiata plantations

    International Nuclear Information System (INIS)

    Walsh, D.; Strandgard, M.


    Significant quantities of woody biomass from the tops of trees and larger woody ‘waste’ pieces that fall outside existing sawlog and pulpwood specifications are left on site post final harvest in Australian radiata Pinus radiata (D. Don) (radiata pine) plantations. Woody biomass is a potential product for pulp making or energy generation. Commercial use of woody biomass from radiata pine plantations would add extra value to the Australian plantation estate through improved resource utilisation, and potentially reduced post-harvesting silvicultural costs. This study investigated the productivity and cost impact of the harvest and extraction to roadside of woody biomass in an integrated harvest operation in a typical Australian two machine (harvester/processor and forwarder), cut-to-length, clearfall operation in a mature, thinned radiata pine plantation. The harvest operation yielded 23 GMt/ha (5% of the total yield) of woody biomass (known as ‘fibreplus’), 443 GMt/ha of sawlogs and 28 GMt/ha of pulpwood. The mean quantity of biomass left on site was 128 GMt/ha, mainly consisting of branches and needles, sufficient to minimise nutrient loss and protect the soil from erosion. Woodchips derived from the fibreplus product were suitable for kraft pulp making, (when blended in small amounts with clean de-barked roundwood woodchips), and for energy generation. The method trialed with the fibreplus product being produced did not impact harvesting and processing productivity and costs, but extraction was 14% less productive. Through analysis of the productivities of each phase and development of a cost model the harvest and extraction of the fibreplus product was estimated to increase total unit costs by ∼4.9%. - Highlights: • Study of the productivity and cost impact of producing a woody biomass product. • We compared two scenarios – harvesting with and without the biomass product. • An additional 23 GMt/ha (5% of the total yield) of woody biomass

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

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    Jean-Pierre eThibaut


    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.

  16. Possible effects of the hurricane Gudrun on the regional Swedish forest energy supply

    International Nuclear Information System (INIS)

    Bjoerheden, Rolf


    This paper presents a snapshot speculative analysis of some possible effects of the massive windthrow in south Sweden on January 8-9, 2005. Hurricane Gudrun damaged buildings and blocked roads, making large areas inaccessible except by helicopter. Electricity and telecommunications were shambolic. Around 70 million cubic metres were windthrown, equalling a 'normal' Swedish annual felling-a gross value exceeding EUR20,000,000,000. The paper presents the subsequent restoration work that has placed a special focus on the forest sector. In south Sweden, logging work will last for a couple of years. The roundwood market will be severely strained. For individual forest owners, the economic effects of the storm are often disastrous. To ensure that forest owners will retrieve at least part of the pre-storm forest value, restoration aims at the salvaging of maximum value. Sawmills try to store the most valuable timber for years to come, decreasing the risk of painful capacity adjustments and protecting export opportunities. Forest fuel value is low compared to sawlogs and pulpwood. Thus, the forest energy sector has received little attention. Forest chippers normally contribute important marginal quantities of wood fuels, but since no logging residues will be harvested from the windthrown forests for a period of 2-3 years, they are put out of business and may disappear from the market. Heating and power plants will receive an abundance of industrial by-products in the coming 2-3 years, followed by a period of expected shortage of woody biomass for energy production. With few forest chippers left, the situation will be troublesome. (author)

  17. Overview and forecast on forestry productions worldwide. (United States)

    Wenjun, Zhang


    Our world is largely dependent upon the forestry productions. Through the exploitation of forest reserves, we manufacture various industrial products, furniture, and obtain fuel and energy. Forestry productions should be conducted without large-scale deforestation and environmental degradation. In present study we perform a review and forecast analysis on forestry productions worldwide, with the objectives of providing an insight into the trend for several types of forestry productions in the future, and providing referential data for sustainable forestry productions and environmental management. Polynomial functions are used to fit trajectories of forestry productions since 1961 and forecasts during the coming 20 years are given in detail. If the past pattern continues, world fibreboard production would dramatically grow and reach 224,300,000 +/- 44,400,000 m(3) by the year 2020, an increase up to 240.7 to 408.9% as compared to the present level. Roundwood production of the world would change by -55.5 to 70.4% and reach 3,526,600,000 +/- 2,066,800,000 m(3) by 2020. In 2020 world production of sawlogs and veneer logs would change by -100 to 164.6% and reach 1,212,900,000 +/- 1,242,600,000 m(3). Global wood fuel production would change by -68.9 to 1.4% and reach 1,130,900,000 +/- 600,800,000 m(3) by 2020. Forestry productions in developed countries would largely surpass productions in developing countries in the near future. World forestry production grew since 1961 excluding wood fuel. Roundwood and wood fuel account for the critical proportions in the forestry productions. Wood fuel production has being declined and rapid growing of roundwood production has slowed in recent years. Widespread use of regenerative wood substitutes and worldwide afforestation against deforestation will be among the most effective ways to reduce deforestation and environment degradation associated with forestry productions.

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

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    William L. Mason


    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.

  19. Net carbon dioxide emissions from alternative firewood-production systems in Australia

    International Nuclear Information System (INIS)

    Paul, K.I.; Booth, T.H.; Jovanovic, T.; Polglase, P.J.; Elliott, A.; Kirschbaum, M.U.F.


    The use of firewood for domestic heating has the potential to reduce fossil-fuel use and associated CO 2 emissions. The level of possible reductions depends upon the extent to which firewood off-sets the use of fossil fuels, the efficiency with which wood is burnt, and use of fossil fuels for collection and transport of firewood. Plantations grown for firewood also have a cost of emissions associated with their establishment. Applying the FullCAM model and additional calculations, these factors were examined for various management scenarios under three contrasting firewood production systems (native woodland, sustainably managed native forest, and newly established plantations) in low-medium rainfall (600-800mm) regions of south-eastern Australia. Estimates of carbon dioxide emissions per unit of heat energy produced for all scenarios were lower than for non-renewable energy sources (which generally emit about 0.3-1.0kgCO 2 kWh -1 ). Amongst the scenarios, emissions were greatest when wood was periodically collected from dead wood in woodlands (0.11kgCO 2 kWh -1 ), and was much lower when obtained from harvest residues and dead wood in native forests ( 2 kWh -1 ). When wood was obtained from plantations established on previously cleared agricultural land, use of firewood led to carbon sequestration equivalent to -0.06kgCO 2 kWh -1 for firewood obtained from a coppiced plantation, and -0.17kgCO 2 kWh -1 for firewood collected from thinnings, slash and other residue in a plantation grown for sawlog production. An uncertainty analysis, where inputs and assumptions were varied in relation to a plausible range of management practices, identified the most important influencing factors and an expected range in predicted net amount of CO 2 emitted per unit of heat energy produced from burning firewood. (author)

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

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    Domke Grant M


    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