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1.
Availability of solid by-products from wood harvesting and mechanical wood processing was estimated as sources for energy production based on recent actual harvesting, sawmill, and plywood production in Northwest Russia at 30 million m3. Nearly 70% of the energy wood, 20 million m3, was from harvesting, consisting of non-industrial round wood, unused branches and tops, defective wood resulting from logging, and spruce stumps removed after final felling. Over 30%, 10 million m3, of the available volume was from sawmills and plywood mills, i.e. wood chips, sawdust, and bark. Due to current low utilization of energy wood for bioenergy in Northwest Russia, delivery cost of energy wood to the potential border-crossing points in Finland was analyzed for three means of transport: railways, roadways, and waterways. Nearly 28 million m3 of the energy wood could be transported by railways and 2 million m3 by roadways and waterways. The costs were lowest by roadways from the nearby border areas (10–15 €/m3 for wood processing by-products and 16–22 €/m3 for forest chips). The costs by railways varied from 12 to 27 €/m3 on shorter distances to 47–58 €/m3 on longer distances. Waterway transportation was the most expensive, about 28–48 €/m3. It should be emphasized that we have estimated availability and delivery costs of energy wood, not prices which are defined by the market based on supply and demand.  相似文献   

2.
Abstract

This study compares two principally different harvesting systems used for the thinning of Norway spruce [Picea abies (L.) Karst.] plantations in the Alps. The first system was whole-tree harvesting (WTH), producing only whole-tree chips for energy purposes. This system minimizes the production costs by simplifying the harvesting process. The other system was cut-to-length (CTL) mechanical harvesting with an excavator-based harvester. This system maximizes value recovery by producing both short sawlogs and quality fuel chips. Trials were conducted on two similar sites in the Dolomites, in northern Italy, and demonstrated that the CTL system resulted in slightly higher harvesting costs, and also higher revenue. The price differences between the different products determine which system offers the best economic results. If the delivered price of sawlogs does not exceed [euro]25 t?1, WTH and CTL harvesting offer very similar economic performances, and become profitable only if the delivered price of raw chip wood exceeds [euro]40 t?1. If the delivered price of sawlogs increases to [euro]50 t?1, the mechanized CTL system always becomes preferable, and it will turn some profits when the price of raw biomass exceeds [euro]35 t?1. The CTL system is less sensitive to long extraction and transport distances than the WTH system.  相似文献   

3.
Waste wood was studied in an economic enterprise by logging, function, tree species and log size in four Caspian hardwood sites. Damaged logs were recorded with additional information obtained for the location, dimensions and type of damage. The data were analyzed statistically to determine significant differences of damage during logging process. The results indicated that animal harvesting systems cause more volume (40.5% of log volume) and value loss (89.5 $·m?3) to logs than mechanized harvesting systems (13.9% and 6.0 $·m?3), also bucking resulted in significantly more volume (9.9% of log volume) and value loss (5.5 $·m?3) when compared to skidding (0.2% of log volume and 0.2 $·m?3), decking (0.4% of log volume and 0.2 $·m?3) and loading (0.2% of log’s volume and 0.3 $·m?3) operations. Study showed that the processes of skidding, decking and loading of logs have very little impact on damage levels. Volume and value losses of damaged logs are not sensitive to tree species and log size. The information from the field study is important in creating new guidelines or training to help minimize hardwood log damage during the timber harvesting process.  相似文献   

4.
Abstract

The interest in using stump biomass as a biofuel has recently increased in Sweden. The uneven consumption of wood fuel during the year creates a need for storage. This study examined the properties of stump biomass and how they vary at two sites in Sweden depending on harvesting technique, storage method and storage period. Norway spruce stumps, extracted using three different stump harvesting heads (Pallari, Rotary Cutter and Aalto), were stored in windrows or heaps. After 3 months, stumps stored in heaps were gathered into windrows. The fuel quality parameters moisture content (MC), ash content (AC) and calorific value (CV) were evaluated on five occasions in the period May 2008–September 2009. After 16 months of storage, the MC in all treatments had decreased to <25% (wet basis). Average AC decreased from 3.8% to around 1% (dry basis), whereas CV marginally increased. Stumps split during harvesting dried better than those harvested in one piece. The influence of storage method was minimal, although initial storage in heaps allowed better drying in the stumps harvested in one piece. In general, fuel quality improved in all treatments after storage.  相似文献   

5.
We developed a model to estimate supply potentials and available amounts of timber and forest biomass resources from profitable sub-compartments of thinning and final felling operations. Economic balances were estimated while considering not only harvesting expenses but also reforestation expenses after final felling, which should be considered for sustainable forest management. Harvesting expenses were estimated based on two types of timber harvesting systems and three types of forest biomass harvesting systems in each sub-compartment. Then, the model was applied to Nasushiobara city of Tochigi prefecture, Japan. Reforestation expenses had large negative impacts on the financial balances of final felling operations. Few sub-compartments were profitable after considering reforestation expenses. Most profitable sub-compartments were those with mechanized operation systems and landing sales. These accounted for 17.19% of all sub-compartments, while only 5.75% of the sub-compartments were profitable based on their current operation systems and landing sales. Although the overall supply potentials of timber and forest biomass resources were 380,000 m3 and 210,000 Mg, respectively, and 15 times the planned harvest of coniferous tree volume of 25,000 m3year-1 and 50 times the annual demand for the woody gasification power generation of 4,000 Mg year-1 in Nasushiobara, available amounts of timber and forest biomass resources were only49,429 m3 and 33,333 Mg, which were 13.0% and 15.7% of supply potentials for landing sales with mechanized operation systems.  相似文献   

6.
A field-based study was carried out to determine the productivity and production cost of the tree length (TL) and the wood assortment (WA) systems implemented under small-scale forestry conditions in two Scots pine stands in Northern Greece. Tree felling and processing productivity were estimated at 8.64 m3 per productive machine hour (PMH?1) and 10.21 m3 PMH?1, respectively. Wood felling and processing times were strongly dependent on dbh and total tree volume. However, when manual debarking was also considered the productivity rates decreased to 1.96 and 1.43 m3 PMH?1, respectively. Skidding productivity was calculated to be 3.35 m3 PMH?1 for TL and 7.17 m3 PMH?1 for WA, respectively. Strong correlations have been found between the net skidding time and (a) the skidding distance and (b) the load per turn in both wood harvesting systems. Production costs varied greatly, from 19.38 € m?3 up to 44.81 € m?3 of roundwood depending on the harvesting system and the inclusion of debarking. The findings suggest that the WA system is more efficient in terms of productivity and production cost than TL, and that there is a substantial optimization potential. The optimization potential can be encoded in four suggestions: (a) opening up of more forest roads to reduce high skidding times, (b) replacement of manual debarking by mechanical debarking at the sawmill, (c) replacement of old pieces of equipment with newer ones and (d) training of the existing workforce.  相似文献   

7.
The paper focuses on the determination of fuel consumption (CO2 emission) and exhaust emissions such as CO, HC, NOx, and PM in the process of timber extraction and transport. A complex assessment of fuel consumption and exhaust emissions was performed for the entire, fully mechanized supply chain including, tree felling, delimbing, and bucking with a harvester, timber extraction with a forwarder and transport with a truck. The performed investigations determined unit exhaust emissions (referred to 1 m3 of timber) for the entire technological process and its individual stages. The investigations of the exhaust emissions and fuel consumption were performed under actual conditions of typical forest operations and transport. State-of-the-art portable emissions measurement system equipment was used for the measurements. The fuel consumption was determined through the carbon balance method. The investigations were performed for the process of extraction and transport of pulpwood. The measurements were performed on location in the town of B?bnik?t near Poznań, in a pinewood forest, typical of this part of Europe. The analysis includes the transport of timber to the lumberyard on a distance of 31.4 km. The total fuel consumption for the entire mechanized supply chain was 2.10 dm3/m3. The total exhaust emissions, however, amounted to: CO—8.91 g/m3, HC—1.19 g/m3, NOx—45.32 g/m3, PM—4.04 g/m3.  相似文献   

8.

Timber use in central Europe is expected to increase in the future, in line with forest policy goals to strengthen local wood supply for CO2-neutral energy production, construction and other uses. Growing stocks in low-elevation forests in Switzerland are currently high as exemplified by the Swiss canton of Aargau, for which an average volume of 346 ± 16 m3 ha−1 was measured in the 3rd Swiss National forest inventory (NFI) in 2004–2006. While this may justify a reduction of growing stocks through increased timber harvesting, we asked whether such a strategy may conflict with the sustainability of timber production and conservation goals. We evaluated a range of operationally relevant forest management scenarios that varied with respect to rotation length, growing stock targets and the promotion of conifers in the regeneration. The scenarios aimed at increased production of softwood, energy wood, the retention of potential habitat trees (PHTs) and the conversion to a continuous cover management system. They were used to drive the inventory-based forest simulator MASSIMO for 100 years starting in 2007 using the NFI sampling plots in Aargau. We analyzed model outputs with respect to projected future growing stock, growth, timber and energy yield and harvesting costs. We found growing stock to drop to 192 m3 ha−1 in 2106 if business-as-usual (BAU as observed between the 2nd and 3rd NFI) timber volumes were set as harvesting targets for the whole simulation period. The promotion of conifers and a reduction of rotation lengths in a softwood scenario yielded 25% more timber over the whole simulation period than BAU. An energy wood scenario that reduced growing stock to 200 m3 ha−1 by 2056 and promoted the natural broadleaved regeneration yielded 9% more timber than BAU before 2056 and 30% less thereafter due to decreasing increments. The softwood scenario resulted in higher energy yield than the energy wood scenario despite the lower energy content of softwood. Retaining PHT resulted in a reduction of timber harvest (0.055 m3 ha−1 yr−1 per habitat tree) and higher harvesting costs. Continuous cover management yielded moderate timber amounts throughout the simulation period, yet sustainably. Considering climate change, we discuss the risks associated with favoring drought- and disturbance-susceptible conifers at low elevations and emphasize that continuous cover management must allow for the regeneration of drought-adapted tree species. In conclusion, our simulations show potential for short-term increases in timber mobilization but also that such increases need to be carefully balanced with future forest productivity and other forest ecosystem services.

  相似文献   

9.
发达国家木材采运工业现状和发展趋势   总被引:3,自引:0,他引:3  
发达国家木材采运生产在进入全面机械化阶段以来的20多年里,不仅主伐的主要生产作业和准备、辅助作业,而且疏伐作业率成倍增长。技术进步的主要特点是:机械系统更新换代速度加快,推广少剩余物、无剩余物生产工艺;节约能源消耗;重视发展森林作业保护技术。90年代是木材采运向高技术迈进的10年,电子计算机,作业机器人、接收卫星信号的环球地理定位系统、遥控以及专家系统等技术将得到推广应用。  相似文献   

10.
ABSTRACT

Wood supply is one of the most significant cost items for most forest industries, and costs of forest operations and sale prices of wood is vital information for forest owners. Cost trends between 2000 and 2017 in Swedish forestry is analysed, separately for final felling and thinning, and subdivided into ordinary and salvage operations. Data on costs for operations totalling 821 million m3 harvested roundwood were analysed, both as actual costs and after adjustment for the consumer price index. Adjusted costs for ordinary harvesting operations declined between 2000 and 2007, increased during 2008 and 2009 and have since been relatively constant. Costs of salvage logging operations performed as thinning were 21% higher than ordinary thinning, and when performed as final felling costs were 64% higher than in ordinary final felling. The relative logging cost trends in Sweden and Finland were similar during the period, and there are similarities with the US. However, while logging costs in Sweden and Finland increased in 2008 and 2009, they declined in the US and did not reach the same relative level as in Sweden until 2013. Results can be used for benchmarking logging costs between regions or larger buyers of logging services.  相似文献   

11.
Coppice regeneration of eucalypt plantations is increasingly being used in Australia to reduce re-establishment costs. However, little is known about the impact of early coppice reduction regimes on harvester performance during clearfelling. The trial compared the productivity, time consumption, cost and fuel use of a single-grip harvester (Hyundai 210LC-9 base and SP 591LX harvesting head) clearfelling a 10.5-year-old, second-rotation coppiced Eucalyptus globulus stand in south-west Western Australia for chip logs. Coppice stems had been reduced to one stem or two stems per stool or left untreated. Time and piece counts were used to determine harvester productivity. Harvester cycle and elemental times and the number of logs and harvester head passes per stem were obtained from video recordings. Harvester fuel use was determined by refilling the fuel tank to the same point each day. Stem size was the major factor influencing harvester productivity (20.8 m3 per productive machine hour without delays [PMH0], 11.8 m3 PMH0?1 and 8.6 m3 PMH0?1 in the single-stem (mean stem volume [MSV] 0.21 m3), two-stem (MSV 0.09 m3) and untreated trial areas (MSV 0.06 m3), respectively. Estimated harvester cost (AU$ m–3) was considerably greater for the two-stem and untreated trial areas, which reflected the lower harvester productivity in these areas. Processing time represented over 60% of the total cycle time for all trial areas. Coppice characteristics resulted in significantly different moving/positioning times between trial areas. However, this difference had no impact on cycle times. Number of logs per stem was a significant variable in cycle and processing time regressions for all trial areas and felling time for the single-stem trial area. Number of harvester head passes was a significant variable in cycle and processing time regressions for the single-stem trial area and processing times for the two-stem trial area, although its effect was less than that of the number of logs per stem. Fuel consumption (L PMH0?1) was relatively constant between the trial areas, hence harvester energy intensity (L m?3) reflected the harvester productivity in each trial area.  相似文献   

12.
Life-cycle analyses, energy analyses, and a range of utilization efficiencies were developed to determine the carbon dioxide (CO2) and fossil fuel (FF) saved by various solid wood products, wood energy, and unharvested forests. Some products proved very efficient in CO2 and FF savings, while others did not. Not considering forest regrowth after harvest or burning if not harvested, efficient products save much more CO2 than the standing forest; but wood used only for energy generally saves slightly less. Avoided emissions (using wood in place of steel and concrete) contributes the most to CO2 and FF savings compared to the product and wood energy contributions. Burning parts of the harvested logs that are not used for products creates an additional CO2 and FF savings. Using wood substitutes could save 14 to 31% of global CO2 emissions and 12 to 19% of global FF consumption by using 34 to 100% of the world’s sustainable wood growth. Maximizing forest CO2 sequestration may not be compatible with biodiversity. More CO2 can be sequestered synergistically in the products or wood energy and landscape together than in the unharvested landscape. Harvesting sustainably at an optimum stand age will sequester more carbon in the combined products, wood energy, and forest than harvesting sustainably at other ages.  相似文献   

13.
This paper analyses industrial round wood flows into, within, and out of Northwest regions of Russia. We examine sawlogs, pulpwood, and fuelwood used for industrial purposes obtained from logging, and chips obtained from the wood-processing industry. We attempt to clarify different recent trends in wood harvesting, industrial round wood export, and forest industries development that have an influence on unreported wood in Russia. Our method, which uses wood balance diagrams, provides an interpretation of data from different Russian sources in order to offer better transparency regarding wood flows from forests to mills. It also helps to explain the apparent imbalance between round wood supply and demand and it helps one to assess the possible share of unreported industrial round wood production in Northwest Russia. Based on annual forest-related statistical data available from the Ministry of Natural Resources, the State Committee of Statistics, and the Russian Federation’s Customs Department, unreported round wood flows can be estimated to be 23% of the total industrial round wood production, or approximately 9 million m3 u.b. per year. Unreported round wood flows are more common in export oriented regions that have poorly developed forest industries.
Yuri GerasimovEmail: Phone: +358-102-113253Fax: +358-102-113251
  相似文献   

14.
15.

Different classification systems for Norway spruce (Picea abies (L.) Karst.) pulpwood were compared. The classification systems were applied on truckloads or single logs in southern Sweden. Truckload classification according to mean annual growth ring width gave better separation of the wood properties basic density, juvenile wood and dry matter content, than classification according to harvest type (first thinning, later thinning or final felling). The assortments did not have significantly different wood brightness. Sorting at log level according to diameter, mean annual growth ring width or number of annual growth rings, which could be done at harvesting, did not drastically improve differentiation of the mean values of the wood properties or reduce variance compared to truckload classification. The variation in wood properties within assortments remained large owing to the large variation in wood properties between and within logs. Substantial reduction in dry matter variation could be achieved by truckload classification during the summer.  相似文献   

16.
The study determined the productivity, fuel consumption and product quality obtained with a new tractor OWered drum chipper, designed to reduce the gap between industrial chippers and small-scale chippers. The machine as tested with poplar logs and beech slabs, considered as representative of the raw material commonly used for ergy wood production. After accounting for accessory work and delays, productivity of green chips ranged between and 6 tons per scheduled machine hour, which was very good for a tractor-powered unit. Specific fuel consumption f oven-dry chips varied between 2.5 and 3.0 L per ton, or 0.6 L per m_3. These figures compared favourably with those btained from previous studies of both smaller and bigger chippers. Chip quality was very good. Samples contained no versize particles, qualifying for use in small-scale plants. The average size of beech chips was significantly larger than r poplar chips, possibly due to the higher strength of beech wood.  相似文献   

17.
Abstract

Methodology to assess the potential for energy wood procurement in Russia is described in this article and applied to the Leningrad region. Wood from thinnings, logging residues, non-industrial roundwood and residues from sawmilling are considered as sources for energy production. Energy wood available in the region, based on the 2004 actual cut, is approximately 4 million m3. Nearly 86% of this is non-industrial roundwood and felling residues, and 14% is by-products from sawmilling. Almost two-thirds of the non-industrial roundwood and felling residues are in cutting areas and one-third is in central processing yards. Deciduous tree species (birch and aspen) dominate in energy wood, representing about 65% of the total amount of felling residues and non-industrial wood. It is possible to intensify utilization of forest resources and thereby also to increase the use of wood in energy production. The total amount could be 54% higher if the allowable cut was fully utilized and 124% higher if thinnings were also utilized completely. There are, however, significant intraregional differences, as the current rate of utilization of forest resources varies in the region.  相似文献   

18.
The Authors tested a mobile small-log sawmill system that could produce cants and boards of variable size, according to the needs and specifications of each property owner. The unit was deployed as part of a comprehensive mechanical fuel reduction operation, aimed at thinning small properties around homesteads. Working on conifer small logs, the mill proved very efficient, with a processing productivity between 0.3 and 2.8 m3 of lumber per working hour and a recovery rate of 50% for boards, and 67% for cants. The mill could be set up and dismantled in a few hours and was easy to move around. However, the exceedingly small amount of logs available at each site entailed a low utilization of the mill (about 25% of the time) and a consequently high processing cost. Under the conditions of the study, milling cost can be contained below 150 US dollars per m3 of lumber only if the single site offers at least 50 m3 of logs, already sorted during harvesting. Hence the suggestion of pooling the wood obtained from small parcel fuel reduction treatments in satellite yards and milling it only when a large enough amount has been accumulated. In turn, satellite yards could be organized into an integrated network complementary—rather than alternative—to stationary mills.  相似文献   

19.
Timber production is an important ecosystem service of European mountain forests. This paper aimed to assess the current practices in logging operations and to identify the efficiency gaps in timber production. The study was located in 7 case study areas from representative European mountain ranges, where 632 logging operations were analysed. The focus was on road infrastructure, transport systems, harvesting methods and extraction technologies. Often inappropriate technology was used in steep terrain; there was no correlation between the average slope and the selection of harvesting systems (HS). Skidding was the most common extraction method (75%), while cable yarding and forwarding had shares of 15% and 8%. The mean road density was 18.5?m?ha?1. The mean extraction distance was 501?m. The mean harvesting and extraction productivity were 9.0 and 10.2?m³?h?1; the mean costs were 11.1 and 11.7?€?m?³, respectively. Non-mechanized and obsolete HS reported the lowest efficiency and the highest environmental footprint, while fully mechanized systems reported the highest efficiency, the lowest number of accidents and the lowest stand damage. Cable yarders are the appropriate extraction technology in steep terrain, but they require a well-developed road network. Higher mechanization degree, improved quality of the road networks, knowledge transfer to practice and training of forest workers are some of the necessary measures to overcome the efficiency gaps in timber production in European mountain forests.  相似文献   

20.

Logging-related damage to forest regeneration is a problem during final cutting in the shelterwood system. In order to compare the effects of logging methods, damage to natural Norway spruce [Picea abies (L.) Karst.] regeneration caused by single- (SGH) and double-grip harvester (DGH) systems was studied in three shelterwoods (132-234 m3 ob ha-1) in Sweden. Between 38 and 65% of the original seedlings (6 400-25 400 ha-1  相似文献   

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