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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.
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   

3.

Efficient forest management, and wood production in particular, requires a forest road network of appropriate density and bearing capacity. The road network affects the choice of a suitable extraction method and the length of the transport route from the forest, while the road standard defines the truck type that can be used.

We evaluate the forest road network’s economic suitability for harvesting operations in the entire Swiss forest, an area of about 13,000 km2 covering a range of topographies, based on the Swiss National Forest Inventory’s (NFI) forest road dataset. This dataset is based on information from an interview survey with the local forest services and includes all forest roads in Switzerland capable of carrying trucks. Extraction options and hauling routes are analysed together; thus, the entire logging process is examined.

Model results include maps of the most suitable extraction method; extraction costs; hauling costs; and a suitability map based on a combination of the results. While the larger part of the Swiss forest is classified as “suitable” for economic harvesting operations, significant portions also fall into the “limited suitability” and “not suitable” categories. Our analysis provides an objective, country-wide, spatially explicit assessment of timber accessibility. The resulting suitability map helps identify areas where timber harvesting is economic using the current forest road network, and where it is not. The model results can be used in road network planning and management, for example, by comparing road-network re-design scenarios, and compared to the spatial distribution of available wood volume.

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4.

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.

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5.
国外林区道路发展现状及启示   总被引：4，自引：2，他引：2  
林区道路是林业和区域发展不可或缺的基础设施。德国、奥地利等较早实现工业化的欧洲国家林道建设起步早, 现已形成了与本国林业生产作业体系相适应的完善的林道路网体系。奥地利林道密度已达到89 m/hm2, 德国超过100 m/hm2, 英国、法国、美国、加拿大、澳大利亚和新西兰等国家也具备了密集的林道路网体系, 而日本、印度、韩国和俄罗斯林道配置水平较低。文中概述了这些国家林区道路的发展现状和经验教训; 针对我国林区道路总量不足、等级低下等严重滞后问题, 提出合理提高林区道路密度和等级, 林道建设要科学规划合理配置、重视森林生态保护, 制定林道建设技术标准和规程, 减少对环境的负面影响等建议。  相似文献   

6.
A forest road network in northeastern Italy was explored by field investigations to evaluate the cost of covering annual demand of woodchips according to three scenarios. The first scenario (A) considered the current extent of the forest road network (mainly tractor road) and the associated qualitative characteristics; the second scenario (B) evaluated the possibility of increasing the availability of the technical amount of forest biomass by extending the forest road network by three tractor roads (3.9 km); the third scenario (C) considered the impact on woodchip supply of converting 9.3 km of tractor forest road into truck forest road. At a woodchip price of 60 € t−1, the cost–supply curve of scenario C indicated a woodchip amount of 2886 t year−1, which was 561 t year−1 greater than scenario A and 161 t year−1 greater than scenario B.  相似文献   

7.
In the international discussion on labels for sustainably produced wood products based on the certification of sustainable forest management (SFM), little attention has been paid to what is probably the most crucial part of any market-based instrument: the potential impact on forest products markets. This paper analyses the potential impact of SFM-certification on forest products markets using a simulation model of the Western European forest sector. Two scenarios with assumptions regarding certification (chain-of-custody costs, timber supply reduction from certified forests) are projected for the period 1995–2015 and tested against the results of a base scenario (‘business as usual’). In general, the results show that rather modest changes are to be expected from SFM-certification in forest products markets. The market impact of a timber supply reduction from certified forest would be more distinct than the impacts of chain-of-custody costs. Industry gross profits would decrease more than production. Due to the large share of roundwood costs in total costs, the sawmill industry would be affected more by even small changes in raw-material prices than the panel and paper industry.  相似文献   

8.
The structure of forest stands changes through developmental phases. This study is carried out in the unmanaged, oriental beech (Fagus orientalis Lipsky) stands in the north of Iran. The aim of this research was to quantify structural characteristics of stands in the stem exclusion phase using common structural indices, which include mingling, tree–tree distance, stem diameter, and tree height differentiation. According to our measurements from three stands, naturally regenerated stands tend to be mixed in species composition have slightly heterogeneous diameter distributions and uniform tree height. The average distance between trees was 3.3 m. Stocking volume of the stands had an average of 540 m3 ha?1 and 412 stem ha?1. Dead wood volume was 24 m3 ha?1, and as a standing volume, the most frequent species in dead wood pool was oriental beech (F. orientalis) (48 %). The common form of dead trees was snag (41 %). The mean value of mingling and tree-to-tree interval indices revealed that beech was mixed intensively with hornbeam and appears to be a more successful competitor for space and light compared with hornbeam; moreover, we found relatively high evidence of inter-species competition in this phase. A better understanding of stand characteristics in the stem exclusion phase as a critical part of the natural dynamics of forest ecosystems could facilitate predictions about the future changes within the stand.  相似文献   

9.
ABSTRACT

Logging operations in Cameroon are based on the extraction of wood from natural forests. In this article, we assessed the carbon stock in a forest management unit (FMU) located in East Cameroon from field inventory to postfelling operations up to sawmill and export terminals. Tree basal area and aboveground biomass were calculated based on trees inventoried in the annual allowable cut. We observed that from an exploitable tree potential of 0.696 trees ha?1 inventoried within a diameter range of 50–110 cm, 0.141 tree ha?1 (i.e., 20% of the inventoried trees) were logged. In other words, out of 6.78 tC ha?1 inventoried, 1.84 tC ha?1 (i.e., 27% was logged), 1.62 tC ha?1 arrived in the log yard and 1.3 tC ha?1 arrived in sawmill, while 0.32 tC ha?1 reached the export terminal. In terms of damages caused on vegetation, 4.45% of all the annual allowance cut (AAC) were affected during logging activities, this represents almost 33,188.07 tons of carbon. These findings show that the implementation of reduced-impact logging (RIL) could reduce these losses throughout the logging steps and help propose a process for the valuation of wood waste in the forest and sawmill. In this context, reducing emissions from deforestation and degradation will be engaged with the right approach.  相似文献   

10.
The demand for wood as construction material, renewable source for energy and feedstock for chemicals is expected to increase. However, timber increments are currently only partly harvested in many European mountain regions, which may lead to supply shortages for local timber industries, decreases in forest resistance to disturbances and functioning as protection from gravitational hazards. Using an inventory-based forest simulator, we evaluated scenarios to increase wood mobilization in the 7105-km2 Swiss canton of Grisons for the period 2007–2106. Scenarios varied with respect to landscape-scale harvesting amounts and silvicultural strategies (low vs. high stand-scale treatment intensity) and accounted for regulations and incentives for protection forest management. With 50 and 100% increases of harvests, the current average growing stock of 319 m3 ha?1 was simulated to be reduced by 12 and 33%, respectively, until 2106 in protection forests of Northern Grisons, where management is prioritized due to subsidies. Outside protection forests and in Southern Grisons, growing stock was simulated to continually increase, which led to divergent developments in forest structure in- and outside protection forests and in the Northern and Southern Grisons. The effect of silvicultural strategies on simulated forest structure was small compared to the effect of future harvesting levels. We discuss opportunities and threats of decreasing management activities outside protection forests and advocate for incentives to promote natural regeneration also outside protection forests to safeguard long-term forest stability.  相似文献   

11.
Forest roads require important design specifications to ensure all-season access for various vehicles. Long and heavy log trucks can face serious maneuvering problems on forest roads due to insufficient amount of area to the left for road widening on horizontal curves. In order to provide safe and continuous shipment and transportation,appropriate curve widening areas should be provided for long vehicles along horizontal curves. In this study, a statistical model was developed to provide curve-widening solutions for long trucks(e.g., those with 18 wheels) considering various curve radius and deflection angles. The dynamic curve widening feature of Plateia 2013 program was employed to calculate curve widening for the specified vehicle. During the solution process, nine different horizontal curve diameters from 10 to 50 m(by 5 m intervals)and 17 different deflection angles from 90° to 170°(by 5°intervals) were evaluated to run horizontal curve-widening analysis. Using a multiple regression model, we made suitable predictions about curve widening. The curvewidening areas decrease as the horizontal curve radius increases, while increasing the deflection angle on horizontal curves increases curve widening areas. Clearly, the computer-based dynamic curve widening model developed in this study can be effectively used in determining optimum widening for horizontal curves by evaluating the number of alternatives that fit geometrical specifications and vehicle types.  相似文献   

12.
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   

13.
Households and wood processing businesses in the provinces of Son La, Dien Bien and Lai Chau in the Northwest of Vietnam were surveyed to determine patterns of local wood demand and supply, changes in species utilized over time, and whether timber from planted trees might substitute for species previously harvested from local natural forests. In each province, 5–6 sawmills and 4–6 villages representing 3 main ethnic groups were selected for investigation. Managers of selected sawmills and 3–4 randomly selected households in each village were interviewed using semi-structured questionnaires. There was high and uniform household demand for fuelwood in the surveyed villages, making fuelwood the dominant use, in terms of wood volume. Use of sawn timber for furniture, home repair and construction consumed less wood but required logs of acceptable species. Sawmills surveyed were small, with input capacity ranging from <15 to 500 m3 of logs per year, suggesting a total log requirement of about 30,000 m3/year for the 192 known wood processing businesses in the three provinces. Most sawmills still used wood from natural forests, sourced locally or imported from Laos. A trend of switching from prized timber species from natural forests, now effectively unavailable, to alternatives from natural and planted forests was reported by both sawmills and households. Some planted species grown on short-medium rotations appear able to substitute for local sawn timber requirements.  相似文献   

14.
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
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15.
为配合国家计委决定开展的《中国全局节约战略、规划和对策研究》,作者对世界发展趋势进行了分析,认为实行开源与节流并举的方针,在不增或少增原木采伐量的前提下,大力节约木材,充分合理利用木材资源,是适合我国国情的最现实、最有效的措施,也是解决我国林业"两危"的重大战略对策。  相似文献   

16.
Summary A new logging-method, developed in Austria, was tested in an upper Bavarian mountainous forest-district. It is based on a semi-stationary debarker, combined with equipment for cutting the stems into lengths; simultaneously the logs were classified. It is installed on a central conversion-site. The trees were felled and limbed as far as possible without being turned. The stems were then yarded by articulated rubbertired skidders, equipped with double-drum winch and chokers, blade and rear supportblade. Later they were transported by trucks on the forest roads to the conversion-site. In the individual operations time-studies were carried out to analyse the working-processes and to explore their interdependency. The results, calculated by applying statistical methods and computer-programs, were expressed in diagrams, which can be used for the calculation of needed workers and machines for comparable conditions. This very efficient logging-method is then discussed. The high performance in the felling-operations (7.74 m3 p.h.) is remarkable. The time for loading the skidders and trucks was noticeably high. The influence of the slope on the skidders on the returntrip uphill is significant. Finally it is to be noted, that in spite of using big machinery for transport-operations (up to 7 skidders and 2–3 trucks) it was not possible to utilize the debarkers capacity.   相似文献   

17.
Modern forwarders are an effective extraction option for timber harvesting operations that provide the opportunity for higher levels of mechanization. With their ability to carry logs from the forest to the roadside or processing areas, they have an established lower environmental impact in comparison to tree-length skidding options. However, little is published regarding their productivity potential or the factors that influence productivity. Three case studies were carried out; (1) a selective harvest in Calabria, Italy, with a smaller 12 t capacity John Deere 1110E, (2) a clear-cut on the West Coast of New Zealand, with a larger 19 t capacity John Deere 1910E and (3) a larger clear-cut operation in Canterbury, New Zealand, with two John Deere 1910E forwarders. An elemental time and motion study was used resulting in 73.4 h of detailed data, with 159 cycles extracting 2241 m3 of timber. Productivity models were created for all three sites as well as one combined model. Average cycle time was 33.2, 24.2 and 22.8 min, and average productivity 24.6, 37.1 and 42.7 t per productive machine hour, respectively. Cycle time was the fastest, and consequently productivity the highest, at the Canterbury site where the terrain roughness was low, overcoming any effect of the average small piece size (0.59 m3). Travel speed was slowest at the West Coast site showing the effect of wet and difficult terrain, with travel empty speed being just 3.8 km/h, compared to 6.7 and 6.9 km/h at the other two sites. Productivity at the two clear-cut operations was significantly higher than the selective cut, compounded by the use of the larger capacity forwarders. Distance and payload were significant factors for each cycle time model; in the combined model the sites were also significant. The calculated unit cost of forwarder extraction in the sites ranged from €2.55 to €4.70/m3. For regions such as southern Italy that have relatively low levels of forest mechanization, this information can be used to help design and improve more traditional labor-intensive harvesting systems.  相似文献   

18.
We used forest management records to estimate the annual supply potential and availability of timber and logging residue from profitable subcompartments for all the cities and towns in the Tochigi prefecture. Five log markets and three factories in the Tochigi prefecture were assumed to be the destination of timber and logging residue, and the forest operation systems were set on the basis of interviews with forestry cooperative officials. The results showed that the annual supply potential of timber and logging residue was 450,304 m3 and 549,957 tons, of which 6 % (26,304 m3) and 37 % (204,122 tons) were from precommercial thinning operations, 61 % (276,180 m3) and 50 % (276,276 tons) were from commercial thinning operations, and 33 % (147,820 m3) and 13 % (69,559 tons) were from final-felling operations, respectively. When the unit price of the logging residue was 10,000 yen/ton, the annual logging residue availability from profitable subcompartments could almost cover the annual demand of the three facilities that we considered in this study. Introduction of feed-in tariffs had a significant impact. However, the ratios of the availability to supply potential with unit prices of logging residue of 3,000, 6,000, and 10,000 yen/ton were estimated to be only 1.67, 2.06, and 4.09 %, respectively. Considering the subsidies, the ratios respectively increased to 5.79, 7.35, and 13.09 %. Furthermore, the annual logging residue availability with subsidy could meet 70 % of the annual woody biomass demand of the large-scale factory in Sano city, which is 100,000 tons.  相似文献   

19.
Mechanised thinning operations can be carried out in the forest where skid roads are provided on which harvesters and forwarders can move. In the transition to continuous cover forestry (CCF) it is better to keep a thinner network of skid roads in the forest. Instead of tracks for harvesters and forwarders, these areas can be used for younger generations of trees. Moreover, fewer skid roads in the forest environment make the stand more natural. Fewer skid roads were introduced in this research as an alternative thinning operation with midfield1 (MF) to the most popular mechanised thinning operation with skid roads2 (SR). The aim of this paper is to analyse the productivity and economic aspects of thinning operations based on harvesters and forwarders, where there are different distances between skid roads. In both of the operations, harvesters and forwarders were used, but in the MF operation a chainsaw was additionally used to cut trees beyond the reach of the harvester boom. The distances between skid roads in the MF operation were 35–38 m, while in the other they were 18–20 m. The research was carried out in premature pine stands in a flat terrain in Poland. Bigger productivity and lower costs were found in the MF thinning operations. In the younger 44-year-old stand, the average harvester (Timberjack 770) productivity (in operational time) in the MF operation was 5.87 m3h−1 and in the SR operation 4.52 m3h−1; forwarding provided by the Vimek 606 6WD achieved a productivity of 5.03 and 4.52 m3h−1, respectively. In the older 72-year-old stand, the Timberjack 1270B productivity was 11.53 m3h−1 in MF and 8.70 m3h−1 in SR; the Timberjack 1010B forwarder achieved 11.22 m3h−1 (MF) and 8.84 m3h−1(SR).The costs of harvesting and forwarding 1 m3 of wood were lower in the MF operations. In the younger stand, harvesting costs were 5.78 €/m3 (MF) and 6.72 €/m3 (SR) while forwarding costs were 1.94 and 2.18 €/m3 respectively. In the older stand, harvesting costs were 5.58 €/m3 (MF) and 6.78 €/m3 (SR); the forwarding costs were 2.65 €/m3 (MF) and 3.41 €/m3 (SR).  相似文献   

20.
Downed and standing deadwood (DW) is a key resource for maintaining forest biodiversity. Although extreme events such as windthrow and fires produce large quantities of DW, this substrate is often drastically reduced by logging activities. To elucidate the respecting consequences of salvage-logging, we assessed both quantity and quality of storm-derived DW (storms Vivian 1990 and Lothar 1999) in Swiss forests using a sample of 90 windthrow sites with ≥3 ha complete windthrow and at elevations ranging from 350 to 1,800 m a.s.l. The majority had been salvage-logged (SL) a few years after the windthrow. On each site, we recorded DW amount and quality on six circular sample plots 20 or 50 m2 in size. DW volume on SL sites was surprisingly high, with 76.4 m3 ha?1 on average 20 years after Vivian and 73.8 m3 ha?1 10 years after Lothar. In comparison, DW volumes on unsalvaged sites, that is, with no post-windthrow intervention (NI), amounted to 270 m3 ha?1. A wide variety of wood decay stages and diameter classes (10 to ≥70 cm) was found on both NI and SL sites, suggesting considerable habitat diversity for DW-associated species irrespective of the treatment. The considerable amounts of DW left after salvage-logging distinctly exceed the minimum DW volumes in forest stands proposed by Müller and Bütler (Eur J For Res 129: 981–992, 2010) in a conservation context, which demonstrates the importance of wind disturbance for biodiversity. Further studies should quantify DW of individual tree species, since habitat requirements are species-specific.  相似文献   

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