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1.
We used GIS on a regional scale to estimate and compare supply potentials and costs of small-scale logging systems, a mini-forwarder and a 4-ton truck operated by private logging contractors, and manual logging and a light truck operated by individual forest own- ers, with the mechanized operational system of the Forest Owners' Asso- ciation. Total potential yields of timber and logging residues were esti- mated as 418,895 m3 and 254,962 m3, respectively. The economic bal- ances were estimated and available amounts were projected as supply potentials from profitable sub-compartments. As a result, available amounts of timber and logging residues were estimated at 375,466 m3 (89.9%) and 203,850 m3 (80.0%), respectively. Because their transport expenses were lower than for other systems the most profitable sub-compartments were operated by private logging contractors who sold logging residues at a plant. The profitable sub-compartments operated by individual forest owners were few because the extracting distances were usually greater than 20 m. Raising logging residue prices from 3,000 yen·m-3 to 4,080 yen·m-3 or 6,800 yen·m-3, and establishing forest roads, which reduced some extracting distances to less than 20 m, increased the number and area of profitable sub*compartments, and increased available amounts of logging residues.  相似文献   
2.
This study examines the optimal method to extract logging residues from small, fragmented and scattered forests separately from the mechanized operational systems used on aggregated forestry operation sites. First, small-scale logging systems operated by a private logging contractor and an individual forest owner were investigated. Regression equations for estimating felling and processing cycle times were established as a function of stem and log volumes, respectively. Equations to estimate the forwarding and transporting cycle times were established as a function of the forwarding and transporting distances using the forwarding and transporting velocities, respectively. Then, equations to estimate productivities and costs were established with the cycle times, volumes and hourly operational expenses consisting of labour and machinery expenses. Finally, costs of the small-scale systems—mini-forwarder and 4 t truck operated by a private logging contractor, and manual logging and light truck operated by an individual forest owner—were estimated and compared with the mechanized operation system operated by the Forest Owners’ Association. The mechanized operation system was found to have the highest cost and could not compete for small forestry operational sites and small stem volumes. The small-scale systems could be effective for harvesting small areas. This was especially true when conducting extracting operations without machines, as done by the individual forest owner, and transporting operations by a private logging contractor, in which the hourly income of the individual forest owner was higher than the hourly labour expenses.  相似文献   
3.
Using the method of a life cycle inventory (LCI) analysis, the energy balance and the carbon dioxide (CO2) emission of logging residues from Japanese conventional forestry as alternative energy resources were analyzed over the entire life cycle of the residues. The fuel consumption for forestry machines was measured in field experiments for harvesting and transporting logging residues at forestry operating sites in Japan. In addition, a total audit of energy consumption was undertaken. It involved an assessment of materials, construction, and the repair and maintenance of forestry machines as well as the costs associated with an energy-conversion plant. As a result, the ratio of energy output to input was calculated to be 5.69, indicating that the system examined in this study could be feasible as an energy production system. The CO2 emission per MWhe (e: electricity) of the biomass-fired power generation plant was calculated to be 61.8kgCO2/MWhe, while that of coal-fired power generation plants in Japan is 960kgCO2/MWhe. Therefore, the reduction in the amount of CO2 emission that would result from replacing coal with biomass for power generation by as much as 3.0 million dry-t/year of logging residues in Japan was estimated to be 1.66 million tCO2/year, corresponding to 0.142% of the national CO2 emission. This study provides evidence that Japan could reduce its domestic CO2 emission by using logging residues as alternative energy resources.  相似文献   
4.
In this study we developed a forest road design program based on a high-resolution digital elevation model (DEM) from a light detection and ranging (LIDAR) system. After a designer has located the intersection points on a horizontal plane, the model first generates the horizontal alignment and the ground profile. The model precisely generates cross-sections and accurately calculates earthwork volumes using a high-resolution DEM. The model then optimizes the vertical alignment based on construction and maintenance costs using a heuristic technique known as tabu search. As the distance between cross-sections affects the accuracy of earthwork volume calculations, the results were examined by comparing them with the exact earthwork volume calculated by the probabilistic Monte Carlo simulation method. The earthwork volumes calculated by the Pappus-based method were similar to those calculated by the Monte Carlo simulation when the distance between cross-sections was within 10m. The model was applied to a high-resolution DEM from the LIDAR of Capitol Forest in Washington State, USA. The model generated a horizontal alignment, length 827m, composed of five horizontal curves. We examined the number of grade change points. The results indicated that tabu search found the best solution ($61.42/m) with five grade change points. This was composed of two vertical curves that almost followed the ground profile. As the accuracy of a high-resolution DEM from LIDAR increases, the model would become a useful tool for a forest road designer because it eliminates or at least reduces the time-consuming process of road surveys.  相似文献   
5.
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   
6.
We investigated a developed arm roll forwarder at Nasu in Tochigi Prefecture, Japan. An arm roll forwarder can only load a steel container that has been fully loaded with logs beforehand, and can later unload such a container. Such a forwarder can shorten the loading and unloading times and improve operational efficiency. We examined two operation systems with an arm roll forwarder and a forwarder. In the first system the loading was done with a grapple-loader. In the second system the loading was done with a processor. The loading times of an arm roll forwarder were significantly less than those of a forwarder. Because the optimal cycle times (excluding the waiting times for an arm roll forwarder) were significantly reduced, the costs of using an arm roll forwarder are lower, although the loading capacity was small and the hourly operation cost was high. The maximum operational efficiencies varied depending on forwarding distances. The second operation system with an arm roll forwarder exhibited the best operational efficiency within a 1,580-m forwarding distance, and beyond that distance it exhibited the highest operational efficiency when a forwarder was used. Similarly, the cost of operation of the system with an arm roll forwarder was the lowest within a 1,130-m forwarding distance, and beyond that distance the cost was the lowest when using the forwarder. Therefore, the arm roll forwarder is effective within a certain forwarding distance.  相似文献   
7.
In this study, we combined a program to optimize forest road alignments with a method for prediction of surface erosion and related sediment delivered to streams. Combining the forest road design program with the high-resolution digital elevation model made it possible to estimate soil sediment based on a standard methodology, because a relatively accurate road prism could be generated. The combined program properly places and spaces drainage structures based on the Washington State Forest practice board manual. We applied the program to a part of Capitol State Forest in Washington State and optimized horizontal and vertical alignments while estimating movement of soil sediment from roads to streams. We discussed the effects of road surface materials, near-stream culvert distance to stream, and out-sloped forest road template on total road costs and soil sediment delivered to streams. Using lower quality rock surfacing reduced total costs, but the amount of soil sediment from lower quality rock surfacing was 1.5 times more than that on a higher quality rock traction surface. Therefore, lower quality rock surfacing should not be used near the stream. The placement of near-stream culverts 15 m upstream and out-sloped road template were examined using a traction surface on 15-m sections upstream and lower quality rock surfacing on other sections in order to reduce soil sediments to the stream and total costs. As a result, placing near-stream culverts 15 m upstream and using an out-sloped road template significantly reduced total road cost and soil sediment. Finally, we optimized horizontal and vertical alignments while limiting soil sediment to a specified maximum level. The model successfully optimized forest road alignments, which reduced total road cost as well as soil sediment.  相似文献   
8.
This article describes a program for optimizing horizontal and vertical alignments of forest roads using Tabu search, a modern heuristic technique. Once a series of intersection points (IPs) is selected manually, the program generates alternative horizontal and vertical alignments. The program precisely generates ground profile and cross sections using a high-resolution digital elevation model (DEM) derived from light detection and ranging (LiDAR) data. It accurately calculates earthwork volumes for curved roadways using the Pappus-based method. The program also estimates construction and maintenance costs. Tabu search optimizes forest road alignments based on the total costs. The application of the program to part of Capitol State Forest in Washington State, USA, indicated that the program successfully found better alignments than manually selected initial alignments. The effect of initial solutions and the number of iterations on the Tabu search process was examined. The result showed that the solutions were improved using the best solutions with the smaller number of grade change points as the initial solutions. It also showed that a small number of iterations could be used to reduce computation time due to the fact that Tabu search is based on a gradient search technique. Finally, the Dijkstra method was examined to find initial solutions without manually initialized solutions. The program, when combined with the Dijkstra method, could find similar-quality solutions from manually initialized solutions. The program will become useful with further tests and verifications.  相似文献   
9.
The purpose of this study was to examine the effect of time for mating and gestation length on reproductive efficiency in dogs. Groups of eight, six and six beagle bitches were mated with a total of three sires on days 3, 5 and 7, respectively, after the luteinizing hormone (LH) surge. All the bitches whelped successfully. The gestation lengths (the intervals from the LH surge to the whelping) were 65.1 +/- 1.9, 65.5 +/- 1.9 and 68.0 +/- 1.8 days, respectively. This length of mating 7 days after the LH surge was significantly longer than that of mating 3 and 5 days after the LH surge (p < 0.05). The litter sizes were 5.5 +/- 2.2, 6.2 +/- 1.9 and 4.8 +/- 2.1, respectively and there was no significant difference between any of the groups. In conclusion, mating 3-7 days after a bitch's LH surge results in a good reproductive efficiency and the intervals from the LH surge to the whelping of mating 7 days after the LH surge shows a longer day significantly in comparison with mating 3 and 5 days after the LH surge.  相似文献   
10.
Medium to large size harvester heads mounted on large machines are popular in Japan. These machines encounter some problems during thinning operations,e.g. damage to residual stand and the compaction of soil. The performance of these large harvesters was compared with that of smaller ones operating simultaneously in the same line thinning operation of the same stand. The results of a time study showed that mean cycle times for the smaller and larger harvesters were not significantly different. This means that the work efficiency of the smaller harvester can be at the same level as the larger harvester on sites similar to those of this study. The mean values “Feed” element of the cycle time, however, were significantly different. Although this time difference appears to provide an advantage to the larger harvester, simulation results show that the advantage is not great enough to significantly shorten the total cycle times. That is to say, the work efficiency remains essentially the same even if the feeding performance of the small size harvester becomes as high as that of larger ones. The small harvester performs adequately in thinning operations, and is not inferior to the larger ones. This result indicates that there is economic potential for small base machines that can be mounted with small harvester heads, resulting in less damage to residual trees and site soils during thinning operation. A part of this paper was orally presented at the 109th Annual Meeting of the Japanese Forestry Society (1998). The time study research presented in this paper was supported by the National Federation of Logging Contractors Cooperative Associations.  相似文献   
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