Estimating harvest costs and projecting quantities of logging residues for small-scale forestry in Nasushiobara,Tochigi Prefecture,Japan     

Chikara Nakahata  Ryo Uemura  Masashi Saito  Kanae Kanetsuki  Kazuhiro Aruga 《林业研究》2014,25(4):965-974

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   

Examining the Optimal Method to Extract Logging Residues from Small-Scale Forestry in the Nasunogahara Area,Tochigi Prefecture,Japan     

Chikara Nakahata  Kazuhiro Aruga  Ryo Uemura  Masashi Saito  Kanae Kanetsuki 《Small-Scale Forestry》2014,13(2):251-266

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   

Color vision, spectral sensitivity, accommodation, and visual acuity in juvenile masu salmon Oncorhynchus masou masou     

Norihiko Nakano  Ryo Kawabe  Nariharu Yamashita  Tomonori Hiraishi  Katsutaro Yamamoto  Katsuaki Nashimoto 《Fisheries Science》2006,72(2):239-249

ABSTRACT:   Color vision, spectral sensitivity, accommodation, and visual acuity were examined in juvenile masu salmon Oncorhynchus masou masou to obtain fundamental information about the visual system. Two types of S-potentials were recorded from 415 horizontal cells in isolated retinas from 34 cultured freshwater masu salmon (114–219 mm standard length, SL). Although horizontal cells recording S-potentials were not identified, the horizontal cells were confirmed because their responses were maintained while the stimulus remained. The variety of chromaticity (C)-type S-potentials indicated well-developed color vision. The analysis of the luminosity (L)-type S-potentials indicated that the peak spectral sensitivity was at 522 nm. S-potentials were also recorded in response to ultraviolet light. The direction and extent of lens movement induced by electrical stimulation was measured in 12 cultured masu salmon (99.0–142.5 mm SL). The results indicated that the visual axis was upward and forward, and that the range of accommodation was from 0.79 × SL in front of the eye to infinity. In histological analysis of the retinas of five wild smolts (100–118 mm SL), the maximum cone densities (276–345 cones/0.01 mm²) were detected in the ventral to temporal regions. The visual acuities assessed by histological methods were 0.069–0.075.  相似文献   

Elemental analysis of otoliths of Japanese anchovy: trial to discriminate between Seto Inland Sea and Pacific stock     

Hiromu Zenitani  Ryo Kimura 《Fisheries Science》2007,73(1):1-8

The ability to discriminate local stocks of Japanese anchovy Engraulis japonicus was assessed based on data from four elements (K, Na, P, and Sr) using an electron probe micro analyzer (EPMA) and data from three elements (Ba, Mn, and Sr) using inductively coupled plasma mass spectrometry (ICP-MS) from the otoliths of 40 anchovy (23.6–47.0 mm body length). Anchovy were caught at three sites (Aki-nada, Hiuchi-nada, and Osaka Bay) in the Seto Inland Sea, and one site (Kuroshio extension) in the Pacific Ocean in 2002. In order to discriminate different spawning grounds, EPMA data from the core portion (from core to 30 μm in the core-posterior axis) were used. Results showed that it was difficult to discriminate between the Seto Inland Sea and the Pacific anchovy by EPMA data. Conversely, it was possible to discriminate between the Seto Inland Sea and the Pacific anchovy by ICP-MS data from bulk otoliths. Our results showed that Mn contents of otoliths using ICP-MS discriminate between spawning grounds most, and Ba and Sr discriminate less. The difference in elemental compositions in anchovy otoliths between the Seto Inland Sea and the Pacific Ocean might be reflected by cumulative experienced elemental composition of ambient sea water during life history between the Seto Inland Sea and the Pacific anchovy.  相似文献   

Newly designed quantitative frame trawl for sampling larval and juvenile pelagic fish   总被引：1，自引：1，他引：1  

Yoshioki  OOZEKI  Fuxiang  HU  Hiroshi  KUBOTA  Hiroya  SUGISAKI  Ryo  KIMURA 《Fisheries Science》2004,70(2):223-232

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Trade-off evaluation using carbon dioxide equivalent and hazard index of a paddy soil with application of organic liquid fertilizer     

Shohei RIYA  Ryo IMANO  Jining LI  Huifeng SUN  Sheng ZHOU  Masaaki HOSOMI 《土壤圈》2022,32(6):928-932

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In vitro development of bovine nuclear transfer embryos reconstructed with mammary gland epithelial cells at different passages     

Masao KISHI  Yasuharu ITAGAKI  Tomoko SUDO  Ryo TAKAKURA 《Animal Science Journal》2003,74(5):363-368

In the present study, the effect of passage of nuclear donor cells on the in vitro development of nuclear transfer (NT) embryos was investigated using colostrum‐derived mammary gland epithelial (MGE) cells at different passages (3–30 passages) to find reliable passages for the efficiency of cloning. Development of NT embryos to the blastocyst stage was affected by the number of passages of MGE cells (P < 0.05). Nuclear transfer embryos reconstructed with MGE cells at 3–7 passages showed a significantly higher blastocyst development (31.3–48.5%) than those with the cells at 10–30 passages (2.5–12.5%, P < 0.05). No difference in the proportion of the MGE cells with normal diploid was observed among passage of 3, 15 and 30 (P > 0.05). The use of MGE cells at early passages for nuclear donor cells may be advantageous for the production of NT embryos.  相似文献   

Evaluation of genetic variation among wild rice populations in Cambodia     

Chhourn Orn  Rieko Shishido  Masahiro Akimoto  Ryo Ishikawa  Than Myint Htun  Ken-Ichi Nonomura  Yohei Koide  Men Sarom  Seng Vang  Sakhan Sophany  Ouk Makara  Takashige Ishii 《Breeding Science》2015,65(5):430-437

A total of 448 samples in five natural populations of wild rice (Oryza rufipogon) were collected in Cambodia. They were examined using 12 SSR and two chloroplast markers to evaluate the degree of variation among populations and the genetic structure within populations. In the two annual populations, the number of plants with homozygous alleles at all 12 SSR loci were high (66.3% and 79.5%), suggesting that these plants propagate mainly through self-pollination. In the three perennial populations, no individuals had all homozygous genotypes, but redundant genotypes resulted from clonal propagation were observed. Percentages of the redundant genotypes were highly varied (3.6%, 29.2% and 86.0%). This may be due to the different stable levels of environmental conditions. As for chloroplast genome, most of the wild plants showed the same chloroplast types as most Indica-type cultivars have. However, plants with different chloroplast types were maintained, even in the same population. In tropical Asian countries, many wild rice populations were observed under similar ecological conditions examined in this study. Therefore, the present results concerning population structure will be important to further elucidate genetic features of wild rice, and will also give strong clues to utilize and conserve wild natural genetic resources.  相似文献   

Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports     

Kensuke Katsuta  Kazuhito Matsuo  Yasuyuki Yoshimura  Ryo Ohsawa 《Breeding Science》2015,65(3):265-275

Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006–2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment.  相似文献   

Remote-sensing Technology for Vegetation Monitoring using an Unmanned Helicopter   总被引：2，自引：0，他引：2  

Ryo Sugiura  Noboru Noguchi  Kazunobu Ishii 《Biosystems Engineering》2005,90(4):369

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