Effects of thinning intensity on species diversity and timber production in a conifer (Cryptomeria japonica) plantation in Japan   总被引：1，自引：0，他引：1  

Kenji Seiwa  Yukino Eto  Masahiro Hishita  Kazuhiko Masaka 《Journal of Forest Research》2012,17(6):468-478

In conifer plantations, enhancement of species diversity has become an important management goal. Although thinning is a useful method to enhance diversity, determining optimum thinning intensities may be rather complicated because of potential trade-offs among a broad array of management goals (e.g., recovery of biodiversity, increasing individual tree sizes, increasing net primary production, saving management costs). To evaluate the optimum thinning intensity by analyzing these relationships, we conducted a thinning experiment with three different thinning intensities—unthinned, 33% thinned, and 67% thinned—in a Cryptomeria japonica plantation in 2003, and investigated the number, diameter at breast height (DBH), and diversity of hardwoods (height?>?1.5?m) in 2008, and the growth of conifers over five?years. In hardwoods, the number of individuals, number of species, mean DBH, and total basal area were greatest in the 67% thinned treatment, irrespective of successional status. However, Shannon’s diversity index did not differ among the three treatments due to a disproportionate increase with thinning intensity in the abundance of a mid-successional species, Cornus controversa. Diameter growth of conifers was also highest in the 67% thinned and lowest in the unthinned treatment, whereas the reverse was true for stand volume increment. These results suggest that intensive thinning is a reliable method to convert conifer plantations into conifer–hardwood mixed forests at canopy level much more quickly and consistently than weak thinning, although primary production is to some extent reduced. If forest managers prefer sustainable timber production of conifers rather than full recovery of diversity, weak thinning may be suitable.  相似文献   

Risk assessment of ozone impact on <Emphasis Type="Italic">Fagus crenata</Emphasis> in Japan: consideration of atmospheric nitrogen deposition     

Makoto?Watanabe  Masahiro?Yamaguchi  Hideyuki?Matsumura  Yoshihisa?Kohno  Takeshi?IzutaEmail author 《European Journal of Forest Research》2012,131(2):475-484

Tropospheric ozone (O₃) is considered to be the air pollutant relating to the decline of Fagus crenata forest in Japan. In the present study, we assessed a risk of O₃ impact on the growth of F. crenata in Japan, giving consideration to the effects associated with atmospheric nitrogen (N) deposition based on the experimental study, national monitoring data for oxidant concentration and atmospheric N deposition, and a national vegetation survey. The average and maximum O₃-induced relative growth reduction (RG_red) of F. crenata across Japan were estimated to be 3.2 and 9.7%, respectively. Current levels of atmospheric N deposition were found to significantly affect the sensitivity of F. crenata to O₃. When the N deposition was assumed as zero, the estimated average and maximum RG_red were 2.3% and 5.7%, respectively. The inclusion of atmospheric N deposition data thus increased the estimated values for average and maximum RG_red (by 38% and 71%, respectively). Our results demonstrate that a change in the sensitivity to O₃ associated with atmospheric N deposition is an important consideration in the risk assessment of O₃ impact on the growth of F. crenata in Japan.  相似文献   

Detection and verification of QTLs associated with heat-induced quality decline of rice (Oryza sativa L.) using recombinant inbred lines and near-isogenic lines     

Asako Kobayashi  Junya Sonoda  Kazuhiko Sugimoto  Motohiko Kondo  Norio Iwasawa  Takeshi Hayashi  Katsura Tomita  Masahiro Yano  Toyohiro Shimizu 《Breeding Science》2013,63(3):339-346

Decline in the apparent quality of rice (Oryza sativa L.) grain due to high temperatures during ripening recently became a major concern in many areas in Japan. The occurrence of white-back kernels (WBK) is one of the main problems of heat-induced quality decline. We identified QTLs associated with the occurrence of WBK using recombinant inbred lines (RILs) and verified their effects using near-isogenic lines (NILs). The QTL analysis used F₇ and F₈ RILs derived from ‘Hana-echizen’ (HE), which is tolerant to high temperature, × ‘Niigata-wase’ (NW), which is sensitive to high temperature. Four QTLs were identified on chromosomes 3, 4, 6, and 9 (qWB3, qWB4, qWB6 and qWB9). To verify the effects of qWB6 and qWB9, we developed two NILs in which qWB6 or both were introduced from HE into the NW background. The HE allele at qWB6 significantly decreased WBK under multiple environments. The combination of qWB6 and qWB9 in an F₂ population derived from a cross between a NIL and NW showed that the NW allele at qWB9 significantly decreased WBK if the qWB6 allele was HE. These results will be of value in marker-assisted selection for the breeding of rice with tolerance to heat-induced quality decline.  相似文献   

Comparison of production systems for efficient use of indigenous pig breeds in developing countries     

Tsutomu Furukawa  Keijiro Nirasawa  Kazuo Ishii  Le T. Thuy  Masahiro Satoh 《Animal Science Journal》2013,84(3):200-205

Conserving pig genetic resources and improving their productivity is important to increase returns over investment in developing countries. The purebred, first‐cross, rotational cross and backcross matings representing production systems based on pig breeds indigenous to the country and exotic pig breeds were investigated. The number of pigs in the nucleus and commercial herds necessary to produce a defined quantity of pork was considered. The amount of heterosis between the indigenous and exotic breeds, superiority in meat production, and degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed were investigated. The number of breeding pigs in the whole system was in the following order: pure breeding (PB) > first‐cross (F1) > rotational cross (RC) > backcross (BC) systems. The number of breeding pigs in the nucleus herds of the RC and BC systems was smaller than that in the nucleus herds of the PB and F1 systems. The degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed affected the efficiency of the production system.  相似文献   

Expression of CD4 T cell cytokine genes in the colorectal mucosa of inflammatory colorectal polyps in miniature dachshunds     

Hiroshi Ohta  Kanae Takada  Shidow Torisu  Masashi Yuki  Yu Tamura  Nozomu Yokoyama  Tatsuyuki Osuga  Sue Yee Lim  Masahiro Murakami  Noboru Sasaki  Kensuke Nakamura  Masahiro Yamasaki  Mitsuyoshi Takiguchi 《Veterinary immunology and immunopathology》2013

Inflammatory colorectal polyps (ICRPs) in miniature dachshunds are recently recognized as a major cause of large bowel diarrhea in this dog breed in Japan. ICRPs are characterized by the formation of multiple small polyps and a space-occupying large polyp in the colorectal area, and are thought to be a novel form of inflammatory bowel disease (IBD). In humans, specific cytokine patterns attributed to T helper (Th)1, Th17 and regulatory T cells have important roles in the pathogenesis of IBD. Thus, the aim of the present study was to assess the gene expression of cytokines of T cell subsets in the colorectal mucosa from dogs with ICRPs. Colorectal mucosal specimens from 10 dogs with ICRPs and 14 control dogs were used in this study. Interferon (IFN)-γ, interleukin (IL)-4, IL-17A and IL-10 mRNA expression was assessed using quantitative real-time PCR. IL-17A mRNA expression was significantly increased in large polyps compared to small polyps and controls. IFN-γ and IL-10 mRNA expression in large polyps were significantly higher than in controls. There was no significant difference in IL-4 mRNA expression among the three groups. IL-17A is thought to play important roles in the pathogenesis of ICRPs. IL-10 up-regulation could oppose the proinflammatory function of IL-17A.  相似文献   

Influence of organic components and inorganic components of reed as a concrete admixture     

Hyodo  Masahiro  Shibahara  Shinya  Ogata  Hidehiko 《Paddy and Water Environment》2019,17(3):411-417

Paddy and Water Environment - Vegetation in closed water area improves the natural environment by providing a habitat for juvenile shellfish and fish and by facilitating the intake of nutrients by...  相似文献   

Application of GCOM-C SGLI for agricultural water management via field evapotranspiration     

Tasumi  Masahiro  Moriyama  Masao  Shinohara  Yoshinori 《Paddy and Water Environment》2019,17(2):75-82

Paddy and Water Environment - Evapotranspiration is a key parameter in agricultural water planning and management strategies because it determines the crop and irrigation water requirements. With...  相似文献   

In vitro evaluation of the growth inhibitory activities of 15 drugs against Babesia gibsoni (Aomori strain)     

Matsuu A  Yamasaki M  Xuan X  Ikadai H  Hikasa Y 《Veterinary parasitology》2008,157(1-2):1-8

The in vitro growth inhibitory activities of 15 drugs against Babesia gibsoni were evaluated following establishment of a continuous culture isolate (Aomori isolate). The culture was successfully continued in an RPMI-1640 medium supplemented with 20% normal canine serum or fetal bovine serum in a humidified atmosphere containing 5% CO(2) and 5% O(2) at 37 degrees C. We used this isolate to evaluate the growth inhibitory effect of naphthoquinone (atovaquone), aromatic diamidine (diminazene and pentamidine), artemisinin compounds (artesunate and dihydroartemisinin), an iron chelator (deferoxamine), quinoline-containing compounds (quinine and chloroquine), macrolide antibiotics (azithromycin), lyncomycin antibiotics (clindamycin), tetracycline antibiotics (doxycycline and minocycline), imidazole antifungals (clotrimazole and ketoconazole), and a nitroimidazole antiprotozoal (metronidazole). Atovaquone and aromatic diamidine showed the highest activity; they were followed by artesunate compounds with nanomole levels of IC(50). Metronidazole did not exhibit activity against the parasite. Other drugs exhibited intermediate in vitro activities with micromole levels of IC(50). This is the first report to screen drug activities against B. gibsoni in vitro. The results of our study may support further in vitro drug evaluation for the establishment of therapeutic strategies against canine B. gibsoni infections.  相似文献   

Retrospective diagnosis of feline GM2 gangliosidosis variant 0 (Sandhoff-like disease) in Japan: possible spread of the mutant allele in the Japanese domestic cat population     

Yamato O  Hayashi D  Satoh H  Shoda T  Uchida K  Nakayama H  Sakai H  Masegi T  Murai A  Iida T  Hisada H  Hisada A  Yamasaki M  Maede Y  Arai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(8):813-818

GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disease caused by simultaneous deficiencies of acid beta-hexosaminidase (Hex) A and Hex B due to an abnormality of beta-subunit, a common component in these enzyme molecules, which is coded by the HEXB gene. In the present study, a retrospective diagnosis was performed in 2 previous suspected cases of feline Sandhoff-like disease using a DNA test to detect the causative mutation identified previously in 4 cats in 2 other families of Japanese domestic cats. Enzymic analysis was also performed using stored leukocytes and plasma collected from the subject families in order to investigate the usefulness of enzymic diagnosis and genotyping of carriers. The DNA test suggested that the 2 cases were homozygous recessive for the mutation. Consequently, 6 cats homozygous for the same mutation have been found in 4 separate locations of Japan, suggesting that this mutant allele may be spread widely in the Japanese domestic cat populations. In enzymic analysis, Hex A and Hex B activities in leukocytes and plasma measured using 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide as a substrate were negligible in affected cats, compared with those in normal and carrier cats. However, there was a wide overlap in enzyme activity between normal and carrier cats. Therefore, it was concluded that enzymic analysis is useful for diagnosis of affected cats, but is not acceptable for genotyping of carriers.  相似文献   

Vitellogenin, a biomarker for environmental estrogenic pollution, of Reeves' pond turtles: analysis of similarity for its amino acid sequence and cognate mRNA expression after exposure to estrogen     

Tada N  Nakao A  Hoshi H  Saka M  Kamata Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(3):227-234

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