MF研究者総覧

Researcher Database

Advance
Researchers' Page on researchmap
Last Updated :2024/10/26

Researcher Profile and Settings

Master

Affiliation (Master)

  • Research Faculty of Agriculture　Fundamental AgriScience Research　Forest Science

Affiliation (Master)

  • Research Faculty of Agriculture　Fundamental AgriScience Research　Forest Science

researchmap

Profile and Settings

Profile and Settings

  • Name (Japanese)

    Miyamoto

  • Name (Kana)

    Toshizumi

  • Name

    201301022110689017

Alternate Names

Achievement

Research Interests

  • 樹病   リター分解   菌類群集   低温   積雪   生産者   分解者   窒素無機化   多様性   菌根菌   消費者   根圏   被食   風害   リグニン   ミズナラ   光-栄養塩   先駆性樹種   生物間相互作用   混合効果   大型植食動物   ミミズ   植生再生   河畔林   保護   採食圧   森林生熊系   硝化   保全   森林生態   物質循環   

Research Areas

  • Life sciences / Ecology and environmental science
  • Life sciences / Forest science

Research Experience

  • 2012/04 - Today 北海道大学農学研究院 講師
  • 2009 - 2011 北海道大学 (連合)農学研究科(研究院) 助教

Published Papers

  • Takatoshi Yamaki, Toshizumi Miyamoto, Hayato Masuya, Hideyuki Saito, Masato Shibuya
    Journal of Forest Research 1 - 5 1341-6979 2024/08/21 [Refereed]
  • Yukako Hattori, Hayato Masuya, Masato Torii, Toshizumi Miyamoto, Toshiyuki Koiwa, Chiharu Nakashima
    Mycoscience 65 (4) 156 - 161 1340-3540 2024/06/05 [Refereed]
  • Takatoshi Yamaki, Toshizumi Miyamoto, Hayato Masuya, Satoshi Urabe, Hideyuki Saito, Masato Shibuya
    Journal of Forest Research 29 (3) 228 - 232 1341-6979 2023/11/28 [Refereed]
  • Kohhei Yamamoto, Toshizumi Miyamoto, Akiko Nagasaka, Yu Nagasaka, Yutaka Tamai, Takashi Yajima
    Journal of Forest Research 29 (2) 137 - 143 1341-6979 2023/10/12 [Refereed]
  • Nobuhito Anzai, Masato Shibuya, Hideyuki Saito, Toshizumi Miyamoto
    Ecosphere 14 (7) 2150-8925 2023/07/09 [Refereed]
     
    Abstract Species diversity encompasses both richness and evenness, but the interrelationship between these two aspects remains poorly understood. The long‐term dynamics of species diversity were examined in three natural secondary forests in Hokkaido, northern Japan, using permanent plot data gathered over 65–66 years after severe windthrow damage. The relationships among species diversity, species richness, and evenness were analyzed in the context of stand dynamics. Temporal trends in species diversity were unimodal‐shaped in three permanent plots, consistent with the pattern predicted by the intermediate disturbance hypothesis. Species richness and evenness increased following the windthrow, but decreased 27–37 years later in all three plots. In two plots, species diversity was closely associated with species richness and evenness at the early and late successional stages, respectively; in the other plot, species diversity was significantly related to both species richness and evenness in the later stage. The former two plots and the latter one plots differed markedly in terms of the extents of fatal tree damage caused by windthrow. Thus, windthrow severity affected the relationships among diversity, richness, and evenness as succession proceeded in these secondary forests. The tree density, species richness, evenness, and species diversity in all three plots decreased when the basal areas exceeded 18–24 m2/ha, indicating that increased competition among trees affected the temporal trends in these metrics. In conclusion, after a severe disturbance, the relationships among species diversity, richness, and evenness in secondary forests change with succession.
  • Takuya Katsuramoto, Yutaka Tamai, Toshizumi Miyamoto, Takashi Yajima
    International Journal of Plant & Soil Science 35 (13) 23 - 32 2023/05/15 [Refereed]
     
    Honeysuckle (Lonicera caerulea), also known as "haskap" in Japan, is a shrub that produces edible berries and inhabits mountainous and wetland areas with harsh environments. In this study, we surveyed the relationship between honeysuckle and the root endophytic fungi. Root samples were collected from the wet land region in Hokkaido, Japan, and subjected to microscopic observation and fungal strain isolation. Totally 47 endophytic fungal strains were isolated from the roots. Inoculation tests showed that a strain of Geomyces sp. promotes the growth of the seedlings and colonizes the epidermal and cortical cells of roots. It suggested that the strain acts as a mycorrhiza-like fungus for the arbuscular mycorrhizal plant. We speculate that honeysuckle establishes a symbiotic relationship with endophytic fungi to overcome acidic and nutrient-deficient environments. This is the first report demonstrating that endophytic ascomycetes promote the growth of host plants belonging to the Caprifoliaceae family.
  • Hirotaka Mori, Keisuke Obase, Takashi Yajima, Toshizumi Miyamoto, Yutaka Tamai
    Asian Soil Research Journal 7 (2) 34 - 45 2023/05/13 [Refereed]
     
    Limestone soils are stressful for plant growth. Plant-associated ectomycorrhizal (ECM) fungi may promote plant growth under stressful conditions, yet available information on ECM fungi in limestone areas is scarce. We investigated the ECM fungal communities associated with dominant tree species in a subarctic limestone area. We aimed to determine whether the ECM species differed between calcareous and non-calcareous areas, and the distribution property common to ECM fungi in limestone areas. Morphological characterization and DNA sequencing of root tips identified 57 ECM taxa. The ECM fungal compositions in the calcareous area differed from those in the non-calcareous area, even when comparisons were made between fungi on the same tree species. Rather, when ECM species were grouped at the genus level, they tended to be dissimilar between calcareous areas and between non-calcareous areas. Especially, Tomentella spp. and Sebacina spp. tended to be present more frequently in calcareous areas, while Cenococcum geophilum and Russula spp. tended to be present more frequently in non-calcareous areas.
  • Mycorrhizal morphology and symbiotic fungi on the root of Pyrola renifolia.
    Kei Kitamura, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto
    Asian Journal of Research in Botany 6 148 - 157 2023/05 [Refereed]
  • Ruy Matsumoto, Jakia Jerin Mehjabin, Hideki Noguchi, Toshizumi Miyamoto, Taichi E Takasuka, Chiaki Hori
    Applied and environmental microbiology e0027223  2023/04/26 [Refereed]
     
    Perenniporia fraxinea can colonize living trees and cause severe damage to standing hardwoods by secreting a number of carbohydrate-activate enzymes (CAZymes), unlike other well-studied Polyporales. However, significant knowledge gaps exist in understanding the detailed mechanisms for this hardwood-pathogenic fungus. To address this issue, five monokaryotic P. fraxinea strains, SS1 to SS5, were isolated from the tree species Robinia pseudoacacia, and high polysaccharide-degrading activities and the fastest growth were found for P. fraxinea SS3 among the isolates. The whole genome of P. fraxinea SS3 was sequenced, and its unique CAZyme potential for tree pathogenicity was determined in comparison to the genomes of other nonpathogenic Polyporales. These CAZyme features are well conserved in a distantly related tree pathogen, Heterobasidion annosum. Furthermore, the carbon source-dependent CAZyme secretions of P. fraxinea SS3 and a nonpathogenic and strong white-rot Polyporales member, Phanerochaete chrysosporium RP78, were compared by activity measurements and proteomic analyses. As seen in the genome comparisons, P. fraxinea SS3 exhibited higher pectin-degrading activities and higher laccase activities than P. chrysosporium RP78, which were attributed to the secretion of abundant glycoside hydrolase family 28 (GH28) pectinases and auxiliary activity family 1_1 (AA1_1) laccases, respectively. These enzymes are possibly related to fungal invasion into the tree lumens and the detoxification of tree defense substances. Additionally, P. fraxinea SS3 showed secondary cell wall degradation capabilities at the same level as that of P. chrysosporium RP78. Overall, this study suggested mechanisms for how this fungus can attack the cell walls of living trees as a serious pathogen and differs from other nonpathogenic white-rot fungi. IMPORTANCE Many studies have been done to understand the mechanisms underlying the degradation of plant cell walls of dead trees by wood decay fungi. However, little is known about how some of these fungi weaken living trees as pathogens. P. fraxinea belongs to the Polyporales, a group of strong wood decayers, and is known to aggressively attack and fell standing hardwood trees all over the world. Here, we report CAZymes potentially related to plant cell wall degradation and pathogenesis factors in a newly isolated fungus, P. fraxinea SS3, by genome sequencing in conjunction with comparative genomic and secretomic analyses. The present study provides insights into the mechanisms of the degradation of standing hardwood trees by the tree pathogen, which will contribute to the prevention of this serious tree disease.
  • Toshiya Yoshida, Haruka Yamazaki, Toshizumi Miyamoto
    Journal of Forest Research 1341-6979 2022/07/22 [Refereed]
  • Nitrous Oxide Emission in Response to pH from Degrading Palsa Mire Peat Due to Permafrost Thawing
    Yuta Takatsu, Toshizumi Miyamoto, Teemu Tahvanainen, Yasuyuki Hashidoko
    Current Microbiology 79 2022/01 [Refereed]
  • Nanami Suzuki, Toshiya Yoshida, Toshizumi Miyamoto, Karibu Fukuzawa, Takeshi Taniguchi, Haruka Yamazaki
    Scandinavian Journal of Forest Research 36 126 - 134 0282-7581 2021/03 [Refereed]
     
    To examine the potential for natural regeneration of Picea glehnii, seeds and current-year seedlings were evaluated at a scarification site. Three surface-soil treatments of different scarification intensity were used: removed, organic soil was mostly removed from the site; remained, some soil remained at the site; and replaced, the soil was removed but replaced. Seeds were sown in the fall, and samples were collected in the following spring to examine the rot rate by fungi. Germination, mortality, growth, and mycorrhiza formation rate of the seedlings were recorded in the first growing season. The seed rot rate was generally low, and no significant differences among surface-soil treatments were observed. The germination rate was higher in the removed treatment than in the other treatments, but seedling survival was lower, and the final seedling density was similar to that in the replaced treatment. Seedling total weight and ectomycorrhizal formation rate were higher in the replaced treatment than in the removed treatment, suggesting that the higher amount of organic soil at the site led to better growth at least in the first growing season. Correlation analysis indicated that a high soil moisture content associated with the presence of organic soil contributed to survival and growth.
  • An unknown nondenitrifier bacterium isolated from soil actively reduces nitrous oxide under high-pH condition.
    Yuta Takatsu, Toshizumi Miyamoto, Yasuyuki Hashidoko
    Microbes and Environments 35 (4) 2020/10 [Refereed][Not invited]
  • 2000年に噴火した有珠山の噴出物堆積地における大型菌類の発生消長
    小長谷啓介, 宮本敏澄, 玉井裕, 矢島崇
    日本菌学会会報 61 81 - 90 2020 [Refereed]
  • A report of dieback and mortality of elm trees suspected of Dutch elm disease in Hokkaido, Japan
    Toshizumi Miyamoto, Hayato Masuya, Akio Koizumi, Takehiro Yamaguchi, Makoto Ishihara, Yuichi Yamaoka, Izumi Okane, Mariko Shizuki, Masahiro Ohara
    Journal of Forest Research 24 (6) 396 - 400 2019 [Refereed][Not invited]
  • Mikio Ueta, Chiaki Hori, Yutaka Tamai, Yusuke Yamagishi, Toshizumi Miyamoto, Yuzou Sano
    Mokuzai Gakkaishi 64 (1) 1 - 9 0021-4795 2018 [Refereed][Not invited]
     
    This study aimed to clarify the factors that influence tree susceptibility to infection by the white-rot fungus Perenniporia fraxinea, by inoculating it into stems of four tree species at butt and breast height, and comparing the alterations in the xylem three to five months after inoculation. The four tree species include Robinia pseudoacacia, Cerasus sargentii, Ulmus davidiana var. japonica and Picea glehnii; the former two species are easily infected by this fungus, whereas the latter two species are not. Polymerase chain reaction (PCR) analysis detected the inoculated fungus only in the butt xylem of R. pseudoacacia and C. sargentii and the cell walls in the butt xylem tissues of these species were eroded by hyphae. Other xylem alterations (e.g., water accumulation and cell occlusion) differed among tree species, whereas no apparent difference was observed between butt and breast height. For example, water accumulation occurred in the discolored wood tissues around the inoculated holes in both R. pseudoacacia and U davidiana var. japonica, while dehydration occurred in the light-colored wood tissues around the inoculated hole in P. glehnii. In the vicinity of the inoculation holes, resin deposits formed in P. glehnii, whereas cell occlusions by tyloses/gums occurred in the other three species. These results suggest that susceptibility to P. fraxinea infection differs not only among tree species but also between heights above ground. It is likely that no particular response to fungal inoculation in the xylem tissues of these four tree species is closely associated with their susceptibility to the infection by P. fraxinea.
  • Use of DNA sequence data to identify wood-decay fungi likely associated with stem failure caused by windthrow in urban trees during a typhoon.
    Yoshie Fukui, Toshizumi Miyamoto, Yutaka Tamai, Akio Koizumi, Takashi Yajima
    Trees 32 1147 - 1156 2018 [Refereed][Not invited]
  • Toshizumi Miyamoto, Keiichi Koda, Arata Kawaguchi, Yasumitsu Uraki
    MICROBIAL ECOLOGY 74 (2) 322 - 331 0095-3628 2017/08 [Refereed][Not invited]
     
    Despite the importance of litter decomposition under snow cover in boreal forests and tundra, very little is known regarding the characteristics and functions of litter-decomposing fungi adapted to the cold climate. We investigated the decomposition of oak leaves in a heavy snowfall forest region of Japan. The rate of litter weight loss reached 26.5% during the snow cover period for 7 months and accounted for 64.6% of the annual loss (41.1%). Although no statistically significant lignin loss was detected, decolourization portions of oak leaf litter, which was attributable to the activities of ligninolytic fungi, were observed during snow cover period. This suggests that fungi involved in litter decomposition can produce extracellular enzymes to degrade lignin that remain active at 0 A degrees C. Fungi were isolated from oak leaves collected from the forest floor under the snow layer. One hundred and sixty-six strains were isolated and classified into 33 operational taxonomic units (OTUs) based on culture characteristics and nuclear rDNA internal transcribed spacer (ITS) region sequences. To test the ability to degrade lignin, the production of extracellular phenoloxidases by isolates was quantified at 0 A degrees C. Ten OTUs (9 Ascomycota and 1 Basidiomycota) of fungi exhibited mycelial growth and ligninolytic activity. These results suggested that some litter-decomposing fungi that had the potential to degrade lignin at 0 A degrees C significantly contribute to litter decomposition under snow cover.
  • H. Arai, Y. Tamai, T. Yajima, K. Obase, T. Miyamoto
    MYCOSPHERE 8 (4) 561 - 567 2077-7000 2017 [Refereed][Not invited]
     
    Coastal forests are exposed to high salinity and drought stress, and plant growth is restricted under such harsh conditions. Quercus dentata is one of the most common species in coastal forests in northern Japan. We investigated the changing vegetation in a coastal forest, shoreline to inland, and examined the ectomycorrhizal (ECM) fungal communities associated with Q. dentata. We aimed to determine whether the ECM changes corresponded with the changes in vegetation. More than 300 m inland, broadleaf trees such as Q. dentata were dominant. An almost pure Q. dentata stand was formed in the area closest to the shoreline. By contrast, as the forest moved inland, the occurrence of other tree species increased and the density of Q. dentata gradually decreased, respectively. In the areas that were furthest inland, Q. dentata, Q. crispula, Acer mono, and Tilia japonica were equally dominant. Five sampling plots (20 m x 20 m, each) were set up in the forest 100 m apart, and soil cores (including the fine roots of Q. dentata) were sampled in each plot. The total ECM colonization rate was > 98% in each sampling plot. Morphological characterization and DNA sequencing of the root tips identified six taxa (Tomentella sp., Russula spp., Tricholoma sp., Hebeloma sp. and Boletales sp.). Tomentella sp. was relatively abundant near the shoreline and its abundance decreased as the density of Q. dentata decreased inland. Conversely, Russula sp. increased as the forest moved inland.
  • Toshimitsu Fukiharu, Kiminori Shimizu, Atsushi Nakajima, Toshizumi Miyamoto, Jay Kant Raut, Noriko Kinjo
    MYCOSCIENCE 56 (4) 413 - 418 1340-3540 2015/07 [Refereed][Not invited]
     
    Coprinopsis igarashii (Basidiomycota, Agaricales, Psathyrellaceae) is a new fimicolous coprinoid fungus from Hokkaido, Japan. In macro-and micro-morphology, this species is similar to C. candidolanata but differs in having globose elements in the universal veil and heart-shaped basidiospores. The results of phylogenetic analysis with the nuclear ribosomal internal transcribed spacer (ITS) data also support this new taxon. (C) 2015 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved.
  • Shinya Mitsuhashi, Chihaya Shindo, Kengo Shigetomi, Toshizumi Miyamoto, Makoto Ubukata
    PHYTOCHEMISTRY 114 163 - 167 0031-9422 2015/06 [Refereed][Not invited]
     
    Mushrooms, including Ganoderma lucidum, have been used as a potential source of therapeutic compounds, and an autophagy inducer would be useful for treatment of diverse diseases in human. Reported here is a full account of screening, isolation, structural determination, and biological activity of an autophagy inducer, (+)-epogymnolactam (1) from a mycelial culture of a Gymnopus sp. strain. Its structure was elucidated by HR-ESI-MS, NMR, and its plus sign by specific rotation. It exists as a tautomeric mixture of la and lb in MeOH. The major tautomer of 1 is (1R,5S)-4-butyl-4-hydroxy-3-aza-6-oxabicyclo[3.1.0]hexan-2-one (la), and the minor tautomeric form is (2R,3S)-3-pentanoyloxirane-2-carbox-amide (1b). (C) 2014 Elsevier Ltd. All rights reserved.
  • Fumito Sasaki, Toshizumi Miyamoto, Aki Yamamoto, Yutaka Tamai, Takashi Yajima
    MYCOSCIENCE 53 (2) 85 - 91 1340-3540 2012/03 [Refereed][Not invited]
     
    To investigate the host specificity of Ophiocordyceps nutans against hemipteran insects in the wild, we determined the relationship between host species and rDNA-internal transcribed spacer (ITS) variation in O. nutans. The analyzed fungal specimens infected 16 host species belonging to four families of Hemiptera. The molecular phylogenetic analysis revealed that O. nutans can be classified into two types corresponding to their host families. The genetic distance values between the two types were very remote (> 0.084), and the strains of O. nutans that parasitized Halyomorpha halys and Plautia crossota stali, well-known insect pests, formed a subclade. The results suggest that O. nutans should have host specificity which can be valuable for developing biological control agents against specific hemipteran insects.
  • Ryo Asai, Shinya Mitsuhashi, Kengo Shigetomi, Toshizumi Miyamoto, Makoto Ubukata
    JOURNAL OF ANTIBIOTICS 64 (10) 693 - 696 0021-8820 2011/10 [Refereed][Not invited]
  • Marina Yoshida, Yutaka Tamai, Toshizumi Miyamoto, Takashi Yajima
    Eurasian Journal of Forest Research Hokkaido University Forests, EFRC 14 (1) 39 - 41 1345-8221 2011 [Refereed][Not invited]
     
    We investigated mycorrhizal status of current-year Acer mono seedlings at different regenerated sites. The arbuscular mycorrhizae (AM) formation degree, spore density, available phosphorus (AP) and total nitrogen (TN) contents of samples were tested. Our results indicated that current-year A. mono seedlings may not be obligatory mycorrhizal species since AM colonization was not found in some of the seedlings in the bare sites. The spore density in the soils can play an important role in AM formation since it has significantly positive correlations with the frequency of vesicles and hyphae. AP and TN contents in the soil also have close relationships with the frequency of hyphae in roots.
  • Souta Fukuchi, Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto
    Eurasian Journal of Forest Research Hokkaido University Forests, EFRC 14 (1) 1 - 11 1345-8221 2011 [Refereed][Not invited]
     
    We investigated the colonization status of mycorrhizal and endophytic fungi in roots of plants established on an acidic barren at volcano Esan, Hokkaido, Japan. In total, 87 individuals of 21 plant taxa were investigated in four different vegetation sites and the surrounding area. Ericaceous plants such as Empetrum nigrum var. japonicum, Ledum palustre var. diversipilosum, Vaccinium vitis-idaea var. minus and Loiseleuria procumbens were the main colonizers at the study sites and dominated under even the most severe conditions of low soil moisture and nutrient content. They were associated with ericoid mycorrhizal (ERM) fungi at all vegetation sites and erratically with dark septate endophytic (DSE) fungi. They commonly associated together with arbuscular mycorrhizal (AM) fungi only at sites where Sasa senanensis dominated. Among the ericaceous plants, only Enkianthus campanulatus associated with AM and DSE fungi and had no associations with ERM fungi. Other herbaceous and woody plants associated commonly with AM or erratically with DSE fungi, except for Carex sp. and Polygonum spp. which erratically associated with AM and DSE fungi. Mycorrhizal associations were common in representative vegetation on the crater basin of Mt. Esan. In particular, ERM associations might play a significant role in invasion and establishment of ericaceous plants, and also in the development of plant communities in the harsh environment at Mt. Esan.
  • Ryoji Sugiyama, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto, Akira Harada
    MOKUZAI GAKKAISHI 日本木材学会 57 (4) 223 - 226 0021-4795 2011 [Refereed][Not invited]
     
    Using Hypsizygus marmoreus (Peck.) Bigelow, the effect of the addition of larch charcoal on mushroom cultivation was examined. Charcoal addition to sawdust-rice bran medium promoted mycelial growth, which reached a maximum when the amount of charcoal was raised to 10% of the culture medium. In contrast, fruit body yield was not influenced by the addition of charcoal. The total cultivation period was shortened by 7-10 days, as estimated from the acceleration in spawn running. Taken together, the results show that the addition of larch charcoal to culture medium is an effective way of shortening the total cultivation period of H. marmoreus.
  • Maria Catarina Megumi Kasuya, Irene da Silva Coelho, Daniela Tiago da Silva Campos, Elza Fernandes de Araujo, Yutaka Tamai, Toshizumi Miyamoto
    REVISTA BRASILEIRA DE CIENCIA DO SOLO 34 (6) 1891 - 1898 0100-0683 2010/11 [Refereed][Not invited]
     
    Eighteen Pisolithus basidiomes were collected from Eucalyptus plantations in the state of Minas Gerais, Brazil. These basidiomes were characterized morphologically and molecularly. The basidiomes varied in shape, color and size. One of them was found underground, indicating a hypogeous fungus. The main morphological distinctive characteristic was spore ornamentation, which distinguished two groups. One group with short and erect spines was identified as Pisolithus microcarpus, and the other with long and curved spines as Pisolithus marmoratus, after analyzing the cladogram obtained by phylogenetic relationship based on internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA of these isolates.
  • Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto
    MYCOSCIENCE 50 (2) 143 - 145 1340-3540 2009/03 [Refereed][Not invited]
     
    Ectomycorrhizal (ECM) syntheses between four ECM fungi, Laccaria amethystina, Hebeloma mesophaeum, Thelephora terrestris, and Tomentella sp., and Populus maximowiczii seedlings that are known to form ECM at a denuded area of Mt. Usu were performed in volcanic debris in a controlled growth chamber. The percentage of ECM colonization and seedling growth were determined 3 months after inoculation. Seedlings were successfully colonized by the inoculated ECM fungi with low contamination ratios. Seedling height and biomass were larger in the inoculated seedlings than in the control, although the effects of inoculation on seedling growth varied with the ECM fungus.
  • Fumito Sasaki, Toshizumi Miyamoto, Aki Yamamoto, Yutaka Tamai, Takashi Yajima
    MYCOLOGICAL RESEARCH 112 1241 - 1244 0953-7562 2008/10 [Refereed][Not invited]
     
    We examined the morphology, genetic variation, and insect host species of the fungus Ophiocordyceps nutans. Fifty-two fruit bodies collected in Hokkaido, Japan, were grouped by host species, and 19 samples were analysed. The ranges of the lengths and breadths of all fruit body parts were similar among host groups. In the genetic analysis, the 5.8S rDNA region showed completely identical sequences, although differences of up to six nucleotides were recognized in the ITS regions. The distance values between our samples using the Kimura two-parameter model were lower than 0.007. Thus, the O. nutans examined here were concluded to form a closely related group with little detectable variability that parasitized nine hemipteran species. (c) 2008 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
  • Maria Catarina Megumi Kasuya, Irene da Silva Coelho, Yutaka Tamai, Toshizumi Miyamoto, Takashi Yajima
    MYCOSCIENCE 49 (5) 334 - 338 1340-3540 2008/10 [Refereed][Not invited]
     
    Pisolithus basidiomes were found under different forest trees in Hokkaido Island, Japan. These basidiomes were characterized morphologically and molecularly. Although presenting different basidiome morphology and growing under different hosts, specimens presented similar spores ornamentation, and diameters. These spores had coarse, crowded, and blunted spines with three to eight basidiospores per basidium. Ribosomal DNA-based phylogenetic analysis indicated that variability of Pisolithus in this area is low. Phylogenetic analysis showed that Pisolithus analyzed in this study did not group with Pisolithus specimens from other geographical origins. These results suggest that Pisolithus from this area should be taxonomically distinguished from other Pisolithus.
  • Toshizumi Miyamoto, Tsutom Hiura
    ECOLOGICAL RESEARCH 23 (4) 673 - 680 0912-3814 2008/07 [Refereed][Not invited]
     
    When two tree species co-occur, decomposition and nitrogen (N) release from the foliage litter depend on two factors: the forest floor conditions under each canopy type and the species composition of the litter. We conducted an experiment using fir and oak to answer several questions regarding decomposition beneath canopies of the two species and the effects of litter species composition on decomposition. We compared the rates of decomposition and N release from three different litters (fir needle, oak leaf, and a mixture of the two) in 1-mm-mesh litterbags on the forest floor under three different canopies (a 40-year-old fir plantation, large oak trees, and mixed fir and oak trees) in Hokkaido, Japan, over a 2-year period. Beneath each of these canopy types, the litter decomposition rate and percentage of N remaining in the litterbags containing a mixture of fir and oak litter were not significantly different from the expected values calculated for litterbags containing litter from a single tree species. Oak leaf litter decomposed significantly faster than fir needle litter beneath each canopy type. The litter decomposition rate was significantly higher beneath the fir canopy than under the oak canopy, and was intermediate under the mixed canopy of fir and oak. No net N release, that is, a decrease in the total N compared to the original amount, was detected from fir litter under each canopy type or from oak leaf litter beneath the oak canopy. N increased over the original amount in the fir litter beneath the oak canopy and the mixed canopy of fir and oak, but N was released from the oak litter under the fir canopy and the mixed canopy of fir and oak. These results suggest that oak leaf litter blown onto fir forest floor enhances nutrient cycling, and this might be a positive effect of a mixed stand of conifer and broad-leaved trees.
  • Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto
    LANDSCAPE AND ECOLOGICAL ENGINEERING 4 (1) 57 - 61 1860-1871 2008/05 [Refereed][Not invited]
     
    We investigated the ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) colonization status of plant seedlings that established in areas devastated by the eruption in March 2000 of Mt. Usu, Hokkaido, Japan. In 2005, we estimated the mycorrhizal colonization ratios and frequencies in seedlings of twelve herbaceous and seven woody plant species. Although arbuscular mycorrhizas were found to colonize Equisetum arvense and Polygonum sachalinense, they were presented at very low frequencies and colonization ratios. Other herbaceous plants exhibited higher frequencies of AM associations and either AM and/or ECM fungal associations were observed in all of the woody plant seedlings investigated. The dominant woody plant species (Populus maximowiczii, Salix sachalinensis and Salix hultenii var. angustifolia) associated mainly with ECM fungi and exhibited variable associations with AM fungi. Mycorrhizal associations were common and significant events for plant establishment, even in the early stages of the revegetation process.
  • SASAKI FUMITO, TAMAI YUTAKA, YAMAMOTO AKI, MIYAMOTO TOSHIZUMI, YAJIMA TAKASHI
    Abstracts of Papers Presented at the Meeting of the Mycological Society of Japan 日本菌学会 52 103 - 103 2008 
    Cordyceps nutans Pat.はカメムシ類にのみ寄生を行なうとされている冬虫夏草菌であるが，寄生されるカメムシ類の種についての報告は少なく，カメムシ目レベル以下の寄主特異性に関しては全く明らかにされていない．本研究ではC. nutansのrDNA-ITS領域の変異と寄主の種との関連性の検討を行なった．さらに，得られた結果に基づき，C. nutans特異的PCRプライマーを設計した．北海道苫小牧および江別，山形，福島，京都，鹿児島より採取された56系統のC. nutansを供試し，各子実体の寄主となっていたカメムシの種を同定した．プライマーセットITS1fおよびITS4を用いて5.8S rDNAを含むITS領域をシーケンシングし，得られた配列についてKimura 2-parameter modelにより遺伝的距離を算出後，近隣結合法で系統樹を作成した．さらにシーケンスで得た他種の昆虫病原性糸状菌の同領域配列を参照し，C. nutansに特異的な配列部分よりプライマーの設計を行なった．56系統のC. nutansの寄主となっていたカメムシ類は4科10属15種に分類された．系統樹には遺伝的距離が0.090以上離れた二つのクレードが形成された．各クレードでC. nutansの寄主は異なり，片側のクレードに属するC. nutansはヘリカメムシ科カメムシに選択的に寄生を行ない (Type 1)，他方のクレードに属するC. nutansはその他の科のカメムシに寄生を行なっていた (Type 2)．ヘリカメムシ科カメムシは，主に草本植物の茎より吸汁を行なう草地性のカメムシであり，Type 2の寄主となる樹上で生活を行なうことの多いカメムシとはハビタットや吸汁対象がやや異なる．この結果から，ITS領域内にType 2にのみアニーリングサイトを持つフォワードプライマーと，両タイプにアニーリングサイトを持つリバースプライマーを作成し，その選択性を確認した．
  • Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto
    MYCORRHIZA 17 (3) 209 - 215 0940-6360 2007/05 [Refereed][Not invited]
     
    We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research site, most of which were associated with ECM and/or AM fungi. In particular, dominant woody plant species Populus maximowiczii, Salix hultenii var. angustifolia and Salix sachalinensis were consistently associated with ECM fungi and erratically associated with AM fungi. We found one to six morphotypes in the roots of each ECM host and, on average, two in the roots of each seedling, indicating low ECM fungal diversity. ECM colonization ranged from 17 to 42% of root tips. Using morphotyping and molecular analyses, 15 ECM fungi were identified. ECM fungi differed greatly between hosts. However, Laccaria amethystea, Hebeloma mesophaeum, Thelephora terrestris and other Thelephoraceae had high relative colonization, constituting the majority of the ECM colonization in the roots of each plant species. These ECM fungi may be important for the establishment of pioneer woody plant species and further revegetation at Mt. Usu volcano.
  • HyeKyoung Cho, Toshizumi Miyamoto, Kunihide Takahashi, SungGak Hong, JongJin Kim
    CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE 37 (2) 371 - 382 0045-5067 2007/02 [Refereed][Not invited]
     
    Abies koreana Wilson is an endemic tree species that is facing critical population declines in Korea. To identify factors affecting the natural regeneration of A. koreana, we examined the role of seed pathogens in the overwintering survival of seeds in natural seedbeds on Mount Halla, Korea. In September 2003, seeds of A. koreana were placed on seedbeds in the following three types of sites: Sasa dominated, shaded by rocks, or forest floor; seeds were then recovered from beneath the snow cover in April 2004 and were analyzed for the occurrence of harmful microfungi. Racodium therryanum Thuem. was the fungus most often isolated from retrieved seeds and was also the most detrimental of the eight fungal species tested in a pathogenicity trial. In vitro, R. therryanum caused a total loss of germination ability in A. koreana seeds at 0 degrees C after 100 days. The infection rate of R. therryanum was negatively correlated with the seed germination rate. The infection rate of R. therryanum was highest on the forest floor and increased with the duration of snow cover. The occurrence of R. therryanum was temporally restricted to the period of snow cover and spatially to the thick A(0) soil layer on the forest floor. This study suggests that R. therryanum may be a significant factor inhibiting the natural regeneration of A. koreana at the seed stage.
  • Morphological characteristics of ectomycorrhizas found in willow and poplar seedlings established in the area devastated by the volcanic eruption of Mt. Usu, Hokkaido, Japan 2000.
    Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto
    Eurasian Journal of Forest Reasearch 10 173 - 178 2007 [Refereed][Not invited]
  • Usami Horoka, Tamai Yutaka, Yajima Takashi, Miyamoto Toshizumi
    The Japanese Forest Society Congress 日本森林学会 118 93 - 93 2007
  • yamamoto mayumi, miyamoto toshizumi, tamai yutaka, yazima takashi
    The Japanese Forest Society Congress 日本森林学会 118 686 - 686 2007
  • Kondou Wataru, Miyamoto Toshizumi, Sano Yuzou, Tamai Yutaka, Yajima Takashi
    The Japanese Forest Society Congress 日本森林学会 118 638 - 638 2007
  • Fumito Sasaki, Toshizumi Miyamoto, Yutaka Tamai, Takashi Yajima
    Mycoscience 48 (5) 312 - 315 1618-2545 2007 [Refereed][Not invited]
     
    We collected Cordyceps brongniartii from the wild associated with coleopteran larvae for the first time in Japan. Morphological comparisons of C. brongniartii with the type specimen showed slight morphological difference, whereas it showed considerable differences from those collected in the wild in China. PCR-RFLP and ITS sequence analyses corroborated the teleomorph-anamorph relationship between C. brongniartii and Beauveria brongniartii. © 2007 The Mycological Society of Japan and Springer-Verlag.
  • Keisuke Obase, Takahito Kobayashi, Toshizumi Miyamoto, Yutaka Tamai, Takashi Yajima
    Mycoscience 47 (5) 293 - 297 1618-2545 2006 [Refereed][Not invited]
     
    A species of the genus Inocybe, which has not been recorded previously in Japan, is described and illustrated as a new record. Inocybe nitidiuscula (Britzelm.) Sacc. belongs to the subgenus Inocibium (Earle) Singer. © 2006 The Mycological Society of Japan and Springer-Verlag.
  • Y Sakamoto, T Miyamoto
    FOREST PATHOLOGY 35 (1) 1 - 7 1437-4781 2005/02 [Refereed][Not invited]
     
    The current knowledge of Racodium snow blight, one of the major snow blight diseases in Japan, is reviewed. This disease was discovered in Aomori Prefecture in 1951. The causal fungus (Racodium therryanum) is distributed in the A(o) layer and affects the seedlings and seeds of many conifers. Hence, it is considered one of the inhibitors of the natural regeneration in the forests of Hokkaido. The perspectives for future research on this disease are discussed.
  • Keisuke Obase, Yutaka Tamai, Toshizumi Miyamoto, Takashi Yajima
    Eurasian Journal of Forest Research Hokkaido University Forests, EFRC 8 (2) 65 - 70 1345-8221 2005 [Refereed][Not invited]
     
    Articles
  • Fumito Sasaki, Toshizumi Miyamoto, Yutaka Tamai, Takashi Yajima
    International Journal of Medicinal Mushrooms 7 (1-2) 301 - 304 1521-9437 2005 [Refereed][Not invited]
     
    Cordyceps nutans Pat. is an entomopathogenitic Ascomycete belonging to the family Clavicipitaceae and is parasitic on hemipteran insects. Very few investigations have been made with this fungus. C. nutans grows very slowly. Thus, further evaluation of culture conditions was necessary. In this research, we examined optimum temperature and pH for mycelial growth of C. nutans. In order to find the optimal culture temperature for growth, three strains were incubated at 5, 10, 15, 20, 25, 30, and 35 °C in darkness for 3 months, with six repetitions. Seven initial pH conditions of the media were adjusted by using 1 N HCl or KOH, and set at every 1.0 pH level from 5.0 to 11.0. Cultures were incubated at 25 °C for 3 months in replicates of six. Mycelial growth was observed at 10-25 °C and was greater at 20 and 25 °C. At 5, 30, and 35 °C, mycelial growth was not observed in any of the strains. Mycelial growth was observed at pH levels from 6.0 to 11.0 and not observed at pH 5.0. The overall tendency was that the strains grew relatively well in neutral to weak alkaline pH levels (pH 7.0-9.0) compared with acidic pH levels, but colonies were sparse. © 2005 by Begell House, Inc.
  • N Kaneko, Y Sugawara, T Miyamoto, M Hasegawa, T Hiura
    PEDOBIOLOGIA 49 (6) 521 - 528 0031-4056 2005 [Refereed][Not invited]
     
    Differences in tree species may lead to contrasting soil environments via differences in litter chemical quality and physical environmental factors, such as soil type and soil moisture. However, separating the effects of litter quality and physical environment is difficult under field conditions. Both litter quality and soil environment affect the species composition of the soil animal community. A diversity gradient of canopy tree species (11-25 species) located on homogeneous soil substrate at Tomakomai Experimental Forest of Hokkaido University was used to analyse the relationship between tree species diversity and oribatid mite community structure. Soil samples were collected from three levels of tree species richness (high, intermediate and low) with three replicates each, in July 2000. Leaf area index (LAI) was positively correlated with tree species diversity suggesting higher litter input into the soils with increasing tree diversity. However, the tree species diversity gradient affected neither accumulation of litter on the forest floor nor abundance and species richness of oribatid mites. Canopy and understory plant species richness, LAI, total soil carbon and biomass of epigeic and endogeic earthworms did not significantly affect mite community structure as indicated by redundancy analysis (RDA). The results suggest that oribatid mite community structure is minimally affected by tree species diversity and associated changes in litter diversity. (c) 2005 Elsevier GmbH. All rights reserved.
  • Toshizumi Miyamoto, Tsuneo Igarashi
    Mycoscience 45 (1) 24 - 29 1340-3540 2004/02/25 [Refereed][Not invited]
     
    Collybia pinastris is a relatively common litter-decomposing basidiomycete in spruce forests in Hokkaido, Japan. The spatial distribution of sporophores of C. pinastris was investigated for 5 years within a plot of 3 m X 10 m in size (subdivided into 0.5 m X 0.5 m subplots) in a pure stand of Picea abies. There were significant differences in the total numbers of sporophores during the sampling years. The total number of subplots in which sporophores occurred were also significantly different during the sampling years. However, the spatial distribution of the subplots with sporophores showed agreement with the distributions in subsequent years. There was no significant correlation between the number of sporophores and the thickness of the litter layer in the subplots, whereas the litter layers in the subplots with sporophores were significantly thinner than those without sporophores. These results suggested that perennial or renewable mycelia of C. pinastris occupied the same or close locations year to year for at least 5 years and that the spatial distribution in this plot was restricted not by a shortage of substrates but by other factors.
  • F Sasaki, T Miyamoto, Y Tamai, T Yajima
    JOURNAL OF INVERTEBRATE PATHOLOGY 85 (2) 70 - 73 0022-2011 2004/02 [Refereed][Not invited]
     
    We isolated Cordyceps nutans from the stipe and abdominal tissues of fruit bodies using a surface sterilization method. Hyphal growth was observed in inocula from both the stipe and abdominal tissue. Some strains from discharged ascospores were obtained and colony characteristics were compared to the strains isolated from the tissues. Colonies of isolates from ascospores grew quite slowly. Isolates of 43 from the 52 examined fruit bodies formed colonies similar to those from ascospores. To confirm the success of isolation, we analyzed by PCR-RFLP of the ITS regions of rDNA samples from fruit bodies, isolates from fruit bodies, and isolates from ascospores. All the isolates obtained from stipe and abdominal tissues presented identical patterns. In this study, we report the first successful isolation of C. nutans from fruit-body tissue using a surface sterilization method. (C) 2004 Elsevier Inc. All rights reserved.
  • Toshizumi Miyamoto, Tsuneo Igarashi
    Mycoscience 42 (2) 177 - 180 1340-3540 2001/04/15 [Refereed][Not invited]
     
    Gymnopus piceipesis proposed as a new species within the section Vestipedes. It is characterized by a brown pileus, pale brown close lamellae, a solid black stipe that is not insititious, and conspicuous pleurocystidia.
  • Toshizumi Miyamoto, Tsuneo Igarashi, KunihideTakahashi
    Mycoscience 41 (2) 105 - 110 1340-3540 2000/04/15 [Refereed][Not invited]
     
    The frequency of occurrence of the litter-decomposing basidiomycetes of Picea abies and P. glehnii forest floors in Hokkaido was investigated. In both the P. abies and P. glehnii forest plots (each 10 m x 10 m), litter-decomposing basidiomycetes of the genera Collybia and Mycena were frequently observed. Species composition, frequency of occurrence, and basidioma numbers of each species were different between the two forest plots, but several species were common to both. Seven species isolated from the P. glehnii forest plot (C. acervata, C. pinastris, Marasmius pallidocephalus, Ma. wettsteinii, My. aurantiidisca, My. clavicularis, Mycena sp. 1) and four species from the P. abies forest plot (C. pinastris, My. alphitophora (= My. osmundicola), Mycena sp. 1, My. vulgaris) were tested for their ability to degrade lignin by a simple plate test for extracellular phenoloxidases and by measuring Klason lignin loss from needle litter of spruce. All the strains of the litter-decomposing fungi tested showed positive reactions on the plate test. Lignin contained in the needle litter was degraded by all strains tested (only My. alphitophora was not tested), and rates varied from 9% to 40% over a two-month period in vitro. Seven species with ligninolytic ability in the P. glehnii forest plot and four such species in the P. abies forest plot were found respectively in 77% and 60% of the 100 subplots in each plot. The results of this study suggest that lignin decomposition of needle litter by litter-decomposing basidiomycetes in the forest floor is a common event in the studied Picea forests of Hokkaido and that the diversity of the ligninolytic activity among the species or strains may cause spatial heterogeneity of litter decomposition in the Picea forest floor.
  • T. Yagihashi, M. Hayashida, T. Miyamoto
    Journal of Forest Research 5 (3) 213 - 215 1341-6979 2000 [Refereed][Not invited]
     
    To evaluate what prevents seed germination and why ingestion by birds enhances germination, we carried out germination experiments using bird-dispersed seeds of two Prunus species (Prunus sargentii and P. ssiori) in the laboratory. Germination of seeds with following four treatments was compared: `Ingested seeds' excreted after feeding of fruits to birds `Extracted seeds' deliberately extracted from the fruit pulp `Juiced seeds' which were supplemented with the juice of the pulp after seeds had been deliberately extracted from the pulp and `Intact seeds' in untreated whole fruits. Many ingested (27%, 23% in P. sargentii, 18% in P. ssiori) and extracted seeds (24% in P. sargentii, 17% in P. ssiori) germinated, and difference in germination percentages between ingested and extracted seeds were not significant, for either Prunus species. The Juiced seeds rarely germinated (2% in P. sargentii, 6% in P. ssiori), and seeds within intact fruits did not germinate. These results suggest that the fruit pulp and the juice of the pulp inhibit germination and the seeds could germinate without ingestion by birds once they had been manually extracted from pulp. Therefore, it is considered that bird ingestion enhances germination by removing pulp, especially juice of the pulp, in these two Prunus species.
  • T Yagihashi, M Hayashida, T Miyamoto
    ECOLOGICAL RESEARCH 14 (1) 71 - 76 0912-3814 1999/03 [Refereed][Not invited]
     
    To evaluate the effects of ingestion by birds on seed germination under natural conditions, we carried out germination experiments in the field using seeds of two Prunus species that have different fruit-ripening seasons. Germination of seeds with the following three treatments was compared: 'ingested seeds', seeds excreted after feeding of fruits to birds; 'extracted seeds', seeds deliberately extracted from the fruit pulp; and 'intact fruit', seeds in untreated intact fruit. Many ingested and extracted seeds of both Prunus species germinated during the first spring, and the difference in germination percentage between ingested and extracted seeds was not significant. Many seeds in intact fruit of Prunus sargentii also germinated during the first spring, but those of Prunus ssiori did not germinate until the second spring. Pulp removal through bird ingestion enabled rapid germination for the autumn-fruiting P. ssiori, whose fruit pulp was not likely to be decomposed until the first spring. In contrast, the effects of ingestion were not striking for the summer-fruiting P. sargentii, whose fruit pulp is quickly decomposed.
  • Toshizumi Miyamoto, Tsuneo Igarashi, Kunihide Takahashi
    Mycoscience 39 (2) 205 - 209 1340-3540 1998/07/15 [Refereed][Not invited]
     
    Two species of Collybia are recorded for the first time from Japan: C. biformis from Hokkaido, and Co pinastris from Hokkaido and Honshu (Nagano Prefecture). Macro- and microscopical descriptions and illustrations are provided for each species.
  • Toshizumi Miyamoto, Tsuneo Igarashi, Kunihide Takahashi
    Mycoscience 39 (2) 211 - 216 1340-3540 1998/07/15 [Refereed][Not invited]
     
    Three species of Marasmius from Japan are described and illustrated here for the first time: M. glabellus, M. pallidocephalus and M. wettsteinii. The specimens were collected in Hokkaido.
  • T Yagihashi, M Hayashida, T Miyamoto
    OECOLOGIA 114 (2) 209 - 212 0029-8549 1998/04 [Refereed][Not invited]
     
    To determine the effects of ingestion by birds on seed germination, we performed germination experiments in the field and laboratory with Sorbus commixta. The germination of four groups of seeds was compared: ingested seeds, seeds defecated in feces after feeding of fruits to birds; extracted seeds, seeds deliberately extracted from the fruit pulp; juiced seeds, seeds plus the juice of the pulp after seeds had been deliberately extracted from the pulp; intact seeds, seeds in untreated intact fruits. In the laboratory, intact and juiced seeds hardly germinated, but ingested and extracted seeds germinated. Thus, the pulp and its juice appeared to inhibit germination, but seeds could germinate without ingestion by birds once the seeds had been manually extracted from the pulp. In the field, intact fruits did not germinate in the first spring, because the seed was still covered with pulp. The pulp of intact seeds decomposed during the first summer, and thus, the seeds had the potential to germinate during the second spring. In fact, most intact seeds do not germinate during the second spring either, since they lose their viability during the first summer. Thus, under natural conditions, most seeds of Sorbus commixta cannot germinate without bird ingestion.
  • Toshizumi Miyamoto, Tsuneo Igarashi, Kunihide Takahashi
    Mycoscience 39 337 - 342 1998 [Refereed][Not invited]
  • Toshizumi Miyamoto, Joo Young Cha, Tsuneo Igarashi
    Mycoscience 37 (4) 463 - 466 1340-3540 1996 [Refereed][Not invited]
     
    Mycena picta, a rare species of Agaricales, is reported for the first time from Japan, based on specimens collected in Hokkaido.

MISC

Research Projects

  • イボタケ類菌糸マットを構成し土壌酸性化作用を担う微生物群の解明とその活性評価
    日本学術振興会：科学研究費助成事業 国際共同研究加速基金(国際共同研究強化(B))
    Date (from‐to) : 2022/10 -2027/03 
    Author : 宮本 敏澄, 原口 昭, 礒田 玲華
  • 腐朽菌を用いた低コストかつ近自然プロセスによる流木の断片化促進技術の開発
    一般財団法人河川財団：河川基金助成
    Date (from‐to) : 2022/04 -2024/03
  • ダムの存在による河川洪水の撹乱頻度と強度の変化が河畔林の立木腐朽に与える影響
    Water Resources Environment Center (WEC)：WEC応用生態研究助成
    Date (from‐to) : 2020 -2021
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2015/04 -2019/03 
    Author : Koda Keiichi, Miyamoto Toshizumi
     
    A novel method applicable to determination of lignin content of tree leaves was developed and proposed. The validity and reliability of this method was confirmed by the comparison with the conventional methods such as Klason and acetyl bromide methods, using wood and leaf samples. It was shown that this method was applicable to leaf samples from conifer and broad-leaved trees, and that lignin contents of leaf samples were found much lower than those obtained by the conventional methods. This method was further applied to field experiments, using leaf litter. Lignin itself was not necessarily the most important rate-limiting factor affecting biodegradation of oak leaf litter, because it was found that oak leaf litter was decomposed in accordance with its lignin at a similar rate. Our results also showed that other environmental factors such as nitrogen influx could affect the degradation of leaf litter.
  • イボタケ類菌糸マットによる北方林のポドゾル形成の検証とその微生物群集の機能性解析
    科学研究費補助金（基盤研究(B)）
    Date (from‐to) : 2016 -2019 
    Author : 宮本敏澄
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2018/03 
    Author : Hashidoko Yasuyuki
     
    Hyper-N2O emitting microorganisms were screened from Sphagnum riparium, which is tolerant to conditions polluted with minerals and ammonia. According to our N2O emission assay, Rhizobium sp. of class Alphaproteobacteria was isolated as a hyper-active N2O emitting eubacteria. This bacterium formed almost equivalent mixture with a Serratia sp. of class Gammaproteobacteria and administered an ability to produce N2O to the Serratia. In addition, we have isolated non-denitrifying N2O quenchers from both Andisol in Hokkaido and degrading palsa mire in Finland, and the potent N2O quenchers were identified as Rhodococcus sp. and Chitinophaga sp. respectively. Both of the N2O quenchers were missing both nosZ gene for denitrifiers and atypical nosZ genes for dissimilatory nitrite reduction to ammonia (DNRA) bacteria. Hence their N2O quenching mechanisms were not simple reduction of N2O to N2 gas, but more drastic and active catabolic reaction of N2O as their nitrogen source was predicted.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2013/04 -2016/03 
    Author : SHIBATA Hideaki, TODA Hiroto, MIYAMOTO Toshizumi, INAGAKI Yoshiyuki, FUKUZAWA Karibu, UGAWA Shin, ISOBE Kazuo, HISHI Takuo, TATENO Ryunosuke, SASAI Takahiro, SUWA Yuichi, ENOKI Tsutomu, SAIGUSA Nobuko, OHTE Nobuhito, FUKUSHIMA Keitaro
     
    This research project aimed to clarify the pattern of abrupt changes of soil environment, vegetation process and dynamics on ecosystem nitrogen cycles during the period between dormant and growing periods, and analyze their impacts on the ecosystem processes and functions including primary productivity, nutrient retention and the environmental conservation functions of the ecosystem during the growing season. Our results indicated that soil freeze-thaw cycle was amplified due to the snowpack decrease in winter, causing the alteration of sol microbe biomass and soil nitrogen mineralization and nitrification. It was suggested that those environment changes in winter impacted to nitrogen cycles of the ecosystem during the growing season.
  • 積雪下でのリグニン分解活性を備えたリター分解菌類の分子系統および生態生理
    科学研究費補助金 (基盤研究(C))
    Date (from‐to) : 2013 -2015 
    Author : 宮本敏澄
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2011 -2013 
    Author : OWARI Toshiaki, MIYAMOTO Toshizumi, SHIBANO Hirofumi, SAKAUE Daisuke
     
    As a novel technique for natural forest management in snowy regions, we aimed at developing snow control treatments that contribute to prevent snow blight diseases at the seed germination stage and to facilitate natural tree regeneration. Results from our field trials indicated that the artificial formation of uneven ground surface may be an effective treatment particularly on a lower elevation. It enhances soil frost during winter, which likely has a positive effect inhibiting seed infection and damage caused by the pathogenic fungus and increasing the rate of germination in a natural forest.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2010 -2012 
    Author : SHIBATA Hideaki, INAGAKI Yoshiyuki, MIYAMOTO Toshizumi, TATENO Ryunosuke, HISHI Takuo, TODA Hiroto, FUKUZAWA Karibu, SUWA Yuichi, NAKATA Makoto, KOBA Keisuke, NAKANISHI Asami, HIRAI Keizo
     
    We conducted the field experiments using natural environmental gradient in Japanese archipelago to clarify the impact of snowpack changes in winter on soil nitrogen dynamics in forest ecosystem. We found that nitrogen mineralization by soil microbe increased by the amplification of soil freeze-thaw cycles induced by the decrease of snowpack and its heat insulation ability. It was suggested that winter processes in biologically dormant season were not negligible for biogeochemical cycles and water quality formation in the growing season.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2009 -2011 
    Author : MIYAMOTO Toshizumi, KOUDA Keiichi
     
    We investigated the decomposition of leaf litter and the composition of litter-decomposing fungal community under snow cover in some forest stands in Hokkaido, and their extracellular enzyme productivity at low temperature. It was observed that while the oak and fir foliage litter lost their original weight under snow during the winter season, some fungi appeared or increased the frequency. Some fungi isolated from oak litter were found to extend the mycelia on the media and indicated ligninolytic activity at 0℃. These results suggest that some litter-decomposing fungi, which have potential ability to degrade lignin at 0℃, significantly contribute the litter decomposition under snow cover.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2008 -2011 
    Author : HASHIDOKO Yasuyuki, HARAGUCHI Akira, KOIKE Takayoshi, HATANO Ryusuke, TAMAI Yutaka, HORIUCHI Junichi, MIYAMOTO Toshizumi
     
    Nitrogen imbalance of the boreal forest ecosystem has long been a mystery, called missing link of nitrogen in boreal forest. We challenged to this mystery, to practically understand the effects of climate change on forest biomass productivity in several types of boreal forests. Precise investigation of optimal culture conditions including compositions of the medium were obviously close to the reported conditions of the forest bed soil in summer seasons. The 16S rRNA gene-targeting DGGE analysis combined with gellan gum medium revealed the presence of Dugnella (class y-Proteobacteria) and Clostridiumin (phylum Firmicutes) in the A-horizon of the subarctic tundra soil, and also showed the aboveground vegetation affect on bacterial activity in soil. Thus, it was strongly suggested that scale of the elemental circulation in the boreal forests near the forest limit highly regulates acetylene reducing activity of free-living nitrogen-fixing bacteria. Also it was speculated that the low acetylene reduction in the forest bed soil would be highly regulated as corroborative events together with ericoid mycorrhizal and/or ectomycorrhizal fungi, leading to effective nitrogen supply to the forest ecosystem.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2006 -2008 
    Author : AGETSUMA Naoki, HIURA Tsutomu, MIYAMOTO Toshizumi, HIURA Tsutomu, MIYAMOTO Toshizumi, MURAKAMI Masashi, HINO Takafumi, TOYOTA Ayu, ARAKI Natsuko, HIRONAGA Takuo, YAMAZAKI Akinobu, AGETSUMA Yanagihara, AGETSUMA Yoshimi
     
    森林環境においてシカ密度と林床植物の生産性(光条件・土壌栄養)を操作し、大型植食者の採食圧と林床植生、土壌動物の反応を調べた。3年間の実験で、シカ密度が林床植物の種数・種多様性・ミミズ密度に対し有意な影響を与えていないことが示された。また、シカが土壌微生物の多様性や活性に促進的な機能を持っていることが示唆された。なお、光条件向上のため択伐を行ったが、この択伐が林床植生・土壌動物ひいてはシカの採食行動に大きな影響を与えることが解った。
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2005 -2006 
    Author : 小泉 章夫, 宮本 敏澄, 矢島 崇, 平井 卓郎
     
    心材腐朽を有する不整な樹幹断面をもつ樹木の暴風による幹折れ挙動を定量的に評価する方法の確立を目的として研究を行った。平成18年度の研究実績は以下の通りである。 1.緑化木樹種の強度データの集積 台風0418による北海道大学構内の風倒木などを供試木として,28樹種の木材の成長・密度分布・強度特性を測定して基礎的データを収集した。 2.不整断面の断面係数の数値計算手法の検討 16本の内部腐朽を持つ広葉樹および針葉樹大径木の伐根を試験対象として,測定を行なった。 対象樹幹の外部形状の計測は以下のようにして行なった。(1)かたどりゲージを用いて外周の形状を30cm区間ずつに分けて順次かたどり,それぞれの測定区間についてかたどった形状をデジタルカメラで撮影する。(2)外周上の測定区間(30cm)ごとに設定した標点間の距離を大型コンパスとスケールで測定する。(3)標点間の距離から各標点の座標を決定し,隣接する標点間に,対応するデジタルカメラの撮影画像を貼り付けて,外周形状を決定する。 内部の木部形状(心材腐朽によって強度のなくなった部分を除く)は以下のようにして推定した。(1)樹幹のいくつかの方向からレジストグラフを用いて強度を有する木部の厚さを測定する。(2)測定した厚さの平均値を一律の木部厚と仮定して,推定した外周形状とあわせて木部断面を決定する。 このようにして決定した木部断面について,前年度に開発した画像解析と数値計算法による断面係数評価法にしたがって,断面係数を算出し,別途撮影した伐根の断面形状の写真と比較してその精度を検討した。検討の結果,断面係数の推定値に対する実測値の比は平均で1.06であり,この方法によって比較的精度よく推定できることがわかった。 以上の結果を総合して,樹木の幹折れ破壊に関する限界風速の評価方法を示すことができた。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2003 -2005 
    Author : HIURA Tsutomu, TODA Masanori, KANEKO Nobuhiro, TAWARAYA Keitarou, MIYAMOTO Toshizumi
     
    1.In this project, we clarified some links among the species diversities of producer, consumer, and decomposer with special reference to the response to environmental gradient for Quercus crispula. 2.We carried out the cutting and fertilization experiment in secondary forests to reveal the community-level and ecosystem-level responses to light-nutrient resource gradient. In results, the fertilization accelerated herbivory in Quercus crispula. 3.We set up the experimental plots that manipulate the density of earthworm, and examined the density effects on ecosystem function. The fact that high accumulation of litter in the low density plots suggests that the lower density of earthworm would result the lower decomposition rate although nitrogen mineralization rates were not different among manipulations at least during the two years. 4.The reconstruction process of species diversity of consumer on the canopy of Quercus crispula was compared between the disturbed canopy by using canopy fogging method and non-disturbed canopy. This experiment suggest that the community of herbivorous insects is converge to single stable equilibrium depend on the quality of a leaf, while the community of detritivorous insects varies depend on the assemblage process of the species (multiple stable equilibria). We also examined the diversity of decomposer community in stands that having different tree species diversity, however, the results suggest that oribatid mite community structure was minimally affected by tree species diversity and associated changes in litter diversity. 5.We manipulated fungal diversity by some sterilizations to examine the function of fungal groups by estimating mineralization, decomposition rate and growth rate of some plants. The results suggested that Basidiomycota had higher decomposition ability than Ascomycota, and mycorrhiza on Maianthemum dilatatum contributed to uptake for phosphorous and its growth.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2003 
    Author : YAJIMA Takashi, MIYAMOTO Toshizumi, KIKUCHI Shun-ichi, TAMAI Yutaka
     
    This study was carried out to elucidate the vegetation-environment interaction in the rooting zone of plants growing on heavily disturbed area for the purpose of applying the relationships to revegetation works. To explain the vegetation-environment interaction, we selected the disturbed areas such as Mt.Usu for volcanic disturbed site which erupted in 2000, river side of Satsunai-gawa for riparian disturbed area, and mountain slopes of Hidaka district for large scale erosion disturbance area. The survey were conducted in each site for the disturbance resume, revegetation process, growth analysis of invaded trees, mycorrhiza infection to the plant roots and physical and chemical site conditions. On the volcanic disturbed site around the new craters of Mt.Usu, early stage of vegetation recovery process was recorded and ectomycorrhiza (ECM) or arbuscular mycorrihza (AM) types which infected to the plant roots were investigated. On the disturbed area of river sides, we investigated the stand dynamics and growth characteristics of Chosenia arbutifolia in addition to the nutrient condition of riparian zone. Further, the infection ratio, the types of ECM and seasonal dynamics of ECM infection on the roots of Salix sachalinensis seedlings were surveyed. And also, we investigated the culture medium of tree seedlings which expected to use for vegetation works. We succeeded in artificial infection of ECM in semi-open condition. These are the certain progress for the application to the advanced works of the vegetation-enbironment interaction systems in the rooting zone.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2002 -2002 
    Author : 日浦 勉, 宮本 敏澄, 金子 信博, 戸田 正憲
     
    1.5月下旬に被食排除区を作るために、ミズナラとシラカバの展葉前の枝先に袋かけを行った。10月下旬の落葉期に、ミズナラとシラカバの調査木の下に設置したリタートラップから落ち葉を回収し、葉の食害の程度を5段階にわけ、各段階の葉の枚数を数えたうえで、食害度別に風乾し、リターバッグを設置した。 2.土壌マイクロコズムを林内に設置し、落葉の多様性(ミズナラ、混合の2処理)、大型土壌動物の多様性(大型なし、ミミズのみ、ヒメフナムシのみ、ミミズとヒメフナムシの4処理)を操作して、落葉の分解速度、土壌化学性の変化、および土壌小型節足動物と細菌群集への影響を解析した。落葉の質が分解系に与える影響を評価するための標準的な方法を確立することができた。フトミミズのバイオマスは日本の森林のなかでも大きい方であり、フトミミズがこの森林でのキーストン種であることが予測された。一方、ヒメフナムシとの相互作用は明確ではなかった。 3.フェノロジーの異なるユリ科草本4種の資源分配と結実率が伐採・施肥によりどのように変化するかを調べた。その結果、開花・開葉の早いミヤマエンレイソウとユキザサのバイオマスと結実率は土壌養分が制限になっており、開花・開葉の遅いチゴユリとオオアマドコロのバイオマスと結実率は光資源が制限になっていることが明らかとなった。 4.春植物(ミヤマエンレイソウとユキザサ)とミズナラリター、夏植物(ヌスビトハギとハエドクソウ)とミズナラリターの混合と伐採・施肥が窒素無機化に与える効果を調べた。その結果、春植物とミズナラリターを混ぜた場合に負の混合効果が検出されたが、夏植物と混ぜた場合は混合効果は検出されなかった。またこの混合効果には伐採・施肥は影響を与えていなかった。

Copyright © MEDIA FUSION Co.,Ltd. All rights reserved.