Researcher Database

Faculty of Environmental Earth Science Integrated Environmental Science Conservation on Natural Environments

Researcher Profile and Settings


  • Faculty of Environmental Earth Science Integrated Environmental Science Conservation on Natural Environments

Job Title






  • Researcching the mechanisms of community diversity maintenance in various ecosystems after human and natural disturbances. Clarifying community maintenance systems in various disturbed areas, such as volcanos, skislopes and wetlands, by analyzing data obtained from permanent plots.

Research Interests

  • plant cmmunity ecology   Plant community ecology   Environmental Conservation   

Research Areas

  • Basic biology / Ecology/Environment

Academic & Professional Experience

  • 1996/01 - 2010/11    Hokkaido UniversityGraduate School of Environmental ScienceAssociate Professor
  • 2010/12    Hokkaido UniversityGraduate School of Environmental Earth ScienceProfessor
  • 2003/09 - 2004/08    The University of Western AustraliaDepartment of Plant SciencesVisiting Scholar
  • 1999/05 - 2000/01    The University of British Columbia Department of BotanyVisiting Scholar
  • 2010/12    - Professor


  • 1987/04 - 1990/03  Hokkaido University  Graduate School of Science  Doctoral course in Division of Botany
  • 1984/04 - 1986/03  Hokkaido University  Graduate School of Environmental Science  Master course in Division of Environmental Conservation

Association Memberships

  • British ecological society   Botanical Society of America   International Association of Vegetation Sciences   Ecological Society of America   Botanical Society of Japan   

Research Activities

Published Papers

  • Michiru Otaki, Shiro Tsuyuzaki
    Acta Oecologica 101 1146609X 2019/11 [Refereed][Not invited]
    © 2019 Elsevier Masson SAS Biological litter decomposition and the litter-associated microbial organisms were monitored for three years to characterize litter decomposition in early and late successional stages. Two forests were used for the investigation: pioneer a forest dominated by birch (Betula platyphylla var. japonica) and a climax forest by oak (Quercus mongolica var. grosseserrata) in the cool-temperate region of northern Japan. Three types of litter were used: birch, oak and mixed litter. The litter decomposition was effective during the first year but 50% of the original litter remained even after three years. Carbon-to-nitrogen ratios in the litter decreased largely in the first year and became stable thereafter. The litter decomposition rates were not different among the litter types and between the forests. The temporal changes in phospholipid fatty acids (PLFAs) showed that fungal biomass reached its peak in the first year and the bacterial biomass increased steadily until the end of the experiment. The concentrations of fungal PLFAs in the litter did not differ between the litter types but were lower in the oak forest. The litter decomposition was performed mostly by fungi, in particular in the early stages, while bacterial decomposition depended on the litter types and/or the forest types. Gram-negative bacteria reached their peak of PLFAs in the second year while gram-positive bacteria PLFAs increased gradually during the three years. Therefore, the succession of microorganisms in the litter occurred from fungi to bacteria and from gram-negative bacteria to gram-positive bacteria in the two forests. Unlike in the case of coniferous or monotonic forests, the effects of forests and litter types on litter decomposition for the first year were weak. The forest types on litter decomposition appeared only for the long-term litter decomposition. The successional changes of microorganisms occurred from fungi to bacteria for long-term litter decomposition processes with increasing N concentration in the litter.
  • Chikako Nagasato, Hiroki Kawamoto, Teruo Tomioka, Shiro Tsuyuzaki, Chika Kosugi, Toshiaki Kato, Taizo Motomura
    Phycological Research 13220829 2019/01 [Refereed][Not invited]
    © 2019 Japanese Society of Phycology Laminarialean plants undergo heteromorphic alternation of generations between the macroscopic diploid sporophyte and the microscopic haploid gametophyte. The generations change through the formation and release of asexual or sexual reproductive cells. It is difficult to monitor the release and diffusion of zoospores into the environment. Furthermore, even if zoospores can be detected, species identification remains difficult. This study attempted to develop a sensitive and fast identification method for laminarialean zoospores using quantitative PCR. In addition, we aimed to estimate the density of zoospores in natural seawater. Specific primers for Saccharina japonica and Undaria pinnatifida were designed and used to estimate the quantity of zoospores in seawater. DNA samples (environmental DNA) were collected from seawater once or twice each month for 2 years at the same area, and seasonal variations in the release of zoospores was monitored. The estimated maturation period based on the number of released zoospores in this study was comparable with those of the previously reported maturation periods of S. japonica and U. pinnatifida sporophytes. This supports the validity of our method in estimating zoospore release from laminarialean plants. The method will be a useful tool for ecological studies on these commercially relevant species.
  • Mukhlish Jamal Musa Holle, Shiro Tsuyuzaki
    Acta Oecologica 93 48  2018/11 [Refereed][Not invited]
  • Shishir Sharmin, Tsuyuzaki Shiro
    Environmental Monitoring and Assessment 190 (6) 0167-6369 2018/06 [Refereed][Not invited]
     Research paper (scientific journal)
  • Tsuyuzaki Shiro, Iwahana Go, Saito Kazuyuki
    Polar Biology 41 (4) 753 - 761 0722-4060 2018/04 [Refereed][Not invited]
     Research paper (scientific journal)
  • Akira S. Hirao, Mikio Watanabe, Shiro Tsuyuzaki, Ayako Shimono, Xuefeng Li, Takehiro Masuzawa, Naoya Wada
    Journal of Biogeography 44 (12) 2740 - 2751 2017/12 [Refereed][Not invited]
     Research paper (scientific journal)
  • 江川知花, 江川知花, 西村愛子, 西村愛子, 小山明日香, 露崎史朗
    保全生態学研究 22 (1) 187 - 197 1342-4327 2017/05 [Refereed][Not invited]
     Research paper (scientific journal)
  • Hirata A.K.B, Tsuyuzaki S.
    Wetlands Ecology and Management 24 (5) 521 - 532 2016 [Refereed][Not invited]
  • Iwahana G, Harada K, Uchida M, Tsuyuzaki S, Saito K, Narita K, Kushida K, Hinzman L.D.
    Journal of Geophysical Research F: Earth Surface 121 (9) 1697 - 1715 2016 [Refereed][Not invited]
  • Kwon T.O, Tsuyuzaki S.
    Ecological Research 31 (4) 557 - 567 2016 [Refereed][Not invited]
  • Otaki M, Takeuchi F, Tsuyuzaki S.
    Journal of Mountain Science 13 (9) 1652 - 1662 2016 [Refereed][Not invited]
  • Narita K, Harada K, Saito K, Sawada Y, Fukuda M, Tsuyuzaki S.
    Arctic, Antarctic, and Alpine Research 47 (3) 547 - 559 2015 [Refereed][Not invited]
  • Kushida K, Hobara S, Tsuyuzaki S, Kim Y, Watanabe M, Setiawan Y, Harada K, Shaver G.R, Fukuda M.
    International Journal of Remote Sensing 36 (17) 4344 - 4362 2015 [Refereed][Not invited]
  • Hoyo Y, Tsuyuzaki S.
    Flora: Morphology, Distribution, Functional Ecology of Plants 210 60 - 65 2015 [Refereed][Not invited]
     Research paper (scientific journal)
  • Nishimura A, Tsuyuzaki S.
    Folia Geobotanica 50 (2) 107 - 121 2015 [Refereed][Not invited]
  • HOYO Yuri, TSUYUZAKI Shiro
    Wetlands 34 943 - 953 2014 [Refereed][Not invited]
     Research paper (scientific journal)
  • Egawa C, Tsuyuzaki S.
    Acta Oecologica 62 45 - 52 2015 [Refereed][Not invited]
    Wetlands 34 (1) 117 - 127 2014 [Refereed][Not invited]
     Research paper (scientific journal)
  • TSUYUZAKI Shiro, NARITA Kenji, Sawada Yuki, Kushida K
    Plant Ecology 215 327 - 337 2014 [Refereed][Not invited]
     Research paper (scientific journal)
    Ecol Res 28 (6) 1061 - 1068 0912-3814 2013/11 [Refereed][Not invited]
    Journal of Vegetation Science 24 (6) 1062 - 1073 1100-9233 2013/11 [Refereed][Not invited]
  • Hoyo Y, Tsuyuzaki S
    American journal of botany 100 (5) 817 - 823 0002-9122 2013/05 [Refereed][Not invited]
    Journal of Vegetation Science 24 (3) 473 - 483 1100-9233 2013/05 [Refereed][Not invited]
    Clim Res 51 (1) 1 - 10 0936-577X 2012/01 [Refereed][Not invited]
    Plant Ecology 213 (11) 1729 - 1737 1385-0237 2012/11 [Refereed][Not invited]
  • Tsuyuzaki S, Nakajima H, Hirata A.K.B, Koyama A.
    Feddes Repertorium 122 (3-4) 275 - 286 2012 [Refereed][Not invited]
  • K. Irie, S. Tsuyuzaki
    Plant Biosystems 145 798 - 801 11263504 2011/12 [Refereed][Not invited]
    Aesculus turbinata acorns were dispersed earlier than other acorn-producing species and are removed completely by rodents, although the acorns are unpalatable. The dispersal timing and low palatability to rodents on A. turbinata acorns promote the seed caching by rodents, facilitating the seedling emergence is possible even in lower-seeding years. © 2011 Società Botanica Italiana.
  • Kimura Hideo, Tsuyuzaki Shiro
    Applied Vegetation Science 14 350 - 357 2011 [Refereed][Not invited]
  • Seed Science Research 20 (3) 201 - 207 0960-2585 2010 [Refereed][Not invited]
  • iForest - Biogeosciences and Forestry 3 52 - 55 2010 [Refereed][Not invited]
  • Wetlands Ecology and Management 18 135 - 148 2010 [Refereed][Not invited]
  • Climatic Change 93 (3/4) 517 - 525 0165-0009 2009 [Refereed][Not invited]
  • Ecological Research 24 (2) 237 - 246 0912-3814 2009 [Refereed][Not invited]
  • International Journal of Remote Sensing 30 1651 - 1658 2009 [Refereed][Not invited]
  • Journal of Forestry Research 20 91 - 98 2009 [Refereed][Not invited]
  • Journal of Vegetation Science 20 (5) 959 - 969 1100-9233 2009 [Refereed][Not invited]
  • Tsuyuzaki Shiro, Sawada Yuki, Kushida Keiji, Fukuda Masami
    ECOLOGICAL RESEARCH 23 (4) 787 - 793 0912-3814 2008/07 [Refereed][Not invited]
  • T. B. Nishimura, E. Suzuki, T. Kohyama, S. Tsuyuzaki
    Plant Ecology 193 315  13850237 2007/12 [Refereed][Not invited]
  • Akasaka M, Tsuyuzaki S, Hase A
    Journal of plant research 120 (2) 329 - 336 0918-9440 2007/03 [Refereed][Not invited]
  • Northwest Science 81 333 - 336 2007 [Refereed][Not invited]
  • Pits conserve species diversity in an overgrazed grassland
    Applied Ecology and Environmental Research 5 25 - 36 2007 [Refereed][Not invited]
  • Tsuyuzaki S, Hase A, Niinuma H
    Mycorrhiza 15 93 - 100 0940-6360 2005/03 [Refereed][Not invited]
  • Shiro Tsuyuzaki, Akira Hase
    Folia Geobotanica 40 319 - 330 12119520 2005/01 [Refereed][Not invited]
    A small eruption occurred in the early spring of 1996 on the summit of Mount Koma, northern Japan, 67 years after the 1929 catastrophic eruption. To identify damage on the plant communities and recovery patterns, we established 400 50 × 50 cm permanent plots in four locations along the gradient of the thickness of tephra produced in 1996: non-disturbed (N), weakly disturbed (W), middle disturbed (M), and heavily disturbed (H). Annual monitoring was conducted from 1996 to 2001. Gullies and rills formed in M and H, indicating that the ground surface movements were more intense there. Mean vascular plant species richness increased from H to N, but did not increase from 1996 to 2001 in any location. In an area where tephra thickness was 10 cm, the recovery was mostly conducted by the species that could have survived during the eruption. A shrub, Salix reinii, was the leading species in most sites throughout most years. Large perennial herbs, Polygonum weyrichii, P. sachalinense and Miscanthus sinensis were common in the disturbed areas, in particular in M and H. Those three species develop large underground organs and enlarge clonally, suggesting that the tolerance to ground surface stability is the most important trait for the recovery of those species. Carex oxyandra established not only by vegetative regeneration but also by seedling regeneration. A short forb, Campanula lasiocarpa, could establish only in W by seedling regeneration. Mosses and lichens were predominant in plots in N and W, but less represented and not greatly increasing their cover in M and H up to 2001. We concluded that the community recovery was delayed in all the disturbed areas, mostly due to low seedling establishment. Only a few specific species established by vegetative reproduction. Disturbance gradients such as thickness of tephra and/or ground surface stability have determined plant community structure and development.
  • Ishikawa-Goto M, Tsuyuzaki S
    Journal of plant research 117 (3) 245 - 248 0918-9440 2004/06 [Refereed][Not invited]
  • IGARASHI Yaeko, IWAHANA Go, SENTO Nobuyuki, TSUYUZAKI Shiro, SATO Toshiyuki
    The Quaternary research 第四紀研究 = The Quaternary research 42 (6) 413 - 425 04182642 2003/12 [Refereed][Not invited]
  • Titus JH, Tsuyuzaki S
    Mycorrhiza 12 271 - 275 0940-6360 2002/12 [Refereed][Not invited]
  • Shiro Tsuyuzaki, Masaki Goto
    American Journal of Botany 88 1813 - 1817 00029122 2001/10 [Refereed][Not invited]
    The topsoil that contained the seed bank became buried under thick tephra after the eruptions of Mount Usu during 1977 and 1978. To determine the seed bank potential of the topsoil 20 yr after the eruptions, i.e., in 1998, 408 100-cm-3 samples were excavated under 115-185 cm of volcanic deposits. The topsoil was collected at 10-cm intervals along the horizontal scale and was divided into a 0-5 cm deep upper layer and a 5-10 cm deep lower layer. The seed bank was estimated by both the germination (GM) and flotation (FM) methods. In total, 23 species with an average seed density of 1317 seeds/m2 were identified by GM, and 30 species with a density of 2986 seeds/m2 were extracted by FM. The dominant species was Rumex obtusifolius, and perennial herbs, such as Carex oxyandra, Viola grypoceras, and Poa pratensis, were common. For nine species this study provided the first records for field seed longevity >20 yr. The seed density in the upper layer was double that in the lower layer, and the horizontal distribution was heterogeneous even at 10-cm intervals. We concluded that the seed bank has retained the original structure of the seed bank under the tephra and will persist longer with soil water content between 20 and 40%, no light, and low temperature fluctuations (±0.17°C of standard deviation in a day).
  • Masahiro Haruki, Shiro Tsuyuzaki
    Ecological Research 16 451 - 457 09123814 2001/09 [Refereed][Not invited]
    The establishment patterns of woody plants were investigated on the volcano Usu, 9 years after the 1977-1978 eruptions. The former vegetation was covered by a 1-3 m thick volcanic deposit. Trees producing wind-dispersed seeds capable of long distance dispersal, such as Populus maximowiczii, Betula platyphylla var. japonica, Salix hultenii var. angustifolia, and Salix sachalinensis, were dominant. Most trees were only 2-4 years old in 1986, suggesting that chances for seedling establishment were restricted. The tree heights did not differ significantly among the species, while lengths of annual shoots differed due to herbivore preferences. Trees were established at higher densities on gravel-dominated pumice surfaces than on fine-textured surfaces. Tree density was not greatly affected by the nutrient content of deposits. From 1987 to 1990, tree height increments did not differ between the gravel and non-gravel areas. Ground surface texture is an important factor in determining seedling establishment in the early stages of volcanic succession, and nutrient status is unimportant.
  • Japanese Journal of Ecology 51 13 - 22 2001 [Refereed][Not invited]
  • Shiro Tsuyuzaki
    Journal of Plant Research 113 415 - 418 09189440 2000/12 [Refereed][Not invited]
    In this report, the author suggests that the number of veins (NV) is useful to estimate leaf maturation for a tropical fern Pteris mutilata, as has been established in ferns of cool temperate regions. NV expressed developmental stages better than any other leaf size parameters, such as blade length, blade width, stipe length, and total length (blade+ stipe length). The leaf shape became more oblong and/or slender after the plant matured, which could be measured by two shape parameters, (blade width)/(total length) and (blade width)/(blade length). Principal component analysis using all the morphological parameters showed that NV is categorized into size parameters, although NV has been considered to differ somehow from the other size parameters. Thus NV represents one of the size parameters that is the most appropriate to estimate leaf maturation.
    Japanese Journal of Ecology Japanese Journal of Ecology 49 (3) 265 - 268 00215007 1999/12 [Refereed][Not invited]
  • Toshihiro Kondo, Shiro Tsuyuzaki
    Diversity and Distributions 5 223 - 233 13669516 1999/12 [Refereed][Not invited]
    The 1929 eruption of Mount Koma (1140 m in altitude) completely deforested the vegetation on the summit area of the volcano. An alien species of larch, Larix kaempferi (= L. leptolepis) was planted on the lower slopes of the volcano between 1953 and 1963, but since then has become abundant on the summit. To determine the regeneration patterns of the larch, we measured stem densities on aerial photographs taken in 1963, 1973 and 1994, and in the field during 1996. Larix kaempferi stems with crown diameters > 2 m were mapped on aerial photographs divided into 1083 100 m x 100 m grids. Stem densities on the summit increased from 0.8/ha in 1963, to 14.1/ha in 1994. Willows and birches also established there but did not grow as large as the larch. All these species are wind dispersed, and larch densities were higher in areas closer to the plantations, suggesting that wind intensity and direction determined seed migration. Four environmental factors - slope gradient, direction, elevation, and distance from the plantations in each grid were correlated with larch stem densities. Multiple regression showed that establishment patterns of L. kaempferi in the early stages were mainly related to distance from seed source (the plantations). Later, geographical disturbances and/or physiological stresses became more important. Density effects on tree invasion have been weak until now. We concluded that revegetation primarily depends on the chance of seed immigration, and that the latches may be an earlier successional species than any other native tree species.
  • Shiro Tsuyuzaki, Takeshi Ishizaki, Toshiyuki Sato
    Ecological Research 14 385 - 391 09123814 1999/12 [Refereed][Not invited]
    Vegetation structure was surveyed in gullies developed by the melting of ice wedges along the Kolyma River, northern Siberia, using 72 50 x 50 cm plots. The mean total plant cover was approximately 50% on gley soils, which were only distributed in the gullies. Based on TWINSPAN cluster analysis, four vegetation types were recognized: (i) Agrostis purpurascens grassland with Ceratodon purpureus moss carpet; (ii) Matricaria matricarioides forbland; (iii) Chamaenerium angustifolium and M. matricarioides forbland; and (iv) Descurainia sophia grassland. Species that produce seeds capable of long-distance dispersal established well. Of the environmental factors surveyed, the gully scales (height and width) and elevational difference within a plot were primarily related to the vegetation development. The gully height was correlated with soil pH and compaction that might be related to intensities of ground surface disturbances. Agrostis purpurascens established in large gullies, while Equisetum arvense and Salix alaxensis established in small gullies. Soil compaction was also related to the vegetation establishment patterns (e.g. Rumex sibirica did not establish on hard soils). We concluded that the gully scales primarily determine soil conditions, including ground surface instability as a function of slope and soil compaction, and subsequent community structure.
  • Shiro Tsuyuzaki
    Japanese Journal of Ecology 49 265 - 268 00215007 1999/12 [Refereed][Not invited]
  • Jonathan H. Titus, Shiro Tsuyuzaki
    Arctic, Antarctic, and Alpine Research 31 283 - 292 15230430 1999/01 [Refereed][Not invited]
    Ski slope vegetation on Mount Hood, Oregon, U.S.A. was surveyed to assess vegetation that has developed under a constant disturbance regime and the environmental factors that are important in structuring the vegetation. Ski runs extend from 1200 to 2200 m on the south face of Mount Hood. TWINSPAN distinguished 17 plant communities including 4 above treeline and 13 below treeline; 3 of the latter also occur in the forest adjacent to the ski runs. Elevation, which is correlated to temperature, precipitation, depth of snowpack, and timing of snow melt, is the most important variable structuring the vegetation. Soil texture is also important. Distance to the forest boundary influences the vegetation only at lower elevations. Most of the slopes we examined were thickly vegetated, except above treeline where vegetation is typically sparse. Non-native species were detected only at the lowest elevations and were infrequently dominant. Non-native species cover and richness were correlated with percent bare area. Relative to ski runs in other areas, those on Mount Hood have little non-native species invasion, probably due to the harsh conditions prevalent on the ski runs and to a relative lack of bare areas, which occupy 17% of the runs below treeline. The relative scarcity of bare areas may be a result of the relatively great age of the ski runs (64 yr). Above treeline there was no detectable difference in vegetative composition on and off the ski run, probably due to extensive trampling of the vegetation in the summer.
  • TITUS Jonathan H., TSUYUZAKI Shiro
    Ecological Research Ecological Research 13 (2) 97 - 104 09123814 1998/08 [Refereed][Not invited]
  • Mandy Tu, Jonathan H. Titus, Shiro Tsuyuzaki, Roger Del Moral
    Folia Geobotanica 33 3 - 16 12119520 1998/01 [Refereed][Not invited]
    The 1980 eruption of Mount St. Helens deposited new substrates upon which wetlands are now developing. We collected soil from five wetlands south of Spirit Lake, Mount St. Helens, Washington, to examine the seed banks. Seedling emergence density in the top 5 cm was highly variable, and ranged from (mean ± s.d.) 15,700 ± 15,200 to 38,000 ± 31,500 per m2. Seedling emergence from soil at 5 to 10 cm depth varied from 800 ± 600 to 18,000 ± 24,800 per m2, and averaged 1/3 as many seeds as the surface. The high proportion of buried seeds may be due to continuing deposition of upland sediments. We identified 17 taxa from the wetland soil samples with Epilobium ciliatum, Juncus bufonius, Agrostis exarata and Juncus ensifolius being the dominant species. Wetland vegetation was dominated by Equisetum arvense, Salix sitchensis, Typha latifolia and the four dominant species in the seed bank. Correlations between vegetation and seed bank were not significant for four of the five wetlands, and the dominance by Typha latifolia in two wetlands contributed to the low correlations. Thus, vegetation of these early successional wetlands generally was not similar to seed bank composition. Canonical correspondence analysis was used to relate soil parameters to vegetation and seed bank data. The vegetation was correlated primarily with soil particle size and secondarily to water temperature, while the seed bank was correlated to pH. texture and temperature.
  • Shiro Tsuyuzaki
    Journal of Vegetation Science 8 353 - 360 11009233 1997/01 [Refereed][Not invited]
    Wetland vegetation developed in the crater of Mount Usu, northern Japan, soon after the 1977-1978 eruptions which destroyed the vegetation. The cover of each species was measured in 1994 in 118 50 cm x 50 cm plots situated in transects and related to environmental factors (elevation, water depth, soil texture, soil compaction, soil organic matter, and soil pH) to clarify vegetation development. Five vegetation types were recognized dominated by Eleocharis kamtschatica, Equisetum arvense, Lythrum salicaria. Juncus fauriensis and Phragmites australis respectively. Sedge/grass marsh and reed swamp dominated deep-water sites; willow swamp and wet meadow vegetation characterized shallow-water sites, indicating that vegetation zonation developed soon after the eruption. Since those wetland plants were derived neither from seed banks nor from vegetative propagules, they had to immigrate from outside the summit areas. However, except for willows, most species lack the ability for long-distance dispersal. Late successional species, such as P. australis established in the early stages of the primary succession. The water depth varied by 27.5 cm among the plots. Coarse soil particles accumulated, and pH (5.22 - 6.55) was low on the elevated sites. Organic matter ranged from 2.8 % to 19.1 % and was high on the elevated sites. Water depth was responsible for the establishment of large-scale vegetation patterns, while edaphic factors, i.e. soil compaction, pH, and organic matter, were determinants of small-scale vegetation patterns. Among the edaphic factors, soil compaction appeared to have a strong influence on vegetation development.
  • Shiro Tsuyuzaki, Jonathan H. Titus, Roger Del Moral
    Journal of Vegetation Science 8 727 - 734 11009233 1997/01 [Refereed][Not invited]
    We examined the factors that control seedling establishment on barren substrates on the pyroclastic flows from Mount St. Helens. From June to September in 1993, we monitored seedling and microhabitat changes in 240 20 cm x 20 cm quadrats on the Pumice Plain. Seedlings emerged in 104 quadrats (43.3 %). The most abundant species were A naphalis margaritacea, Hypochaeris radicata, Lupinus lepidus and Epilobium angustifolium. Measured site characteristics included topography, particle size distribution, ground surface movements, soil water content, organic matter, pH, and presence or absence of dead lupines. Quadrats with seedlings had higher cover of dead lupines, higher amount of rock and gravel substrate, and a greater cover of rills. More seedlings emerged where eroded material accumulated. Compared to coarse-textured surfaces, silt surfaces had higher organic matter, held more water, and showed higher pH. However, seedlings became established more frequently on coarse-textured surfaces. In greenhouse experiments, a higher percentage of Hypochaeris seeds germinated on silt than on sand or gravel. The germination of Anaphalis and Epilobium did not differ with soil texture, but was higher at higher moisture levels. Seedling colonization is more dependent on ground surface microtopography, particle size, and ground movement than on the chemical status of these volcanic deposits.
  • Shiro Tsuyuzaki
    Vegetatio 122 151 - 156 00423106 1996/01 [Refereed][Not invited]
    To evaluate alpha diversities, various variables such as density, cover, volume, and weight have been used. However, density is often a distinct variable from the remaining three. To clarify differences in diversity measured by those two kinds of variables, the data collected in fourteen 2 x 5 m permanently-marked plots on Mount Usu, Japan, which erupted during 1977 and 1978 in growing seasons from 1983 to 1989 was analyzed, using Shannon's species diversity (H′) that is represented as a result of combination of species richness and evenness (J′). H′ and J′ were evaluated by density (density H′ and J′) and cover (cover H′ and J′). Cover H′ and J′ were significantly lower than density H′ and J′, indicating that cover H′ has different characteristics from density H′. Those differences are due to differences in evenness, because species richness is the same. The rank orders of species density are different from those of cover. The predominance of a few perennial herbs greatly decreases cover evenness, while seedling establishment success influences density evenness. Therefore, I propose that, during the early stages of succession on harsh environments such as volcanoes, density diversity represents seedling establishment success rate while cover diversity expresses vegetative reproduction success rate. © 1996 Kluwer Academic Publishers.
  • Shiro Tsuyuzaki, Masahiro Haruki
    Vegetatio 126 191 - 198 00423106 1996/01 [Refereed][Not invited]
    Although the summit of Mount Usu was deforested by the 1977-78 eruptions, vegetative regeneration on the caldera rim was rapid due to the erosion of thick volcanic deposits by snow and rain. To obtain the mechanisms underlying regeneration patterns after the eruptions, we monitored the growth of permanently-marked stems from 1983 to 1990. Regeneration was from resprouting-branches buried in the volcanic deposits on the caldera rim, while on the crater basin, where thick volcanic deposits accumulated, regeneration was from seedlings. The seedling regeneration lagged approximately 3 years behind vegetative regeneration. Stem densities averaged 14,000 ha-1 in the vegetatively-regenerated community on the caldera rim, and 28,000 ha-1 in the seedling regeneration on the crater basin. Populus maximowiczii accounted for ca. 75% of total stems on the caldera rim, while P. maximowiczii accounted for ca. 30% on the crater basin where Salix integra and Betula platyphylla var. japonica were also common. In both stands, immigration and mortality rates were very low. The growth of vegetatively regenerated stems expressed as stem height and diameter was significantly faster than that of stems grown from seedlings. Herbivory damage on the terminal shoots of tall stems was restricted on the caldera rim and was restricted for B. platyphylla var. japonica on the creater basin, perhaps due to fast growth supporting herbivore avoidance or low palatability. Height growth was restricted when neighbors established in close proximity, especially in the seedling-regenerated forest. The results suggest that vegetative regeneration is rapid due to three mechanisms: 1) faster plant growth; 2) herbivore avoidance; and 3) decreased interference by neighboring.
  • Shiro Tsuyuzaki, Fusayuki Kanda
    American Journal of Botany 83 1422 - 1428 00029122 1996/01 [Refereed][Not invited]
    To compare revegetation patterns between native and exotic species on abandoned pastures in northern Japan, we surveyed the vegetation structure and the seedbank using a flotation technique in 140 1 x 1 m plots. Previously introduced grasses such as Poa pratensis, Phleum pratense, and Dactylis glomerata were abundant 20 yr after the pasture abandonment, while Sasa senanensis, native shrub species, regenerated from propagation that had spread from the surrounding forests. S. senanensis shrublands and P. pratensis/P. pratense grasslands established on deep soils while D. glomerata grasslands established on shallow soils. Trees rarely became established on abandoned pastures. The seed density in the seedbank, representing 19 species, ranged from 542 to 2957 seeds/m2. The dominant species in the vegetation (P. pratensis, Trifolium repens, and Rumex acetosella) were also common in the seedbank, whereas Cerastium holosteoides var. angustifolium, Chenopodium album var. centrorubrum, and Erigeron canadensis were widespread in the seedbank but did not occur in the extant vegetation. S. senanensis regenerated by vegetative propagation, and P. pratensis and P. pratense developed a seedbank. We concluded that for native species, particularly S. senanensis, vegetative reproduction has an important role on revegetation rather than regeneration from the seedbank, and the dwarf bamboo may be a keystone species in the ecosystems.
  • Shiro Tsuyuzaki, Jonathan H. Titus
    American Midland Naturalist 135 172 - 177 00030031 1996/01 [Refereed][Not invited]
    We surveyed 28 pairs of 2 × 5 m plots located inside and outside of six gullies on the Pumice Plains of Mount St. Helens to study the effects of gully development on vegetation. These gullies are the result of the movement of volcanic deposits laid down by the eruption in 1980. Surveyed gullies were more than 5.0 m wide, 1.5 m deep and 200 m long. Mean cover of vegetation inside and outside the gullies was, respectively, 1.5% and 8.0%. Anaphalis margaritacea, Carex mertensii and Penstemon cardwellii were common both inside and outside the gullies, but cover and frequency of each species were significantly lower inside the gullies than outside. Lupinus lepidus was dominant outside gullies with a mean cover of 5.0%, but only 0.3% inside gullies. These results suggest that gully development strongly restricts cover development of most species, in particular L. lepidus. Total cover and species richness were significantly lower inside gullies, but species diversity was not significantly different. Because of the reduction of L. lepidus cover inside gullies, evenness was higher and species diversity did not differ between inside and outside the gullies.
  • Hypochoeris, a misspelling of Hypochaeris (Asteraceae)
    Journal of Japanese Botany 71 302 - 303 1996 [Refereed][Not invited]
  • Shiro Tsuyuzaki
    Environmental Management 19 773 - 777 0364152X 1995/09 [Refereed][Not invited]
    To determine the status of the vegetation of ski slopes in northeastern-central Honshu, Japan, 94 plots (2×2 m) were set up on five ski areas (101-520 m elevation) which were established between 1945 and 1985 by forest clear-cutting, land modification, and seeding. Six vegetation types were recognized: five grasslands dominated by Digitaria adscendens, Miscanthus sinensis, Zoysia japonica, Festuca rubra, and Pteridium aquilinum var. latiusculum, respectively, and bare areas of very low to no vegetation cover. Of the dominant species, F. rubra is the only introduced species; it does not, however, appear to persist. After the introduced grassland declines M. sinensis or annual grasslands develop. Native plants, especially woody species, can establish in M. sinensis grassland but do not establish in the other grasslands. It is concluded that the introduction of exotic species is inappropriate to maintain ski slope vegetation, and the development of M. sinensis grassland is desirable to promote natural revegetation. © 1995 Springer-Verlag New York Inc.
    Journal of Plant Research Journal of Plant Research 108 (1090) 241 - 248 09189440 1995/06 [Refereed][Not invited]
  • Shiro Tsuyuzaki, Roger del Moral
    Journal of Vegetation Science 6 517 - 522 11009233 1995/01 [Refereed][Not invited]
    Abstract. We predicted that plants that can establish on volcanic soils with similar disturbance histories will have similar growth characteristics. We tested this prediction by a multivariate analysis of 27 traits of 84 species found six years after an eruption on Mount St. Helens, Washington State, USA, and Mount Usu, Hokkaido, Japan. These traits include vegetative, life‐history, phenological and seed‐biology characteristics. Cluster analysis revealed five species groups: annual herbs, perennial forbs, graminoids, shrubs and trees. Each group has distinct vegetative, life‐history, and seed‐biology traits. Except for shrubs, which were lacking on Mount Usu, both floras were well represented in each group. On intensely disturbed sites on both volcanoes, perennial forbs, whose development is dependent primarily on well‐developed below‐ground organs and wind‐dispersal, expanded their cover more rapidly than did graminoids. These graminoids generally produce gravity‐dispersed seeds and have close‐set rhizomes and/or shoots. These results suggest that species that can establish during the early stages of succession on each volcano have similar vegetative, life‐history, and seed‐biology traits. 1995 IAVS ‐ the International Association of Vegetation Science
  • S. Tsuyuzaki, F. Kanda, K. Narita
    Acta Oecologica 15 461 - 467 1146609X 1994/12 [Refereed][Not invited]
    Japanese Journal of Ecology 日本生態学会誌 44 (3) 315 - 320 00215007 1994/12 [Refereed][Not invited]
     Research paper (scientific journal) 
    I studied the structure of a thinned Larix olgensis HENRY forest located on Sandaohu peatland in northeastern China. In the peatland where peat accumulation was less than 20 cm, three tree species, L. olgensis, Betula platyphylla and Populus koreana, occurred. Forest did not develop at sites where peat accumulation exceeded 40 cm. No tree seedlings were present on the forest floor. Forty-one L. olgensis stems were established in a 15 m×15 m plot. The age of L. olgensis ranged from 20 to 29 (averaged 30.9) years. Height and DBH, varied from 1.8 to 14.9 m, and from 0.9 to 22.3 cm, respectively. The thinning, which had been conducted 10-18 years previously, had reduced tree density by 1/3 and created crown gaps. At the time of observation, there were 32% gaps and 12% tree crown overlaps, both of which were also considered to have been created by thinning. However, the thinning had little influence on stem width growth. These results suggested that the growth and seedling establishment of L. olgensis are little affected by light conditions. Soil status such as nutrient availability is considered to be more important.
  • TSUYUZAKI Shiro, MORAL Roger del
    Ecological Research Ecological Research 9 (2) 143 - 150 09123814 1994/08 [Refereed][Not invited]
  • Shiro Tsuyuzaki
    Environmental Conservation 21 121 - 125 03768929 1994/01 [Refereed][Not invited]
    Ski slopes are commonly established following clearcutting of areas of well-developed forests, scraping off the surface soil, and seeding the entire ground-surface, as forests widely remain in mountainous regions where skiing is developed in Japan. The ski slopes are then sown with seeds of exotic plants in an attempt to prevent soil erosion. However, many bare areas remain, or develop, on ski slopes. Due to this landscape fragmentation, not only deterioration of Nature but also environmental problems develop, including those of water, garbage, and traffic, pollution. The ski-resort concentration occurs mainly in regions of high-quality landscape around urbanized areas, and derives mostly from economic benefits. Yet any regulation of ski-resort construction has unfortunately been delayed. Areas where ski-resorts have been concentrated have a high risk of damage, and further studies of the situation are overdue. We should reconsider the construction, enlargement, and distribution patterns, of skiresorts, and any further development should be based on sound ecological and conservational knowledge rather than mere transient economic considerations. © 1994, Foundation for Environmental Conservation. All rights reserved.
  • S. Tsuyuzaki
    Natural Areas Journal 14 59 - 60 08858608 1994/01 [Refereed][Not invited]
    Weed Research 34 433 - 436 00431737 1994/01 [Refereed][Not invited]
    In this study a flotation method is described which enables the rapid extraction of seeds from soil. Essentially, soil is mixed with 11.0 M K2CO3 and thoroughly dispersed by mechanical stirring for 3–6 min. The dispersed soil samples were delivered to plastic tubes, then centrifuged at more than 4000 g for about 5 min. Buried seeds and lighter organic materials floated in the supernatant and could be removed by filtration, washed and subsequently identified. This method performed reliably using soil samples artificially loaded with white clover and a range of cultivated grass species. In addition, a wide range of weed seeds which differed in size and density were also effectively recovered from a range of soil types from loam to gravel. Extraction rapide de graines à partir du sol par une méthode de flotation Cet article décrit une méthode de flotation qui permet l'extraction rapide de graines à partir du sol. Pour l'essentiel, le sol est mélangé avec du K2CO3 11,0 M et complètement dispersé par agitation mécanique pendant 3 à 6 min. Les échantillons de sol dispersé sont placés dans des tubes en matière plastique et contrifugés à plus d 4000Xg pendant environ 5 min. Les graines enfouies et le matériel organique plus léger flottent dans le surnageant, sont récupérées par filtration, lavées et identifiées. Cette méthode s'est révélée fiable avec des échantillons de sol portant artificiellement de fortes densités de trèfle blanc et une série de graminées cultivées. De plus, de nombreuses graines de mauvaises herbes qui différaient par leur taille et leur densité ont été efficacement récupérées de plusieurs types de sol (limons à graviers). Schnellmethode zur Bestimmung des Samengehalts im Boden durch Abschwemmen Es wird eine Methode beschrieben, mit der Samen aus Boden schnell ausgelesen werden konnen. Bazu wird dem Boden 11,0 M K2CO3 zugesetzt und der Boden 3 bis 6 Min. lang grundlich gemischt. Danach wird das Bodenmaterial in Plastikzylindern bei mehr als 4.000 g 5 Min. lang zentrifugiert. Die im Boden enthaltenen Samen und organisches Material sammeln sich im Uberstand und konnen durch Filtration abgetrennt und nach dem Waschen identifiziert werden. In einem Modellversuch, bei dem Samen von Weiß‐Klee und einer Reihe Graser dem Boden beigemischt worden waren, erwieß sich diese Methode als zuverlassig. Auch andere Samen unterschiedlicher Große und Dichte wurden in verschiedenen Bodenarten von Lehm bis grobem Sand vollstandig wieder aufgefunden. Copyright © 1994, Wiley Blackwell. All rights reserved
  • S. Tsuyuzaki
    American Journal of Botany 81 395 - 399 00029122 1994/01 [Refereed][Not invited]
  • S. Tsuyuzaki
    Seed Science and Technology 21 479 - 482 02510952 1993/12 [Refereed][Not invited]
    Biological Sciences (Tokyo) 生物科学 45 (4) p177 - 181 00452033 1993/11 [Not refereed][Not invited]
  • Shiro Tsuyuzaki
    Biological Conservation 63 255 - 260 00063207 1993/01 [Not refereed][Not invited]
    This paper describes the characteristics of the present vegetation on highland ski grounds, predicts its successional sere, and proposes methods for the restoration of natural vegetation. Vegetation data were collected from Nakayama (836 m altitude, 40-ha ski area), Teine Highland (1000 m, 40 ha), and Sapporo International (1100 m, 61 ha) ski grounds located around the city of Sapporo, Hokkaido, northern Japan. These ski areas were established by clearcutting of forest, scraping off the soil surface, and artificial seeding over the whole ground surface at the time of opening. Petasites japonicus var. giganteus was dominant in all three ski grounds. Based on species clustering and quadrat data, including cover, species numbers, life forms, and stem densities, three phases of vegetation establishment were noted: (1) artificially introduced plants gradually declined in cover; (2) three types of native vegetation were then recognized, dominated by P. japonicus var. giganteus, Juncus effusus var. decipiens and Sasa kurilensis; and (3) there was invasion by woody plants consisting of sun trees, e.g. Betula spp. and Salix spp. Based on these vegetational changes, successional seres are suggested, together with problems of vegetation maintenance in highland ski grounds in relation to the establishment of native plants. © 1993.
  • S. Tsuyuzaki, T. Tsujii
    Canadian Journal of Botany 70 2310 - 2312 00084026 1992/01 [Not refereed][Not invited]
    While tussocks did not exceed 26 cm in height, the basal area of tussocks continually expanded. Mature tussocks sometimes resulted in aggregation of tussocks. Carex meyeriana rarely developed long horizontal rhizomes and produced shoot rhizomes that led to the development of bell-shaped tussocks as a result of basalt shoot (tiller) development patterns. Equisetum limosum invaded and grew in immature tussocks, while Potentilla anserina and Chamaesium paradoxum invaded tussock summits. -from Authors
    Japanese Journal of Ecology Japanese Journal of Ecology 41 (2) 83 - 91 00215007 1991/08 [Not refereed][Not invited]
    To obtain characteristics of ski ground vegetation and predict its successional sere, surveys were undertaken on three ski grounds in Hokkaido : Play Bankei (constructed in 1968), Teine Olympia (1971) and Makomanai (1980), whose land surface were modified by heavy human impact, i.e., land cutting, sowing of herbs, and regular bush cutting. Analysis of species composition and clustering revealed vegetation of sites surveyed to be mainly divisible into four vegetation groups as follows : al) grassland of sowed herbs ; a2) Artemisia montana grassland ; b) low-cover grassland ; c) Miscanthus si...
  • S. Tsuyuzaki
    Canadian Journal of Botany 69 2251 - 2256 00084026 1991/01 [Not refereed][Not invited]
    Even after 10 yr burial by 65-140cm volcanic deposits, 16.6% of the seeds, representing 25 species, were viable. Speed volume of most species was less than 2.0 mm3. Smaller seeds had a greater rate of survival than larger seeds; seed survival rates of Poa annua, Rumex obtusifolius, Alopecurus aequalis var. amurensis and Viola grypoceras were positively correlated with thickness of volcanic deposits. -from Author
  • S. Tsuyuzaki
    Japanese Journal of Ecology 41 83 - 91 00215007 1991/01 [Not refereed][Not invited]
    The vegetation was divisible into four vegetation groups: 1) grassland of sowed herbs; 2) Artemisia montana grassland; 3) low-cover grassland; 4) Miscanthus sinensis grassland. Many native plants were unable to colonize and/or establish themselves in the artificial vegetation, but were able to establish themselves at sites where coverage of sown herbs was reduced. Woody plants, eg Salix hultenii var. angustifolia, gradually established themselves at sites where sown herbs had decreased and/or M. sinensis was well-established. -from English summary
  • Shiro Tsuyuzaki
    Journal of Vegetation Science 2 301 - 306 11009233 1991/01 [Not refereed][Not invited]
    To study the rate of revegetation during succession on the volcano Usu, northern Japan, vegetation structure and species composition were monitored from 1984 to 1988 in permanent quadrats near the summit of the volcano, which had been almost completely deforested by 1 to 3 m thick volcanic deposits in 1977–78. Analyses of vegetation structure included species richness, species diversity IT, evenness (J'); year‐to‐year changes were quantified using Community Coefficient (CC), and Percentage Similarity (PS). While species turnover rates fluctuated and vegetation cover gradually increased, species richness, diversity and evenness did not fluctuate much. The diversity parameters showed slightly different levels for three habitat types distinguished. CC values comparing subsequent years with the starting year 1984 suggest only minor changes in qualitative species composition; PS values decreased more rapidly, indicating larger changes in species cover. A few well‐rooted perennial plants were predominant, therefore, PS decline resulted from dominance‐controlled community structure. PS‐value detected not only habitat difference, but also the rate of the volcanic succession, suggesting that PS is most effective to evaluate successional pace. 1991 IAVS ‐ the International Association of Vegetation Science
  • Shiro Tsuyuzaki, Tatsuichi Tsujii
    Ecological Research 5 271 - 276 09123814 1990/08 [Not refereed][Not invited]
  • Shiro Tsuyuzaki, Shin ichi Urano, Tatsuichi Tsujii
    Vegetatio 88 79 - 86 00423106 1990/07 [Not refereed][Not invited]
    To obtain the characteristics of Chinese alpine grassy marshland, the vegetation of Ruoergai marshland, which is the largest peatland in China, and of neighboring areas was surveyed along mountain slopes in three areas, Ouhailao, Waqie and Kaharqiao. Based on the clustering of 122 1 m × 1 m quadrats surveyed, the vegetation was grouped into 8 types. From bottom to top of mountain slopes, the dominant species, zonally established, were: 1) Carex enervis and Equisetum limosum; 2) Carex meyeriana; 3) Deschampsia caespitosa, Caltha scaposa and Anemone obtusiloba; 4) Koeleria cristata; 5) Kobresia tibetica and Caltha scaposa; 6) Blysmus sinocompressus; 7) Polygonum sphaerostachyum and Trollius ranuncloides; and 8) Ranunculus pedicularis. In this order, species richness increased gradually along the slopes. A principal component analysis demonstrated that water depth partly regulated the establishment of vegetation. The geographical difference of vegetation was also observed, in particular, in Waqie. Likewise, grazing is considered to modify this vegetation. © 1990 Kluwer Academic Publishers.
  • Shiro Tsuyuzaki
    Environmental Management 14 203 - 207 0364152X 1990/03 [Not refereed][Not invited]
    In 1986 and 1987, a study on factors governing revegetation on ski grounds was conducted at Teine ski ground (built in 1971) located near the city of Sapporo in northern Japan. Soil movement, slope gradient, distance from forest edge, vegetation cover, and number of species on the ski ground were examined. Although artificial sowing of exotic plants was undertaken in the whole ground surface at the time of opening, bare land occurred in ca. 50% of surveyed plots and the ski ground was mostly covered with native plants. The number of species was positively correlated to vegetation cover, which was low in the sites where intensive soil erosions occurred in winter. A principal component analysis of plant species distinguished three major groups of factors, i.e., vegetation cover (first axis, contribution rate 30.3%), soil erosion in winter and slope gradient (second, 23.1%), and distance from forest edge (third, 16.3%). The vegetation characteristics on the ski ground were not determined by a single environmental gradient but by the combination of factors described above. In particular, soil movements, which are mostly derived from snowmelt, are considered to be the initiator of vegetation changes. © 1990 Springer-Verlag New York Inc.
  • Shiro Tsuyuzaki
    The Botanical Magazine Tokyo 102 511 - 520 0006808X 1989/12 [Not refereed][Not invited]
    Soon after the 1977-78 eruptions of the volcano Usu, there were created many gullies in which former topsoil, i.e., well-developed soil accumulated before the eruptions, was eroded in the crater basin, whereas the outside of the gully was covered with thick volcanic deposits. The short-dispersal-seed plants were the most abundant in the inside of gully where the former topsoil was exposed, however, they have not immigrated from external environments. The germination tests of the seeds extracted from the former topsoil demonstrated that viable seeds were buried at 1683.3/m2 for 9 years after the eruptions. At least, 12 herbaceous species, e.g., Rumex obtusifolius, Geum macrophyllum var. sachalinense and Poa annua, were derived from the buried seeds in the former topsoil. Their contribution to revegetation was estimated to be 40.0% in the inside of gully where the former topsoil was exposed in 1983, suggesting that buried seeds are one of the most important seed source for revegetation even in the case of a volcano which produced pumice and ash by eruption. © 1989 The Botanical Society of Japan.
  • Shiro Tsuyuzaki
    Ecological Research 4 167 - 173 09123814 1989/08 [Not refereed][Not invited]
    In 1987, a study on buried seed populations was conducted in the crater basin of Mt. Usu, a volcano located in northern Japan, where the vegetation had beeen almost completely destroyed by eruptions in 1977 and 1978. The former vegetation had consisted of grassland and broad-leaved forest. In the areas formerly occupied by this grassland and forest, 2128.0 and 1985.3 seeds per square meter, respectively, were extracted from 12 blocks of the former topsoil using a floattion method. This revealed that many seeds were still viable even after ten years of burial under thick volcanic deposits. The seeds were distributed more in sandy soil than in rocky soil of the former topsoil. Twenty-five species, most of which favored grassland, were detected in both the former grassland and forest. From comparison of α-and β-diversities between the grassland and forest, the structure of the buried seed population was considered likely to have been more diverse in the forest than in the grassland. The determinants of composition of the buried seed populations were discussed with reference to the former vegetation and soil characteristics. © 1989 the Ecological Society of Japan.
  • S. Higashi, S. Tsuyuzaki, M. Ohara, F. Ito
    Oikos 54 389 - 394 00301299 1989/01 [Not refereed][Not invited]
    Trillium tschonoskii is a perennial herb which grows in single-species stands in the cool temperate broad-leaved deciduous woodland of Hokkaido, Japan. Its many-seeded fruit initially falls close to the parent, >50% within 20 cm. Ants, principally Myrmica ruginodis and Aphaenogaster japonica, transport seeds to their nests, a mean distance of 64 cm. The nests are overdispersed and short-lived, and are no richer in N or P than surrounding soils. There are proportionally more older than younger juvenile Trillium plants at distances >60 cm from the nearest parent plant, ie the relatively short-distance dispersal of seeds by ants is sufficient to reduce seedling mortality, by reducing competition between seedlings. -from Authors
  • S. Tsuyuzaki
    American Journal of Botany 76 1468 - 1477 00029122 1989/01 [Not refereed][Not invited]
    Since seedling mortality appeared mostly due to the frequent erosion of the volcanic deposits, ephemeral annuals and well-rooted perennials or woody plants were successful here. The high mortality of seedlings resulted in intensive fluctuation of plant density in all habitats, but owing to the expansion of perennials, once they became established, the plant cover increased from year to year. In particular, Polygonum sachalinense and Petasites japonicus var. giganteus, seeds of which were frequently provided from their community vegetatively recovered on the wall of the caldera rim soon after the eruptions, were remarkably contributive to the revegetation. Perennial plants were derived not only from the seeds but also vegetatively from the old stumps buried in the former topsoil by extending their rhizomes up to the present gound surface. -from Author
  • Toshiyuki Sato, Shiro Tsuyuzaki
    The Botanical Magazine Tokyo 101 267 - 280 0006808X 1988/09 [Not refereed][Not invited]
    Developmental leaf architecture was quantitatively described in terms of measurements of various parameters on leaf blade from different size of sporophytes in Dryopteris monticola, D. tokyoensis and a putative hybrid, D. kominatoensis in the natural site of Hokkaido, to compare the ontogenetic differentiation in foliage structure among allied ferns. The morphological stage of leaf and sporophyte was tentatively quantified by the number of midrib branches of the leaf (NV, number of veins), which exhibited a significant correlation to the leaf-shape complexity from a circle (DI=marginal length/2×(3.14×square)1/2) of leaf blade. D. kominatoensis showed intermediate values between others in following characters; DI increase, maximum NV (also blade length), maximum number of costa branches of pinnae (NVMP), number of costa branches of the lowest pinna (NVLP), difference between NVMP and NVLP (NVMP-NVLP), during heteroblastic leaf development. A larger number of leaves per sporophyte was found in D. kominatoensis than in others. The fertility rate (%) and initiation of fertility (IF) in the relative developmental stage (RDS) of D. kominatoensis shifted to that of D. tokyoensis, while the order of pinnae with NVMP shifted to that of D. monticola. Even in the intermediate characters in D. kominatoensis, slight shifts in characters to those of putative parents were found during heteroblastic leaf development. © 1988 The Botanical Society of Japan.
  • Shiro Tsuyuzaki
    Vegetatio 73 53 - 58 00423106 1987/12 [Not refereed][Not invited]
    The vegetation near the summit of the volcano Usu was destroyed during eruptions in 1977 and 1978 by 1-3 m thick layers of volcanic deposits. Thereafter, the vegetation gradually recovered and by 1984 134 plant species were recognized of which 95 species had established by vegetative reproduction, 18 by seed immigration from elsewhere, 5 by artificial introduction for soil erosion control and 17 species from viable seeds buried in the former topsoil. The summit area was still covered by thick layers of volcanic ash, which were however rapidly eroded by rains. Vegetatively reproducing plants such as Petasites japonicus var. giganteus and Polygonum sachalense contribute more effectively to the revegetation process than plants of other types of origin. © 1987 Dr W. Junk Publishers.
    Tropics Tropics 12 (4) 287 - 294 0917-415X 2003 [Not refereed][Not invited]
    A plot census for trees over 5 cm in diameter at breast height was conducted in tropical wetlands to understand the effects of distance from river and peat depth on the development of communities, using 14 50 m_50 m plots in Central Kalimantan, Indonesia. There are 294 taxa of woody species were recorded. Combretocarpus rotundatus, Palaquium leiocarpum, Stemonurus scorpioides and Tristania whittiana are the common species. In the 14 plots, Stem density and cumulative basal diameter ranged from 1612-3088/ha, and 18.5-44.6 m2//ha, respectively. Species richness (S) ranged from 41 to 87. Diversity index (H') and evenness (J') varied from 1.29 to 1.68 and 0.771 to 0.910, respectively. Stem density was positively related to distance from river but not to peat depth. Geographical differences were also related to the stem density. H' was related to distance from river, but S and J' were not explained by any environmental factors examined. Plot distribution patterns were examined by detrended canonical correspondence analysis (DCCA). DCCA ordination indicated that distance from river, and hence the intensity and/or frequency of flooding more adequately explained plant community distribution patterns than peat depth. Geographical differences also significantly affected the distribution patterns. Therefore, the distance from river is a suitable parameter to use to investigate plant community distribution in tropical wetland forests, even if peat thickness differs greatly.
  • Soil Biology and Biochemistry 33 1419 - 1423 2001 [Not refereed][Not invited]

Books etc

  • Dictionary of biology
    TSUYUZAKI Shiro (succession, climax)
    Tokyo Kagaku Dojin 2010 Contributor
  • TSUYUZAKI Shiro ()
    Hokkaido University Press 2007/03 4832981811 246 Contributor
  • TSUYUZAKI Shiro (Ultraviolet and organisms)
    Hokkaido University Press 2007/03 483298179X 408 Contributor
  • Plant Ecology
    TSUYUZAKI Shiro ()
    2004 Contributor

Conference Activities & Talks


  • 佐藤利幸, 露崎史朗, 吉田静男  長野県植物研究会誌  50-  95‐99  2017/06   [Not refereed] [Not invited]
  • Tatsuya I. Saito, Shiro Tsuyuzaki  Weed Biology and Management  12-  63  -70  2012/06   [Not refereed] [Not invited]  
    In order to explore the methods of recovering native grasses into exotic vegetation, the response of riparian vegetation to the removal of the above-ground shoots and/or litter of Solidago gigantea in a flood plain in Hokkaido, northern Japan, was investigated. The four treatments were: the removal of the above-ground shoots of S.gigantea (A); the removal of the litter of S.gigantea (L); the removal of both the above-ground shoots and litter of S.gigantea (AL); and a control (C). The vegetation cover and S.gigantea cover decreased in the A and AL treatments and increased in the L and C treatments. The understory plant cover increased in the A and AL treatments, but did not change in the L and C treatments. The increases in the understory cover in the A and AL treatments were associated with increases in Phalaris arundinacea. The seedling emergence of P.arundinacea was promoted by AL. In a greenhouse, the S.gigantea litter tended to decrease the seed germination of P.arundinacea. The AL treatment also increased the abundance of the other exotic plant, Solidago altissima. The continuous removal of the above-ground shoots and litter of S.gigantea long term is effective for promoting the recovery and emergence of native riparian grassland vegetation. However, this method also promotes the recovery of other exotics. © 2012 The Authors. Weed Biology and Management © 2012 Weed Science Society of Japan.
  • Appiah Catherine, Shiro Tsuyuzaki, Djietror Jonathan Castel  Research Journal of Seed Science  5-  126  -135  2012/01   [Not refereed] [Not invited]  
    Gold mining occurs in four administrative regions in Ghana with tropical forest cover. Establishment of pioneer vegetation immediately after the mining process is one of the most important rehabilitation practices leading to land reclamation and eventual habitat restoration. A major environmental challenge is that post-mining vegetation sites are prone to wild forest fires that dry up the topsoil and produce a layer of ash on the soil surface. We experimentally tested the effect of post-fire ash and soil moisture on seed germination using the Black-eyed pea (Vigna unguiculata L. Walp) and Egusi (Citrullus colocynthis L.). The study focused on the potential for seed germination in ash under high and low moisture conditions within a greenhouse environment. The viable seeds of the two species were planted at depths; 0.0, 0.5 and 1.0 cm. V unguiculata exhibited the highest germination percentage at 0.0 cm in both moisture treatments, but no germination occurred at 0.5 and 1.0 cm depth, showing that germination was considerably inhibited by the ash depth. C. colocynthis showed a comparatively longer dormancy period but with superior germination percentage at all 3 depths under wet conditions. Due to the lower seed germination rate for V. unguiculata under ash, the species might not be easily adapted to ash-covered soils. However, due to significantly higher germination rates under similar conditions, C. colocynthis could potentially be adapted for post-mine vegetation restoration after the occurrence of wild forest fires. © 2012 Academic Journals Inc.
  • Yuki Sawada, Masami Fukuda, Koichiro Harada, Kenji Yoshikawa, Yuji Kodama, Shiro Tsuyuzaki  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2011-  240  2011/01   [Not refereed] [Not invited]
  • Handbook for eco-campus in Hokkaido University (2nd edition)
    TSUYUZAKI Shiro  Hokkaido University Museum  2005   [Not refereed] [Not invited]  Introduction and explanation (others)
  • TSUYUZAKI Shiro  Japanese Journal of Ecology  52-  (1)  2002/04   [Not refereed] [Not invited]
  • Tsuyuzaki Shiro, Hase Akira, Niinuma Hiroko, Hanada Yasuji  36-  (0)  1  -6  2001/03   [Not refereed] [Not invited]
  • TSUYUZAKI Shiro  Japanese Journal of Ecology  46-  (1)  1996/08   [Not refereed] [Not invited]
  • Research bulletin of the Hokkaido University Forests  46-  (1)  p191  -222  1989   [Not refereed] [Not invited]

Awards & Honors

  • 1994/09   Botanical Society of Japan   Encouraging prize
    Winner: TSUYUZAKI Shiro

Research Grants & Projects

  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2009 -2011 
    Author : Shiro TSUYUZAKI
    北海道大学Although facilitation that is one of the mechanisms of multi-species coexistence becomes remarkable with developing litter and microtopography, the ecosystem recovery delays when facilitation promotes biological invasion. To clarify the mechanisms, therefore, comparative experiments were conducted in the two fields where native or biologically-invasive species establish. The species attributes are closely related with the development of litter that was regulated by climate. I concluded that the establishment off species was determined more by litter development than light, soil and microtopography.
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2005 -2006 
    Author : Shiro TSUYUZAKI
    北海道大学Biological invasion (BC) means that non-native species establishes in natural ecosystems via human impacts. In particular, BC is remarkable on severely-disturbed communities in the early stages of succession. The mechanisms are related to various spatial scales from microtopography to landscape. This study compares plant communities between Mount Usu where BC is not conspicuous and Mount Koma where BC is conspicuous, to clarify the significant differences between native and non-native species with different environmental scales. The abstracts of published papers are as follows : 1) On Mount Koma after the 1996 eruptions as well as Mount Usu, vegetative reproduction contributes revegetation more than sexual reproduction. In addition, microtopography is important to determine the community development. 2) Mycorrhizal colonization differs along elevational gradient. I confirmed that a few vascular plant species that have not been reported were inoculated by mycorrhiza. The contribution of mycorrhiza on the growth of larch was low. 3) Temporal changes in the characteristics of survival and germination on seedbank are greatly related to the experienced environments, such as temperature fluctuations. 4) BC species have higher survival rates than native species by higher morphological plasticity adapted to various disturbances and stresses, such as strong wind, drought and low nutrients.Based on those results, top-down and bottom-up analyses have been conducted on the interactions between different scales. Weather conditions have been measured by weather stations purchased by this grant on Mount Koma. By the combinations of those results, I completed that the quantification of the interactions on various life history stages (seed dispersal, germination, establishment and growth) under certain environmental gradients, e.g., ground surface moisture and microtopography.
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2001 -2003 
    Author : Shiro TSUYUZAKI
    北海道大学There are wide environmental gradients on volcanoes, e.g., thickness of volcanic deposits, indicating that the areas are convenient tools for the survey on the relationships between plants and mycorrhizae with different microtopography for long-term changes. Based on these consideration, I research the plant community dynamics on volcanoes. The major results are as follows :1.Permanent plots were set up in bareground, grassland and forest in some microhabitats, i.e., understory, rill, flat, etc., to examine the relationship between microhabitats and dominant plants. The microhabitat is most important factor on tree establishment in the early stages. Furthermore, the distribution of mycorrhizae is related to microtopography.2.All dominant seed plants and some other cohabitants were excavated to examine mycorrhizal colonization on roots in each plant community. The quantification of mycorrhizal colonization was made by the frequency of root fragments colonized by mycorrhizae, instead of mesh counting method, because preliminary experiment showed that counting is inappropriate. By this way, ectomycorrhizae colonized on a few herbs that have never been reported.3.Endomycorrhizae have been considered mostly to uptake phosphates from soil and supply the excess phosphates to plants in nutrient-poor environments. The total organic matter, total nitrogen, soluble phosphates, etc. were measured. Nitrogen increased with increasing elevation, and frequency of endomycorrhiza increased. While, there was no significant relationship between elevation and endomycorrhiza frequency.4.Based on those results and literatures, the characteristics of early volcanic succession were reviewed. In particular, biological invasion, e.g., Larix kaempferi on Mount Koma, and the importance of mycorrhizae for biological invasion were discussed.
  • Structure and dynamics of plant communities after disturbances
    Date (from‐to) : 1984

Educational Activities

Teaching Experience

  • Advanced Course in Environmental Conservation
    開講年度 : 2017
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 生態系、環境、撹乱、遷移、保全、復元 ecosystem, environment, disturbance, succession, conservation, restoration
  • Advanced Course in Natural Environmental Studies
    開講年度 : 2017
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 生態系、環境、気候、物質循環、モデル ecosystem, environment, climate, material cycling, model
  • Field Work in Integrated Observation
    開講年度 : 2017
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 同定、植物種、動物種、気象 Identification, plant species, animal species, climate
  • Advanced Course in Watershed Environmental Science
    開講年度 : 2017
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 湿地、河川、植物、食物網、流域管理、生態系機能、保全と復元 wetlands, rivers, plants, food-web, watershed management, ecosystem function, conservation and restoration
  • General Education Seminar
    開講年度 : 2017
    課程区分 : 学士課程
    開講学部 : 総合教育部
    キーワード : environments, natural sciences
  • General Education Seminar
    開講年度 : 2017
    課程区分 : 学士課程
    開講学部 : 現代日本学プログラム課程
    キーワード : environments, natural sciences
  • Arts and Science Courses in English 2
    開講年度 : 2017
    課程区分 : 学士課程
    開講学部 : 国際本部
    キーワード : environments, natural sciences

Committee Membership

  • 2006/04 -2014/03   Botanical Society of Japan   Editorial Board of Journal of Plant Research   Botanical Society of Japan
  • 2001/04 -2004/03   Ecological Society of Japan   Editorial Board of Japanese Journal of Ecology

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