研究者業績

Yoshihiro SAWADA

  (澤田 佳宏)

Profile Information

Affiliation
准教授, 大学院 緑環境景観マネジメント研究科, 兵庫県立大学
兵庫県立淡路景観園芸学校
Degree
博士(農学)(Mar, 2006, 岐阜大学)

J-GLOBAL ID
202001021056472839
researchmap Member ID
R000000750

Papers

 22
  • Ryo Furumoto, Masato Ohtani, Naoko Sashimura, Yoshihiro Sawada, Masashi Yokogawa
    Bulletin the Osaka Museum of Natural History, 73(73) 7-11, Mar, 2019  Peer-reviewed
    To determine the population status of Apocynum venetum var. basikurumon, we counted the numbers of shoots, flowers, fruits, and observed body structures at a site in Niigata Prefecture, Japan. We established 27 quadrats( 1 m2) in which we observed 341 terrestrial shoots. Habitats were categorized as“ tuff ”,“ soil ”, “protected slope ”, and“ shingle beach ”. The numbers of shoots and the proportions of flowering shoots were not significantly different among habitats. No fruits were found in any habitats. Rhizomes extended outward 14–20 cm under the ground surface, and bore many branches. This population was supposed to be maintained by clonal growth, rather than by seed production.
  • Naoko Sashimura, Masato Ohtani, Ryo Furumoto, Masashi Yokogawa, Yoshihiro Sawada
    Vegetation Science, 35(1) 1-19, 2018  Peer-reviewed
  • UEDA Moeko, HATTORI Tamotsu, SAWADA Yoshihiro, KAMIHOGI Akiharu
    Journal of The Japanese Institute of Landscape Architecture, 78(5) 659-662, 2015  
    On beaches, there is generally the vegetational zonation distributed into five zones in order of drift line communities, dune grasslands, dune dwarf shrubs, dune scrub and dune forest in the direction from shoreline toward inland. In the warm-temperate zone between the central Honshu and Kyusyu, Japanese black pine (Pinus thunbergii) forests are commonly deployed in zones of dune scrub and dune forest. Because most Japanese black pine forests are planted by artificial means, other plant communities originally existed in the distribution areas of those forests. In this study, we investigated the distribution of dune scrub that remains on the beaches. The results show that Quercus phillyraeoides communities are recognized as dune scrub. Species composition of Quercus phillyraeoides communities on beaches was similar to those on rocky seashores, where Quercus phillyraeoides communities are commonly distributed. It is suggested that Pittosporo-Quercetum phillyraeoidis is one of the natural vegetation in distribution areas of Japanese black pine forests on beaches between Izu Peninsula and Tanegashima Island.
  • Takuo Kanamaru, Yoshihiro Sawada, Satoshi Yamamoto, Michiro Fujihara, Toru Umehara
    Journal of Japanese Society of Revegetation Technology, 40(3) 437-445, 2015  Peer-reviewedCorresponding author
    Myriophyllum aquaticum is an invasive alien aquatic plant and causes many problems such as water pollution, elimination of native plants, and obstructs water ways. To prevent these problems, suppression of M. aquaticum has been often implemented by local governments and/or NPOs. However M. aquaticum regenerate rapidly and suppression is not effective. In this study, to establish a method for eradicating M. aquaticum, vegetation and population surveys and test extermination were carried out in the field, and shading experiment took place in the laboratory. M. aquaticum covered the whole of the pond, but it rooted only on the shallow area near the waterside. During the laboratory shading experiment, M. aquaticum individuals survived the darkness for 158 days, but the length of M. aquaticum stems decreased through that period. It suggests that shorter fragments of M. aquaticum can die by short periods of darkness. At test extermination in the field, M. aquaticum did not regenerate after shading treatment with soil removed. Most fragments of M. aquaticum were removed with soil, and remnants of fragments were killed by the long darkness period. Exterminating M. aquaticum might be possible by using shading together with removing soil.

Misc.

 18
  • Toshikazu Matsumura, Kei Uchida, Yoshihiro Sawada
    Vegetation science, 31(2) 193-218, Dec, 2014  Peer-reviewed
    Worldwide, field boundaries are one of the most important habitats for biodiversity. The diversity of these field boundaries is, however, rapidly declining as a consequence of land-use change. Semi-natural grassland on rice paddy field levees (Keihan or Aze in Japanese), which is one of the types of field boundary that contains many grassland plants, is also under serious threat due to farmland consolidation and abandonment. The objectives of the present study are to review the relevant literature, to clarify the factors that affect biodiversity, to present conservation measures, and to suggest the direction of future studies. Before 1990, the vegetation on paddy levees had not been considered as a type of semi-natural grassland. Thereafter, however, the importance of traditional paddy fields as a habitat for biodiversity was indicated, and the detrimental effects of farmland consolidation and abandonment were reported. After 2000, numerous studies reported on topics such as conservation strategies, comparisons of biodiversity on the lowermost hillside slopes, and soil seed banks. Traditional terraced paddy fields play a significant role in the conservation of biodiversity, pest control, and environmental conservation, and are also of high cultural value. Hypotheses on the diversity of the grasslands on paddy levees differ according to scale. Large-scale hypothesis, such as those relating to historical factors, have not been well discussed. The vegetation on paddy field levees is affected by the surrounding grasslands, to which they are been historically closely related. Therefore, when attempting to determine the establishment of paddy levee flora, it is important to clarify the history of the paddy fields and their surrounding grasslands. In order to clarify the history of paddy fields, the following approaches can be adopted: researching historical data, surveys of the agricultural landscape, and analyses of pollen, plant opals, charcoal particles, and plant residues from archaeological sites. Vegetational studies, biogeography, and population genetics can also be of value in clarifying the establishment of paddy levee flora. The nature of the vegetation on paddy levees depends on various factors, including habitats, environmental conditions, and management regimes; however, the relationships between the vegetation and these various factors have yet to be clarified. The area of paddy fields is decreasing as a consequence of the abandonment of cultivation. The species richness of the vegetation on paddy levees is rapidly decreasing and its composition is rapidly changing. In order to improve the problems associated with abandonment, it is necessary to identify hotspots that include rare species, to increase the efficiency of cutting machines and methods, to obtain external assistance, and to introduce grazing. Farmland consolidation changes the vegetation of paddy levees. For the improvement of problems resulting from consolidation, the reuse of topsoil and establishment of seed sources are suggested, along with modification of the agricultural engineering of consolidation. Further measures for conservation include the sowing of seeds, transfer of seedcontaining hay, transfer of seed-containing soil, and removal of exotic plants in the consolidated fields. In future investigations, the compilation of a representative list of grassland species and a comparison of species richness will be necessary. It is also necessary to collect and analyze past information on paddy levee vegetation, to urgently investigate the present vegetation on paddy levees, to establish conservation strategies, and to conserve various semi-natural grasslands including paddy levees.

Books and Other Publications

 2

Presentations

 2

Professional Memberships

 3

Research Projects

 5