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学術研究成果リスト

Detail of Grant Awarded Academic Researches

Project

Study on the Classification of Vegetation in Satoyama Remaining in the Areas along the Tama River

Academic
Research
No.315
Principal
Investigator
Kojiro Suzuki
Affiliation
(at that time)
Professor, Department of Landscape Architecture Science, Faculty of Regional Environment Science, Tokyo University of Agriculture
Research
Summary

In recent years, areas of suburban satoyama are decreasing year by year, owing to their segmentation and isolation. Being susceptible to human activities, vegetation of these satoyama needs to be recorded in detail even if it is impossible to research them all. On the other hand, there are many unrecorded giant trees growing in suburban satoyama, and they are weakening due to environmental degradation. Hence we should lose no time to collect detailed data (such as species and size) of these trees. While the definition of satoyama is ambiguous, this study uses the term to mean a concept close to “natural green area.” In our study we have done the following:

1. We investigated the topography of satoyama in the targeted areas of the study and calculated their size;

2. Since satoyama along the Tama River rather have complex topographic features, we identified what factors (sunlight and moisture level) contribute to the growth of specific species, such as dwarf lilyturf, in specific topography, and also investigated anthropogenic influence, such as trimming of Pleioblastus chino, on them;

3. Focusing on the giant trees that grow in suburban areas, we conducted field investigations in 81 satoyama areas. Then we classified them by the number of trees and species (we found in the investigations a total of 1072 giant trees (trunks) of 41 species), by maximum tree circumference and the total sum of tree circumference;

4. We collected documents on recorded plants in each satoyama and made a listing of them; and

5. We conducted a field investigation on the factors that affect the growth of plants in satoyama. And to assess the conservation state of satoyama we surveyed vegetation under the Prunus jamasakura, which is considered most characteristic of satoyama. We have also investigated the existence of the objects of worship that seemed to have a long history with the local people in each satoyama.


Collaborators

Yoshiaki Kameyama, Plant Ecology, Faculty of Regional Environment Science, Tokyo University of Agriculture


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