Effects of tree regeneration and topography on vegetational shift in forest ecotones

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K01016
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 04010:Geography-related
• Research Institution: Tokyo Metropolitan University (2022-2023); Yokohama National University (2021)
• Principal Investigator: Yoshida Keiichiro 東京都立大学, 都市環境科学研究科, 教授 (60377083)
• Co-Investigator(Kenkyū-buntansha): 比嘉 基紀 高知大学, 教育研究部自然科学系理工学部門, 講師 (60709385) ; 石田 祐子 神奈川県立生命の星・地球博物館, 学芸部, 学芸員 (80846725)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 森林の長期変化 / 更新動態 / 植生帯境界 / 地形 / 森林限界

Outline of Final Research Achievements

In this study, to examine the effects of the topography on the vegetational shifts, we examined the long-term changes of the forests at the vegetation boundaries, given the forest dynamics depending on the topography. We found the upward shifts of the vegetation boundaries along the elevation in the Rishiri Island and Kannami old-growth forest, and they were related to the regeneration processes and interspecific interactions of the dominant species. Micro-topography, especially the conditions of the ground surface affected the regeneration processes of dominant species, and it was inferred that these factors were involved in the different patterns of upward shifts of vegetation boundaries with topography. These results indicate that the upward shifts of vegetational significantly depend on topography in the mountainous region, and therefore topography should be taken into account in future projections of vegetation distribution due to climate change.

Free Research Field

自然地理学

Academic Significance and Societal Importance of the Research Achievements

本研究において，植生変化の駆動力となる森林の動態プロセスと地形との関連性を明らかにしたことで，日本の山岳域で進行しつつある植生帯境界の変化に対する地形の影響を把握できる．また，地形の影響を考慮することで，現在進行しつつある気候変化のみによって生じた植生帯移動を正しく捉えることができ，気候変化に対する日本の植生の脆弱性を評価することにつながり，有効な緩和策や適応策の立案に寄与するものと考える．