Establishment of a new natural symbiosis system in abandoned agricultural land and water areas in hill-bottom valleys

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K12330
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 64040:Social-ecological systems-related
• Research Institution: Kitasato University
• Principal Investigator: Kakino Wataru 北里大学, 獣医学部, 准教授 (10623936)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 管理放棄 / 谷底 / グリーンインフラ / 水生生物

Outline of Final Research Achievements

A field survey was conducted in abandoned waterways, rice paddies, and reservoirs to determine how the distribution of habitats is affected by human intervention (e.g., agricultural work and management), and to propose ecological management methods from the perspective of utilizing natural resources in these waterways and habitats.
As a result, it was found that the waterway, which is located in an abandoned valley, is prone to flooding due to the accumulation of fallen leaves and branches in the meandering parts, and that the water content of the surrounding soil is high throughout the year. From the viewpoint of green infrastructure, it is expected to be utilized as a water playground, and in particular, there is room to secure a living environment for aquatic organisms (fish, frogs, dragonflies). Based on these findings, we proposed the use of the site as a resource for environmental education and tourism.

Free Research Field

農村生態工学

Academic Significance and Societal Importance of the Research Achievements

谷底面で管理放棄されると幹線水路の蛇行部に落葉落枝が堆積し，洪水が生じやすくなる。このため蛇行部付近には，小規模の止水域が複数形成され，水田水域の魚類等水生生物の繁殖場，生息場になっていることが明らかになり，新たな土地利用としてグリーンインフラを踏まえた遊水地が生物生息場としての水田水域の代替地となる潜在性が高いことが判明した。遊水地の形成プロセスや草刈り等の人為的・部分的な管理が魚類等水生生物の個体数や種数に与えた影響については学術的意義がある。また，新たな土地利用に環境教育や観光に資する試行，提案を行ったことは社会的意義がある。