Impact of forest grazing for forest ecosystem and water environment

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21151
• Project/Area Number (Other): 18H06011 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0602:Agricultural and environmental biology and related fields
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: YAMAZAKI Yuri 東京農業大学, 地域環境科学部, 助教 (00826696)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: 林間放牧 / 河川水質 / 環境保全型農業 / 窒素循環

Outline of Final Research Achievements

Water sampling and discharge measurements were carried out at the main river and the tributaries of the Samani River, which flows down the Samani Town, Hokkaido. In the tributaries located on the forest grazing area, the nitrogen concentration was higher than that in the main river. However, the main river located downstream of the pasture kept a low concentration, and it is clear that the effect of forest grazing on the Samani main river is not so large.
14 sensor cameras were installed in the forest grazing area to investigate the behavior of the grazing cattle. From April to October, when the grazing land was opened, grazing cattle repeatedly moved between the grazing areas within about one month. This suggests that this may prevent excessive accumulation of livestock excreta, and promote the nitrogen cycle in the pasture.

Free Research Field

農業土木

Academic Significance and Societal Importance of the Research Achievements

森林を使用して家畜を放牧する林間放牧は環境保全型農業として注目されている一方，林間放牧による環境への影響に関する報告は少ない。本研究では，林間放牧がおこなわれている地域において河川の水質調査を行い，放牧地付近では河川水中の窒素濃度がわずかに上昇傾向にあった。しかし，放牧牛は一定期間で林間放牧地内の移動を繰り返すことで，放牧地への家畜糞尿の過剰な蓄積や流出を抑制している可能性が示唆された。