A Study of the Relationship between Vertical Evacuation Behavior and Species Diversity of Terrestrial Beetles in Floodplains

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14278
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Nagasaki University
• Principal Investigator: Tanaka Wataru 長崎大学, 工学研究科, 助教 (60795988)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 地表性甲虫 / 洪水 / 垂直退避行動

Outline of Final Research Achievements

The objective of this study was to ascertain the relationship between vertical evacuation behavior and species richness of terrestrial beetles in response to flood disturbance. Pitfall trap surveys of surface beetles on floodplains were conducted on a monthly basis, and the results indicated that the abundance and species richness of Anisodactylus spp. tended to increase on floodplains with abundant vertically evacuated material. In contrast, autumn-breeding Harpalus species demonstrated no significant impact from the August floods during the study period, as they are capable of flight until early summer. This study provides preliminary evidence that the presence or absence of vertical structures on a floodplain influences the species diversity of surface beetles.

Free Research Field

応用生態

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は，現地における生物調査と氾濫解析をベースとし，近年自然再生の一環として人工的に造成される例が増えつつある人工氾濫原における垂直方向の環境構造（樹木・草本管理）の整備のあり方について技術的な示唆を与えるものである．氾濫原の垂直構造については，必ずしも樹木や草本でなく人工物で代替できる可能性もあり，近年「Eco-DRR」や「グリーンインフラ」の一環として多く整備されている農地として普段利用する人工氾濫原でも生物多様性を高めることができる．本研究によって，こうした基礎的な知見が蓄積され，氾濫原の設計に生かされるなどの波及効果が期待できる．