2018 Fiscal Year Final Research Report

Ecological study on irreversible change of the forest and process of biodiversity restoration in an area of high sika deer density

Research Project

PDF

Project/Area Number	15K07231
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Ecology/Environment
Research Institution	Osaka Sangyo University
Principal Investigator	MAESAKO YURI 大阪産業大学, デザイン工学部, 教授 (90208546)
Co-Investigator(Kenkyū-buntansha)	名波哲大阪市立大学, 大学院理学研究科, 准教授 (70326247) 鈴木亮琉球大学, 理学部, 博士研究員 (90418781)
Project Period (FY)	2015-04-01 – 2019-03-31
Keywords	シカ / 照葉樹林 / 外来種 / 生物多様性 / 動態 / 拡散 / 不可逆的
Outline of Final Research Achievements	A warm temperate evergreen forest in Kasugayama Forest Reserve, Nara, Japan, designated as a World Heritage site, had suffers from long-term grazing by a high-density sika deer population. The relative abundance of deer varied with forest vegetation and location, ranging from 2.2 to 108.6 heads/100 days (Maesako et al., 2018). The results in the experimental sites were showed as follows: 1) The restoration of species diversity was related with natural disturbance. In the area the establishment of three invasive alien species, Nageia nagi, Sapium sebiferrum and Litsea cubeba were recognized in the experimental enclosured forest. 2) Especially, it was considered that the establishment of N. nagi lead to the irreversible change from evergreen broad leaved forest to evergreen coniferous forest. 3) Under old gap, regeneration of the forest and the restoration of biodiversity was not smoothly progressed for the reason of seed bank depletion by high deer pressure.
Free Research Field	生態学
Academic Significance and Societal Importance of the Research Achievements	森林生態系におけるシカの影響を定量化し，再生の可能性や生物多様性の復元(レジリエンス）に関する研究は多いとはいえない。なかでも長期的なシカの採食影響を受けた常緑広葉樹林が，質的に大きな変化を示し，耐陰性の高い外来針葉樹や先駆的な落葉広葉樹の定着を定量評価することができた。これは，日本の森林を考えるうえで貴重な情報であり，学術的にもあらたな検証がなされ，森林再生に向けた指針作成に大きな貢献を果たした。研究の成果を公表することによって，市民の方の関心をたかめるとともに，シンポジウムなどにおいて，現状と未来への考え方を示すことに貢献した。