noun
forest reserve; protection forest
A forest designated for conservation purposes, such as preventing erosion or preserving water sources, under Japanese law.
この地域の保安林は水源を守る役割を果たしている。
The protection forest in this area serves to safeguard the water source.
Compound of 保安 (ほあん, 'preservation, security') and 林 (りん, 'forest').