belowground

The belowground roots of the tree extend deep into the soil.

用法提示：belowground 作形容词，修饰 roots，表示“地面以下的”。

Belowground storage tanks are often used for rainwater collection.

用法提示：belowground 作形容词，修饰 storage tanks，表示“地下的”。

Many insects live in the belowground parts of plants during winter.

用法提示：belowground 作形容词，修饰 parts，表示“地面以下的”。