under·storey
noun/ˈʌndəstɔːri/
/ˈʌndərstɔːri/
(North American English understory
(specialist)(plural understories)
)- a layer of plants, bushes, etc. that is found below the main canopy of a forest (= the top leaves and branches of the trees that form a thick layer)
下木层（上层林冠下的林木）