translation.en: Why do understory trees, which are subject to lower sheer forces from the wind and have to carry less weight than the big canopy trees, why are they so much tougher and harder to break than the canopy trees are?
translation.zh: 为什么下层木 受到的风小 承受的重量 比大型乔木轻 为什么它们却如此强硬 难以折断？