返回

十万个为什么·科学阅读30篇(8)

23 / 30
已读 0 / 30 课
Why Do Some Trees Lose Leaves Only in Winter?

Why Do Some Trees Lose Leaves Only in Winter?

为什么有些树只在冬天落叶?

  1. Deciduous trees drop leaves when days get shorter and colder.
  2. They seal off leaf stems and store useful nutrients first.
  3. This saves water and energy during freezing winter months.
  4. Evergreen trees keep leaves year-round but shed them slowly.
  5. Maple, oak, and birch trees follow this winter-leaf rule.
  6. Leaf loss helps avoid damage from heavy snow and ice.
  7. Bright fall colors appear when green chlorophyll fades away.
  8. Spring brings new leaves as sunlight and warmth return.
上一页
/ 30
下一页