科学素养与生活应用·英语30篇（2）

22 / 30

秋叶变色为何源于色素分解？

Chlorophyll gives leaves their green color and breaks down as daylight shortens in fall.
With less sunlight, trees stop producing chlorophyll and reabsorb its nutrients before leaf drop.
Carotenoids, always present but masked by green pigment, become visible as yellows and oranges.
Anthocyanins form only in autumn from excess sugars trapped in leaves under cool, sunny days.
Soil acidity and tree species influence whether reds, purples, or browns dominate the display.
Maple trees produce vivid reds due to high sugar concentration and efficient anthocyanin synthesis.
Drought or early frost can dull colors by stressing trees and halting pigment production.
Deciduous trees shed leaves to conserve water during winter when roots absorb less from frozen soil.
Leaf litter later decomposes, returning nutrients to forest soil for next year’s growth.
Scientists study pigment chemistry to understand plant responses to climate change patterns.