Why Do Leaves Fall in Autumn?
Why Do Leaves Fall in Autumn? In temperate regions of the world, autumn is marked by the brightly colored foliage that slowly drops from trees and shrubs to carpet the ground. But why do some plants shed their leaves before winter? It turns out autumnal leaf drop is a form of self-protection. While evergreen plants in cold climates have thick waxes and resins to protect their leaves from freezing and fracturing, deciduous species generally have thin leaves that are susceptible to cold temperatures. Because water expands when frozen, soft leaf cells burst during the winter, rendering them unable to photosynthesize. Without shedding these leaves, such a tree would be left with thousands of non-reproductive appendages and no means of making food! As if that weren't enough, the surface of all those leaves will also pose a threat to the physical integrity of the plant. The winter months are often windier than other seasons, and wind blowing against the cold, brittle leaves of tree...