What is evolutionary biological reason some trees keep their leaves through most of the winter?
Trees that keep their leaves during winter are ones that have evolved to grow in temperate climates where there is sufficient sunshine in winter to power enough photosynthesis to gain more energy than the ‘upkeep’ of the leaf and where there is not a great risk of leaves being (literally) a burden on the tree when there is a heavy snowfall.
And some retain their leaves to provide food and cover for some animals that live in trees. 1) Birds make nest and sit in the trees for protection 2) Squirrels live in the trees 3) Termites and beetles live, eat, and kill the trees 4) Worms eat tree leaves 5) Insects lay eggs on their branches and leaves 6) Ants and other insects live in some trees and eat the leaves, nuts, and berries 7) Birds and other animals eat the nuts, berries, bark, leaves, and insects in/on the trees Sources: http://72.14.209.104/search?q=cache:iaqOJTU_t1QJ:www.cdpheritage.org/educator/classroomLessons/TreesPlateauGrandCanyon.
