Why don't evergreens change color and drop their leaves every fall?

(The Conversation) - It’s autumn in the Northern Hemisphere – otherwise known as leaf-peeping season. Now is when people head outside to soak up the annual display of orange, red, and yellow foliage painted across the landscape.But mixed among those bright, colorful patches are some trees that stay steadfastly green. Why do evergreen conifers sit out this blazing seasonal spectacle?Like so many other challenges, the problem of winter can be solved by trees in more than one way.As tem