Mary Jo DiLonardo has worked in print, online, and broadcast journalism for 25 years and covers nature, health, science, and animals. Young trees sometimes have smooth bark that's unbroken by ridges.

Why do trees have bark? Julien, age 6, Melbourne. This is a great question, Julien. We are so familiar with bark on trees, that most of us just take it for granted. But bark is one of the most complex ...

The seasons are changing from fall to winter, and one of the major changes to the environment is that the deciduous trees have lost their leaves. Evergreen trees may still have green needles, but all ...