Introduction

A tree and each of its parts busily work from the tiniest rootlet buried deep underground to the topmost twig of the highest branch. A tree lives and breathes steadily and constantly. It uses the light from the sun to convert minerals and water from the soil, and the carbon dioxide it receives from the air to sustain that life.

Like other living things, a tree may get diseased or have its limbs cut or broken. While the tree can often heal itself over time, it may sometimes be prudent to consult a professional on how to save the life of the tree.

A healthy tree can be very long-lived, certainly much more so than its human counterpart. Indeed it will remain on a property, becoming a source of enjoyment for many generations to come.

Trees have been called the structural elements of the ecosystem. They form the most noticeable living objects except in the driest and coldest climates. Trees have whole communities of other organisms associated with each type. Some birds or insects are found only in broad-leaved trees, others in conifers. In addition, trees form levels in which these communities of other animals are found. Blackburnian Warblers are found at the tops of trees, Canada Warblers lower down. Nuthatches, Brown Creepers, and Woodpeckers are typically found on the trunks and larger branches.


                       

Most botanists define trees as woody plants having a single stem and growing at least 10 feet tall -- the height of a basketball goal. Other definitions are used, but they are similar. A shrub or bush, on the other hand, is a woody plant having multiple stems growing from the same roots and is usually lower growing. An oak is a tree. Most lilacs are shrubs. At the other end, trees can be gigantic. Some species, like Giant Sequoias, Coast Redwoods, Douglasfirs, and some Eucalyptus, grow 300 feet tall or more and have trunks 30 feet across. Some species also have very long life spans. The Great Basin Bristlecone Pine often lives longer than 4,000 years.