Woods of Wonder

Woods of Wonder

Oh, That's Old! Imagine you're in a dark, lovely forest. Trees with trunks wider than cars tower overhead and block almost all the sunlight. Small ferns and other plants soak up what little light they can find. Pine needles and other dead leaves cover the ground. Like something out of a fairy tale, an old-growth forest is a place of wonder and mystery.

For some old-growth forests, this scene wouldn't be far from the truth. Others might look quite different. Some old-growth forests have only one type of tree, while others have many. Some may have trees that seem to touch the sky, while others have trees shorter than a house. Because of this variety, scientists do not have one definition for old-growth forests. Still, they have found some features that many old-growth forests share. Many scientists agree that an old-growth forest must be at least 150 years old. The age of each tree in the forest may vary widely, however. The forest's structure must also be complex. This means that the canopy must have varying layers with large trees, both living and dead (or dying). Fallen trees create holes in the canopy where young trees can find the sunlight to grow. Fallen trees and upright dead trees, called snags, provide food and shelter for many animals, plants, and fungi. Some of these species live nowhere else on Earth.

Old-growth forests are some of the most beautiful and scientifically interesting places on Earth. Yet because of humans, many of them have shrunk or disappeared. By carefully studying and protecting the ones that remain, we can understand the complex and delicate ecosystems they create.

United States Sequoia and Kings Canyon National Parks in California together cover more than 1, 353 square miles (3, 504 sq km). They hold more than 300 square miles (777 sq km) of old- growth forest. This forest includes a variety of tree species, mostly coniferous but deciduous as well. One of the most amazing of these is the giant sequoia. Found only in California, these huge trees are among the oldest on Earth. They can live for more than 3, 000 years. A giant sequoia known as the General Sherman Tree is the largest tree in the world.

Thousands of creatures live in the park, including the Pacific fisher. This relative of the weasel lives under the thick canopy in old-growth forests. It hunts birds and small mammals-but its favorite meal is porcupine. Because its habitat is limited to old-growth forests, it is now rare in California, Oregon, and Washington.