Rain Forests in Surprising Places

When you think of "rain forests," what comes to mind? Chances are good you think of the tropical rain forests in South America or Africa. But did you know rain forests also thrive outside the tropics—even in North America?

What Is a Rain Forest?

There are two types of rain forests: tropical and temperate. Both types are defined as areas with very tall trees and high rainfall. Tropical rain forests are mostly found where humidity and temperatures are high year-round—much like the National Aquarium's Upland Tropical Rain Forest exhibit. Temperate rain forests, on the other hand, are found on almost every continent with cooler temperatures than their tropical counterparts.

The Pacific Northwest rain forest ecoregion stretches from northern California to Alaska, largely located between the Pacific Ocean and the Cascade Range. These North American rain forests are home to a variety of wildlife, towering trees and heavy rainfall, classifying them as temperate rain forests.

Although Pacific Northwest temperate rain forests, like others of its kind, experience less sun and precipitation than tropical rain forests, they still receive at least 55 inches of rain every year. Their high rainfall is due to the orographic effect, which occurs when the topography of an area changes airflow by forcing air upward. In other words, when moist air from the ocean blows over land, the coastal mountains cause the air to rise, which cools and condenses the water, creating clouds and rain.

Let's Go to the Parks!

Within the expansive Pacific Northwest temperate rain forest region are multiple parks in the United States and Canada, including Redwood National and State Parks in California, Olympic National Park in Washington, and Tongass National Forest in Alaska, each with notable features.

Redwood National and State Parks, California

The most famous part of Redwood National and State Parks is their namesake—the redwood tree. Located in northern California, Redwood National and State Parks include three parks: Jedediah Smith Redwoods, Del Norte Coast Redwoods and Prairie Creek Redwoods. Redwood trees include three species—dawn redwoods, giant sequoias and coast redwoods—and can grow over 300 feet tall and live for a couple thousand years.

Redwoods "drink" hundreds of gallons of water daily and can even pull water from fog in the dryer summer months. Redwoods actually get 40% of their water from fog every year with the help of specialized needles. These redwood needles catch the fog and condense it into water droplets, which fall into bodies of water under the canopy that the trees can eventually absorb through their roots.

Olympic National Park, Washington

Moving farther north to Washington state, we find Olympic National Park and its four rain forest valleys on the park's west side: Hoh Rain Forest, Quinault Rain Forest, Queets Rain Forest and Bogachiel Rain Forest.

These rain forests produce hundreds of inches of rain yearly and maintain cool temperatures. Throughout the damp environment, moss and ferns cover coniferous and deciduous trees like cedar and spruce, creating a lush forest. Like other forests in this region, these rain forests are also home to elks, mountain lions, bears, and even 7-inch-long banana slugs known for being active on damp days.

Tongass National Forest, Alaska

At the edge of this temperate rain forest region is the Tongass National Forest in southeast Alaska. It spans 17 million acres of land and is the largest national forest in the United States. Much like other forests in this region, trees like cedar, hemlock and Sitka spruce (Alaska's state tree) fill the forest and can live for hundreds of years.

Another prominent feature in this part of the region is muskeg—a peat bog made up of dead plants at various stages of decomposition. Muskeg envelopes about 10% of southeast Alaska and is full of sphagnum moss, which creates a wet sponge texture due to its ability to hold over 15 times its own weight in water. Very few plants grow in muskeg's acidic soil, but those that do include bog blueberries, bog laurel, bog rosemary and stunted shore pine trees.

Closer Than You Think

Rain forests exist on six continents and are essential to maintaining the biodiversity and health of our planet. While tropical rain forests receive a lot of attention, temperate rain forests are also wildlife and vegetation hubs—just in cooler climates. So, the next time you think about rain forests, remember that the nearest one might be closer than you think.