Oregon is known for its gorgeous, green forests, which make up almost half of our state. From the mist-shrouded forests along the coast to the ones nestled against the Cascade Mountain Range, these special areas are a big part of what makes Oregon…well, Oregon.

But what exactly makes a forest a forest?

Not surprisingly, it’s all about the trees. A forest is an area whose ecosystem is built around trees. Many other species are present in a healthy forest—there are mushrooms, undergrowth plants like ferns and trilliums, and a wide variety of birds and insects—but all of these plants and animals are specially adapted to life among the trees.

Earth is home to three main types of forest, and each one is largely defined by its trees. First, there are boreal forests, which exist in the cooler, northern parts of the world and contain mostly conifer trees—like spruces and pines—whose needle-like leaves remain green through the fall and winter.

Then there are the temperate forests—warmer zones south of the boreal zone, where different kinds of trees intermingle. Some bloom in spring, and then lose their leaves during the colder months. These leaf-shedding, or deciduous, trees include maples and oaks, and in a temperate forest, they often stand side-by-side with evergreen conifers.

Finally, there are tropical forests, which are even wetter and warmer than temperate forests and are located close to Earth’s equator. Tropical forests are known for their broad-leaved trees, which form a dense network above the forest floor and shade the many species of flowering plants below. Tropical forests are home to about half of the world's species, making them the most biodiverse regions on the planet!

Once you know a little about the trees that define Earth’s forests, you can start to identify the different types of forests you see. Think about the kinds of trees you encounter in Oregon. Are they all conifers? Or do you notice a mix of different kinds? Based on these observations, how would you categorize Oregon forests?   

If you guessed temperate, you’re right! Western Oregon forests generally have a mix of evergreen conifers (like Douglas firs) and deciduous trees (like alders and vine maples)—a dead giveaway that you’re in a temperate forest. East of the Cascades, you’ll find pine forests and juniper woodlands with fewer deciduous trees, but even these are considered temperate because they, like the rest of Oregon, are located in Earth’s temperate zone, where we have four distinct seasons but generally don’t get the heat of the tropics or the extreme cold of the boreal zone. As you continue to investigate forests, you’ll find that there are many different subtypes of temperate forests—some are wet rainforests, others are drier coniferous forests, and still others are dominated by deciduous trees. So much forest to explore!

Got a preschooler in your life? Invite them to join you beginning May 21 for Little Wonders Online with the Museum of Natural and Cultural History! This month, we’ll enjoy a story and activities celebrating forests and some of the amazing animals who call them home. Visit mnch.uoregon.edu to learn more and register for the free virtual story time set for 10:30 a.m.