Types of Forests: Definitions, Examples, and Importance

Boreal Forests

Boreal forests, or taiga, are found between 50 and 60 degrees latitude in North America, Asia, and Europe. Beneath boreal forests is land shaped by glaciers that left a legacy in the geology, hydrology, and soils of the area. Boreal forests’ bitter cold climate makes it difficult for life, leading to low species diversity compared to temperate and tropical forests. The plants and animals that do live in boreal forests are specially adapted to cope with short growing seasons and cold temperatures. Due to their vastness and remoteness, boreal forests are important stores of carbon.

Of the three forest types, boreal forests have the shortest growing season, about 130 days. Boreal forests tend to have shallow, acidic, nutrient-poor soils. Conifers are the most abundant type of tree, although there are some well-adapted deciduous trees, such as willows, poplars, and alders, as well. Prominent species include black and white fir, jackpine, balsam fir, and tamarack. In the understory, blueberry and cranberry bushes provide high-energy food for wildlife. 

The animals that live in boreal forests are specially adapted to cope with extremely cold temperatures and low resource availability for large portions of the year. Boreal caribou are one of the few animals that live in the taiga year-round, and they survive by ranging areas of nearly one million acres to find food. These once-abundant caribou, however, are now at risk of extinction from loss of habitat and infrastructure carving up remaining forests. Many bird species visit boreal forest wetlands during their annual migrations, moving south as temperatures drop and food becomes scarce. 

Climate change is a major threat to boreal forests. Almost 80% of boreal forests are on top of permafrost, a layer of soil that remains frozen throughout the year. As temperatures increase at unnaturally fast rates, the ground becomes soft and swampy and many trees eventually lose stability and die. Scientists from the International Boreal Forest Research Association believe that boreal forest conservation is key to slowing climate change.

Temperate Forests

Temperate forests are located at mid-latitudes, which gives them their characteristic four seasons. Very few patches of old-growth temperate forest remain; the zone is dominated by secondary forests. Temperate forests accounted for 16% of the Earth’s total forest cover.

Temperate forests are inhabited by species adapted for seasonality. Deciduous trees like maples, hickories, oaks, and many others drop their leaves and become dormant in the fall and winter to save energy. Bears, bobcats, squirrels, and deer make their homes in temperate forests and can store food, adapt their diet, or hibernate to cope with the lack of nutritious foods in the winter. 

Although temperate forests have seasonality in common, they vary widely in yearly precipitation and temperature. Annual temperatures range from -22 degrees to 86 degrees Fahrenheit depending on location and season. Temperate forests receive an average of 30 to 59 inches of rain per year. Soils are generally fertile, with a thick layer of organic matter from which plants can extract nutrients to grow. 

Temperate forests are home to many endangered species. In the U.S., 12 mammal species listed as Endangered by the Fish and Wildlife Service live in temperate forest habitats. The red wolf, native to the temperate forests of eastern North Carolina, is listed as Critically Endangered by the IUCN. The northern spotted owl was federally listed as Endangered in 1990 and is currently considered Threatened. These birds of prey prefer the old-growth forest habitat of Washington, Oregon, and California, which has continued to decline in recent decades.

Tropical Forests

Located between the Tropics of Cancer and Capricorn at 23 degrees north and south, tropical forests are some of the most biodiverse ecosystems on Earth. These forests cover only a tenth of the surface of the planet, yet harbor half of all species. They are also some of the most threatened by human activities.

Tropical forests have relatively stable conditions that have allowed life to thrive. They are the warmest and rainiest forests on Earth, with temperatures ranging between 68 degrees F and 77 degrees F, with 79 to 394 inches of rain annually.

Tropical forests are known for their extraordinary biodiversity. The Amazon rainforest, for example, is home to 10% of the world's described species.

The diversity of tropical forests makes them very efficient at processing nutrients. Dead and decaying matter is quickly broken down by decomposers and almost instantly taken up by another organism. This makes tropical forest soils nutrient-poor. To cope with poor soils, many tropical trees have adapted shallow root systems that spread across the forest floor and can more easily take in nutrients. 

Many charismatic tropical forest species are threatened with extinction. For example, the African forest elephant, found in West and Central Africa, is listed as Critically Endangered by the IUCN due to habitat loss and poaching. Primates live almost exclusively in the tropics, and most live in tropical forests. In some Brazilian forests, as many as 13 kinds of primates live in the same area.

Human activities such as logging, land clearing for agriculture, and poaching are a threat to the future of tropical forests. In 2023 alone, nearly 4 million hectares of tropical forests were lost, according to the World Resources Institute.