Think back to your last hike through a local forest. When you close your eyes and listen, a forest is usually quiet but rarely ever silent. Birds are chirping and singing, deer and other animals are grazing, and squirrels are scurrying from tree to tree. 

Ideally, a healthy forest has a diverse range of species hailing from every kingdom of life. There should also be a variety of young and old trees, and many species of trees, shrubs, grasses and flowers. According to Rick Kuyper of the U.S. Fish and Wildlife Service, “when forests are rich in plant life, they also tend to be rich in birds, insects, large carnivores and prey animals.”

When a forest has healthy biodiversity, it's a good indication that things like the food web, soil nutrient exchange, and water cycle are functioning well. A forest where nature's cycles are working as they should will be more resilient to disturbances.

Different species require different forest features for their survival. Climate, elevation, and water access are just a few elements that determine whether a species can thrive in a specific area. The next time you’re exploring a forest, see if you can find any habitat types that help sustain living things. 

Habitats that are commonly found in forests include downed logs, snags and rocks that provide shelter to species who require cavities and burrows, ponds, creeks, lakes and rivers where aquatic plant and animals thrive, and dense old-growth areas where prey animals can find shade and cover.

The level of biodiversity in a forested area directly correlates with the variety of habitat types it supports.

Typically, whenever we think of forests, we think of grand, old trees towering over us. While those trees are beautiful and important, the true sign of a healthy forest is trees of all different ages and sizes. 

Trees are incredibly adaptive, but if there aren’t saplings and young trees mixed in with more mature trees, it could be a sign of poor soil conditions that are preventing new trees from growing. If mature trees are dying, that could mean drought or disease are present, both of which are detrimental to the health of the forest.

A healthy forest will have a variety of young and mature trees wherever you go, helping to provide diverse habitat types and support biodiversity. 

Clean water is a basic necessity for survival. A healthy forest will have abundant trees, shrubs and grasses that absorb stormwater and hold the soil together. When soil erosion occurs, aquatic species are directly affected. Forests provide drinking water to billions of people, fish and wildlife around the world.

Watersheds are impacted by a range of factors, including stormwater runoff, deforestation, dams and other infrastructure, human development, air pollution, industrial pollutants and spills, household pollutants, and agricultural runoff. When a watershed is unhealthy, everything that lives in or depends on it is impacted. Erosion and flooding increase, fish populations dwindle, water quality is degraded, toxins accumulate in seafood, making it unsafe to eat, and more.