Effects of Deforestation

Forest ecosystems encompass richly layered habitat types, which provide shelter to a breathtaking range of biodiversity — including 80% of amphibian species, 75% of bird species, and 68% of mammal species. From the Kirtland’s warbler that builds a nest amongst trees to the millions of species of plants, insects, and microorganisms scientists estimate are still undiscovered in tropical rainforests, countless species depend on trees to survive. When deforestation occurs, many species are unable to survive in the remaining fragments of forest. According to the World Wildlife Fund, this can make them more accessible (and therefore, vulnerable) to hunters and poachers; their populations are reduced, and some go extinct. Because many endemic species live in small, isolated locations, any amount of deforestation can result in extinction.

Trees not only provide critical habitat for many animal species, but they also help clean the air and remove carbon from the atmosphere. Deforestation means there are fewer trees available to sequester carbon — at a time when we need to reduce greenhouse gasses more than ever. And forest loss itself can accelerate the effects of climate change. According to the World Economic Forum, if deforestation were a country, it would be the third largest CO2 emitter in the world after China and the US.

Trees have intricate root systems that help prevent soil erosion by holding the soil firmly in place. Their leaf canopies also help prevent erosion by slowing and absorbing precipitation. By helping the land retain water and remain healthy, the soil is able to provide rich nutrients to help sustain life. When deforestation occurs, soil is significantly more likely to erode. Erosion reduces soil fertility, which can negatively impact crop yields. During precipitation events, soil-laden water is also more likely to travel downstream, collecting in heavy layers of sediment that can cause significant damage to watersheds.

Forests don’t just improve water quality and flow: they also play a critical role in our water cycle by regulating precipitation, evaporation, and flows. The entire forest structure, from the canopy to the roots, stores and releases water vapor — controlling rainfall. Deforestation directly impacts this important function, destabilizing rainfall patterns and increasing the likelihood of flooding and drought. And these effects aren’t just local — studies have shown that deforestation in one part of the world can cause significant decreases in rainfall thousands of miles away.

While we often think of forests in connection with the environment and nature, many communities rely on their local forests. There are about 250 million people who live in forestsand rely on trees for their incomes and to sustain their livelihoods. While deforestation can greatly affect people’s livelihoods, it also leads to more infectious diseases in humans. These are just a few of the ways deforestation can directly affect people