In many areas of the world, a drive in the country involves traveling down winding roads surrounded by large open fields. Even though this is what is often called the countryside, this landscape is actually man-made. According to the University of Michigan, more than half of North America was originally covered with forest before mankind came and progressively deforested the land. This change has occurred over centuries, if not millennia, but it still means that deforestation is a major negative influence on biodiversity, soil quality and even climate.
Changes in Soil
Soil in forested land is covered with a rich layer of nutrients. The nutrients come from leaf litter that falls from the trees, and the trees also contain lots of nutrients. If the forest were not there, the soil would be unprotected from the elements, and wind and rain tends to erode it or wash it away. Forest trees normally take up water from the rain, but when the trees are cut down, the rain has nowhere else to go but into the soil, where it can cause flooding. This flooding has the additional effect of washing away the nutrients into the rivers. All of these detrimental effects mean that the deforested land is less able to support trees or other plants like crops.
Loss of Biodiversity
Many plants and animals are specially adapted to forest life and cannot thrive and grow outside of the forest. The effect of deforestation can therefore cause extinction, and competition by other, more adaptable, plants and animals can also place pressure on species in danger of extinction. The National Geographic website says that 70 percent of the Earth's species dwell in forests, so taking away this type of habitat is extremely damaging to biodiversity.
Alterations in Climate
Trees eat up greenhouse gases like carbon dioxide, thereby removing them from the atmosphere and preventing them from contributing to global warming. When forests are burned to clear them, this stored carbon also returns back into the air. Another way deforestation can affect climate change is the way that rain is recycled through the ecosystem. Normally, when rain falls on forests, much of it evaporates off into the air and recycles itself into more rain. This cools the land surface, but the NASA Earth Observatory says that rain falling on deforested land probably does not produce the same cooling intensity, thereby producing a climate that is hotter and more dry than forested land.
Impact on People
Many poor people rely on collecting firewood for cooking and for heat. In addition to these people chopping down trees for firewood, farmers and developers may also cut down swathes of forest for more space for agriculture or business. This has the effect of making wood more scarce and also causes localized natural disasters like mudslides or severe flooding, which can endanger people and their livelihoods.