1. Habitat Destruction

What's happening to this land?

This picture, taken in southern Mexico, shows land being cleared for agriculture. The forest has been cut down and burned to make room for a a farm. In the process, homes to many plants and animals were destroyed. This is an example of habitat destruction.

Habitat Destruction

A habitat is the natural home or environment of an organism. Humans often destroy the habitats of other organisms. Habitat destruction can cause the extinction of species. Extinction is the complete disappearance of a species. Once a species is extinct, it can never recover. Some ways humans cause habitat destruction are by clearing land and by introducing non-native species of plants and animals.

Land Loss

Clearing land for agriculture and development is a major cause of habitat destruction. Within the past 100 years, the amount of total land used for agriculture has almost doubled. Land used for grazing cattle has more than doubled. Agriculture alone has cost the United States half of its wetlands and almost all of its tallgrass prairies. Native prairie ecosystems, with their thick fertile soils, deep-rooted grasses, diversity of colorful flowers, burrowing prairie dogs, and herds of bison and other animals, have virtually disappeared.

Wetlands such as this one in Cape May, New Jersey, filter water and protect coastal lands from storms and floods.

Big bluestem grasses as tall as a human were one of the species of the tallgrass prairie, largely destroyed by agricultural use.

Herds of bison also made up part of the tallgrass prairie community.

Slash-and-Burn Agriculture

Other habitats that are being rapidly destroyed are forests, especially tropical rainforests. The largest cause of deforestation today is slash-and-burn agriculture (shown in the opening image). This means that when people want to turn a forest into a farm, they cut down all of the trees and then burn the remainder of the forest. This technique is used by over 200 million people in tropical forests throughout the world.

As a consequence of slash-and-burn agriculture, nutrients are quickly lost from the soil. This often results in people abandoning the land within a few years. Then the top soil erodes and desertification can follow. Desertification turns forest into a desert, where it is difficult for plants to grow. Half of the Earth’s mature tropical forests are gone. At current rates of deforestation, all tropical forests will be gone by the year 2090.