Deforestation, Desertification & Declining Biological Diversity

Natural Environments

Imagine that you are out on a camping trip deep within the forest. During the day, you enjoy watching the animals and birds as they play among the trees and plants. Then, at night, you climb into your tent and fall asleep listening to the crickets, bullfrogs and other creatures of the night. But, as morning breaks, you step out of your tent to find that all of the plants and animals have disappeared and, in their place, is dry and barren land.

Okay, this is a bit extreme, and this drastic of an environmental shift could not happen overnight. However, with mismanagement of woodland and natural disasters, lush forests can be negatively impacted and can even turn into deserts over time. In this lesson, we will take a look at how these changes take place and how they impact the biological diversity of the ecosystems.

Deforestation

Deforestation is the term that describes the cutting down or clearing of trees from a wooded area. There are a number of reasons woodlands or forests are cut down. In some cases, the trees themselves are the desired resource. Trees have been a source of fuel for many generations and continue to be used in this way today. They are also turned into timber for use in building and carpentry, as well as used in the production of paper products.

In other cases, trees are cleared because they are in the way of progress. Forests may be cleared to make room for farmland or for grazing land for cattle, or they may be removed to make room for new houses, neighborhoods or expanding cities. Some deforestation is not intentional and can result due to natural causes, such as wildfires.

Regardless of the cause, deforestation can be detrimental to the environment. A forest acts as a carbon sink because it absorbs carbon dioxide from the atmosphere during the process of photosynthesis. When trees are destroyed, they release their stored carbon dioxide back into the atmosphere, which contributes to the greenhouse effect. The greenhouse effect is the phenomenon whereby atmospheric gases, like carbon dioxide, trap the sun's heat, causing the earth's surface to warm.

The harmful effects of deforestation can also be seen on land. Without trees to protect soil and hold it in place, soil erosion, or the washing away of soil, can occur during periods of rain. Trees also play a pivotal role in the water cycle, which is the constant movement of water between the earth and the atmosphere.

Tree roots absorb water from the ground and return water vapor back to the atmosphere. If trees are removed and can no longer contribute to the water cycle, the previously forested land can transform into a much drier climate. This dry environment can spread due to a decrease in atmospheric water vapor and results in a decline in precipitation levels in the area.

Desertification

These factors all combine to create a warmer and drier climate and may result in desertification, which is the transformation of once fertile land into desert. Deforestation is not the only cause of desertification. Land can turn dry and barren due to drought, shifts in the climate or aggressive agricultural or grazing practices.

All of these causes, along with deforestation, lead to the loss of vegetation in the area. Without the vegetation, soil erosion accelerates and water does not easily absorb into the ground. The soil becomes dry and deplete of moisture and groundwater reserves go unfilled. The soil is left unfertile and barren with nothing to do but bake in the hot sun.