The Impact of De-Forestation on the Environment

Deforestation leads to many negative effects on the environment, from physical degradation to reduced biodiversity, global warming to disturbance of the water cycle. It is important to be aware of and understand these effects, so that steps can be taken to minimize their impact.

Why is it a Problem?

Deforestation involves the mass removal of trees from an indigenous forest or woodland area, either in the search for timber and other wood products or to clear land for human agriculture and industrialization. Unfortunately, this severely upsets the balance of nature as trees play vital roles in maintaining not only important biodiversity but ultimately, in maintaining the climate and geography as well.

Effects of Deforestation

Global warming – as trees absorb carbon dioxide and expel oxygen through the process of photosynthesis, they are essentially the “lungs of the world” and act as sinks for the carbon dioxide generated, thus helping to prevent the “greenhouse effect” and global warming.

When trees are destroyed through deforestation, there is a reduced capacity to remove carbon from the atmosphere – in fact, human deforestation activities are said to contribute to a third of all carbon dioxide. Forests also help to extract pollutants from the air so their destruction contributes towards biosphere instability.

Disturbed Water Cycle – trees are an important part of maintaining the Earth’s water resources. By drawing up groundwater through their roots and then releasing it into the atmosphere through their foliage, they play a significant role in the hydrologic cycle. In addition, their roots also help to create large conduits in the soil, which helps water to infiltrate through the ground area; their trunks and stems help to stop surface runoff, which contributes to erosion, and a large proportion of precipitation is intercepted by their leaf canopies and then re-evaporated back into the atmosphere.

Furthermore, the leaf litter and other organic residue from trees help to provide a ground covering and increase the soil’s capacity to store water.Trees literally control the amount of water available in the atmosphere, the soil or even in the ground water. Thus, areas that have been cleared of trees cannot retain as much moisture in the ground and atmosphere and this very often leads to a drier climate and eventual desertification.

For example, instead of intercepting precipitation and allowing the rain water to gradually percolate down to the soil to eventually join the groundwater systems, the bare, tree-less areas promote surface water run-off – which might convert into dangerous flash floods. Also, this water – instead of being reabsorbed by tress and re-released back into the atmosphere, is lost in the run-off and ultimately to the oceans.

Loss of Biodiversity – forests support a huge number of wildlife and plant species – therefore, the destruction of forests automatically leads to the destruction of habitats and the possible extinction of many species. This drastically reduces the overall biodiversity in an area or ultimately on earth. Furthermore, deforestation is a threat not only to endangered species but also to research potential and medicinal conservation – forest biotopes provide a major, irreplaceable source of new drugs and they also harbour genetic variations which may have evolutionary importance, eg. pest resistance. Once lost, this genetic material is lost forever and yet we have no idea of what vital role it might have played in the future.

Soil Erosion – deforestation can lead to increased soil erosion, due to the increased surface runoff water, the lack of root structures of stabilize the soil and the reduced protection of the soil due to missing leaf litter. This erosion can lead to damage to local waterways and serious flooding (such as with China’s Yellow River) and can also lead to dangerous landslides, especially on steep slopes. This is because tree roots normally help to keep the top soil in place by binding it to the underlying bedrock. Without the tree roots, there is nothing holding the topsoil and sudden landslides can occur. However, it must be noted that deforestation only removes the trees at trunk level and therefore leaves the tree roots intact in the ground.

How do we Control Deforestation?

The best way of limiting the damage done by deforestation is to promote sustainable practices in all arenas, whether it is in agriculture or forest management. For example, avoiding modern intensive farming methods which deplete the soil of its vital nutrients in favour of traditional cyclic agriculture where land is allowed to rest and rejuvenate and maintain soil fertility.

More directly, reforestation (planting X number of trees for every one removed) and establishing sustainable forest plantations for the timber industry go a long way towards mitigating the harmful effects of deforestation. As a consumer, demanding accountability from suppliers and manufacturers of timber products and making an active decision to only purchase wood products from sustainable sources can have a significant influence on forestry management and timber harvesting practices.