When an area of rainforest is either cut down, destroyed by fire or some other means of perturbation, there are various levels of climate change that happen as a result. These impacts have a positive feedback effect at differing geographical ranges, from local, regional, national, continental and ultimately global. Rainforest is an extremely complex ecosystems and the destruction and fragmentation not only effects climates, but also leads to the loss of plant species and habitat for animal species that make a living from forest habitat. (Christopherson, 2009)
All the major causes of global deforestation are human caused. Farming, mining, poor land management practices, burning for fuel, logging and urban expansion are just a few of the ways in which humans are having an effect on forests through clear felling of entire tracts of forest or through fragmentation of the forests. (Christopherson, 2009) As with the causes, the effects are also numerous.
1.Desertification of previously moist forest soil.
When the soil is exposured to the sun, the soil gets baked and the lack of canopy leaves nothing to prevent the moisture from quickly evaporating into the atmosphere. Thus, previously moist soil becomes dry and cracked. (Hoffman, 2003)
2.Dramatic Increase in Temperature Extremes.
Trees provide shade and the shaded area has a moderated temperature. With shade, the temperature may be 35 degrees Centigrade during the day and 15 degrees at night. With out the trees, these temperatures would be much more extreme, colder during the night and hotter during the day. (Hoffman, 2003)
3.No Recycling of Water.
Moisture from the oceans fall as rain on adjacent coastal regions. The moisture is soon sent up to the atmosphere through the transpiration of foliage to fall again on inland forest areas. This cycle repeats several times to rain on all forest regions. When these trees are removed it results in the climate getting drier in that area. (Hoffman, 2003)
4.Less Carbon Dioxide and Nitrogen Exchange.
The rainforest's are an important sink within the carbon cycle. Studies on deforestation and greenhouse gas emissions report that deforestation may account for as much as 10% of current greenhouse gas emissions. Greenhouse gases absorb infrared radiation as it is emitted out to space and the current theory is that this is the major cause of the global rise in temperature we have seen over the past 10 years. (Hoffman, 2003)
5.Soil Erosion.
When forest areas are cleared, it results in exposing the soil to the sun, making it very dry, In addition, the trees that protected it and bound it together with their roots are no longer there. So when rains do come, they are not absorbed by the soil and run off taking the soil and any reaming nutrient with them. (Hoffman, 2003)
6. Flooding and Drought.
One of the vital functions of forests is to absorb and store great amounts of water quickly when there are heavy rains. When forests are cut down, this regulation of the flow of water is disrupted, which leads to alternating periods of flood and then drought in the affected area. (Hoffman, 2003)
7.Global Climate Impacts.
It is believed that global warming is being caused largely due to emissions of greenhouse gases like carbon dioxide into the atmosphere. However, what is not well understood is that deforestation has a direction association with carbon cycle and atmospheric carbon levels. Trees act as a major storage depot for carbon, since they absorb carbon dioxide from the atmosphere, which is then used to produce carbohydrates, fats, and proteins that make up trees. When deforestation occurs, many of the trees are burnt or they are allowed to rot, which results in releasing the carbon that is stored in them as carbon dioxide. This, in turn, leads to greater concentrations of carbon dioxide in the atmosphere. (Hoffman, 2003)
8.Loss of biodiversity.
The unique biodiversity of various geographical areas is being lost on a scale that is quite unprecedented. Even though tropical rainforest's make up just 6 percent of the surface area of the Earth, about 80-90 percent of the entire species of the world exist here. Due to massive deforestation, about 50 to 100 species of animals are being lost each day. The outcome of which is the extinction of animals and plants on a massive scale. (Hoffman, 2003)
9. Disruption of indigenous populations.
Very little attention or thought is given to the effects of deforestation on indigenous population who spend their lives within forests, with the loss of forest comes a loss of culture and of peoples identity. Many of these indigenous populations have cared for the land they live on for thousands of years, only to have it stolen from them by greedy western companies whose only interest is profits for their shareholders. (Stilling, 2002)
References.
Christopherson. R.W., (2009), Geosystems, Pearson Education Inc. p.507-521.
Grotzinger. J., Jordon. T.h., Press. F., Siever. R., (2007), Understanding Earth 5th Ed, W.H. Freeman and Company. p.474-479.
Hoffman. D.J., Rattner. B.A., Burton G.A., (2003), Handbook of ecotoxicology, CRC Press. P 645-663.
Stilling. P., (2002), Ecology Theories and Applications 4th Ed, Pearson Education Inc. p.237-239.
