There are 4 key reasons for the bulk of deforestation occurring. Firstly growing crops is one of them. As the human population increases more crops are needed, so more land is cleared in order to do this Often, though population in a country is stable deforestation still occurs, this is because crops are grown to be sold as export to boost the countries economy.
Secondly, deforestation can occur as clearance for urban developments. When new roads are built it may need the removal of a forest especially if it runs through a forest area. Large areas either side of the road may be cut down, houses built and land for agriculture cleared.
The main cause of deforestation is commercial logging. The unmanaged operations cut down trees without replacing them. Even when only some trees are required for their work – cutting down and removal often damages large areas of the forest.
High demand for fuel wood can also be a big cause of deforestation in certain parts of the world e.g. Developing countries. The people living in rural areas collect their own fuel wood however for people in cities large amount of fuel wood are often brought from the distant forests and sold commercially.
Deforestation has a strong impact on diversity and the cycling of nutrients. The 5 main effects are reduction in soil fertility, flooding and landslips, changes in recycling of nutrients, climatic changes and species extinction. Once deforestation has occurred soil fertility can be reduced as deciduous trees can contain up to 90% of nutrients and so when trees are cut down nutrients are not available to the soil and are not replaced. Soil erosion is much faster due to the absence of trees. Due to no root system wind may remove soil and soil structure is no longer balanced.
Flooding and landslips also occur. This is because heavy rainfall on deforested land isn’t ‘held up’ usually 25% on rainfall is absorbed by follage or evaporates and 50% is absorbed by root systems. This results in water rapidly accumulating in river valleys causing landslips from steep hillsides.
Deforestation also brings about changes in recycling of materials. Having fewer trees results in an increase of Co2 in the atmosphere as less is removed for photosynthesis. Also less o2 which is vital for aerobic respiration is produced because there are les trees for photosynthesis. Lastly the atmosphere may become drier and the soil wetter as evaporation from soil is slower than transpiration from trees.
Climatic changes occur due to deforestation. Transpiration rates reduce and the drier atmosphere affects the water cycle and reduces rainfall. Rapid heat absorption by bare soils raises the temperature of the lower atmosphere in some areas causing thermal gradients which result in more frequent and intense winds.
One of the most alarming effects of deforestation is species extinction. Many species are dependant on forest conditions. It is estimated that one plant and one animal become extinct every 30 minutes due to deforestation.
Deforestation and its effects can be reduced in 3 main ways – by having conservation areas, forest management systems and using other sources of energy.
Due to the concerns about the loss of the Tropical Rainforests (T.R.F) financial help has been given to developing countries by industrialised countries to establish conservation areas. To make this scheme successful it is essential to involve not only the local government but also the local people. Forest management systems include rules such as when trees are cut down for timber it is done selectively and without damaging surrounding vegetation. The forests should then be left to regenerate naturally or replanted. Another way in which deforestation and its effects can be reduced is by using other sources of energy i.e. Solar Power egg using very simple solar heated ovens which could reduce use of fuel wood.
To conclude, we can see that the main reasons for deforestation are the needs of hardwood, agricultural needs and urban development needs. These all have serious effects such as reduction in soil fertility, flooding, species extinction, climatic changes and changes in recycling of materials. As we can see all these effects are very serious and must be reduced. I feel that deforestation is a very important issue that must be dealt with immediately. The ways in which this can be done is by providing financial support for conservation areas, setting up forest management systems and using other sources of energy. I feel if steps aren’t taken to reduce the effects of deforestation and deforestation itself it may lead to a total loss of our T.R.F which may lead to much more serious consequences that we are unable to deal with.
