The Tropical Rainforest (TRF) has its own biome that is the key to such a wide diversity of flora and fauna. The TRF biome is situated around equatorial regions and occurs on a number of continents (South America, Amazonian, and Central Africa, The Congo). The TRF biome is characterised by climatic, topographic, biotic and biotic factors. The climate of the TRf is characterised by all year round warm temperatures (above 21ï¿½c), precipitation and also light intensity.
These conditions provide ideal conditions for plants to photosynthesise. Topographic factors, which characterise the TRF biomes, are altitude, aspect and slope angle. The a biotic factors are parent rock type which affect the soil texture, pH, structure, organic content, depth, water and oxygen content and also nutrient content. Finally, biotic factors which include the element of competition for food, space, nutrients and light (in the case of plants).
In recent years, the TRF has come under increasing pressure to be developed by humans in order to exploit its vast wealth in natural resources. This problem has only grown as technology and global demand has increased. It is now accepted that the rate of forest clearance is of great international concern. Clearance of the world’s forests affects us all as the level of carbon dioxide in the atmosphere governs our climate and weather patterns. Recently, world climates and biomes are slowly becoming endangered as global warming threatens to change weather patterns.
Pressure is put on the TRF from many different activities all of which lead to forest clearance. Commercial logging is one activity that leads to forest clearance. This involves selective removal of hardwoods such as oak and mahogany. This occurs in selective areas by large scale felling to meet the needs of industry. Only about 1/20 trees is of economic value to loggers yet loggers often pay scant attention to the trees that are brought down along with the tree that they are trying to fell. Loggers are inefficient which leads to unnecessary forest clearance.
The heavy machinery brought in compacts the soil, which leads to surface run-off and more damage to the TRF. Road construction to transport the timber means lager areas are cleared. Critically, road construction in logging areas opens up huge tracks of forest to the landless poor who then move in to practice a version of the traditional method of cultivation, ‘slash and burn’. However, the ‘shifting cultivators’ do not allow the forest soil long enough to regain its fertility and so, the settlers simply clear more forest land and start again.
The need for cheap, reliable power in the TRF for economic and domestic purposes has resulted in the damming of large rivers to produce Hydro Electric Power (HEP). Large areas of the forest are cleared and flooded in order to store water for the HEP.
The political ambition to become a wealthy and prosperous country has resulted in large-scale mineral extraction. The TRF hold rich deposits of gold, precious stones and hydrated stones, for example iron ore. Large areas of the forest have been cleared to reach these resources. The need to exploit the Forest has resulted in the opening of the forest as roads and rail are built to transport the material. The supporting infrastructure of power, services and housing for the workforce has also lead to more forest clearance.
The TRF biome has come under increasing pressure from agriculture as the region has the highest NPP, suggesting high yields and multiple harvests. Multinational companies have set up large sugar and tobacco plantations. Large areas of the forest are cleared to grow these cash crops. As global demand for meat has increased, the clearance and burning of forest vegetation has also increased to provide suitable pastureland for the cattle to graze on. An area of 80,000kmï¿½ of forestland in Brazil was converted into 300 ranches. After a period of time, the land becomes infertile and the ranches must be relocated to provide fresh pastureland.
Large areas of forestland have been cleared in the Amazon to create a city in order to provide for Brazils increasing population. Manaus, situated in central Amazonian, has a rising population of 1,000,000,000. Here large areas of forest have been cleared to construct housing, roads, electricity, office blocks, manufacturing plants and other buildings.
As the number of cars has increased in Brazil, the need for petroleum has resulted in the construction of an oil pipeline that runs from Venezuela to Brazil. This has leaded the clearance of large areas of the forest, which has seen the destruction of flora and fauna.