The Tropical Rainforest

The tropical rainforest is the biggest and most complexed ecosystem in the world. It holds more than half of the world's animals and plantlife, Including a huge majority that haven't even been discovered yet. The rainforest compared to Britain is 30 times larger, covering around 8 million km. Some of the forest is destroyed everyday, including animal and plantlife. The forest from above is a vast green quilt of trees, giving off several different shades. From air you can see the emergents, which grow up to around 50m in height, these are accompanied by the canopy, which are 15m lower down. The under canopy's are 10m in height and the lowest of all are the shrubs and bushes. The ground of the forest is dark and damp, smelling of decaying matter. Long creepers or lianas trail to the ground, entangling themselves in the branches. The forest canopy is described to as the ‘engine' of the rainforest. This is because, it's where most of the photosynthesis takes place, and you will also be able to discover all of the forests fruits and animals. The average rainfall of the forest is 2,000mm. All of this rain is called classic convectional rainfall, it falls regularly every day at the same time (throughout the year). 80% of this rain is recycled back up into the atmosphere. The rest of the rain is collected in the rivers and streams which flow back out to the sea. The soils of the rainforest are of a poor quality, this is due to all the leaching that takes place. The soil is very thick, about 20m (60feet). This is because it has been weathered for a long time, with all the heat and wetness. The roots in the trees are found close to the surface of the ground, this is where all of the nutrients are found, from falling leaves. There are two cycles in the tropical rainforest, a nutrient cycle, where the leaves fall and hit the ground to be fed on by the decomposers, and a water cycle, where the rain falls, some of it collecting in the leaves and some of it making it's way down to the forests floor, and rivers, 80% of it is recycled. In this essay I will be writing about the tropical rainforest. It will consist of 7 different parts including the introduction, the other parts are the location of the forest, the structure and diversity of the forest, forest processes, about slash and burn, other human use of the rainforest, opinions on the forest and the future. The location of the tropical rainforests is the following; inside the tropics, 23.5 degrees north and south equator. South America, Africa and South East Asia. Most of it locating in south America. In Asia it is 0.7% a year, Africa it is 0.3% a year and in Latin America it is 0.5% a year. The tropical rainforest has an incredible amount of diversity about it. The forests cover around 6% of the earth's land surface. What is diverse about this? Well it's diverse in lots of ways, not only does it contain no less than half of all the worlds species of plants, animals and insects, but it also has had hundreds of them destroyed (extinct). Because of mans choice to cut down parts of the forest. The forest can be known as a treasure house of resources. The bird life of the forests is unbelievingly profuse, brilliant and melodious. The trees and the forest floor teem with animals that few people have ever seen or even heard of. Many hundreds of fish have been evolved in the forests rivers and streams. The most diverse of all the living things in the tropical rainforest though is the insects, there are many hundreds of thousands, and maybe even about this amount not even discovered. The diversity is also shown by the Indians of Amazonia, with their ability to use more than 1600 pharmaceutical plant extracts. This vast medical potential has only been scratched. Each year 100,000-140,000 square kilometres of forest is destroyed. In a few decades a quarter of the entire world's store of biological species could vanish into oblivion. This deforestation brings local ruin, flooding, soil erosion and land infertility. World-wide it threatens to change climates, to accelerate global warming. And large areas of former rainforest end up as tough, virtually inedible grass, of no use to man or beast-natures ecological revenge! The loss of new drugs could prove disastrous, because many of the drugs that have not been discovered could well be cures to diseases such as cancer and the common cold. The forest processes are the soil system, rainforest ecosystem and the water cycle. The soil system, where the forests trees shed their leaves and branches. There is a layer of decomposing litter on the surface of the ground. Which is followed by a thin layer of nutrient rich soil. This is where the trees roots take back up all the nutrients. If trees are removed, then the whole nutrient cycle is broken, and all of the existing nutrients are washed away, this is called leaching. Leaving the soil infertile. The next process is the rainforest ecosystem. This is when the precipitation (rain) falls onto the trees leaves, and the suns energy also shines down onto the leaves, this causes evaporation in water vapour. Some of the water seeps through into ground water and surface run-off. The ecosystem is also when the nutrients are recycled, as stated in the soil system. The water cycle is when all the heavy rainstorms fall down on the forests layer of trees, and is evaporated or transpirated. A lot of this is recycled through the rivers, as they carry a lot of it back to the sea. The slash and burn process is a long one. It begins with human activities, as they cut down an area of the forest by hand. Some trees are left standing to protect the soil and if they have fruit and crops growing on them, then they will be left to. The wood is then burnt, destroying the natural seeds which reduces weeding. Ash from the burnt trees is then dug into the soil to provide fertiliser. New crops are the planted (e.g. yams, manioc, cassava). There is less vegetation to cover the ground, which exposes the soil, causing leaching and erosion. The yields then get less each year, mainly after 2-3 years. The farmers move on to clear a plot somewhere else, and start the whole process again. The plot in which the farmers have demolished is now abandoned. And will soon start to re-grow again, but less luxuriant, with fewer and lower species. This is called secondary growth. The ecological balance is restored after about 20 years. There are mainly 4 different other ways in which humans use the forest. (1), there is clearcutting, in which an area of the forest is completely cleared. Only valuable species are taken out and the rest are left and burned. This is a useful source of income. (2), Agroforestry, this is a farming technique that imitates the canopy and ‘layer' structure of the natural forest by planting trees as well as shorter- lived farm crops. This idea is similar to that of the Indian forest ‘gardens', but the area does not need to be abandoned for a fallow period. (3), this is biosphere reserve, this is a way of protecting part of the forest by leaving it ‘untouched' except for research and the collection of materials for plant breeding etc. The protected ‘core' area is surrounded by a ‘buffer zone' in which only certain human activities are allowed. The activities permitted will cause little damage to the ecosystem and will stop more demanding activities invading the area. (4), trees for annual crops and timber. The forest is cleared and replaced by stands of tree crops or quick-maturing timber trees. Once the trees grow, they again provide a protective canopy. Humans also use the forest for things such as mining, drugs and research for new drugs, fruits and other forms of food. There's lots of opinions on the rainforests. ‘Not to exploit and populate an area, is a luxury that people in Brazil cannot afford'. A question is, ‘what is more important man or tree?† This was taken from a former commander of the amazon region. An African farmer said, ‘If you pay me, I'll happily keep the forest standing. Otherwise I'll cut it down to make a living.† This is a very true remark, in which I have no arguments about. The farmer has to cut down forest, so he can continue living his life. The Observer and WWF (World Wildlife Federation) ‘not World Wrestling Federation! Wrote a section on the rainforest, which talks about how the forests are so good, yet humans are constantly at war with it. It says, ‘Trees bind the soil to the ground, regulate the waters of life, and manage the climate. They stand at the heart of the world's religions, and pervade our literature and culture. This is the good news, but the bad news is, ‘Yet we seem to be permanently at war with them. Barely a quarter of the world's primaeval forests still remain, and they are usually in remote places. Even these are now falling so fast that little of our natural heritage will be left for the next generation. In LEDC's such as Malaysia, where it has to use the forests resources. The only way to save the forests in the future is to help out the LEDC's and help them develop, therefore we will be saving the forest. 232,000 kilometres squared of tropical rainforest. The tropical rainforest in central areas and inaccessible areas, this is where urbanisation is destroying the forests. Conclusion; I have discovered some fascinating facts and opinions on the tropical rainforests. I have discovered all about the rainfall, soils, humans use of the forests, the extreme diversity, where the rainforests are to be located, the whole slash and burn process, and what to do in the future. I can now understand why the rainforests are so vital and important to us now and in the future, whether it is to do with drugs and cures, or the research of animals and other living creatures. My opinion is that everyone should try and do something to help in preserving the tropical rainforests. As it is for their own good, and something that has been created in the rainforests could help us in a big way in our futures e.g. a cure for a horrible disease.