2. Uses and importance of rainforest
1. What are the uses of tropical rainforests?
· Water catchment
o When it rains, the trees stop the rain from reaching the ground directly. As water slowly drips from the trees, it seeps into the ground and become groundwater. The water reappears on the surface as springs, streams and rivers. Thus the tropical rainforests are large water catchment areas.
o Water that flows through rainforest is filtered by the soil and rocks which trap impure materials. Thus the forests surrounding the reservoirs help to maintain the quality of water.
· Green Lungs of the Earth
o Trees absorb carbon dioxide from the atmosphere and release oxygen through the process of photosynthesis.
o Tropical rainforest help to absorb almost one-third of the carbon dioxide emissions given off when fossil fuels are burnt.
o Help to keep the earth cool as trees transpire water through their leaves and roots.
· Habitat to flora and fauna
o Tropical rainforests are home to over half of the world’s species of plants, animals, insects and fungi with more than 2 million species.
o Abundant diversity of flora and fauna due to:
§ Ample sunlight helps plants to grow and the plants are eaten by animals.
§ The continuous canopy provides the habitat for the plants to grow and animals to live.
· Habitat to indigenous people
o About 60 million people live in the tropical rainforests e.g. Yanomami in the Amazon rainforest and the Penan in the rainforest in Sarawak.
o Rainforest provide the indigenous people with daily necessities such as food, clothing and medicine.
o The indigenous people obtain food either by hunting (animals and fishes) and gathering (wild fruits or nuts) or growing crops just enough to feed them known as subsistence cultivation.
o The shifting cultivators first clear the land by burning the vegetation which will also provide the nutrients to fertilise the soil and grow their crops. When the nutrients in the soil are used up and the soil cannot support any plants, they would move t another plot of land in the forest. The original plot is left alone to regain its fertility naturally.
· Source of timber
o Wood used as fuel for cooking.
o Timber is wood used to build or make things.
o Topical hardwoods such as teak, ebony, mahogany and meranti are valued for their strength, durability, texture and beauty.
o Products made from tropical hardwoods include doors, window frames and furniture.
· Medical application
o Many of the foods from tropical rainforest, such as Brazil nuts, have cancer-fighting properties.
o Some medicinal values of rainforest plants: Cinchona tree is used to treat Malaria, Clavillia plant is used to treat eczema and itchiness, Madagascar periwinkle plant used to treat childhood leukaemia.
o The potential medicinal value of tropical rainforest plants is still largely untapped.
o 25% of all modern medicines come from rainforest plant.