GEOG S1 chap 6 Flashcards
What are the environmental functions of tropical forests?
Provide habitats for diverse animal life.
Tropical forests are rich in biodiversity. The warm climate and the abundance of water and food courses all year round make them very suitable habitats for a wide variety of animals. For example, over 300 species of mammals, reptiles and amphibians have been discovered to date int he Amazon Rainforest alone.
Generate oxygen
Tropical rainforests support the survival of many organisms in the physical environment due to their ability to generate oxygen. Rainforest and mangrove plants carry out oxygen production through photosynthesis in which they absorb carbon dioxide, water and sunlight to produce food for their own survival and growth. Furthermore, they are capable of producing oxygen throughout the year as they are evergreen.
Contribute to carbon storage
Rainforest and mangrove plants contribute to carbon storage when they absorb carbon dioxide from the atmosphere during photosynthesis. This helps to balance the amount of carbon dioxide being added to the atmosphere through natural processes like respiration and decomposition.
Carbon dioxide in the atmosphere is absorbed through photosynthesis and is stored in solid form in plants - in their leaves, branches, stems and roots. The roots of the plants also produce soil carbon. Dead leaves and branches that fall to the ground add carbon to the soil. All of these together increase the total amount of stored carbon.
Protect against soil erosion.
Tropical areas regularly experience heavy rainfall, which is likely to cause soil erosion. Rainforest plants can help to prevent this from happening as they provide a protective cover over the ground surface.
The leaves, branches and stems of rainforest plants slow down falling raindrops before they reach the ground. Hence, more rainwater can infiltrate and percolate into the soil, thus reducing surface runoff. This allows the raindrops to hit the soil with less force. The roots of rainforest plants also bind the soil together, making it harder to erode. The overall soil erosion by the flowing water is minimised.
Protect against coastal erosion
Mangroves play an important role in protecting coastal areas from erosion as they help to reduce the power of strong waves and storms.
The dense root systems of the mangrove plants help to trap and stabilise loose sediments on the coast. The sediments are less likely to be washed away by waves, currents and tides. The roots, trunks and branches of the mangrove plants cause friction with waves hitting the coast. The waves lose a significant amount of energy, thus reducing coastal erosion.
How are tropical forests used by people?
Place for habitation
Several million people around the world continue to live in tropical rainforests. They are often known as Indigenous people as they are considered to be the ‘original’ inhabitants of the areas. They depend on the physical environment on the physical environment to meet their basic needs such as food, water, shelter and clothing. Some examples would be the Korowai tribe, which lives on the island of New Guinea in Indonesia, and the Moken people who inhabit the mangroves along the coasts of Southern Myanmar and Thailand.
Place for recreation
Tropical forests are recreational sites for people who live in towns and cities to get close to nature, Trekking, camping and birdwatching are some common activities that people take part in while visiting tropical forests. Researchers have found that visiting forests has a positive effect on people’s health. The natural sights, smells and sounds of the forest have a calming effect on people, which helps to give them a sense of well-being. It is also a way for people to exercise and to lead an active lifestyle. An example would be the elevated wooden bridge over a tropical rainforest canopy in Phuket, Thailand.
Source of food
Mnay common types of foods come from plants that grow in tropical rainforests. Apart from harvesting many different types of edible plants from the tropical forests where they live, indigenous people also often hunt wild animals for food. This manner of obtaining food is known as hunting and gathering. More developed societies convert mangroves in some coastal areas to farms to have sufficient food. This is known as aquaculture. Some examples would be the cacao tree (used to make chocolate), nuts like Brazil and cashew nuts, spices like pepper and cinnamon, fish, deer and wild birds, and fruits like bananas and mangoes, vegetables like cumbers and eggplants.
Source of raw materials
Tropical forests are best known for being valuable sources of wood for certain types of trees that are valued for their strength, durability and colour. Many different kinds of products are made from them, including flooring, doors, furniture and even musical instruments. Some examples are wood obtained from mangrove trees used to build houses, jetties, and boats. Also used as fuel wood or turned into charcoal for cooking and heating. Mangrove trees in Malaysia/Indonesia are cut down to produce paper products.
What are the 2 consequences (negative impacts) of extracting resources from tropical forests?
Deforestation. Deforestation is the permanent removal of tropical forests for human needs and activities e.g. wood, paper products, mining, agriculture, and aquaculture. This prevents the forests from regenerating, and the species and 1000s of animal species face extinction. Even if forests manage to re-establish themselves on a piece of deforested land, they will still lack the biodiversity of tropical forests that have been untouched by humans as it takes 1000 years to re-establish.
Enhanced greenhouse effects
The enhanced greenhouse effect refers to the increase in the average temperature of the earth’s surface due to the presence of more greenhouse gases in the atmosphere, trapping heat. This is the result of more human activities taking place, such as industrialisation.
Steps:
- Sunlight passes through the atmosphere and reaches the earth’s surface.
- Greenhouse gases in the atmosphere trap heat so not all escape to outer space.
- Earth warms up when heated, then radiates heat. Higher amounts of greenhouse gases in the atmosphere trap more heat released by the earth’s surface.
- Less heat is able to escape into outer space, leading to a rise in temperature on the earth’s surface.
How can tropical forests be managed sustainably, establishing protected areas.
The government conserve the remaining tropical forests by setting them aside as protected areas. The level of human activity varies from country to country. Governments also put laws in place to ensure people do not damage these protected areas, such as having heavy fines or being sent to jail. Protected areas are also known as national parks and biosphere reserves. Some examples would be the Nam Ha National Protected Area- the first national park of Laos and the ASEAN national heritage site, and the Bukit Timah Nature Reserve.
Strengths:
-Protected areas restrict human activity to prevent plants and animals from being harmed.
- Protected by law, which will result in consequences if the law is broken.
Limitations:
- Effectiveness of protected areas depends on the strong enforcement of laws, which is sometimes a challenge in less developed countries (LDCs) due to the lack of funding.
How can tropical forests be managed sustainably, regulating forestry activities.
The careful regulation of control or resource extraction is a way to strike a balance between obtaining economic benefits from tropical forests and conserving them. An example would be controlled logging. Companies are only allowed to cut down older trees or a particular species of trees which are economically viable e.g. Malaysia.
Strengths:
- Overall damage to the forest is reduced and the forest is able to recover quickly as younger trees grow.
- Patch is small enough for vegetation to regenerate quickly from surrounding untouched forest.
Limitations:
- The effectiveness of controlled logging depends on strong enforcement of laws, which can be a challenge in LDCs and the size of land to monitor by limited manpower.
- It is very difficult for a country’s government to set aside all of its remaining tropical forests as protected areas due to the high economic value of resource extraction activities.
How can tropical forests be managed sustainably, rehabilitate disturbed areas.
The diversity of plant and animal species in deforested areas is usually much lower compared to the original so rehabilitating disturbed areas means reintroducing some plant and animal species originally found in an area. Reforestation refers to the rehabilitation of a deforested area by planting new trees (sometimes using species not native to the area which are able to grow more quickly and easily).
Some examples would be the rehabilitation of mangrove forests in Pulau Semakau, Singapore (also called Pulau Tekong and Pulau Ubin), and in Trombetas, Brazil, they replace soil removed by mining and replanting saplings of native trees from surrounding rainforest in disused mining sites.
Strengths:
- Ensures the survival and growth of particular species that are replanted
- Restores some of the rainforest biodiversity.
Limitations:
- The effectiveness of rehabilitation depends on efforts by the government and people, which they may not be motivated to carry out.
- Sometimes a challenge in LDCs due to lack of funding to buy plants or soil.
How can tropical forests be managed sustainably, promoting public education.
Much of worldwide deforestation is due to people’s consumption of products directly or indirectly obtained from tropical rainforests, and many people are unaware that they are partly a reason for it. Public education lets people know the importance of tropical forests and understand why they are under threat, making them more likely to play a part in helping to reduce deforestation. An example would be NParks, Singapore. They regularly organise exhibitions, festivals, talks and workshops which people can take part in to learn more about tropical forests.
Strengths:
- Encourages sustainable extraction of resources.
- Tourism income may encourage governments to conserve forests so more tourists will visit.
Limitations:
- Effectiveness of P.E. depends on the willingness of people to cooperate, the availability os funding volunteers who will run the programme, etc.
