Geography Report Tropical Rainforests
Tropical rainforests are the Earth's oldest living ecosystems and are filled with a wide diversity of flora and fauna. Rainforests are characterised by their humid climate and by having no dry season where all year around there is an average precipitation of at least 60mm. Tropical rainforests cover about 7% of the worlds dry surface yet include half of the whole worlds plant and animal species (see Fig. 1). There are many factors that are causing change in rainforests around the world. These include Climate change and deforestation. Both are causing irreversible change in rainforests and because of this, many animals and plants and even humans will suffer.
Climate Change
Climate change is a change in the patterns of weather that effects oceans, land surfaces and ice sheets, occurring over many years. Climate change is amplified by human activity on the earth that produces greenhouse gasses and is called the enhanced greenhouse effect. This is when sunlight shines onto the Earth's surface and is absorbed and radiated back into the atmosphere as heat. Greenhouse gases then traps some of this heat. Over time the earth has been continually heating. There has been an increase in emissions of greenhouse gasses in recent years which is causing a faster rate of warming around the world (Fig. 3)
Climate change will affect rainforests in many ways.
Rainforests are ecosystems meaning that they are a biological community of organisms that interact with their physical environment. This means that one change to one element of a rainforest will have a knock-on effect on all other organisms and eventually contribute to a decrease in biodiversity over time. For example, trees are dependent on the climate’s constant supply of water which helps them to grow. As the trees grow it creates the different layers of a rainforest that different animals have adapted to. If there are changes in the climate that affect the water cycle in rainforests, all other plants and animals will be affected. This will also then affect the globes climate as water that is released by plants by evapotranspiration influences world climate and ocean currents. Changes in climate will also affect animals that have adapted to the specific temperatures of tropical rainforests.
Long Term Effects:
It is expected that by the year 2050, temperatures in the Amazon will increase by 2–3°C. There is also expected to be a decrease in rainfall during dry months. This will in turn bring about loss of ecologically and agriculturally valuable soils the degradation of freshwater systems, increased erosion and increased insect infestation and spread of diseases. Also, there has been research done by the INPE that suggests that the Amazon could convert from being 30% dry savanna to up to 60%.
Deforestation
Deforestation is another threat facing tropical rainforests around the world. Deforestation can come in all different forms but the most common is the clearing of land for development or agriculture. Around the world every year around seven million hectares of forest is logged or destroyed. This has many effects on rainforests over time such as habitat loss, decreased biodiversity and a lack of nutrients in the soil.
Agriculture is a large cause for deforestation around the world. It contributes up to 80% of the worlds deforestation (see Fig.1) Agriculture causes land to be cleared and stripped of nutrients. This leaves it desolate and useless when no longer in use. Cash Crops and Cattle Ranching are large culprits for deforestation. They are profit-driven and environmentally unsustainable. The land use is also driven by increased world demand for rainforest products such as hardwood, fuelwood, paper pulp, rubber and palm oil.
Human development is another cause for deforestation of our rainforests. Development for tourism, transport and resources is causing large areas of land to be stripped of vegetation. Large areas of land are stripped for mining which then causes water, air and land pollution. Hydroelectric dams take up large areas of land and then destroys water based ecosystems within rainforests by silt trapping (this leads to the withholding of nutrients and also leads to erosion). Tourism also causes large scale deforestation across the world and has devastating effects to rainforests. Tourism can cause imbalance to an areas resources and ecosystem by causing soil erosion, pollution, habitat loss, heightened vulnerability to forest fires and strain on water resources. Hotels and resorts require large amounts of resources to be sustainable. For example: ‘An average golf course in a tropical country such as Thailand needs 1500kg of chemical fertilizers, pesticides and herbicides per year and uses as much water as 60,000 rural villagers.’ New buildings also need area cleared for roads, fences which are used for construction and transport.
Long Term effects:
This deforestation will bring about many long-term effects to our rainforests. One main effect of deforestation is an impact to the Earth’s climate. Trees and plants take in carbon dioxide and release oxygen. When trees die, and rot they produce carbon dioxide. While this is a natural occurrence in rainforests when trees die, mass deforestation is amplifying this effect and accounts for 18% of all global greenhouse gas emissions. Also, the constant land clearing will mean that eventually there will be no trees left to clear. This will mean that thousands of species will be left without a home and a source of food.
Geography Report Tropical Rainforests
Tropical rainforests are the Earth's oldest living ecosystems and are filled with a wide diversity of flora and fauna. Rainforests are characterised by their humid climate and by having no dry season where all year around there is an average precipitation of at least 60mm. Tropical rainforests cover about 7% of the worlds dry surface yet include half of the whole worlds plant and animal species (see Fig. 1). There are many factors that are causing change in rainforests around the world. These include Climate change and deforestation. Both are causing irreversible change in rainforests and because of this, many animals and plants and even humans will suffer.
Climate Change
Climate change is a change in the patterns of weather that effects oceans, land surfaces and ice sheets, occurring over many years. Climate change is amplified by human activity on the earth that produces greenhouse gasses and is called the enhanced greenhouse effect. This is when sunlight shines onto the Earth's surface and is absorbed and radiated back into the atmosphere as heat. Greenhouse gases then traps some of this heat. Over time the earth has been continually heating. There has been an increase in emissions of greenhouse gasses in recent years which is causing a faster rate of warming around the world (Fig. 3)
Climate change will affect rainforests in many ways.
Rainforests are ecosystems meaning that they are a biological community of organisms that interact with their physical environment. This means that one change to one element of a rainforest will have a knock-on effect on all other organisms and eventually contribute to a decrease in biodiversity over time. For example, trees are dependent on the climate’s constant supply of water which helps them to grow. As the trees grow it creates the different layers of a rainforest that different animals have adapted to. If there are changes in the climate that affect the water cycle in rainforests, all other plants and animals will be affected. This will also then affect the globes climate as water that is released by plants by evapotranspiration influences world climate and ocean currents. Changes in climate will also affect animals that have adapted to the specific temperatures of tropical rainforests.
Long Term Effects:
It is expected that by the year 2050, temperatures in the Amazon will increase by 2–3°C. There is also expected to be a decrease in rainfall during dry months. This will in turn bring about loss of ecologically and agriculturally valuable soils the degradation of freshwater systems, increased erosion and increased insect infestation and spread of diseases. Also, there has been research done by the INPE that suggests that the Amazon could convert from being 30% dry savanna to up to 60%.
Deforestation
Deforestation is another threat facing tropical rainforests around the world. Deforestation can come in all different forms but the most common is the clearing of land for development or agriculture. Around the world every year around seven million hectares of forest is logged or destroyed. This has many effects on rainforests over time such as habitat loss, decreased biodiversity and a lack of nutrients in the soil.
Agriculture is a large cause for deforestation around the world. It contributes up to 80% of the worlds deforestation (see Fig.1) Agriculture causes land to be cleared and stripped of nutrients. This leaves it desolate and useless when no longer in use. Cash Crops and Cattle Ranching are large culprits for deforestation. They are profit-driven and environmentally unsustainable. The land use is also driven by increased world demand for rainforest products such as hardwood, fuelwood, paper pulp, rubber and palm oil.
Human development is another cause for deforestation of our rainforests. Development for tourism, transport and resources is causing large areas of land to be stripped of vegetation. Large areas of land are stripped for mining which then causes water, air and land pollution. Hydroelectric dams take up large areas of land and then destroys water based ecosystems within rainforests by silt trapping (this leads to the withholding of nutrients and also leads to erosion). Tourism also causes large scale deforestation across the world and has devastating effects to rainforests. Tourism can cause imbalance to an areas resources and ecosystem by causing soil erosion, pollution, habitat loss, heightened vulnerability to forest fires and strain on water resources. Hotels and resorts require large amounts of resources to be sustainable. For example: ‘An average golf course in a tropical country such as Thailand needs 1500kg of chemical fertilizers, pesticides and herbicides per year and uses as much water as 60,000 rural villagers.’ New buildings also need area cleared for roads, fences which are used for construction and transport.
Long Term effects:
This deforestation will bring about many long-term effects to our rainforests. One main effect of deforestation is an impact to the Earth’s climate. Trees and plants take in carbon dioxide and release oxygen. When trees die, and rot they produce carbon dioxide. While this is a natural occurrence in rainforests when trees die, mass deforestation is amplifying this effect and accounts for 18% of all global greenhouse gas emissions. Also, the constant land clearing will mean that eventually there will be no trees left to clear. This will mean that thousands of species will be left without a home and a source of food.