Battle for the Biosphere
- What is the Biosphere?
- What factors can change biomes?
- What is the Tropical Rainforest?
- What impact are humans having on the Tropical Rainforest?
- What goods and services can be provided by the Tropical Rainforest?
- How can we sustainably manage biomes?
What is the Biosphere?
The biosphere is the part of the Earth’s surface that is inhabited by living things.
A biome is a large ecosystem. Climate (temperature, Rainfall and sunshine) determines what animals and plants live in a biome.
Biomes are different in different parts of the world because of the difference in climate.
Latitude has an effect on climate so often biomes change as you travel north or south.
The Sun’s rays are more intense at the Equator leading to hotter temperatures in the Tropics.
Apart from temperature, rainfall and sunshine there are local factors which can change a biome.
Local Factors that change biomesNear the coast land is cooled by the sea, decreasing the average temperature / Limestone bedrock creates dry soil conditions as it does not retain water.
Temperature decreases by 10C for every 100m gained in altitude. / Inland areas isolated from the sea suffer from low rainfall.
What is a Tropical Rainforest?
Found mostly in a band around the equator. Here the concentrated Sun’s rays heat the moist air causing it to rise. Heavy rainfall is the result and a climate with near perfect all year growing conditions.
The climate graph shows a constantly high temperature (line graph) and generally very high levels of rainfall (bars).
The rainforest is very biodiverse – this means it has a great variety of different types of plants and animals.
What impacts are humans having on the Tropical Rainforest
Human Activity / Effects/ImpactLogging / Commercial logging destroys the forest and animal habitat. Often several trees are destroyed in the process of cutting down and removing one tree.
Conversion to farmland / Commercial intensive farming requires massive areas of land to be deforested. Either plantations of crops such as soya and coffee are grown or the land is used for grazing cattle for beef.
Mining / Mining cuts away whole hillsides. Opencast mining destroys the surface and restoration is only partially successful. Transport to and from the mine also causes pollution. Case Study Carajas Scheme, Amazon.
Road building / Although it only damages a small area it allows access to previously inaccessible parts of the forest. This can then lead to deforestation for logging or farming. Often creates a “fishbone” effect where areas of forest are destroyed either side of the road.
All forms of deforestation have an impact on the processes that take place on the forest. The removal of trees reduces the leaf litter falling onto the forest floor, which in turn will reduce the amount of nutrients that enter the soil. This therefore reduces the soils ability to allow new plant growth.
What goods and services can be provided by the Tropical Rainforest?
Goods are products which can be removed from the forest. This can be done in a sustainable way (this means without damaging the forest).
Services are things which the forest does for the biosphere, these are usually processes that the forest helps to run that benefit life on the planet.
Process / BenefitAtmosphere / Forests removes Carbon dioxide from the atmosphere and this reduces global warming.
Water control / Forests intercept rainwater on their leaves. This slows the water down in getting to the river. This reduces the risk of flash floods. However, following deforestation trees are no longer able to hold the topsoil together this is then washed into the river by the heavy rain and increases the risk of flooding.
Nutrient Cycle / Leaf litter from dying plant leaves are broken down by termites and fungi on the forest floor. This releases nutrients into the soil to help make the soil fertile and allow other plants to grow.
How can we sustainably mange biomes?
Sustainable management means to make use of a resource in a way that:
- Protects it for future generations to enjoy.
- Benefits and trains local people.
- Is environmentally friendly.
To make use of the goods that the tropical rainforest provides we must sustainably manage it.
Sustainable Management StrategiesStrategy / Benefits / Case Study
Ecotourism / This encourages tourists to visit a biome such as a rainforest. However the aim of the holiday is to promote environmental awareness. Often tourists will take part in conservation activities such as monitoring bird life or replanting trees. Local people run the resort so earn money and learn new skills. The resorts are often small so have only a minimal impact on the environment. / Santa Lucia, Tropical Rainforest in Ecuador.
National Parks / These are conservation areas which are set up in valuable or rare environments. They have very strict rules about what can be built by the landowners and residents of the park and what industry can take place in the park. Tourists are encouraged to visit and learn about the area and park rangers are employed to run conservation projects and help tourists enjoy the environment. / Exmoor National Park, UK.
International Laws / Many biomes or ecosystems cover several different countries. This requires international laws to be set up which many countries sign up to. They all agree on how best to use the ecosystem to ensure it is not being destroyed. / Ramsar Convention on Wetlands. Signed in 1971 by 153 countries to ensure that 1.5 million square hectares of wetland across the world are protected.