Living Things. Ecosystems An ecosystem is made up of biotic parts (living) and abiotic parts (non...
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Transcript of Living Things. Ecosystems An ecosystem is made up of biotic parts (living) and abiotic parts (non...
Living Things
Ecosystems
• An ecosystem is made up of biotic parts (living) and abiotic parts (non living).
• Ecosystems can vary in size e.g. from a small pond to a desert.
• A large ecosystem is referred to as a biome.
Click on the video link to watch a short clips about Biomes
World Ecosystems
Global distribution of biomes
There are only a small number of major biomes and their
distribution is influence by :-
• Relief• Geology• Soils
most importantly • Climate
Climate
• The most important factor affecting the distribution of the Worlds biome is climate.
• Climate has a major influence over what plants grow in an area and what animals live there.
Climate
• The climate of an area is mainly influenced by its location on planet earth. The further north or south you go from the equator the colder the climate is, the closer to the equator the warmer the climate is.
Climate
• The circulation of air in Hadley cells also influences climate.
• Places located on the equator tend to be wetter as air rises and condenses to form clouds. Tropical rainforests are usually found on the equator.
• Places located on the tropics tend to be drier as air is sinking. Deserts tend to be found on the tropics.
Nutrient Cycle• All living things need nutrients to live and grow. Nutrients are
found in water, rocks and the atmosphere.
Weathered rock released
nutrients into the soil
Water is added to the soil by
rainfall
Plant absorb the nutrients
through their roots and
leaves
Animals gain nutrients by
eating plants.
Energy Flows
• An energy flow shows how energy moves through an ecosystem. They are very similar to a food chain. (food provides energy)
Casestudy – Rainforest
• The ecosystems you have studied in detail for this topic is the rainforest
But remember to show case study knowledge you will have to name specific places within the
rainforest
Rainforests
Click on the video link to watch a short clip about ‘Rainforests’
Rainforest
• Rainforest is located at 23.5°North and south of the equator. Up to the lines of the tropic of cancer and the tropic of Capricorn.
• Examples of rainforest areas. Amazon • They contain the most diverse range and highest volume of
plant and animal life found anywhere on earth.• They have hot and humid climates. Temperatures are
constantly high (29°C). They have very high amounts of rainfall (2000 mm per year)
Location of the Tropical Rainforest
Rainforest
Water cycle – the trees play a very important role in the water cycle. Rates of transpiration and evapotranspiration are high. this returns much of the rainwater that falls in the rainforest back to the atmosphere, where it falls as rainfall again. This means that 80% of the water in the rainforest is trapped in a cycle within the rainforest
Rainforest
Nutrient cycle – Most of the nutrients in the rainforest are stored within the vegetation (biomass).
The trees in the rainforest rarely lose their leaves. This means that very little nutrients are transferred to the soil. The soil in the rainforest contains few nutrients. Most nutrients are leached (washed away) by rainwater
Rainforest
Vegetation is divided into layers. Each layer contains different levels of sunshine. Therefore the plants and animals you find on each layer is different.
Human uses of the Rainforest
Click on the video link to watch a short clip about ‘Human uses of the Rainforest’
• Human activity has destroyed and changed parts of all ecosystems.
• In the exam you will need to give examples of how people have change, destroyed or used ecosystems.
• The tropical rainforest is particularly under threat of human activity.
• Over the last 100 years 50% of the tropical rainforest has been destroyed.
Rainforest - destruction
Rainforest - destruction
There are many reasons why the rainforest has been destroyed. You will need to give examples in your exam answers : - • Arable farming – large parts of the Indonesian
rainforest have been cut down to be used to farm palm oil. A vegetable oil that is used in many food and beauty products. This has had a massive impact on the orangutans.
• Pastoral farming – large areas are also cut down to be used as land for animals. For example large areas of the Amazonian rainforest have been cut down to create massive cattle ranches. The beef produced is sold to big fast-food chains like McDonalds
Rainforest - destruction
• Mining – reserves of minerals such as gold, copper and iron ore are found in the rainforest. In order to mine these areas trees are cut down and chemicals used to mine the minerals can pollute the environment. For example coltan a metal used in mobile phones is mined from the Congo basin.
• Logging – trees are often cut down to use the trees themselves. Expensive wood such as mahogany are exported across the world.
• Population – the number of people living in rainforest areas is increasing rapidly. This means that tree are often cut down to build homes and create new industries.
Rainforest – Impacts
Negative • Nutrient cycle is change. Once the trees are removed, all the
nutrients in the soil are washed away. • Soil erosion – with no tree roots holding the soil together the soil
is eroded away. If washed into rivers this can cause flooding.• Climate – 80% of the water is recycled. Without the trees this
doesn’t happen. The area become drier. • Burning of the rainforest releases CO2 into the atmosphere
(global warming) • Many important medicines are lost• Profits made from logging companies go back to MEDCs• Loss of animal habitats• Loss of biodiversity • Tribes living in the rainforest lose their home and cultural
traditions may be lost.
Rainforest – Impacts
Positive• Jobs have been created by logging, farming and
mining• LEDCs have used it as a resource to improve
wealth of the country. • Helped LEDCs to develop. Standard of living
improves.
For and Against For Against
Poverty means the country need to use the rainforest to help its people
Medicinal products could be destroyed before they have been discovered or researched.
Many MEDCs have destroyed their forests why shouldn’t LEDCs
Preserving cultural traditions of tribes by protecting their home, the rainforest.
75% of CO2 comes from MEDCs Rainforests help to reduce global warming.
Many LEDCs are in debt to MEDCs, why should they be allowed to sell/use the rainforest to pay off some of the debts
Removing rainforests changes the climate
MEDCs continue to buy products which are sourced in the rainforest
Removing rainforests for farming is pointless as the nutrients will be lost
Rainforest management
• To protect ecosystems from destruction they need to be sustainably managed. There are a variety of ways that the rainforest can be sustainably managed to protect it from destruction.
Rainforest management
Case study – Kalimantan • Kalimantan is located in Indonesia (on the island of Borneo)• The government sold off the rainforest land to timber barons. • They logged large parts of the rainforest using a technique called
slash and burn. • The land cleared was to be used for farming • However the removal of the trees completely change the area and
its climate. • They were unable to grow the crops and the land was unusable. • The areas will never fully recover from the deforestation.
Click on the video link to watch the video clip shown in class on ‘deforestation in
Kalimantan’
Case study – Debt for nature swap
• Central America• Western government are encouraging
rainforest conservation by offering to write off debts if the country in return conserves an area of their rainforest
• For example the Costa Rica committed to spending $26 million on conservation of their rainforest. In exchange the USA (and NGOs) agreed to buy back a similar amount of Costa Rica's debt.
Case study – Eco tourism Costa Rica
• Government is encouraging the growth of eco tourism.
• These are small scale projects that create money for conservation as well as jobs.
• 70% of tourists here have visited protected areas• Earned $1.25 billion from ecotourism
Possible exam questions• Explain the consequences of unsustainable use of an
ecosystem on local people and the local environment. • Describe how people can manage ecosystems sustainably. • To what extent have people been successful in managing their
use of natural ecosystems • Describe and explain how one named ecosystem can be
managed sustainably• Explain the links which exist in an ecosystem.• Describe the evidence to show that it has been used in an
unsustainable way. • Explain two effects on local people of this unsustainable use. • Describe and explain ways in which people use ecosystems. • For one ecosystem that you have studied, describe and explain
two ways in which it can be used sustainably.Notice that many of the longer question are similar Learn deforestation and sustainable management in detail.