Comp 3- Topic 7 Flashcards
What are Biomes?
Large scale global ecosystems with distinctive vegetation.
What is an ecosystem?
An ecosystem includes all the living and non living things in an area
What is the climate of an area?
The climate in an area determines what biome will form there
Describe the climate of Tropical rainforest.
- The climate is the same all year, no definitive seasons
- its hot (20-28), because its on the equator
- Day length is always around 12 hours providing the light for plants
- rainfall is high 2000mm a year it rains every day
Describe the characteristics of Tropical Forests
plants- most plants are evergreen to take advantage of the continual growing season.
Animals- dense vegetation provides lots of food and different habitats, there are lots of different species of animal
Soil- plants grow quickly and shed leaves all year round. These decompose quickly so theres a constant supply of nutrients in the soil
Describe the climate of temperate forests.
- They have four distinctive seasons
- Rainfall is very high (1500mm yearly)
- the hours of sunshine vary, longer in summer shorter in winter
Describe the characteristics of temperate forests
Plants- the mild wet climate supports fewer plants than tropical rainforests but more than boreal forests. They are made of broad-leave trees that drop their leaves In autumn
Animals- the mild climate and range of plants provide a lot of food.
Soil- plants lose their leaves in autumn and the leaf litter decomposes quickly in the moist rich climate
Describe the climate and characteristics of a boreal forest
They have short summers (10 degrees) and long winters (-20)
Less than 500mm pf rain yearly
Lots of sun in the summer but very little in the winter
Most plants are evergreen but there are also coniferous trees too.
There are relatively few animals, because there is less food available and animals need to be adapted to the cold
The cool dry climate mean that the pine needles decompose slowly so soils are thin and nutrient-poor and acidic in some areas its frozen
Describe the climate and characteristics of a grassland
Low rainfall and have distinctive rainy and dry seasons temperatures range from 15 to 35
They have hot summers and cold winters, because they’re further from the equator they receive less sun.
The consist mostly of grass, shrubs and small plants with a few scattered trees. Grass dies during the dry season forming a thin nutrient rich soil however it is washed out during the wet season
There are a variety of animals, lots of insects and big mammals.
High temperature is summer mean that the soil is nutrient
Describe the climate and characteristics of desserts
Rainfall is very low. It may only rain once every two or three years.
Temperatures range from 0 at night to 45 in the day.
Desserts get more sun in the summer than winter.
Plant growth is very low due to no rainfall
Few animals live there if they do they are well adapted
Soils are thin and nutrient poor as there is no plant life to provide nutrients
Describe the climate and characteristics of a tundra
Temperatures are low
Rainfall is low
Found at high latitudes so it gets near continuos daylight in summer but little to none in the winter
There are hardly any trees, lots of shrubs and mosses.
The cold climate and lack of vegetation means that few animals live.
Low leaf litter, cold climate, means slow decomposition sos oil is thin and nutrient poor there is a layer of permafrost which can stop water from draining away
What factors affect distribution of biomes?
Altitude- higher climates are colder so less plants can grow and less animals which can live
Rock Type- weathering, minerals they contain, permeable or not
Soil type- nutrient rich soils can support more plants, acidity and drainage of soils also affect what can grow.
Drainage- if drainage is poor soil gets waterlogged and only adapted plants can grow.
How do biotic and abiotic factors of a biome interact?
Water availability affects the plants that can grow as only dessert plants can grow in areas with low rainfall
The type and density of vegetation affects the plants which can grow as the decomposition of the plants provide nutrients for the soil which provides nutrients for further plant growth.
Some organisms causes biological weathering
What resources does the biosphere provide for humans?
Food - we all eat fruit and vegetables gathered from the environment
Medicine - plants have medicinal properties. 7000 drugs from rainforests
Building Materials- trees are used to build houses and furniture all over the world. Sap is used for glue or straw for roofs.
Fuel - poorer people rely on wood and animal dung for fuel for cooking
How do humans exploit the biosphere?
Energy - forests are cut down to clear land for growing biofuels or building power stations. Areas of forest are flooded when dams are built and drilling in tundra for gas is melting permafrost.
Water - over exploited water sources such as lakes and rivers are being sucked dry for humans leaving animals and plants no water to live.
Minerals - minerals are needed fro the construction of many things. Mining in the environment can e extremely damaging to plants and animals living there.
How does the biosphere help regulate gases in the atmosphere? Why is it important to regulate these gases?
- Plants in carbon dioxide and release oxygen, animals breath in oxygen and release carbon dioxide.
- Increased levels of co2 lead to global warming, it can also cause ocean acidity.
- some Co2 is needed to keep the earth warm.
How does the biosphere help to keep the soil healthy?
- plants roots and worms spread nutrients through the soil to maintain structure and fertility allowing plants to grow.
- the roots of plants hold the soil together to stop it being eroded by wind and rain
- vegetation intercepts rainfall before it hits the ground stopping the nutrients being washed away
How does the biosphere help regulate the water cycle?
- water is taken up by plants, so less reaches rivers, preventing flooding and reducing erosion
- plants help to reduce the global water cycle by storing water and releasing it into the atmosphere slowly. Large areas of forest can reduce droughts and flooding in areas long away
How does population growth increase the demand for resources?
More people require more resources.
Demand for one resource can increase demand for another. E.g. an increased demand for food means an increase in demand for water.
How does increased wealth, urbanisation and industrialisation increase the demand for the resources?
Wealthier people have more disposable income:
- they can buy more food, often they don’t need it
- they can afford cars, fridges, televisions which use lots of water to manufacture
- more people can afford showers, toilets and use more water this way
Urbanisation tends to increase resource consumption:
- neon signs and street lights use energy and fountains use water.
- Food and water has to be transported long distances to meet increased demand in cities, and waste water needs to be removed increasing energy use.
Industrialisation:
- manufacturing uses lots of energy and water, as countries become more industrialised their demand for this increases.
- people want more processed goods such as margarine which uses palm oil
What is Malthus’s theory?
He believed that the population was increasing faster than the supply of resources, he believed that there would be a point in the future that the population would exceed the resources we had resulting in a catastrophe such as war, famine or illness which would continue until the population dropped to a level which could be sustained by the resources.
What is Boserup’s theory?
His theory was that no matter how fast the population grew people would find a way to supply sufficient resources. He believed that if resources ever became limited people would create new technology to avoid hardship.
