GILES ACADEMY GEOGRAPHY

GCSE REVISION

UNIT 1—PHYSICAL UNIT

The Living world

This unit explores ecosystems, the interactions and influences that can

change them over time – in both a positive and a negative way. You need to

understand the key factors that make an ecosystem and why there are

differences. There are a number of biomes that you need to be aware of and

where they are located, providing reasons for why they are where they are.

An ecosystem that you need to know in-depth is an example of a rainforest,

the characteristics that make it and the different challenges and opportunities

it faces. You also need to be aware of the different approaches to managing a

named rainforest. In contrast, you also need to understand the

characteristics, problems and challenges that a hot environment faces and

how it is being managed.

Case study examples needed

- Amazon Rainforest

- Sahara desert

The Living World - Key Words

Abiotic - Non Living items in an ecosystem such as rocks, soil and water Acid Rain - Caused by industrial pollution and affects ecosystems - especially areas of Coniferous woodlands Afforestation - The large scale planting of trees Biodiversity- Great numbers of plants and animals living in an ecosystem Biomass- The total mass of plant and animal life occurring in an ecosystem Biome- A very large type of ecosystem such as a Tropical Rainforest Biotic - The living parts of an ecosystem Boreal - Another name for coniferous woodlands Carnivore - An animal or plant that eats animals Coniferous Woodland - Forests consisting of trees such as conifers (spruce and pine) Deforestation- The cutting down of large areas of forests Ecosystem- This includes the living communities of plants and animals and what they depend on ie - climate and soil Food web/chain - A hierarchy of plants and animals relying on each other for food Habitat - The natural home of a plant or animal species Horizon - A layer within a soil Humus - Decomposed organic matter found in the soil Hydrology - Water movements both on the surface and underground Latosol - The red and yellowish soil found under tropical rainforests Photosynthesis- The process by which plants transfer carbon dioxide/water into growth which also gives out oxygen Podsol- The type of soil found under coniferous woodlands Savanna Grassland - An area containing grasslands found mainly in tropical areas Slash and burn - A method of clearing forest by primitive people for subsistance farming Soil - Loose material found below the surface which is a mixture of minerals, organic material, air and water Tropical Rainforest - An area of dense jungle which grow in hot wet climates near to the equator Sustainable - Preserved and able to use for many years to come - It does not do any lasting damage

= I know ? = unsure X = don’t know

Carry out a self review

The Living world

Ecosystems are communities of living organisms and their interaction with the physical environment – as environments change, so do the living organisms that are found there. Ecosystems consist of different interactions and interconnections of a biotic and abiotic nature Biotic = living interactions Abiotic = non living Extension question Choose 2 of the above and explain how they interact with each other (4 marks)

Are these biotic or abiotic?

Ecosystems can vary in size but show the connections and interactions between different organisms that make them up (see image below). This also illustrates a food chain and shows how different organisms rely on each other

Primary producers

Primary consumers

Secondary consumers

Tertiary consumers

Quaternary consumers

Use the diagram to write

definitions of these terms

The figure above shows how the ‘levels’ of a food chain change. Consider the following -Identify how the diagram changes …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….. -Explain why you think the levels of a food chain change …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………..

Nutrients and the nutrient cycle are a key element within any ecosystem. The quality and quantity of nutrients in turn influence the quantity and quality of to grow. species within a system. Although nutrients occur naturally, they are also recycled within an ecosystem, ensuring that life can continue to grow. If one of these flows is ‘interupted’ it can affect the nutrient cycle. EXAMPLE If an ecosystem experiences torrential rainfall, it can increase the surface run off, removing litter which in turn decomposes back within the soil

How do physical and human forces disturb ecosystem balance?

Extreme weather Climate change

Trees felled (cut down) Soil erosion (due to deforestation)

Increase in impermeable surfaces

Decline in a species

Introduction of a new species

Decide if these are human or physical

How can changes within an ecosystem affect food chains? In woodland ecosystems for example, trees often provide the food source for many of the primary consumers who in turn, provide food for the consumers above them. When trees are removed, this affects the food supply which impacts on the food chain as a whole. In some instances, such as the grey wolf in Yellowstone, this is a species that after careful management has been reintroduced to the ecosystem and has not damaged the food chain. Managing food chains requires careful consideration.

Biome- A very large type of ecosystem such as a Tropical

Rainforest

Describe the distribution of global biomes (4 marks) ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. EXTENSION Choose 2 biomes and compare the climate conditions they are likely to experience.

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Annotate this image to identify key characteristics of a tropical rainforest.

Describe the climate typical of a rainforest

Rainfall (mm)

Temperature 0C

Question time Why is the nutrient cycle for a rainforest different? HINT Look at the diagram below compared to the other image

Sunlight changes as the layers progress from shrub level to emergent. This influences the rate of growth Vegetation type also

changes throughout the layers as the access to sunlight and water changes

Higher rates of decaying at the shrub level

http://www.tropical-rainforest-facts.com/Tropical-Rainforest-Layer-Facts/Tropical-Rainforest-Layer-Facts.shtml

Within many natural environments and ecosystems, adaptation is key to the survival of different plants and animals. Within the Amazon rainforest, various different forms of adaptation have taken place to ensure that vegetation survive and thrive for various different reasons Butress roots allow trees to absorb nutrients faster, allowing trees to grow to the heights of 60m+. This is essential in an ecosystem that has poor, thin soils Drip tips Plants grow thick leaves with drip tips and waxy surfaces to allow water to drain quickly to prevent rotting. This also directs rainfall to lower layers of the rainforest, assisting with their growth Lianas are woody vines that start at ground level, and use trees to climb up to the canopy where they spread from tree to tree to get as much light as possible.

Research further to find other examples

Both of these figures are showing the levels of deforestation that is taking place within

the Amazon Rain Forest…what is deforestation?

1. Describe the information shown in both figures

2. Suggest WHY rates of deforestation are increasing

How can the Amazon Rain Forest be managed sustainably?

ECOTOURISM Educates people whilst allowing them to

enjoy the natural environment. It supports conservation, protecting biodiversity

CONSERVATION Responsible for sustainable use of resources. The Government have set up measures and laws to stop people from damaging the environment. The WWF

assist with this too

SELECTIVE LOGGING This limits the number and type of

trees that can be logged – only trees of a certain height and age can be

cut down. Replanting trees in their place helps to maintain levels

CONSERVATION SWAPS HICs have set up agreements

with LICs to reduce their debt if they agree to plant

tress and add to their rainforests

Why are different approaches needed?

Logging -3% of deforestation through logging -Timber companies are interested in the hard expensive woods of mahogany and teak found in the ARF and sell to other countries -Smaller trees are logged and used as fuel

Farming CATTLE

-Large areas are cleared for life stock

rearing -Responsible for 80% of the destruction -Cattle ranches quickly move on as the land loses its fertility CROPS -Clearing is taking place to grow crops such as bananas, palm oil, sugar, tea and coffee -Like the ranches, farmers quickly move on as land loses its fertility

Minerals -The ARF has lots of minerals that developed countries want -Trees are cleared to mine for gold and bauxite (used to make aluminium)

Road building -As the forest is used more, roads are required to transport goods. -With more roads, this makes the forest more accessible so more businesses are encouraged to use it -The Trans-Amazonian Highway is a good example of how the forest has opened up more

Energy Development -Rivers in the ARF have encouraged the building of dams

-HEP is very popular, this requires

flooding parts of the ARF -The flooded areas then rot, further destroying trees

Illegal wildlife trade -Hunting, poaching and trafficking are still big business -The jaguar is an example of one species under threat

HOT ENVIRONMENTS – DESERTS As a starting point, compare and contrast the Amazon Rain Forest and Sahara desert using the images above. Deserts are another example of a global biome but differ from that of a rain forest. Although some aspects and features are similar, their key characteristics are very different. They are defined due to -Lack of rainfall -Extremes in temperature -Adaptation of vegetation to cope

Adaptation

Both plants and animals have had to adapt to conditions within the Sahara desert to ensure that they survive. For both, coping with the weather conditions is the main issue to overcome and be able to cope with. Choose 2 of the images above and explain how they have adapted and how this helps with survival

What are the opportunities within the Sahara desert?

Egypt is a popular tourist destination and the Sahara desert offers various attractions such as camel safaris, camping under the starts and dune quads

The world’s largest solar farm is located in Morocco and makes use of the natural environment to create a sustainable source of energy

Algeria and Libya both have huge oil and gas reserves that would provide an excellent trade source with many other countries

Throughout the Sahara, there are many opportunities to access water below the surface that could be extracted and used for farming purposes

For each of these opportunities, consider the challenge(s) that they

face

How are desert fringes affected?

Over the years, areas found on the fringes of the Sahara desert have started to develop more of the characteristics of a desert. This process is called DESERTIFICATION and is having an increasing affect on people, the economy and the environment. The Sahel region is a prime example of how desertification is having an impact

There are many different human and physical causes for desertification including -Deforestation -Over Population -War -Change in climate pattern -Over grazing -Over farming Question time Explain why desert fringe locations are experiencing increased rates of desertification (6 marks)

Decide if these are human or physical

causes

Using the images above, generate the effects that desertification can have on people, the economy and the environment. Use these to create flow charts to show the further knock-on effects

How can desertification be managed?

A wall of vegetation planted to draw water to the surface

http://www.greatgreenwall.org/great-green-wall/#great-green-wall-internal

The growth of vegetation brings nutrients to the soil, improving the quality of it

This is helping to improve millions of lives of the people that depend on this area