Maintaining the balance

Subsistence agriculture

• Answer the questions in your book

1. What are the two types of subsistence agriculture in the Amazon Rainforest?– Seasonal and shifting cultivation– Varzea is the place where seasonal cultivation occurs

2. How do they maintain the balance with nature?– They allow the area to naturally replenish itself, either in a

one or thirty year cycle

Cycles of the two methods• Draw a cycle for each of the methods• This is an example of the humus fertility cycle– Use it as an example for your cycles of cultivation

Litter falls from vegetation to the ground

The litter decays on the forest floor

Fertility of the humus layer is enhanced

Further Vegetation growth

The ecosystems model – please copy

• Geographers developed the ecosystems model to describe the interaction and interdependence between the elements of the natural environment

Climate

Relief

Vegetation

Soils

The geosystems model– please copy

• They then developed the geosystems model to show how people and the environment work together to generate products useful for people

InputsReliefClimateSoilVegetationPeopleCows

TransformationsDairy Farming

OutputsMilkEffluent

FeedbackMoneyWaste

The ecosystems model – please copy

• This new model reflects Western cultures perceptions of the natural world– The natural environment is there for the use of

people– The extraction of resources provides unlimited

economic growth and consumerism– The balance between the ecosystem and people is

not considered

Another New model• A new model is needed now to reflect the interdependence of all

things in nature• This model can be called the ecolosystem model

– Based on the word ecology it includes the relationship between all things in the natural world

– It assumes to co-existence and interdependence of all its members

Relief

Vegetation Soil

Climate

People

The ecolosystem model – please copy

• This model emphasises that people are simply one part of the natural environment

• The underlying principle is interdependence– A recognition by people that there is and must be

a natural balance of the ecosystem– This recognition allows humans to gain from the

natural environment while the environment is not forever changed

Imbalance and broken cycles

• The Amazon Indians have lived for thousands of years in balance with the natural cycles of the Amazon Basin

• This balance was shattered for the first time with the rubber boom in the 1850s

Boom and Bust• 1839

– Charles Goodyear accidently discovers that rubber mixed with sulphur formed vulcanised rubber, a very versatile product

• 1850s– World demand for rubber exploded– The Amazon was the only place where large

quantities of rubber grew• Rubber barons emerged controlling extraction and

becoming very rich• Indians used as slave labour to harvest rubber form

the wild and often scattered rubber trees– Thousands died

• Trees were often damaged and rarely replaced• 1876

– An English Biologist smuggled 17,000 rubber seeds out of Brazil and they were planted in the British colony of Malaya in plantations• Harvesting was more efficient and easier

• 1910– The Amazon rubber boom collapsed

Boom and Bust

• Which model would you apply to the rubber boom?

• If you applied the ecolosystems model what would have had to change?