2 EQ2 - Amazon Rainforest - Facts and Figures

How large is the Amazon rainforest in km2?

6 million km2

What percentage of water is recycled by evapotranspiration?

50-60%

How much carbon does the Amazon store?

Around 100 billion tonnes

How much carbon does the Amazon absorb each year?

Net absorption is 0.7 billion tonnes

absorption - decomposition = net

Therefore it is a carbon sink.

Since 1970 ____ of the primary forest has been destroyed or degraded

one-fifth

When were the devastating floods and where did they occur?

2014, the Madeira river (tributary of the Amazon River)

What caused the floods?

Human activity modified the drainage basin and therefore shifted the stores and flows of the water cycle. Deforestation reduced water storage in forest trees, soils, permeable rock and in the atmosphere. Total run off and run-off speeds increased rapidly.

Rain runs off the surface so quickly that there is no time for the water to infiltrate into the soil and percolate into the permeable rock below.

How does deforestation affect the water cycle?

The trees in the Amazon are crucial to the water cycle, taking up water from the soil and releasing through evapotranspiration. They also reduce run off through interception and their roots which slow through flow.

Deforestation ==decreases atmospheric humidity== and therefore precipitation declines. There is less conventional rainfall and this becomes a positive feedback loop of decreasing trees and then decreasing rainfall. This can lead to permanent climate change.

Which factors contribute to high NPP?

NPP: net primary productivity

Factors contributing to high rates in the Amazon:

* High temperatures, caused by intense insolation
* High precipitation, mainly caused by conventional rainfall
* Intense sunlight

All of these factors give the Amazon ideal conditions for photosynthesis.

What are the three types of strategies to manage the Amazon rainforest?

* Protection through legislation and law enforcement of primary forest unaffected by commercial developments
* Projects to reforest areas degraded or destroyed by subsistence farming, cattle ranching, logging and mining
* Improving agricultural techniques to make cultivation more sustainable

What percent of the Brazilian Amazon is made up of national parks, or is in some way protected from deforestation?

Around 50%

Give an example of how indigenous people can be involved in sustainable forest management

The indigenous Surui people participate in a scheme where they plant seedlings in deforested areas. The native species of tree are chosen to provide them with timber or food. They can now sell carbon credits to companies who have exceeded their annual carbon emissions quotas.

The Surui scheme is part of the UN’s Reducing Emissions from Deforestation and Forest Degradation (==REDD==) scheme.

How can agricultural techniques be improved?

* Soil fertility can be improved by rotational cropping and combining livestock and plants e.g. growing trees in the same field as cows
* Soil fertility can also be enhanced using human engineered ‘dark soils’ which attract micro-organisms
* Increasing soil fertility means that there is no longer a need to abandon an area once it has become overgrazed and infertile
* Improving the fertility of existing deforested land therefore increases productivity and decreases deforestation