The Amazon case study

Question 1

Basic facts about the Amazon rainforest:

Answer 1

Basic facts about the Amazon rainforest:
World's largest rainforest and one of the most diverse.
300 billion trees and 15,000 species.
Covers aroun 5.5 million km2
Spread across 9 countries

Question 2

How much of the earth’s carbon does the Amazon store?

Answer 2

1/5 of all the carbon in the planet’s biomass.

Estimated between 80 and 120 billion tons of carbon.

Question 3

Location of the Amazon

Answer 3

South America

Question 4

1-3GtC/year

Answer 4

The carbon sink that the Amazon forms with other rainforest.

Question 5

The carbon sink that the Amazon forms with other rainforest.

Answer 5

1-3GtC/year

Question 6

Give an example of negative feedback involving the Amazon and carbon.

Answer 6

Increased carbon in the atmosphere due to human activity.
Sequestering of increased CO2 concentrations in the atmosphere increases the productivity of tropical rainforests.
Offsets the rising atmospheric levels of CO2

Question 7

A study in 2015 revealed what about the Amazon?

Answer 7

It is losing its capacity to absorb CO2 from the atmosphere.

Peak 1990s - 2 billion tonnes of CO2/year.

Now, this has been havled.

Question 8

What will lead to a surge in the rates of trees dying across the Amazon?

Answer 8

Increase in atmospheric CO2 led to growth spurt for the Amazon’s trees.
Growth stimulation feeds through the system, causing trees to live faster, and so die younger.

Question 9

What is the average discharge of water from the Amazon?

Where does this discharge go?

Answer 9

175 000 m3/s or around 15 per cent of the fresh water entering the oceans each day.

Flows into Atlantic Ocean.

Question 10

Name a tributary of the Amazon.

Answer 10

Rio Negro - second largest river in the world in terms of water flow.

Question 11

What is the average rainfall across the whole Amazon rainfall?

How much never reaches the ground?

Answer 11

2, 300 mm annually.

Up to half of it never reaches the ground.

Question 12

Of the rainfall evapotranspired back into the atmosphere, how much falls again as rain?

Answer 12

48%

Question 13

How much rainfall actually reaches the sea?

What happens to the rest?

Answer 13

30%.

The rest is caught up in the constant closed system loop.

Question 14

Describe the movement of water throughout the Amazon:

Answer 14

Rainfall.
Half intercepted by the canopy and re-evaporated into atmosphere.
Additional water evaporates from the ground and rivers or is released into the atmosphere by transpiration from plant leaves.

Question 15

Deforestation of Amazon

How much per year is deforested?

Answer 15

Deforestation of Amazon
Brazilian Amazon deforested at rate of nearly 20 000 km2 per year.

Area larger than Greece destroyed.

Question 16

Describe the impact of slash and burn techniques on the Amazon.

Answer 16

Reduces retention of humidity in the soil’s top layer down to depth of 1 metre.
Facilitates sudden evaporation of water retained in forest canopy.
Increases albedo (reflectiveness) and temperature.
Reduces porosity of soil, causing faster rainfall drainage, erosion and silting of rivers and lakes.

Question 17

Describe the evaporation of moisture from deforested areas:

Answer 17

Form shallow cumulous clouds which usually do not produce rain.

Question 18

Why does deforestation inhibit cloud formation and reduce rainfall?

Answer 18

Forests emit salts and organic fibres along with water when they transpire.
Act as condensation nuclei and assist in cloud and rain formation.

Question 19

Why has their been a net loss of forest in the Amazon Basin?

Answer 19

Deliberate deforestation and climate change.

Question 20

How can climate change cause a net loss in forests?

Answer 20

Some species limited by tolerance to temperature change, drought and seasonality.
CC can affect species sustainability by directly altering conditions needed to grow and survive.

Question 21

What did a 2009 study conclude about temperature rises and the effects on the amazon?

Answer 21

2°C temperature rise abouve pre-industrial levels would see 20-40% Amazon die off.
4°C rise would kill 85%

Question 22

How much carbon do Amazonian soild contain in comparison to pasturelands?

Answer 22

4-9 kg of carbon in upper 50cm of soil layer, while pasturelands contain only about 1 kg/m2.

Question 23

What happens when forest clearance first occurs?

Answer 23

Soils are exposed to the heacy tropical rainfall.
This rapidly washes away the topsoil and attacks the deep weathered layer below.
Most of the soil is washed into rivers before the forest clearance has caused a reduction in the rainfall.

Question 24

Changes in total precipitation, extreme rainfall events and seasonality may lead to what in river?

Answer 24

Overall reduction in discharge.
Increase in silt washed into rivers - disrupt river transport routes.
Flash flooding
Destroy freshwater ecosystems - remove source of proteina and income to locals
Destroy water supply for Amazonian peoples.

Question 25

How might warming temperatures affect rivers?

Answer 25

Kill of temperature dependent species.
Change in biodiversity of river system by introducing new species and killing others.
Reduce water-dissolved oxygen concentrations, could destory eggs and larvae, which rely on dissolved oxygen for survival.

Question 26

How are people mitigating against effects of environmental change in Amazonia?

Answer 26

Creation of national parks and forest reserves, eg Para Rainforest reserve.
Forest biofuel prouction could compete with ethanol production from sugar cane by 2030.
Refroestation.
Enrichment of degraded forests using native species.

Question 27

What are some National and International agreesments aimed to protect Amazonia against the effects of environmental change?

Answer 27

TARAPOTO process to help achieve harmonious forest development.
Amazon Cooperation Treaty Organisation (ACTO) to help promote harmonious development.