Amazon Tainforest Case Study

Question 1

How big is the Amazon rainforest and how many countries does it span

Answer 1

8 countries in Northern South America

Occupying over 6,000,000km2

It stretches from the Atlantic Ocean (east) to the Andes (West)

The forest widens from 320km front along the Atlantic belt to 1,900 km wide where the lowlands meet the Andean foothills

Question 2

What is the average rainfall in the Amazon rainforest

And what can the northwest portion reach

Answer 2

3000 mm- average

6000mm- northwest portion of

Question 3

Why is the precipitation really high in the Amazon rainforest

Answer 3

Evaporation over the Atlantic Ocean

The warmest temperature near the equator mean evaporation is high in the rainforest itself- further evaporation

Question 4

How much water in the Amazon remain in the ecosystems water cycle

Answer 4

50%-80%

Question 5

Why does 50% of the water in the Amazon rainforest never reach the ground

Answer 5

After precipitation, much rainfall is intercepted by the dense canopy and is converted into stem flow, eventually evaporated back into the atmosphere

Question 6

What is the impact on rivers and surface runoff because if the dense canopy intercepting the water

Answer 6

Less water flows into rivers and slower because of the interception

Also meaning less runoff

Question 7

How does deforestation increase run off and risk of flooding

Answer 7

There is no tree canopy to intercept rainfall- more water reaches the ground

The soil reaches field capacity quickly and water is unable to infiltrate further, as it’s in water surplus

This causes runoff and increase flood risk

Question 8

What is the impact of deforestation on evapotranspirstion and the amount of rainfall and drought

Answer 8

Less trees = less evapotranspirstion

This means less water Vapour reaches the atmosphere, fewer clouds form and rainfall is reduced

Increasing the risk of drought, particularly in the dry season of SSE Amazon

Question 9

What is the effect of deforestation in Rondonia, Brazil in terms of th rainy season

Answer 9

Rodonia is one of the most heavily deforested areas in Brazil

Daily rainfall data suggests that since the 1970s deforestation has caused an 18 day delay in the onset of the rainy season

Question 10

What is the positive feedback look between Amazonia deforestation and wild fires

Answer 10

Increased deforestation and climate change means the soils become drier

More fires in SSE Amazonia which increases atmospheric aerosol loads- burning produces stored biomass carbon into the atmosphere

This causes a decrease in droplet size and increase in cloud height and lifetime which inhibit rainfall, particularly during the dry season in SEE Amazonia

Question 11

How does the deforestation of trees and vegetation transfer the carbon from the soil into the hydrosphere

Answer 11

Deforestation - no roots to hold soil together

Rain washes away nutrient-rich top layer of soil, transferring carbon stored in the soil into the hydrosphere

Negative knock on impact because less nutrient soil means that it limits vegetation growth in the future.

Question 12

How much anthropogenic carbon emissions come from burning the Amazon rainforest

Answer 12

800 million tonnes

Question 13

How much less carbon does disturbed forests, logging and fires, store compared to undisturbed forest

Answer 13

Disturbed forests store 40% less carbon

This makes the impact of tropical forest destruction significant in the carbon cycle

Question 14

How many dams are there in the Amazon and what are they for

Answer 14

150 dams for hydroelectric power

Question 15

What is the power in the Amazon often used for

Answer 15

Mining

Question 16

What are the negative impacts of dams in the Amazon

Answer 16

Displace people and create large flood areas of land which would’ve been forest

They alter the water cycle and trap huge quantities of sediment behind

Question 17

What is the large dam which opened in April 2016 and how much power does it produce

Answer 17

11,000 MW of power

Belo Monte dam

Question 18

What is the impact of replacing forests with crop land and pastureland

Answer 18

Crop and pasture land has a higher albedo and decreased evapotranspirstion and canopy interception compared to the forest they replace

Question 19

How much evapotranspirstion (km3) did the forests in the state of Mato Grossi contribute in 2000

Answer 19

50km3 per year of evapotranspirstion in the year 2000

Question 20

What did deforestation cause in Mato Grosso throughout 2000-2010

Answer 20

The forest flux rage reduces by 1km3 per year

Question 21

What was the contribution of evapotranspirstion in Mato Gross in 2009 and what is the impact

Answer 21

40km3

As a result affecting atmospheric circulation and rainfall.

Question 22

Where is mining in the rainforest most prevalent in countrywise

Answer 22

The Brazilian part

Question 23

What minerals are people mining in the Amazon

Answer 23

Iron, nickel, gold, lead and manganese

Question 24

How much carbon does dead Amazonian trees emit per year, how much if the biomass is dead Amazonian trees and biw much does the rainforest absorb every year

Answer 24

1.9 billion tonnes per year

Dead Amazonian trees account for 20% of total biomass

The rainforest absorbs 2.2 billion tonnes of carbon annually

Question 25

How much has rates net increase of above ground biomass declined by in the last decade compared to the 90s What does this mean for carbon

Answer 25

Net increase of Above ground biomass has declined 1/3 Tropical forests are becoming less efficient at trapping carbon

Question 26

How do forest fires impact the carbon cycle in the Amazonian rainforest

Answer 26

Growing forests remove carbon from the atmosphere Forest fires release carbon stored in trees and soils as co2 and methane negating years of sequestration The release of carbon exacerbates climate change, creating a positive feedback loop where warmer temperatures increase the frequency and intensity of wildfires Therefore affecting the amazons carbon balance

Question 27

How does climate change affect the rivers in the Amazon in terms of rainfall

Answer 27

Less rainfall during dry months mean that there is less nutrient input into streams and rivers, greatly affecting organisms across the food web

Question 28

What is the effects of flooding associated with sea level rise in the Amazon river delta

Answer 28

Over the last 100 years the delta has risen by 1-2.5mm per year, potentially rising to 5mm per year This leads to more frequent and extreme flood events- damaging infrastructure and ecosystems Mangrove ecosystems will also struggle at may drown at the rapid increase in sea level rise The rise will increase pest infection- affecting the economy of rural communities

Question 29

What is the effect of removing trees and depriving the forest of proportions of its canopy in terms of temperature

Answer 29

The canopy blocks the suns ray during the day and holds heat at night Without it there will be more intense temperature swings, harming both plants, animals and causing moist tropical soils to dry out- potentially leading to increased rates of desertification

Question 30

How much carbon is held in tropical soils, how much is held in the top 0.3m What is the effect on this carbon when deforestation occurs

Answer 30

The top meter contains 66.9pgc Top 0.3m - holds 52% of the carbon Much of the carbon is released through burning

Question 31

What occurs to the remainjng carbon in the soil which has been burned or cleared previously

Answer 31

When it rains soil erosion will wash much of the carbon into the rivers and some will be lost to the atmosphere via decomposition

Question 32

What are the impacts of deforestation and climate change for the water cycle in forests

Answer 32

1. Increased soil erosion and weathering or rainforest soils as water acts immediately upon them rather than being intercepted 2. Flash floods occur more frequently as there is less interception and absorption by forest cover 3. Interruption of normal water cycle leads to more droughts- increasing wildfire risk