The Amazon - W&C

Question 1

Where are tropical rainforests found

Answer 1

In a band between the tropics and cover parts of South Americs, Central Africa and south-east Asia. A smaller area exists in North-eastern Australia

Question 2

Where does the Amazon rainforest lay

Answer 2

Mostly Within Brazil, with the remainder mainly in Peru and Columbia

Question 3

How big is the Amazon rainforest

Answer 3

The largest rainforest and covers 2.1 million square miles

Question 4

What percentage of the earths surface do tropical rainforests cover

Answer 4

6%

Question 5

What percentage of global photosynthesis do tropical rainforests account for

Answer 5

30-50%

Question 6

How much of the worlds oxygen do tropical rainforests emit

Answer 6

28%

Question 7

What is the annual rainfall in rainforests

Answer 7

2000+mm

Question 8

What is the average temperature in tropical rainforests

Answer 8

27*C

Question 9

What do the characteristics of tropical rainforests make ideal conditions for

Answer 9

Plant growth

Question 10

What do rainforests have

Answer 10

A very high biodiversity

Question 11

What percentage of the worlds species of plants and animals are tropical rainforests home to

Answer 11

50%

Question 12

Why are inputs to the water cycle of a rainforest high

Answer 12

Because precipitation is very high, occurring throughout the year and usually in daily torrential downpours. It is a consequence of low pressure and high humidity in the tropics.

Question 13

How much precipitation does the dense canopy of the rainforest intersect

Answer 13

75%

Question 14

What happens to the intercepted water

Answer 14

Some is evaporated and some reached the ground via stem flow or drips from leaves.

Question 15

How much of the available rainwater is used by plants and returned to the atmosphere by evapotranspiration

Answer 15

50%

Question 16

How much of the available rainwater is infiltrated into the soil

Answer 16

50%

Question 17

What is critical to the regions water supply

Answer 17

Trees of the forest as, through the process of transpiration, trees ensure water enters the atmosphere and in turn produces rain.

Question 18

What fraction of its own precipitation does the Amazon Basin produce in the recycling of evapotranspiration

Answer 18

1/3, the other 2/3 arrive as moisture-laden air from the Atlantic Ocean

Question 19

How do raindrops from tropical storms cause soil erosion

Answer 19

They hit the ground with great force

Question 20

What does a continuous canopy prevent

Answer 20

Soil erosion because the canopy acts as an umbrella so water is transferred through stem flow so have less force than just rain hitting the ground

Question 21

How is rain water transferred to the forest floor

Answer 21

By a combination of drip flow and stem flow. Drip-tips help the tree to shed water from each leaf, and the rest trickles down branches and stems

Question 22

What do most rainforests plants have

Answer 22

Very shallow roots that take rainwater and dissolved nutrients directly from the decomposing leaf litter

Question 23

What is the estimated loss of the Amazon basin in the last 50 years

Answer 23

17%

Question 24

What is the primary reason the Amazon basin has lost 17% of its primary rainforest

Answer 24

Cattle ranching (80%)

Question 25

When is the impact of cattle ranching mostly seen

Answer 25

In the east and south-east parts of the basin (Brazil) and in the north-western arc (Columbia and Ecuador)

Question 26

How does the removal of trees have a massive impact on the rainforest water cycle

Answer 26

It almost wipes out some of the components and significantly affecting others

Question 27

What does reduced evapotranspiration from cleared areas mean

Answer 27

The air is less moist, resulting in a reduction in cloud cover and less pricks prion.

Question 28

With fewer trees, what happens to the rainfall

Answer 28

Most rainfall reaches the frond immediately as there is little compacting it. The water leaves the area as overland flow so less is returned to the atmosphere locally. The increased rates of runoff increase the risk of flooding.

Question 29

In cleared areas, why does temperature increase

Answer 29

Becsuse more solar radiation is reflected by cleared land (than the darker forest canopy)

Question 30

What limits the chance of regrowth if the forest has been cleared

Answer 30

Exposed soil is at risk of erosion

Question 31

In a fully forested area, what usually happens to rainfall

Answer 31

It is recycled within the local region

Question 32

What are the effects some studies have shown about the replacement of forests by pasture or crops

Answer 32

It leads to a reduced atmospheric humidity and suppressing precipitation. This is because rainforests allow a considerable amount of water to be returned to the atmosphere through evapotranspiration. However, other studies have shown an increase in local rainfall downwind of a deforested area.

Question 33

What has a recent study suggested that rainfall levels in the wider region are likely to do where there is extensive deforestation

Answer 33

Reduce

Question 34

What have some studies found about the changing patterns of rainfall

Answer 34

air that has passed over extensive forest produces twice as much run compared to air that has passed over little forest. The study estimates that future deforestation of the Amazon rainforest could lead to a 20% decline in regional rainfall.

Question 35

At a local level, why have some cleared areas experienced an increase in rainfall

Answer 35

Due to 'vegetation breezes'

Question 36

What are vegetation breezes

Answer 36

Air over cleared land warms faster, rises quicker and creates localised low pressure, drawing moist air from forested areas. The result is an increase in cloud coverage, thunderstorms and rainfall over the cleared , at the expense of forested areas.

Question 37

Why is there less rain in places that have been deliberately burned to clear for agriculture

Answer 37

The burning produces airborne aerosols around which water vapour condense. As a result, smaller droplets occur in clouds, which are too small to precipitate, resulting in less rain

Question 38

Why do tropical rainforests account for between 30-50% or global photosynthesis

Answer 38

Because the warm, humid tropical climate is ideal for plant growth

Question 39

Why are tropical forests sometimes called the 'Lungs of the Earth'

Answer 39

Becsuse the forest absorbs huge amounts of carbon from the atmosphere and emit a great deal of oxygen

Question 40

What percentage of wood is carbon

Answer 40

50%

Question 41

Rainforests are carbon sinks, why is this good

Answer 41

They help mitigate the effects of climate change

Question 42

In a typical year, how much carbon dioxide does the Amazon rainforest absorb

Answer 42

2.2 billion tonnes

Question 43

In a typical year, how much carbon dioxide does the Amazon rainforest emit through decomposition and organism respiration

Answer 43

1.9 billion tonnes

Question 44

What can be the outputs of carbon in a rainforest

Answer 44

Decomposition Organism respiration Soil removed by streams

Question 45

What do rainforests store more of than any other type of ecosystem

Answer 45

Carbon (as sugar and starches)

Question 46

What percentage of the terrestrial biomass is though to be stored in rainforests

Answer 46

40-50% , which has been estimated as more than 17 kilograms of carbon per square metre

Question 47

How much carbon does the Amazon rainforest contain per square meter

Answer 47

Between 14 and 40 kilograms , the soil lying under rainforests also contain substantial amounts of carbon

Question 48

Where does soil contains its carbon

Answer 48

In roots, microorganisms, soil fungus and plants

Question 49

What percentage of global soil carbon is stored in the Amazon

Answer 49

27%

Question 50

What percentage of all carbon in tropical rainforests is found in below ground root systems and soil organic matter

Answer 50

40%

Question 51

How much carbon in the upper 50 centimetres of the soil level does Amazonian soil confirm

Answer 51

Four to nine kilograms

Question 52

How much carbon in the upper 50 centimetres of the soil level does pastureland soil confirm

Answer 52

One kilogram

Question 53

Why are tropical rainforests capacity to recycle the worlds increasing carbon dioxide emissions beginning to appear in doubt

Answer 53

As human activity alters their extent and dominant processes

Question 54

What is the second largest anthropogenic source of carbon dioxide to the atmosphere

Answer 54

Deforestation

Question 55

Of global carbon emissions, what percentage does deforestation in tropical rainforests create

Answer 55

6%-17%

Question 56

When forests are cleared and burned, whether for farming, mining, rocks or settlements, what percentage of carbon is lost to the atmosphere

Answer 56

30-60%

Question 57

What happens to unburned vegetation

Answer 57

It decays and is lost within 10 years

Question 58

At what rate has the size of the Amazon been decreasing per year since 2000

Answer 58

0.3%

Question 59

What are the pros and cons of burning

Answer 59

It is cheap and effective but can burn out of control for weeks

Question 60

Why does deforestation mean that photosynthesis rates drop

Answer 60

Because there is less vegetation, especially if it is brunt as it will only start again once new plants start to colonise the area

Question 61

Due to deforestation, what does plant and animal respiration drop to

Answer 61

Almost zero

Question 62

Due to deforestation, what happens to de composers

Answer 62

They become largely absent from the environment

Question 63

Due to the slash and burn technique, what increases the carbon content in the soil

Answer 63

Becsuse the rain will wash the ash into the ground so that, in the short term, the carbon content increases

Question 64

In the past (1990) how much carbon dioxide did the Amazon absorb

Answer 64

2.2 billion tons

Question 65

In the Amazon, what is declining

Answer 65

Its capacity to operate as a major carbon sink

Question 66

In 2015, how much carbon dioxide did the Amazon absorb

Answer 66

1 billion

Question 67

Why does the Amazon basin no longer represent a continental carbon sink

Answer 67

Because the recent absorption of carbon is less than the total co2 emitted by Latin America counties each year

Question 68

What is the reason for the decline of carbon capture in the Amazon thought to relate to

Answer 68

Substantial tree death within the Amazon basin - it has been assumed that increased atmospheric carbon dioxide levels would stimulate biomass growth (carbon fertilisation) and regulate the emission rise. However it appears that while rainforest plants do grow faster, they die sooner. This has increased metabolic stress that has been compounded but recurrent drought, unusually high temperatures, continued illegal logging and conversion to agriculture.

Question 69

What does it appear the rainforest is under threat from

Answer 69

Both direct human activity and climate change arising from indirect action in releasing stored hydrocarbons in such massive quantities