ET3 - Ecosystem functioning

Question 1

% of Carbon emissions buffered by oceans and vegetation

Answer 1

• Since 1955 >90% excess heat from GHG stored in oceans.

- Forests exchange 45% atmospheric CO2 per year and draw down 1/5 of atmospheric CO2.

Question 2

Flood defences of trees

Answer 2

• 100m x 1m block of mangrove reduces tsunami damage by 90%.

- 10,000 trees retain 35 million L of water.

Question 3

Cultural value of green space

Answer 3

Access to adequate greenspace could save NHS up to £2billion per year.

Question 4

Forests and water cycle

Answer 4

• Business as usual deforestation of Amazon 3–>6 month dry season by 2050.
• Tropical rainforests regulate 1/3 worlds rainfall.

Question 5

Soil loss

Answer 5

75 billion tonnes of soil lost per year, up to 40x faster than soil formation.

Question 6

Role of pollinators in agriculture

Answer 6

~35% global food supply is dependent on animal pollinators.

“insect apocalypse, 40% of all insect species are in decline”

Question 7

Ecosystem services

Answer 7

Provisioning
Cultural
Regulating
Supporting

Question 8

Effects of yellow crazy ants on Christmas island

Answer 8

20-25% of red land crabs wiped out by YCAs.
YCAs farm scale insects –> fungi.
Formation of dense understorey.