Ecosystems - Tropical Rainforests

Question 1

Climate

Answer 1

No definite seasons

Hot - 20-28 degrees → sun’s energy is more intense near the equator as it is overhead all year round

High rainfall → 2000mm per year

Question 2

Plants

Answer 2

Most trees are evergreen → help take advantage of the continual growing season

Vegetation cover is dense → little light reaches the floor

Epiphytes (plants that grow on other living plants + take nutrients + moisture from the air)

Question 3

Soil

Answer 3

Isn’t fertile → heavy rain washes nutrients away

Surface nutrient due to decayed leaf fall → thin surface as decay is fast in warm, moist conditions

Question 4

People

Answer 4

Many native people have adapted to life in the rainforest

They make a living by hunting, fishing, gathering nuts and berries + growing vegetables

Question 5

Animals

Answer 5

Rainforest ecosystems are believed to contain the most animal species

e.g Gorillas, jaguars, anacondas, tree frogs, sloths, monkeys

Question 6

Biodiversity

Answer 6

The variety of organisms living in a particular area - plants + animals

Question 7

Biodiversity in the Rainforest

Answer 7

High biodiversity → contain approx 50% of the world’s plant, animal and insect species

Climate is constant → Plants and animals don’t have to adapt to changing conditions

Question 8

Interdependent ecosystem

Answer 8

All components depend on each other

Question 9

Nutrients cycle

Answer 9

Warm + wet climate helps fungi + bacteria on the forest floor to decompose dead plant material → surface soil high in nutrients

Plants pass on nutrient when eaten by animals

When animals die nutrients is transferred back to the soil → making it richer

Question 10

Symbiotic relationship

Answer 10

Animals and plant species depend on one another for survival

e.g Agouti (rodents) eat Brazil nuts + bury them which sprout new seedlings → increases population of Brazil nut trees
If agouti became extinct Brazil nut tree population would decline

Question 11

Plant adaptations

Answer 11

Adapted to:

• high rainfall
• high temperatures
• competition for light

Question 12

Adaptations - Trees

Answer 12

Compete for sunlight by growing tall

Smooth, thin bark → helps water run off

Tree trunks are supported by large stable buttress roots

Question 13

Adaptations - Plants

Answer 13

Thick waxy leaves → Repel the rain

Drip tips → Channel rainwater + encouraging runoff so the leaf is not damaged by the weight
→ No standing water for bacteria + fungi to grow

Drop leaves through the year → They can go on growing all year round

Climbing plants (lianas) use tree trunks to reach the light

Under canopy plants have large leaves → to absorb as much light

Question 14

Adaptations - Animals

Answer 14

Animals in the canopy have strong limbs → to move around quickly

Camouflage → Hide from predators

Adapted to low light levels the forest floor → Sharp sense of smell + detect predators

Some are nocturnal → feed at night when cooler - saves energy

Suction cups → helps to climb

Flaps of skin → helps to glide between trees

Question 15

The Amazon

Answer 15

Largest rainforest on earth → covers 8 million square km including:

• Brazil
• Peru
• Columbia
• Venezuela
• Ecuador
• Bolivia
• Guyana
• Suriname
• French Guiana

Question 16

Deforestation in the Amazon - Commercial farming

Answer 16

Forest cleared to make space for cattle grazing + plantations

Cattle ranching is the main source of deforestation → 200 million cattle on 450,000 square km of pasture

Soy, Rice corn + Sugar cane are farmed on former forest land

Question 17

Deforestation in the Amazon - Subsistence farming

Answer 17

Small scale farmers need the land to grow food for themselves

Question 18

Deforestation in the Amazon - Commercial logging

Answer 18

Amazon full of hard wood trees (mahogany) → makes logging tempting for businesses

Question 19

Deforestation in the Amazon - Mineral extraction

Answer 19

Gold, iron, copper are mined + exported → boost countries development

Question 20

Deforestation in the Amazon - Energy development

Answer 20

Building hydroelectric dams → floods large areas

Question 21

Deforestation in the Amazon - Population growth

Answer 21

Population growth + migration puts pressure on the Amazon rainforest → Brazilian government offers land to poor from overcrowded cities

Question 22

Deforestation in the Amazon - Road building

Answer 22

4000km Trans-Amazonian highway connects Brazilian coast to Peru, Columbia + Ecuador through the Amazon → destroying more forest

Question 23

Deforestation in the Amazon - Environmental impacts

Answer 23

• Climate change - 75% of Brazils CO2 emissions come from deforestation
  Fewer trees mean less CO2 is removed from the atmosphere
• Soil Erosion - Brazil is losing 100 tonnes of topsoil per year → lead to landslides and flooding

Less tree canopy to intercept rainfall → more water reaches the soil taking away the nutrients

Farmers are forced to find new areas to farm

Question 24

Deforestation in the Amazon - Economic impacts

Answer 24

Farming has brought wealth → March 2018 Brazil exported $600 million of beef

Mining industry creates jobs → Buenaventura company in Peru employs 8000 people

Logging contributes to Brazils economy BUT reduces attractiveness of the area

Rubber tappers have lost their livelihoods as trees are cut down

Question 25

Sustainable management - Replanting

Answer 25

New trees are planted → matching the types that were cut down

Some laws make logging companies replant trees that they have cleared

Question 26

Sustainable management - Selective logging

Answer 26

Only some trees are felled → to maintain overall forest structure + make sure the soil isn’t exposed

Least damaging forms - horse logging, helicopter logging

Question 27

Sustainable management - Ecotourism

Answer 27

Minimises damage to the environment + benefits locals by providing income

Helps raise awareness of conservation issues

If more people are employed in tourism → don’t have to log or farm to make money → fewer trees are cut down + there is an incentive to conserve the environment

Question 28

Sustainable management - Education

Answer 28

Educating people about the impacts of deforestation encouraged people to buy products from sustainable sources → helps reduce damage

The Rainforest Alliance (Guatemala) teaches communities about sustainable livelihoods

Question 29

Sustainable management - Conservation

Answer 29

Countries have set up national parks + nature reserves within rainforest → prevents illegal logging

Countries have set up funds which overseas governments can invest in → countries get money in exchange for rainforest conservation → money is used to enforce restrictions

2018 Norway payed $70 million to Brazils Amazon fund to be used for conservation

Question 30

Sustainable management - Reducing debt

Answer 30

Countries don’t have to log, farm + mine the rainforest to make money + pay back the debt → rainforest is conserved

Conservation swap → part of a country’s debt is payed off in exchange for guarantee that the money is spent on conservation

2019 USA reduced Indonesia’s debt by $29 million in exchange fro conserving the rainforest

Question 31

Sustainable management - International hardwood agreement

Answer 31

Prevent illegal logging + promote use of hard wood from sustainable managed forests