Ecosystems - Tropical Rainforests Flashcards
Climate
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
Plants
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)
Soil
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
People
Many native people have adapted to life in the rainforest
They make a living by hunting, fishing, gathering nuts and berries + growing vegetables
Animals
Rainforest ecosystems are believed to contain the most animal species
e.g Gorillas, jaguars, anacondas, tree frogs, sloths, monkeys
Biodiversity
The variety of organisms living in a particular area - plants + animals
Biodiversity in the Rainforest
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
Interdependent ecosystem
All components depend on each other
Nutrients cycle
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
Symbiotic relationship
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
Plant adaptations
Adapted to:
- high rainfall
- high temperatures
- competition for light
Adaptations - Trees
Compete for sunlight by growing tall
Smooth, thin bark → helps water run off
Tree trunks are supported by large stable buttress roots
Adaptations - Plants
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
Adaptations - Animals
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
The Amazon
Largest rainforest on earth → covers 8 million square km including:
- Brazil
- Peru
- Columbia
- Venezuela
- Ecuador
- Bolivia
- Guyana
- Suriname
- French Guiana
Deforestation in the Amazon - Commercial farming
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
Deforestation in the Amazon - Subsistence farming
Small scale farmers need the land to grow food for themselves
Deforestation in the Amazon - Commercial logging
Amazon full of hard wood trees (mahogany) → makes logging tempting for businesses
Deforestation in the Amazon - Mineral extraction
Gold, iron, copper are mined + exported → boost countries development
Deforestation in the Amazon - Energy development
Building hydroelectric dams → floods large areas
Deforestation in the Amazon - Population growth
Population growth + migration puts pressure on the Amazon rainforest → Brazilian government offers land to poor from overcrowded cities
Deforestation in the Amazon - Road building
4000km Trans-Amazonian highway connects Brazilian coast to Peru, Columbia + Ecuador through the Amazon → destroying more forest
Deforestation in the Amazon - Environmental impacts
- 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
Deforestation in the Amazon - Economic impacts
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
Sustainable management - Replanting
New trees are planted → matching the types that were cut down
Some laws make logging companies replant trees that they have cleared
Sustainable management - Selective logging
Only some trees are felled → to maintain overall forest structure + make sure the soil isn’t exposed
Least damaging forms - horse logging, helicopter logging
Sustainable management - Ecotourism
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
Sustainable management - Education
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
Sustainable management - Conservation
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
Sustainable management - Reducing debt
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
Sustainable management - International hardwood agreement
Prevent illegal logging + promote use of hard wood from sustainable managed forests
