🌿 Physical: Tropical Rainforests Flashcards
What is an ecosystem?
A community of plants and animals that interact with each other and their environment.
What is a biome?
A very large scale ecosystem found on a regional scale e.g. tropical rainforests.
What is nutrient recycling?
A set of processes whereby organisms extract minerals necessary for growth from soil or water, before passing them on through the food chain.
What is a biotic factor?
A factor relating to the living parts of an ecosystem.
What is a producer?
An organism that uses solar energy to produce food.
What is a consumer?
An organism that gets its energy by eating other organisms.
What is a decomposer?
An organism that gets its energy from breaking down dead material.
Outline the difference between food chains and webs.
Food webs are more accurate to the complexity of real ecosystems.
Give an example of a producer and consumer in Reigate Heath.
Rabbits eat heather.
Describe an interrelationship in Reigate Heath.
Rabbits eat heather and heather provides shelter for rabbits.
Describe the location and characteristics of tropical rainforests.
Close to the equator. Warm, wet, rich in vegetation and biodiverse.
Describe the distribution and location of tropical rainforests.
- Between tropics
- Mainly in SE Asia, Central Africa and South America (Amazon)
- Covers 8% of Earth’s surface
Describe the climate in tropical rainforests.
- Hot and wet
- Temperature range from 20°-28°
- 2k - 10k mm of rainfall yearly
- Equatorial climate
Describe the soil in tropical rainforests.
- Poor quality due to high acidity
- Mean pH of 4.7
- Poor ability to trap nutrients
- High temp + moisture allow fast decomposition
How does the Global Atmospheric Circulation model lead to tropical rainforests being located at the equator?
Warm air rises as there is low air pressure and then air cools to surrounding temp forming clouds and rainfall. These are perfect conditions for growth, therefore a rainforest develops.
Why is there a rapid transfer of nutrients in tropical rainforests?
Climate conditions. Heavy rainfall washes the nutrients from the soil.
How much of the world’s oxygen is produced by vegetation in tropical rainforests?
28%
Name the 4 layers of the structure of a rainforest starting from the highest.
Emergents –> Canopy –> Understorey –> Ground Layer
What are lianas and how have they adapted to the conditions of tropical rainforests?
A woody climbing vines that don’t have their own roots and climbs trees for sunlight.
What are drip tips and how have they adapted to the conditions of tropical rainforests?
Leaves with a pointed tip that helps heavy rainfall runoff the leaves efficiently without damaging them.
What are buttress roots and how have they adapted to the conditions of tropical rainforests?
Large, wide roots that spread over large areas to maximise nutrient absorption and provide stability to tall trees.
What are poison dart frogs and how have they adapted to the conditions of tropical rainforests?
Poisonous frogs that absorb the toxins from it’s prey to use on predators and have extra strong suction cups on its feet to climb and hold on to slippery branches.
What are three-toed sloths and how have they adapted to the conditions of tropical rainforests?
Mammals with extra vertebrae to be able to turn their neck 270° to check for predators. They can also swim in floods and grow green algae in their fur for camouflage.
What are some socio-economic values of rainforests?
- Rich in resources like wood (doesn’t rot), nuts, cocoa, sugar, fruits + minerals (copper, tin + gold)
- 25% of all medicines come from TRFs 2k+ plants have anti-cancer properties
- Thousands of people live in TRFs: tribe in Peru with 11k+ ppl rely on TRF
- High rainfall creates potential for hydroelectric power for local people
- Can provide employment in industries like tourism
What are some environmental values for rainforests?
- They’re important sources of freshwater, about 20% of the world’s freshwater comes from the Amazon basin
- TRFs contain 50% of the world’s plants + animals, including thousands of different species
- They contribute to 28% of the world’s oxygen and moisture feeds the water cycle, preventing the climate getting too dry
- TRFs are known as a carbon sink as they contribute to most of the world’s natural carbon absorption
What is biodiversity?
A measure of how many different species live in an ecosystem.
Why are minerals returned to the soil quickly?
Hot and moist conditions that speed up decaying plants.
How many different species of plants and animals are in the Amazon in total?
15 million
How many insect species are in 1 hectare of the Amazon?
30,000
What are two threats facing biodiversity?
- Natural events: like drought and lightning. They can cause fires, floods and diseases
- Commercial agriculture: people ‘slash and burn’ the land to create big plantains. They also do unsustainable timber harvesting and road building + mining leading to subsequent water pollution
What happens if biodiversity declines?
- Other species will die that eat them will die
- Some plants and species become extinct
- Important medical plants may become extinct
Why are there changing rates of deforestation?
- Agricultural expansion
- Infrastructure development (roads)
- Logging
- Mineral extraction
- Population growth
What is logging?
The process of cutting, processing and moving trees to a location for transport.
What are the causes for deforestation in the amazon?
- Logging
- Mineral Extraction
- Energy development
- Farming (cattle ranching)
- Crop Farming + Road Building
- Population Growth
Explain logging as a cause of deforestation in the Amazon Rainforest.
It accounts for only 3% of deforestation, however deforestation must occur before the other land uses occur. Logging companies are mainly only interested in high value timber like mahogany (doesn’t rot)
Explain mineral extraction as a cause of deforestation in the Amazon Rainforest.
The main type of mining in the Amazon is for gold. In 1999, 10k hectares of land were used for mining, however this increased to 50k Ha in 2016. Mining means clear felling and it’s illegal.
Explain energy development as a cause of deforestation in the Amazon Rainforest.
An unlimited supply of water has led to HEP stations. Constructing dams and reservoirs involves flooding vast areas of RF. Over time, the submerged forest causes the water to become acidic as it rots which can cause the turbines to corrode.
Explain cattle ranching as a cause of deforestation in the Amazon Rainforest.
This is the leading cause of deforestation in the Brazilian Amazon. Deforestation leads to the destruction of the nutrient cycle, which means the land can only sustain herds for short periods of time, meaning they have to cut more trees.
Explain crop farming as a cause of deforestation in the Amazon Rainforest.
Crops like oil, pineapple and sugar cane are grown. The land can only be sustained for short periods and leads to more deforestation.
Explain road building as a cause of deforestation in the Amazon Rainforest.
Roads are required to access the RF for heavy transport. Once roads are built, it leads for more people to access the RF + more deforestation.
What are the impacts of deforestation?
- Local Climate Change
- Soil erosion and fertility
- River pollution
- Decline of indigenous
- Climate change
- Biodiversity loss
Explain soil erosion and fertility as an impact of deforestation in the Amazon Rainforest.
The top layer of soil will keep getting removed as it is exposed which leads to lack of nutrients plants need to survive and therefore biodiversity would decrease detrimentally.
Explain river pollution as an impact of deforestation in the Amazon Rainforest.
Gold mining uses mercury which leaks and means river pollution that kills marine life.
Explain decline of indigenous tribes as an impact of deforestation in the Amazon Rainforest.
Most tribes won’t know how to survive without their normal way of living which leads to the decay of culture and death of indigenous tribes.
Explain climate change as an impact of deforestation in the Amazon Rainforest.
The removal of the worlds carbon sink and the CO2 stored will all be released back into the atmosphere, adding to the enhanced greenhouse effect.
Explain biodiversity loss as an impact of deforestation in the Amazon Rainforest.
Destroys the rainforests species’ habitats meaning some species could be extinct.
What are the strategies used to manage rainforest sustainability?
- Selective logging
- Agroforestry
- Replanting
- 2006 International Tropical Timber Agreement
- Debt Reduction
- Ecotourism
- Education and conservation
What is selective logging and how does it manage rainforest sustainability?
Only felling full grown trees, so younger trees can be allowed to mature and provide protection from soil erosion. Trees will not be felled until they are at least 30 years old. In addition, regional governments are clamping down to stop illegal logging
What is agroforestry and how does it manage rainforest sustainability?
Growing crops and trees together which reduces the need for felling trees for new land.
What is replanting and how does it manage rainforest sustainability?
Recreates forest cover that has been lost by collecting seeds and growing them into saplings, once they’re strong enough they’re replanted back.
What is the 2006 international tropic timber agreement and how does it manage rainforest sustainability?
Restricts trade in TRF hardwoods, making it difficult to sell and make money from them. Only trees that have been registered by the government can be cut and sold.
What is debt reduction and how does it manage rainforest sustainability?
Usually located in developing nations with large debts linked to loans and overseas aid. In order to combat this some countries arrange ‘debt for nature swaps’ such as the scheme in place between USA and Brazil. The USA allowed Brazil to convert the £13.5mil it owed in debt repayments into a fund to protect large areas of the Amazon rainforest
What is ecotourism and how does it manage rainforest sustainability?
Many countries with TRFs like Brazil, Costa Rica and Belize have promoted their forests for ecotourism, with scenery, wildlife, remoteness and culture being the main attractions. The purpose is to educate visitors to about understanding wildlife and cultures. The money generated is invested back into conservation projects.
What is education and conservation and how does it manage rainforest sustainability?
Supported by NGOs which rely on dedicated volunteers and fundraising to finance important projects, such as Greenpeace, the WWF and Birdlife International - they write education programmes which include schemes of work, resource packs and classroom videos
