Tropical Rainforests Flashcards
What is a tropical rainforest?
A warm, wet ecosystem located within the Tropics
What are some examples of rainforests?
Amazon rainforest, South America
Congolian rainforests, Central Africa
Daintree rainforest, Australia
What is rainfall like in tropical rainforests?
- Extremely high rainfall
- Usually seasonal, with a distinct wet season
- Very humid due to precipitation levels
What is temperature like in rainforests?
- High, at around 26-27c
- Temperatures stay consistent
- This is due to sun shining directly on Equator throughout the year
What are tropical rainforest soil characteristics?
- extremely nutrient deprived and infertile
Why are rainforest soils the way they are?
- Nutrients are washed away and dissolved are very quickly by intense rainfall- leaching
- this leaves an infertile, iron-rich soil called a latosol
What is the nutrient cycle like?
- Very quick
- This means nutrients are transported from vegetation, to soils, and back to vegetation very quickly
What are the 4 layers of the rainforest?
Emergent layer
Canopy
Understory
Forest floor
What lives in the emergent layer?
- Birds and flowers
- Tall, fast growing trees
What lives in the canopy?
Mammals such as sloths and monkeys
What lives in the understory?
Insects, snakes, frogs and other animals
- Some predators, such as jaguars, also hunt in the understory
What lives on the forest floor?
Rodents, larger mammals and decomposers
What are rainforest plant adaptations?
Buttress roots
Leaf structure such as drip tips
Lianas
Epiphytes
What are Buttress roots and how do they help plants?
- Large roots that are above ground
- Grown by trees that have adapted to nutrient deprived, water-logged soils by growing large roots above ground
- They ensure tall trees stay stable, and that roots get enough air
What leaf structures have plants developed and how are they beneficial?
DRIP TIPS
- some leaves have adapted to heavy and consistent rainfall with drip tips
- a tapered end of a leaf that allows excess rainfall to quickly run off a leaf, ensuring plants aren’t left too wet, which can cause rotting
FLEXIBLE STEMS
- many leaves have flexible stems that move to find light
What are Lianas and how are they beneficial for plants?
- Woody vines that have adapted to the dark lower levels
- Lianas have roots that grow in the ground, but their vines grow high up in the canopy by climbing up trees
- This means they can access nutrients on the forest floor but also the light in the canopy
What are epiphytes and how are they beneficial for plants?
- Plants that live on the surface of other plants, receiving their nutrients from them
- Adapted to growing on trees high up in the canopy so they receive more sunlight
What animal adaptations are present in the rainforest?
Poisons and Venoms
Physical Characteristics
Camouflage
Size
How do poisons and venoms help animals to survive?
- Many ants, spiders, frogs and snakes can paralyse or kill other animals, reducing the chances of them being eaten
How do physical characteristics help animals to survive?
- Animals that live in trees have adapted to help them move around and find food
- Primates have long limbs, and long, strong tails
- Some animals have strong claws to help with climbing trees
- Geckos have special ‘pads’ that stick to leaves and trees
How does size help animals?
- Many animals have adapted to be a smaller size so they can move through the undergrowth easily
- Rainforest jaguars are smaller than other types of jaguar
What are some examples of interdependence in the rainforest?
- Hot and humid conditions speeds up decay, which provides nutrients for plant growth
- Plants provide food and shelter for animals
- Traditional agriculture ensures nutrients aren’t depleted from the soil
Biomass store?
- Very large
- This is due to dense vegetation, large trees, and high biodiversity
Fallout?
(e.g dead animals, faeces, leaves)
- Constant, continually adding nutrients to litter store
Litter store?
- Small, because decay is so rapid
- Any litter is quickly decomposed or washed away
Plant uptake?
- Large, as plants grow continuously throughout the year
- Nutrients are transferred from soil to biomass quickly because there are many plants absorbing nutrients, and growth is accelerated by the climate
Nutrient additions?
- High levels of precipitation, adding nutrients that are dissolved in rainwater
- Chemical weathering is greater due to hot, wet conditions, releasing nutrients from rocks into soils
Nutrient removals?
- High rainfall means a lot of litter is washed away
- Heavy rainfall washes water soluble nutrients from the soil in a process known as leaching
How much forest cover has the Amazon rainforest lost in the last 50 years?
17%
Why does deforestation occur?
Land clearing for plantations and cattle ranches
What is subsistence farming?
- Where farmers only produce enough food for themselves and their families to eat, rather than growing surplus food for profit
How do subsistence farmers clear land?
Slash and burn
How does slash and burn clearing work?
- Famers cut down trees and use the wood for building or to sell
- Land is left to dry our
- Shrubbery left behind is burnt to quickly clear the land and release nutrients into the soil
- After a few years of cultivation the land becomes infertile and they move onto a new area
Why is slash and burn clearing no longer sustainable?
- Less land available and people aren’t educated in the farming practice
- Less time is being left for the rainforest to recover
- Poorly controlled fires can lead to wildfires
What is commercial farming?
Farming to make profit
Why is commercial farming so bad for the rainforest?
- Huge areas of land are cleared for plantations
- A lot of the deforestation is done illegally, with little consideration for environmental impacts
What happens in rainforests when gas and oil isn’t available?
Trees are cut down to use for fuel, or to process into charcoal
What is logging?
The process of cutting down trees for wood, which is then sold as timber or processed into other products
What is clear felling / cutting?
A form of logging where all the trees in an area are cut down, including young trees
- This method is more profitable as it can be done more quickly
Why is clear felling bad?
- Habitats completely destroyed
- Vegetation severely disrupted
- Animals displaced
- Leaving land bare exposes soil to heavy rainfall, causing soil erosion
Why can biofuels be bad for rainforests?
- Large areas need to be cleared to grow the crops biofuels are made out of
- Such as palm oil, soy, and sugarcane
How does mineral extraction negatively impact rainforests?
- Large areas of land cleared for roads and mines
- Severen environmental degradation
Why is energy development, such as hydroelectric power, bad for the rainforest?
- Causes deforestation as large areas of land need to be flooded to make reservoirs
- Tropical rainforests are very flat, so a lot more land is flooded than necessary, destroying habitats and displacing indigenous communities
How can changing patterns of precipitation and temperature damage the rainforest?
- Prolonged droughts can dry out the forest floor, killing decomposers and altering the nutrient cycle
- Lack of water can cause dehydrated trees to lose their leaves, creating gaps in the canopy and thus changing behaviour of plants and animals that are adapted to the dark understory
- Droughts canc create forest fire conditions
What is CITES?
- An international agreement adopted by 183 members that work to protect threatened wildlife from exploitation
What do CITES aim to do?
- Regulate international trade of wildlife, and wildlife products
- This is because current trading is unsustainable and threatening endangered species
What species from tropical rainforests are protected by CITES?
- Ring-tailed lemur
- Channel-Billed Toucan
- Lilac-crowned Amazon
What are the advantages of CITES?
- Many countries are part of it, which allows international collaboration
- CITES has had successes in tropical conservation
- Meetings, research and reports spread awareness to country leaders and decision-makers, allowing them to take action
What is REDD?
- A scheme created by the UN that aims to reduce emissions caused as a result of forest degradation by conserving and sustainably managing forests
What are the disadvantages of CITES?
- Each party is in control of their own management and laws against international trade, meaning they could break their own rules with no consequences
- LIC’s may not have the money to implement management strategies, and wildlife trading can often be people’s only reliable income source, making it difficult to ban completely
- The agreement focuses on species, not habitats, and habitat loss is also a major threat to tropical species
What do REDD do?
- Offers financial incentives to developing countries for conserving their forests and offsetting carbon emissions
What is the UN-REDD programme?
- Assists countries in reaching their goals
- E.g by educating farmers and workers on sustainable practices
- Providing resources for small-scale bases and camps to help with monitoring and conservation
What are the advantages of REDD?
- Countries are more likely to take direct action if they get a financial reward
- Their are monitoring, reporting and verification systems in place to ensure that countries are doing what they should
- The UN-REDD programme helps other aspects of tropical rainforests by including communities in conservation efforts, which can also create jobs
What are the disadvantages of REDD?
1.The scheme has been criticised for putting an economic value on forests
- The scheme focuses on LIC’s, which may push the blame for deforestation onto them, when in fact its often developed countries that drive deforestation
- Some argue that the schemes don’t actually reduce emissions, only offset them, which means countries can still technically emit high amounts of greenhouse gases
What are the reasons for falling deforestation rates?
- Forest Protection laws
- Growing urban population means less people rely on income from tropical rainforest activities
- Increasing use of National Park and Reserve status
- Education
What forms of sustainable management are there for tropical rainforests?
Selective logging and replanting
Ecotourism
International agreements
Conservation and education
What is selective logging and how is it sustainable?
- Partial felling of trees in an area
- Usually only mature trees are cut down, and younger trees are left to grow
- Trees are cut to fall away from other trees so as not to damage them, and they are also marked, so that illegal logging can be traced
What is replanting and how is it sustainable?
- Reduces environmental impacts by preventing soil erosion and ensuring carbon dioxide intake is not lost
- After many years, replanted trees can eventually be felled
What is ecotourism and how is it beneficial?
- Eco-tourism is a form of sustainable tourism that aims to have reduced environmental impacts and support conservation efforts
- It can also provide income for indigenous communities and fund conservation efforts
Where is somewhere that eco-tourism take place?
- Chalalan ecolodge in Bolivia
- Ran by an indigenous community and attracts 1600 tourists a year
What is a type of international agreement?
- Debt-for-Nature swaps
- These are agreements where one country cancels part of a debt of another country in return for the owing country agreeing to conserve and protect their environment
What act has allowed many Debt-for-Nature swaps?
Tropical Forest Conservation Act
- The US recently cancelled $30 million of debt owed by Indonesia in agreement that Indonesia would better protect Sumatra island
What are International Agreements also useful for?
- To spread awareness of issues and collaborate with other countries to find solutions
How is conservation and education beneficial?
- Designating protected status to tropical rainforests legally enforces protection by making damaging activities illegal
- National parks and nature reserves are a sustainable way to ensure the protection of nature, and can also encourage tourism, which is economically beneficial, and can be used in further conservation
- Educating consumers and companies on the environmental impacts of rainforest products such as palm oil reduces the demand for them, and encourages brands to use more sustainable products
