Tropical rainforests Flashcards
Define ecosystem
A community of plants that interact with one another and their physical environment
What are the two types of components in an ecosystem and give examples of each?
Biotic - plants, animals etc
Abiotic - climate, water soils
What example of a small scale UK ecosystem should you use?
Reigate Heath, Surrey
Describe the producers in your chosen small scale UK ecosystem
Heather - plant that thrives in acidic, nutrient-poor soils, providing food and habitat for many species
Gorse - Offers shelter for insects and birds
Describe the primary consumers in your chosen small scale UK ecosystem
Primary consumers - Rabbits and Silver-studded blue butterflies. Herbivores which feed directly on producers
Describe the secondary consumers in your chosen small scale UK ecosystem
Dartford warbler bird - Feeds on insects
Weasel, a small mammal - Preys on rabbits and rodents
Describe the tertiary consumers in your chosen small scale UK ecosystem
Birds of prey such as the kestrel, hunting small mammals (weasel) and birds
Describe the decomposers in your chosen small scale UK ecosystem
Fungi - Decompose leaf litter and dead wood and release nutrients back into the soil
Detritivores such as beetles and worms - feed on decomposing plant and animal matter
Describe a food chain in your chosen small scale UK ecosystem
Heather –> Rabbit –> Weasel –> Kestrel
Describe a few of the interrelationships in your chosen small scale UK ecosystem
Heather serves as food as well as shelter for insects and small mammals
Gorse offers nesting sites for the Dartford warbler
Decomposers ensure that nutrients are recycled, maintaining soil fertility and supporting plant growth.
Describe nutrient cycling in your chosen small scale UK ecosystem
Photosynthesis - Plants convert sunlight into energy, producing biomass
Herbivores - consume plant matter, transferring energy up the food chain
Decomposition - Dead plants and animals are broken down by decomposers returning nutrients like nitrogen and phosphorus to the soil
Soil enrichment - Decomposed organic matter enriches the soil, promoting plant growth and continuing the cycle.
What are the two inputs for nutrient cycling?
Rainwater - contains dissolved micro-nutrients
Weathering of rocks - releases chemicals into the soil
What are the 3 nutrient stores in a nutrient cycle and describe each one?
Biomass - Nutrients held within animals and plants
Litter - Dead material (previous biomass)
Soil - Nutrients held within the soil
What is the nutrient transfer between soil and biomass?
Plant roots take up nutrients from the soil
What is the nutrient transfer between biomass and litter?
Fallout as tissues die. Either dead plant or animal matter.
What is the nutrient transfer between litter and soil?
Released into the soil as litter decomposes
What are the (wasted) outputs of a nutrient cycle?
Output from soil store, loss by leaching due to rainfall
Output from litter, loss in runoff
Describe how climate change and extreme weather events (heatwaves and drought) can affect a pond ecosystem
Can affect water levels
Low water levels will cause stress to organisms, causing them to die
Describe how the introduction of an alien species would affect an ecosystem
If predatory species introduced, food supply reduced for organisms further up the food chain.
Describe the location and characteristics of coniferous forests
60 degrees north
Cold, dark winters, quite warm summers
Describe the location and characteristics of deciduous forest
50 degrees north
Trees shed their leaves in winter to retain moisture
Moderate climate, mild and moist conditions
Describe the location and characteristics of desert ecosystem
30 degrees north and south of equator
Arid conditions. Hot in daytime, cool at night.
Describe the location and characteristics of Mediterranean ecosystem
40-45 degrees north of equator
Hot, dry summers, wet, mild winters
Describe the location and characteristics of polar/tundra ecosystem
Arctic and Antarctic (polar)
High latitudes such as Canada and Siberia (tundra)
Polar - extremely cold
Tundra - cold winters, warm brief summers
Limited precipitation
Describe the location and characteristics of temperate grassland ecosystems
30-40 degrees north and south of the equator in continental interiors
Hot summers, cold winters, low rainfall
Describe the location and characteristics of tropical rainforest
Close to the equator, widespread across Asia, Africa, South America
Heavy rainfall, high temperatures
Describe the location and characteristics of tropical grassland (savanna)
15 - 30 degrees north and south of the equator
Distinct wet and dry seasons
Fires are common during dry season
What factors influence the location of biomes?
Climate
Warm and cold ocean currents
Describe the location of TRFs
Found in a broad belt close to the equator.
Describe the climate of TRFs and what effect does it have on vegetation
Equatorial climate
High temperatures (27oc) throughout the year and high rainfall (2000 mm per year)
Perfect growing conditions for vegetation .
Describe the soil of TRFs
Not very fertile. Nutrients are concentrated in upper topsoil and are quickly taken up by plants as they grow.
Intense leaching removes nutrients from the topsoil and redeposits them further down
Describe water in TRFs
Experience a distinct wet season with high rainfall that lasts for many months. During the wet season, there is excess water on the ground, swelling local rivers and causing flooding. Water will soak into the soil, dissolving and transporting away nutrients (leaching)
Describe plants and animals in TRFs
Highest level of biodiversity in the world due to large range of habitats available. TRFs contain 50% of the world’s plants and animals.
Describe people in the TRF
Traditional tribes living in TRFs live in harmony with the natural environment, hunting and gathering only what they need to survive (sustainable system). People are chopping down trees for timber or clearing room for ranching and commercial gain. Reduces biodiversity as habitats are destroyed.
Why is the TRF interdependent?
Fragile environment - easily damaged by people’s activities so needs to rely on its components parts
Describe the biomass store in nutrient cycle of the TRF
Stores the vast majority of nutrients (mostly trees)
Describe the litter store in the nutrient cycle of the TRF
Few nutrients in the litter store. Decomposers thrive in warm, wet conditions so litter is broken down very quickly.
Describe the soil store in the nutrient cycle of the TRF
Contains few nutrients because:
- any nutrients released by decomposers (litter) are quickly absorbed by trees or plants
- Nutrients are leached into soil by heavy rainfall/carried away
How fast is the transfer between nutrients in the TRF and why?
Rapid transfer of nutrients due to climatic conditions. Warm, moist conditions promote chemical weathering.
Explain how plants in TRF have adapted to heat and humidity
Drip tips and waxy leaves - Allow water to run off them easily.
Can cope with large amounts of water falling on them
Passing water to the soil or returning it to the atmosphere acts as a cooling system as water circulates.
Describe how plants in the TRF have adapted to competition for sunlight
Most sunlight is received by emergent trees and least sunlight by the vegetation on the forest floor.
In the lowest two layers plants rely on the soil or other methods for their food supply instead of photosynthesis.
Liana plants attach themselves to a host tree and share its supply of nutrients. They also climb up trees so their leaves can grow in the canopy and receive sunlight.m
Using specific plant examples, describe how plants have adapted in TRF
Drip tips and waxy leaves - Allow water to run off plants easily so it is passed to the soil or atmosphere instead of weighing down the leaf. Also acts as cooling system. Also prevents soil erosion as water is let down more gently to the soil.
Lianas - Attach themselves to a host tree and share food and water. Leaves also climb up other trees to reach canopy layer to receive sunlight.
Buttress roots - Stabilises trees in canopy layer and spread wide to absorb the limited nutrients present in the soil
Name the 4 layers of TRF, from top to bottom
Emergent layer
Canopy
Under-canopy
Shrub layer
Describe how animals have adapted to competition for food in TRF
Some animals live off a specific plant/animal that few others eat. Parrots have developed strong beaks to crack open hard nuts.
Using specific animal examples, describe how animals have adapted in TRF
Poison dart frog - Bright colours warn predators to leave them along. If they eat poisonous insects, they absorb the toxins in their mucus, protecting them from predators due to high biodiversity. Suction cups on feet to climb and hold slippery branches
Three-toed frog - Green algae in fur to camouflage. Long claws, enabling them to climb tress, away from forest-floor predators. Extra vertebrae to be able to turn neck 270o to check for predators.
Why is TRF so biodiverse?
Wet, warm climate encourages plant growth, providing habitats for many animals.
Rapid recycling of nutrients speeds up plant growth and provides food for consumers.
Many parts of TRF are untouched by people, allowing plants and animals to thrive
Stats about deforestation in the Amazon Rainforest
Since 1970, 20% of the Amazon Rainforest has been cleared.
Over half of the remaining rainforest in Brazil is now protected from deforestation
Case study used for TRF?
Amazon Rainforest
Describe subsistence farming as a cause for deforestation in the Amazon rainforest
Indigenous rainforest tribes practice subsistence farming. This usually does little lasting damage to the forest.
Describe commercial farming as a cause for deforestation in the Amazon rainforest
In Brazil, cattle ranching accounts for 80% of deforestation. Large areas are cleared for livestock rearing. However, quality of pasture quickly declines and cattle farmers have to move on, destroying more of the rainforest to clear space.
Cultivation of soy bean - amount of rainforest cleared for this crop doubled between 1990 and 2010. Soil won’t sustain crop for long so more land has to be cleared.
Describe logging as a cause for deforestation in the Amazon rainforest
Mahogany and teak is cut down to be sold and made into furniture. Selective logging is often used so that only the required tree is cut down.
Describe road building as a cause for deforestation in the Amazon rainforest
Trans-Amazonian highway stretches for 4000km through the rainforest, bringing supplies and providing access to settlements, mining areas and energy projects.
Describe mineral extraction as a cause for deforestation in the Amazon rainforest
Gold is mined extensively, with 50,000 hectares being used for it. Rainforest is clear-felled to make room for the mines. Carajas mine is the largest iron ore mine in the world.
Describe energy development as a cause for deforestation in the Amazon rainforest
High rainfall creates ideal conditions for HEP. Bele Monte dam blocks Xingu River (tributary of Amazon), flooding 40,500 hectares of forest.
Describe settlement and population growth as a cause for deforestation in the Amazon rainforest
Knock-on effect of other factors as workers are required for farming and mining and by extension, their families need homes and services.
Describe economic development as an positive impact of deforestation
Positive: Mining and commercial farming generates employment and income for the government. Taxes paid can be used to improve education and hospitals.
Products of commercial farming (rubber) provides raw materials for processing industries which increases value of products.
HEP is cheap and renewable, boosting industrial development as it is cheaper to use energy.
Improved infrastructure (roads etc) opens up new areas for economic development and settlement.
Describe economic development as a negative impact of deforestation
Long-term, it is a negative impact
Forest ecosystem are destroyed, land and rivers become polluted. Cost of repairing damage is high.
Loss of biodiversity may reduce tourism
Describe soil erosion as a negative impact of deforestation
Once land is exposed by deforestation, soil becomes more vulnerable to torrential tropical rain. Without roots to bind it together, loose soil can be easily eroded and washed away
Describe climate change as a negative impact of deforestation on a local scale
Deforestation disrupts the water cycle as felling trees reduces the return of moisture to the atmosphere. Local climate becomes drier. High levels of evaporation from leaves cools the air, when trees are cut down the air becomes warmer. Combination of increasing dryness and rising temperatures affects activities such as agriculture
Describe climate change as a negative impact of deforestation on a global scale
Trees act as ‘sinks’ for carbon dioxide as they absorb it during photosynthesis. When trees are cut down, carbon dioxide isn’t removed from the atmosphere. When trees are burned (during slash and burn), carbon is released back into the atmosphere, enhancing the greenhouse effect and contributing towards global warming.
What are the 5 values of TRF to people
Resources
Medicine
Indigenous tribes
Energy
Employment
Describe how TRF resources are valuable to people
Rich in reserves of wood, nuts, fruit, minerals. Everyday items such as bananas and sugar come from TRF
Describe how medicine from TRF is valuable to people (mainly stats)
25% of all medicines come from rainforest plants. 2000 plants have anti-cancer properties. Only 1% of rainforest plants have been tested for medicinal properties.
Describe how TRFs are valuable to indigenous tribes
Brazil’s TRF is home to 1 million indigenous people.
Achuar tribe in Peru, 11,000 people, live in small communities, relying on TRF for food, building materials and fuel
Describe the value of TRF in terms of energy for people
High rainfall creates opportunities for HEP, providing much-needed light and power for local people. Local micro-hydro schemes can serve isolated communities.
Describe the value of TRF in generating employment for people
Provides employment opportunities in tourism (guides, stewards), construction, farming, mining.
Describe the value of TRF in terms of water for the environment
20% of world’s freshwater comes from the Amazon Basin. Important source of freshwater.
Describe the value of TRF in terms of biodiversity for the environment
Tropical rainforests contain 50% of world’s plants and animals yet only cover 6% of the earth’s surface.
Describe the value of TRF in terms of maintaining the climate for the environment
Known as the ‘lungs’ of the world. Rainforests contribute to 28% of world’s oxygen. Moisture emitted via transpiration feeds into the water cycle, preventing the climate from becoming too dry and hot. Evaporation of water from rainforests helps to cool the air.
Describe the value of TRF in offsetting climate change for the environment
TRF absorb carbon dioxide (an important greenhouse gas) from the atmosphere, acting as a ‘carbon sink’, helping to offset global warming.
Describe the value of TRF in preventing soil erosion
Rainforests shelter and bind together the tropical soils, preventing harmful soil erosion, which can silt up rivers and reservoirs. Canopy of leaves intercept rain before it hits the ground, with drip and stem flow preventing rain from hitting the soil with force.
What are the 5 values of TRF to the environment
Water
Biodiversity
Climate
Climate change
Soil erosion
State the 3 ways TRF can be managed sustainably on an international level?
International agreements about the use of hardwoods
Debt reduction
Conservation and education
Describe how international agreements about the use of hardwoods help to manage TRF sustainably
FSC approves timber from sustainable sources. Suppliers are encouraged only to buy wood with FSC stamp.
International Tropical Timber agreement (2006) restricts trade in hardwood timber to timber that has been felled in a sustainably managed forest, which has to be marked with a registration number.
Describe how debt reduction helps to manage TRF sustainably
Most countries with TRF are LICs or NEEs. To promote development, some took out large loans which they now find hard to repay. Some HICs have agreed to write off debts in return for the protection of rainforests.
2010 debt for nature swapping - USA agreed to convert a Brazilian debt of £13.5 million into a fund to protect areas of the rainforest.
Describe how conservation and education helps to manage TRF sustainably
Action taken by NGOs, such as WWF, involves promoting rainforest conservation in schools, training conservation officers.
Some countries have areas of TRF as national parks, protecting them from development.
Some international organisations support conservation projects in exchange for using raw materials. Givaudin (Swiss perfume) works with Conservation International in Venezuela in exchange for tonka beans, used in perfumes.
State ways TRF can be managed sustainably at a local level
Selective logging and replanting
Ecotourism
Describe how selective logging and replanting helps to manage TRF sustainably
Trees (usually older to allow younger ones to grow) are selected by professionals. felled and extracted to minimise danger to other trees.
Officials monitor the logging to ensure it is done legally.
New trees are planted to ensure system is sustainable.
Drones and satellites help to reduce illegal logging.
Introduced in Malaysia in 1977.
Describe how ecotourism helps to manage TRF sustainably
Form of tourism that focuses on the environment and has a very low impact. Small scale and local. Supports local communities, employing indigenous people as guides, offering education and social improvements, only using local produce. Ecotourism offers local people and governments a financial return for preserving rainforests
Has become widespread in Costa Rica.
