The Living World Flashcards
Define ecosystem
All of the living and non-living components of an area
What does the nutrient cycle show?
How nutrients move through an ecosystem
Briefly explain the nutrient cycle [5]
- When dead material decomposes, nutrients are released into the soil
- The nutrients are then taken up from the soil by plants
- The plants may be eaten by consumers
- The plant or consumer dies
- The nutrients are returned to the soil
What does a food chain show?
What eats what
What does a food web show?
Lots of food chains and how they overlap
What is the climate like in tropical rainforests? [3]
- No definite seasons
- Hot (20 - 28°C)
- High rainfall (2000 mm per year)
Why isn’t the soil very fertile in tropical rainforests? [2]
- Heavy rain washes nutrients away
- High levels of biodiversity take up the nutrients in soil very quickly
What are plants like in tropical rainforests? [3]
- Evergreen trees
- Tall trees
- Thick vegetation
Why are most trees in tropical rainforests evergreen?
To help them take advantage of the continual growing season
Define biodiversity
The variety of organisms living in a particular area
What are the 4 layers of the rainforest?
- Forest floor
- Undercanopy
- Main canopy
- Emergent trees
Why do plants have thick, waxy leaves with pointed drip-tips? [2]
- Channel rainwater to the point, encouraging runoff so the weight of the water doesn’t damage the plant
- This also means there is no standing water for fungi and bacteria to grow in
How are lianas adapted to the rainforest? [2]
- Climb up trees
- To reach sunlight in the emergent layer
Why do many trees have smooth, thin bark?
Allows water to run off easily
Why do trees have buttress roots?
Provides the support the tall trees need
Why do plants drop their leaves gradually throughout the year?
Enables them to grow all year round
How are spider monkeys adapted? [2]
- Long tail - allows them to swing from tree branches
- Highly developed larynx - allows them to communicate across the treetops
How are geckos adapted? [3]
- Camouflaged - to hide from predators
- Stick toe pads - allows them to grip onto tree trunks and climb vertically
- Detachable tail - allows them to escape predators more easily
How are jaguars adapted? [3]
- Can swim - helps them cross river channels
- Camouflaged - allows them to stalk prey invisibly
- Large claws - allows them to climb trees to catch prey
How does deforestation disrupt tropical rainforest ecosystems? [3]
- Trees stabilise soil with their roots and provide nutrients when they drop their leaves
- With fewer trees, the soil would have less protection from heavy rainfall and the few nutrients left would wash away more easily
- Plants would struggle to grow
How much of the Amazon Rainforest is estimated to be deforested by 2050 at the current rate?
40%
How do tropical rainforests benefit people? [2]
- Products like rubber, coffee, chocolate and medicines sourced from the rainforest
- Sustainable development can offer long-term economic benefits e.g. ecotourism
How do tropical rainforests benefit the environment? [2]
- Protecting the rainforest may reduce the greenhouse effect
- Regulate climate and water cycle
How can tropical rainforests be managed sustainably? [3]
- Replanting trees
- Selective logging
- Ecotourism
What does replanting trees involve?
New trees are planted to replace the ones that were cut down
What does selective logging involve?
Only some trees (e.g. old ones) are felled - most remain
Why is selective logging less damaging?
The overall structure of the forest remains, the canopy remains and the soil isn’t exposed
What are the 2 least damaging forms of selective logging?
- Horse logging
- Helicopter logging
How does ecotourism benefit tropical rainforests? [3]
- Raises awareness of conservation issues
- Brings in money to help protect rainforests
- If local people are employed in tourism, they don’t have to log or farm to make money, reducing deforestation
How does education benefit tropical rainforests? [2]
- Encourages people to buy products from sustainable sources
- Teaches local people sustainable ways to make a living e.g. employment in ecotourism
How does conservation benefit tropical rainforests? [2]
- Within conservation areas, activities such as logging are restricted
- Countries can receive money from other countries for protecting rainforest, which can then be used to enforce restrictions
How does debt reduction benefit tropical rainforests?
Countries don’t have to pay off debt quickly by logging, farming and mining and instead rainforest can be conserved
How do International Hardwood Agreements benefit tropical rainforests?
Prevents high levels of illegal logging, reducing deforestation
What are polar and tundra like? [3]
- Very cold
- Low precipitation
- Well defined seasons - cold summers and even colder winters
What is the average winter temperature in polar regions?
-40°C
What is the average winter temperature in tundra regions?
-35°C
How much precipitation per year in polar regions?
100 mm
How much precipitation per year in tundra regions?
380 mm
What is the soil like in polar regions?
Ice sheets cover polar areas, so no soil is exposed
What is the soil like in tundra regions?
Thin, acidic and not very fertile
What is beneath the soil in tundra regions?
Layer of permafrost (holding trapped greenhouse gases)
What plants grow in polar regions? [3]
- Lichens
- Mosses
- Grasses
What plants grow in tundra regions? [4]
- Lichens
- Mosses
- Grasses
- Shrubs
What animals inhabit polar regions? [4]
- Polar bears
- Penguins
- Whales
- Seals
What animals inhabit tundra regions? [3]
- Lemmings
- Wolves
- Reindeer
What types of people do polar and tundra regions have? [2]
- Indigenous people
- Workers (scientists, oil, gas)
Cold environment plant adaptations
Why do most plants become dormant during the winter months?
To survive the cold, dark winters
Cold environment plant adaptations
Why are plants low-growing and round-shaped?
To provide protection from the wind
Cold environment plant adaptations
Why do most plants have shallow roots?
Because of the layer of permafrost beneath the soil
Cold environment plant adaptations
Why do plants have small leaves?
To limit the amount of mositure lost through transpiration
Cold environment plant adaptations
Why do plants have a short growing season?
The warmer, wetter summer when they grow is very short
Cold environment plant adaptations
Why do many plants reproduce using underground bulbs?
To cope with the cold and because the growing season is short
Cold environment animal adaptations
Why are animals well-insulated?
Reduces the amount of energy they have to use to keep warm
Cold environment animal adaptations
Why do some animals hibernate?
To conserve energy and survive the winter
Cold environment animal adaptations
Why do some animals have white fur?
For camouflage - helps predators sneak up on prey or helps prey hide
Do cold environments have low or high biodiversity?
Low
What are the issues related to low biodiversity levels in cold environments? [2]
- If the population of one species changes, it can affect the population of dependant species
- Global warming could cause extinction - species adapted to cold temperatures and can’t go anywhere colder
Why is it important to conserve wilderness areas in cold environments? [3]
- Provide habitats for organisms that can’t survive elsewhere
- Scientsists can study these unaffected areas
- Studying these ecosystems may help scientists to replicate the same conditions in controlled areas - can preserve rare species outside protected areas
Whay are cold environments fragile/take a long time to recover? [2]
- Plant growth is slow - if plants are damaged, regrowth takes time
- Species are highly specialised, so find it hard to adapt to change
What strategies can be used to balance economic development with conservation in cold environments? [4]
- International agreements
- Using technology
- Conservation groups
- Governments
What are the terms of the 1959 Antarctic Treaty? [4]
- Limits vistors to 100 per site
- Ensures peaceful non-military activities
- Prohibits nuclear activities
- Prevents cruise ships with over 500 passengers from stopping
What does the Antarctic Treaty enable?
Tourism but in a controlled way which won’t harm the fragile ecosystem
How many nations signed the Antarctic Treaty?
12
What do conservation groups do? [2]
- Pressure governments to protect cold environments
- This leads to more sustainable development that doesn’t damage areas
How does technology reduce damage to cold environments?
Modern construction methods can minimise environmental impacts (e.g. building on gravel to prevent ground warming)
What does the 1964 Wilderness Act do?
Protects designated wildnerness areas (e.g. much of Alaska) from development