Ecosystems Flashcards
What is an ecosystem?
A natural enviroment made up of plants, animals and the environment
What does biotic mean?
Living things
What does abiotic mean?
Non-living things
What are the two scales ecosystems can be found at?
Small scale and large scale (biomes)
What does a food chain show?
It show the direct link between producers and consumers
What do producers do?
Make their own food via photosynthesis
What do consumers do?
Get energy from eating others consumers and also producers
What do decomposers do?
Break down plant and animal material and return it to the soil
Give an example of a food chain
Plant → insect → mouse → owl
What is a food web?
A more complex food chain
What is nutrient cycling?
When plants or animals die, they decompose and their nutrients go into the soil. The soil becomes fertile allowing plants to grow.
What happens if a change occurs in an ecosystem?
If a change occcurs in an ecosystem there can be knock on effects to the rest of the ecosystem
What is a natural changes that can occur in an ecosystem?
Drought - it can dry up ponds meaning fish may not survive and plants can dry up
What are two human changes that can occur in an ecosystem?
- Eutrophication
- Woods cut down - destroys habitats for wildlife and affects the nutrient cycle
What is eutrophication?
Agricultural fertilisers are harmful and can get washed into rivers causing algae to grow. The algae covers the surface of the rivers blocking out sunlight. Plants/fish do not get water and are starved of oxygen
How can changes affect the pond ecosystem?
- Adding some perch, a predator
- The perch will eat the smaller fish and animals like frogs
- This will reduce the amount of food further up the chain e.g. heron
- With fewer frogs there will be an increase of creatures below frogs
What is the case study for changes in an ecosystem?
Yellowstone National Park
What animals were introduced?
Wolves
What are five changes that the wolves made to the ecosystem?
- They changed the behaviour of the deer - they started to avoid certain places in the park
- The areas where the deer were avoiding started to regenerate
- In some places, the height of the trees quintupled in just 6 years
- The number of beavers started to increase and the dams they built provided habitats for other animals such as otters, ducks, fish, reptiles
- They changed the behaviour of rivers. They began to meander less and there was less erosion as the regenerating forests stabilised the banks so they collapsed less often so the rivers became more fixed in their course
Give four large scale ecosystems
- Tropical rainforest
- Tundra
- Polar
- Deciduous and coniferous forests
What are the characteristics of tropical rainforests?
They have equatorial low pressure belts (high temperatures and heavy rainfall)
What are the characteristics of tundra ecosystems?
Cold, windy and dry conditions
What are the characteristics of polar ecosystems?
Polar high - cold air sinks at the north and south poles which results in very low temperatures and dry conditions
What are the characteristics of deciduous and coniferous forests?
Deciduous trees shed their leaves in the winter to retain moisture. Coniferous trees retain their leaves to maximise photosynthesis during short summer months.
