Roles in Ecosystems
Habitat
– A habitat is the place an organism lives.
Ecological Niche
The ecological niche is an organism’s “job” in an ecosystem.
It includes:– its place in the food web– where it lives– the time of day it is active
Ecological Niche
Each organism in an ecosystem usually has a different niche.
This helps to reduce the amount of competition for habitat and resources (like food, water, etc.).
Do they have the same niche?
Do they have the same niche?
1) Red-tailed hawk
- eats mice
- hunts in fields
- hunts during the day
Do they have the same niche?
2) Eastern screech owl
- eats mice
- hunts in forests
- hunts at night
Biodiversity
Biodiversity is the variety of life in a particular ecosystem; also known as biological diversity
Since organisms within an ecosystem have different niches, it allows for greater diversity
Native vs. Introduced Species
A native species is a species that has lived in an ecosystem for a long time.
An introduced species is a species that is new to an ecosystem.
Introduced species can arrive naturally (animals move, seeds carried by wind) or by humans.
Impact of Introduced Species
Introduced species usually cause problems in an ecosystem.
They compete for a niche with the native species.
Example - Starling
Sixty European starlings were released in North America in honour of Shakespeare.
There are now 200 million of them!
Example – Cane Toad
Cane toads were introduced into Australia to control insects.
Example – Cane Toad
They did not really help with
the insects. Now they are causing a
lot of problems. They are poisonous, so anything that eats
them dies. They are HUGE – and will eat anything they
can swallow including many native species.
Example – Rabbits
Rabbits were brought to Australia by people.
People brought rabbits to Australia.
Example – Rabbits
When the rabbits multiplied, they tried many ways to stop them:- fences- viruses- fleas
Nothing has worked!
Vocabulary
Habitat Ecological niche Competition Native species Introduced species
Make sure you know
these words!