1. Ecological Relationships
31/05/2018
Ecological Relationships

2. Ecosystems
31/05/2018
“Ecosystem” is a term used to describe all of the organisms living together as a community in a particular habitat.
Ecosystems are constantly changing:
Changes in population due to predation, disease etc
Physical changes (e.g. temperature change)
Changes in ecosystems
Pollution
Human interference
Changes in soil conditions

3. Taking samples of an ecosystem
31/05/2018
Using different “sampling techniques” we can measure changes in an ecosystem. The two main measurements are:
The physical conditions of a habitat (temperature etc)
The populations of different species in that habitat
Some common ways of measuring…
Help!
Measuring temp, pH etc
Taking animal samples
Taking samples using quadrats

4. Food chains
31/05/2018
A food chain shows where the energy goes in a food chain (in other words, “what gets eaten by what”):
Rabbit
Cabbage
Fox
Stoat
The arrows indicate where the energy is going
Plants convert the sun’s energy into food

5. Pyramids of number
31/05/2018
In this food chain we can see that the number of organisms in each stage is less than in the previous stage:
Cabbage
Rabbit
Stoat
Fox
We can draw a “Pyramid of Numbers” to show this pattern:
One fox
A few stoats
Some rabbits
Lots of cabbages

6. “Funny looking” pyramids
31/05/2018
Consider this food chain instead:
Tree
Greenfly
Ladybird
Bird
One bird
Some ladybirds
Many greenfly
ONE tree