Download Ecological Relationships

22/05/2017
Ecological Relationships
W Richards
The Weald School
Ecosystems
22/05/2017
“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
Taking samples of an ecosystem
22/05/2017
Using different “sampling techniques” we can measure changes
in an ecosystem. The two main measurements are:
1) The physical conditions of a habitat (temperature etc)
2) 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
Food chains
22/05/2017
A food chain shows where the energy goes in a food chain (in
other words, “what gets eaten by what”):
Cabbage
Rabbit
Plants convert the
sun’s energy into food
Stoat
Fox
The arrows indicate where
the energy is going
Pyramids of number
22/05/2017
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
“Funny looking” pyramids
22/05/2017
Consider this food chain instead:
Tree
Greenfly
Ladybird
One bird
Some ladybirds
Many greenfly
ONE tree
Bird