Upload
haroun
View
26
Download
1
Embed Size (px)
DESCRIPTION
Feeding relationships. Food chains We will be talking about the transfer of energy through an ecosystem- food chain Rabbit, fox & grass. Source of energy. The original source of all energy is the sun Green plants and algae produce food They are called producers - PowerPoint PPT Presentation
Citation preview
Feeding relationshipsFood chains
We will be talking about the transfer of energy through an ecosystem- food chain
Rabbit, fox & grass
2
Source of energy• The original source of all energy is the sun• Green plants and algae produce food– They are called producers
• Producers produce their own food from non-living substances such as light.
• What is the name of the process where plants getenergy from the sun?• Our source of energy?
3
Flow of Energy• Energy only moves in one direction within the food chain.
• The links within the food chain are known as ‘trophic levels’
• Organisms that can’t produce their own food are know as consumers.
4
Flow of EnergyProducers are green plants and algae – eg. grass
First order consumers- herbivores- eg. grass hoppers
Second order consumers – carnivores- eg. toad
Third order consumers are carnivores – eg. snake
*it is possible for an animal to belong to more than one group.
5
Flow of EnergyFood Pyramid• Where do producers gain
their energy?• When consumers eat
producers, this energy is passed up the food chain.
• Some of this energy is lost at each stage (eg. heat, wastes). This means that not all the energy from the sun reaches the top consumer
If energy is lost at each level, how does energy reach the top consumer?
Grass is eaten byRabbits which are eaten byOwls
Food chain: a flow of energy in a habitat
Grass Rabbit
The arrows show the direction of energy flow.
Owl
7
Flow of Energy
• Examples of food chains– Owl, mouse, grass & snake– Leaves, frog, slug & heron– Plant, bird, spider, cat & ants
Pondweed
HeronInsect larvae
small fish
HeronPondweed Insectlarvae
Minnow(little fish)
Food webs• Sometimes we need to join a number of food
chains together.• This is when many animals eat more than one
kind of food.
-What does the hawk eat?-Which animals are the herbivores?-Are these 1st, 2nd or 3rd line consumers?
RabbitOwl
ShrewPlantmatter
Worm Snail
Weasel
Grass
Hedgehog Fox
How many food chains are there now?
Write down as many food chains you can find within this web. What do you start with in a food chain?
ShrewPlantmatter
Worm
Snail
Weasel
Grass
Hedgehog
Plantmatter Shrew Fox
Plantmatter
Plantmatter
Owl
Grass
Rabbit
OwlShrew
Fox
Grass Rabbit Fox
Hedgehog
WeaselGrass Shrew Fox
Fox
Fox
13
Decomposers• Decomposers break down and recycle matter
within their ecosystem, so that plants can reuse the nutrients.
• Decomposers return nutrients from dead plants and animals into the soil plants.
• Examples: bacteria, fungi & worms.
Detritivores
• Detritivores eat small particles of dead plant and animal matter. They also eat animal waste products. Detritivores include: worms, insect larvae, snails and some crustaceans.