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 Producers produce their own food from non- living substances such as light. What is the name of the process where plants get energy from the sun? Our source of energy? 2

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. 3

Flow of Energy Producers 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. 4

Flow of Energy Food 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 5 If energy is lost at each level, how does energy reach the top consumer?

Grass is eaten by Rabbits which are eaten by Owls Food chain: a flow of energy in a habitat GrassRabbit The arrows show the direction of energy flow. Owl

Flow of Energy Examples of food chains – Owl, mouse, grass & snake – Leaves, frog, slug & heron – Plant, bird, spider, cat & ants 7

Pondweed Heron Insect larvae small fish

HeronPondweed Insect larvae 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 1 st, 2 nd or 3 rd line consumers?

Rabbit Owl Shrew Plant matter WormSnail Weasel Grass HedgehogFox 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?

Shrew Plant matter Worm Snail Weasel Grass Hedgehog Plant matter Shrew Fox Plant matter Plant matter Owl Grass Rabbit OwlShrew Fox GrassRabbitFox Hedgehog Weasel Grass Shrew Fox

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. 13

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.

Scavengers Scavengers are consumers that eat dead animals.

REFERENCES INFORMATION: Nardelli, D (2008). Science Alive 5, Jacaranda Wiley, Australia IMAGES: