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?

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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.

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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.

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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

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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

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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.

Scavengers

• Scavengers are consumers that eat dead animals.

REFERENCESINFORMATION:http://www.tes.co.uk/teaching-resource/Food-Chains-and-Webs-6005349/Nardelli, D (2008). Science Alive 5, Jacaranda Wiley, Australia

IMAGES:http://blogs.wpri.com/2012/09/17/change-of-seasons-change-of-color/http://www.wachusettpediatrics.com/fun-in-the-sun/http://pdsblogs.org/pdsapes510/2009/09/21/ecosystems-and-more/http://www.tutorvista.com/content/biology/biology-iv/ecosystem/food-web.php#http://www.fws.gov/pacific/ecoservices/envicon/pim/reports/Hawaii/Golfcaves.htmlhttp://eopugetsound.org/articles/herbivores-and-detritivores-puget-soundhttp://www.glogster.com/nruff/the-food-web-decomposers/g-6n4g0n4faauksqmhifrjda0?old_view=Truehttp://www.scetv.org/index.php/web_of_water/photos/decomposers_in_a_large_tree_photo_terry_manier/http://www.alaska-in-pictures.com/eagle-scavenger-836-pictures.htm