Small Changes in Ecosystems

7/29/2019 Small Changes in Ecosystems

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FEATURES OF ECOSYSTEMS

SMALL SCALE EXAMPLES

WHAT HAPPENS IF THEY ARE CHANGED?


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Ecosystems food chains

Starter: Can you

think of a five levelfood chain?


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Key terms in Trophic levels

Producer(plants)

Primary consumer(herbivores)

Secondary consumer(carnivores or omnivores)

Tertiary consumer(top/apex predator = carnivores)

Decomposer(fungi and bacteria = recyclers)

NOTE: When you combine the concept oftrophic

levels, it becomes challenging, depending on how

many consumers are in the chain/web.


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Do you eat the same thing every day? Didnt think so.

Food chains are in fact, more often than not, actually not

linearthey are more like webs

Ecosystem Food Web for a deciduous forest


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Deciduous forest food web -

Sort it out!!! Cut up your sheet and set it out across a double

page in your exercise book to show a food web.

Follow the remaining instructions at the bottom

of the sheet for labels and information.


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What if ecosystemsare experiencechanged?

Are there short termeffects?

Are there long termeffects?


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The impact of change on an

ecosystem The diversity and relative numbers of the

components of an ecosystem can change over

time.

This can be caused by factors such asenvironmental change (e.g. flood, fire,

drought) or human-induced change (e.g.

drainage, reclamation, fish stocking). Once a change has occurred it is rarely

isolated and often has an impact on other

parts of the ecosystem.


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Ecosystem interdependence

Interdependence is a relationship in which

each member is mutually dependent on

the others.

Describe and

explain the

interdependent

relationshipshown here..


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Freshwater pond ecosystem (small scale)

- the impact of change

What if the following happened?

1.Introduction of another predatory fish.

2. Removal of Lily pads. 3. The pond is dredged to increase its depth.

4. Pollution incident kills Great Diving Beetles.

In groups, describe and explain

what the consequences would be

up and down the food web


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What would adding this species do?

What category is it?

What Trophic level is it?

What would happen tothe ecosystem?

Short term

Long term


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What would adding this plant do?




Short term

Long term


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Homework

EITHER:

OR:

OR:


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Short term

Long term

This is a Crane. They are being reintroduced into wetlands in Somerset

after being hunted to extinction in the past. H/W = research this!


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Short term

Long term

This is a Beaver ! They have been reintroduced into river systems in Devon

after being hunted to extinction in the past. H/W = research this!


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Short term

Long term

This is a Burmese Python ! They have been introduced into the everglades

in Florida after Hurricane Andrew (1992) destroyed a reptile centre. H/W = research this!

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Small Changes in Ecosystems