Success Criteria 2
Energy Flow in an Ecosystem
Learning Intentions & Success Criteria for This Topic
Learning Intentions:
Ecosystems are connected and interdependent, and any change in
environmental living or nonliving things can have an effect on the entire
system.
Success Criteria: By the end of this unit you will be able to:
• Analyse the living and non-living components of an ecosystem
• Construct and interpret food chains and food webs to show
relationships between organisms in an environment
2
1/13/2020
Ecosystems Unit
Learning Intentions & Success Criteria for This Topic
Learning Intentions:
Ecosystems are connected and interdependent, and any change in
environmental living or nonliving things can have an effect on the entire system.
Success Criteria: By the end of this topic you will be able to:
Construct and interpret food chains and food webs to show relationships
between organisms in an environment
•
•
•
•
•
•
3
1/13/2020
I can create a food chain given a scenario or ecosystem
I can create a food web given a scenario or ecosystem
I can interpret food webs or chains, and describe the movement of energy
I can name roles and relationships within an ecosystem
I can explain the role of microorganisms in ecosystems
I can justify why photosynthesis is the basis of all food chains
Ecosystems Unit
Key Terminology
Carnivore
Autotroph
Consumer
Chlorophyll
Decomposer
Primary consumer
Energy flow
Secondary Consumer
Food Chain
Tertiary Consumer
Food Web
Microorganism
Herbivore
Oxygen Production
Omnivore
Photosynthesis
Producer
4
1/13/2020
Ecosystems Unit
Photosynthesis
• Light energy from the Sun hits the Earth.
The leaves of plants contain a chemical
called chlorophyll, which enables the plant
to use the Sun’s energy to convert water
from the soil and carbon dioxide from the air
into simple sugars and oxygen.
• This process is called photosynthesis
• Key Concept: Because photosynthesis
allows for a conversion of sun energy into
chemical energy that can be used by other
organisms, it is the basis of all food chains.
5
1/13/2020
Ecosystems Unit
6
1/13/2020
Ecosystems Unit
Energy flows through all ecosystems
The Sun is the first energy source for all ecosystems.
Plants are the key to unlocking sun energy and turning it
into chemical energy.
Plants are producers of their own food, so they are
called autotrophs: auto means self, troph means food,
or producers
When other organisms eat plants, some of this energyrich sugar is passed on to them. Organisms who get
their energy from consuming other organisms are
known as consumers
The Secret Life of Plankton
https://youtu.be/xFQ_fO2D7f0
Microorganisms in an Ecosystem
Role in Ecosystems
• Animals are only one small part of an ecosystem. For an ecosystem to work, it has to have many
organisms that all work together in a continuous cycle.
• Microorganisms form part of that cycle, and because of their huge numbers, the part they play is
an important one. Microorganisms have several vital roles in ecosystems: decomposition,
oxygen production, evolution, and symbiotic relationships.
• Decomposition is where dead animal or plant matter is broken down into more basic molecules.
This process only happens because of the microorganisms that find their way into the dead
matter. The process of decomposition provides nutrients that future plants and animals will be
able to reuse, making soil more fertile. Plants would not continue to grow without it - not to
mention the world be really cluttered with dead animals and plants without it.
• Oxygen production is where carbon dioxide or other elements are turned into oxygen through
chemical reactions. Trees are most well known as oxygen producers, and rainforests are often
described as 'the lungs of the world', but microorganisms actually produce just as much oxygen
as the rainforests.
8
1/13/2020
Ecosystems Unit
Food Chains & Food Webs
• We it is possible to work out where each of these organisms obtains its
food and hence its energy.
• A food chain is a model that shows how energy flows from one organism
to another in an ecosystem. There are four levels of organisms in a food
chain. Plants are always at the bottom due to photosynthesis. They are
the producers. After the producers are three levels of consumers:
primary, secondary & tertiary.
• Primary consumers feed only on plants. These organisms are also called herbivores.
• A secondary consumer feeds on herbivores. It may eat both plants and animals
(omnivore) or just animals (carnivore)
• Tertiary consumers feed on secondary consumers.
• Eventually all organisms die and are broken down by Decomposers
• When drawing a food chain, the arrows point in the direction of energy flow
9
1/13/2020
Ecosystems Unit
Food Webs
• An ecosystem has a variety of organisms with large
numbers of relationships. Most feed on more than one
plant or consumer. (Don’t you eat more than one food?)
• Simple food chains can be connected together into a
more complex arrangement called a food web.
• A food web models the energy flow through an
ecosystem and shows the type of relationships between
organisms.
• Food webs help us predict what could happen if one of
the organisms in the food web was disrupted in some
way.
10
1/13/2020
Ecosystems Unit
11
1/13/2020
Ecosystems Unit
You try it
• Using information in the previous slide, predict
what would happen if a drought caused much of
the grass to die. Be sure to include the impact of
this on primary, secondary and tertiary consumers
• Create a food chain with you in it based on your
breakfast
• Create a food web with you in it based on the past
few days of eating
12
1/13/2020
Ecosystems Unit
Check Your Understanding
• Explain why producers are always at the bottom of a food chain or
food web model.
• Draw a simple food chain for each of the organisms pictured below.
Correctly label the food chains
with producers & consumers
For extra challenge, try to have
a go at a decomposer in your
chain.
Explain how energy comes into
and then flows through this
food chain.
13
1/13/2020
Ecosystems Unit
Check Your Understanding
• Relating to the food web provided, answer the
following questions
• State which organisms are producers and which are
consumers
• Give an example of a herbivore, an omnivore and a
carnivore
• A food web shows the links between various food
chains. Write down three food chains that are in this
food web.
• Describe the role the feral cat has in this food web.
• Explain what might happen if the European rabbit were
introduced to this community.
14
1/13/2020
Ecosystems Unit
For Your Assessment
• You can use the knowledge and skills from
this topic to:
• Draw food chains and food webs for the
environment you are investigating
• Describe the energy flow in your food chains and
food webs
• Review what techniques and equipment you will
need to conduct your investigation and be sure
you have it if you are doing this on camp!
15
1/13/2020
Ecosystems Unit
Learning Intentions & Success Criteria for This Topic
HOW DID YOU DO?
Learning Intentions:
Ecosystems are connected and interdependent, and any change in
environmental living or nonliving things can have an effect on the entire system.
Success Criteria: By the end of this topic you will be able to:
Construct and interpret food chains and food webs to show relationships
between organisms in an environment
•
•
•
•
•
•
16
1/13/2020
I can create a food chain given a scenario or ecosystem
I can create a food web given a scenario or ecosystem
I can interpret food webs or chains, and describe the movement of energy
I can name roles and relationships within an ecosystem
I can explain the role of microorganisms in ecosystems
I can justify why photosynthesis is the basis of all food chains
Ecosystems Unit
Key Terminology: Be Sure you know these terms
Carnivore
Autotroph
Consumer
Chlorophyll
Decomposer
Primary consumer
Energy flow
Secondary Consumer
Food Chain
Tertiary Consumer
Food Web
Microorganism
Herbivore
Oxygen Production
Omnivore
Photosynthesis
Producer
17
1/13/2020
Ecosystems Unit