Download Interactions in Ecosystems

Interactions in Ecosystems
Food Chains, Food Webs
What is an Ecosystem?
 A system formed by the interaction of a community of
organisms with their physical environment
How are Ecosystems divided up?
 Ecosystems can be divided a few ways:
 1) Producers and Consumers
 A producer is an organism that use photosynthesis to capture
energy by using sunlight, water and carbon dioxide to create
carbohydrates, and then use that energy to create more
complex molecules like proteins, lipids and starches that are
crucial to life processes.
How are Ecosystems divided up?
 Producers make their own food and other organisms can then
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eat producers.
What are 3 examples of producers you can think of?
1) __________________
2) __________________
3) __________________
How are Ecosystems divided up?
 Consumers are organisms that get their energy from
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producers, by eating them.
They are not able to make their own food and therefore,
must get it from elsewhere.
Consumers can also eat each other, but it always comes back
to a consumer eating a producer.
What are 3 examples of consumers you can think of?
1) __________________
2) __________________
3) __________________
Another Name for Producers and
Consumers
 A producer can be called an AUTOTROPH.
 Auto means ‘own’ and troph means ‘eating’.
 Therefore, producers survive by ‘eating’ their ‘own’ food.
 A consumer can be called a HETEROTROPH.
 Hetero means ‘different’ and troph means ‘eating’.
 Therefore, consumers survive by ‘eating’ ‘different’ foods
made by other organisms.
How are Ecosystems divided up?
 2) Trophic Levels
 In ecosystems, organisms occupy different levels based on who
eats who. These levels are known as Trophic Levels.
 Plants are Producers and they occupy trophic level 1
 State an example here: _______________
 Animals that eat plants occupy level 2
 State an example here: ______________
 Animals that eat other animals tend to occupy at least level 3
(animals tend not to occupy trophic levels higher than 5)
Types of Producers and Consumers
 Producers: There is only 1 level of producer as only plants
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and some bacteria can make thier own food.
Primary (1) Consumer: Eats the producers directly
Secondary (2) Consumer: Eats the primary consumers
directly
Tertiary (3) Consumer: Eats the secondary consumer
Quaternary (4) Consumer: Eats the tertiary consumer
directly.
Types of Producers and Consumers
 Some organisms can occupy more than one tertiary level
depending on what they can eat.
 For example: A bear will eat just about anything, however,
they will eat a salmon from the river (secondary consumer)
as well as blueberries (producer).
 The more types of foods the animal eats, the higher the type
of consumer.
Food Chain
 This is a linear ranking
system of organisms
showing what niches
(roles) animals in an
ecosystem occupy.
 A food chain is easily
identified as it is one line
from organism to
organism.
 Draw a food chain incorporating the following. Indicate what
trophic level each organism would be at.
 eg. wild rice(plant) , minnow (little fish), pike (big
fish), eagle
Food Web
 A food chain is too
simplistic to show the true
interactions that occur in
an ecosystem. It is merely
one branch of the larger
food web that can exist in
nature.
 You can easily identify a
food web by the many lines
connecting the organisms.
 Draw a food web incorporating the following (some
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organisms occupy more than one level)
Before you start, make a list of who eats who
Find your level 1 producers, primary/ secondary/ tertiary /
quaternary consumers and label them
Also label the trophic levels
water lilly, pond weed, snapping turtle, minnow,
northern pike, loon, wild rice, frog. moose,
mosquito, dragonfly, blackbird, human, eagle
Organisms are also defined by what
they eat:
 Herbivores: Plants
 Omnivores: Plants/Animals
 Carnivores: Other Animals
 Decomposers: an organism that gets energy by breaking
down the remains of dead organisms
 Example: bacteria or fungi
 Label the organisms in your web with these.