Aim: How do organisms have different roles in the
environment?
DO NOW:
Every population is linked, directly or indirectly,
with many others in an ecosystem. The table to
the right shows the size of the moose and wolf
populations that live on an island in Lake
Superior.
• State how the information in the table
can be used to determine that the
wolves are the predators.
• Identify two limiting factors that keep the wolf
population size from growing any larger.
____________ and _____________
What type of ecosytem does
Nemo live in?
What ecological level is this?
Community
The different types of
populations in a given
amount of space.
Habitat
A specific area where an
organism lives
What is Nemo’s habitat?
Does everybody in a community have the
same job?
■
No, each organism
has its own ROLE
in a community or
NICHE
What is the niche of a plant
population in a community?
■
■
To produce
food using the
energy from
the sun
Producers organisms that
can make their
own food
What is the niche of herbivores in
a community?
■
■
■
To eat plants
They act as a limiting
factor for plants!
Primary Consumersanimals that eat
plants.
What is the role of carnivores in a
community?
■
■
■
To eat animals
They are a limiting
factor! They control
the amount of prey!
Secondary Consumerseat primary
consumers.
What is the niche of
bacteria & fungi?
■
■
■
To return nutrients
back to the soil by
breaking down dead
organisms
Decomposers –
breakdown dead
organisms
Bacteria & Fungi
(mushrooms).
Why are decomposers the
“Recyclers” of the ecosystem?
They break down dead
organisms & at the
same time return raw
materials back to the
ecosystem.
What is a scavenger’s niche?
■
To eat animal’s
that were killed
& leftover by
secondary
consumers
What happens if two organisms
occupy the same niche?
■
■
Organisms would compete
until the best adapted
population wins.
Organisms can sometimes
appear to occupy the same
niche, but under more
careful examination, they
do not.
Compare and Contrast
Primary & Secondary
Consumers
US movie: populations, habitats & niches
1. Decomposers are necessary in an ecosystem because they
(1) produce food for plants by the process of photosynthesis
(2) provide energy for plants by the process of decay
(3) can rapidly reproduce and evolve
(4) make inorganic materials available to plants
An earthworm lives and reproduces in the soil. It aerates the soil and adds organic
material to it. The earthworm is a source of food for other organisms. All of these
statements together best describe
(1) a habitat
(2) autotrophic nutrition
(3) an ecological niche
(4) Competition
Abiotic factors that characterize a forest ecosystem include
(1) light and biodiversity
(2) temperature and amount of available water
(3) types of producers and decomposers
(4) pH and number of heterotrophs