Ecology: The Study of
Ecosystems
Mrs. Hart
Biology
What is an Ecosystem?
An ecosystem includes all the living and
non-living things in a given area
 Biotic Factors: Living Things
 Ex:
 Abiotic Factors: Non-Living Things
 Ex:

How does the ecosystem get
energy?
Autotrophs
Living things that can make their own food
 Green Plants that have “chlorophyll” are
able to convert the sun’s energy to
chemical energy (food)
 This process is called photosynthesis
 Autotrophs are also known as “Producers”
because they produce the energy for the
ecosystem

How do the rest of us get energy?
We’ve got to EAT!!!
Heterotrophs: Living things that are NOT
able to make their own energy; we must
eat other living things for energy
 Heterotrophs are also known as
“Consumers” because they consume other
living things for energy
 But what kind of living things do we eat???

Herbivores

Eat only plants!!!
Carnivores

Eat only meat
Omnivores

Eat both plant and animal material
Is there another type of feeder?

Decomposers: Live off of dead living
things and wastes
Scavengers

Consumers that eat animals that are
already dead
How can we organize the
different types of feeders?
Food chain- A diagram of what eats what
 Trophic Levels- A name for the feeding
levels within a food chain
 Producers, Primary Consumers,
Secondary Consumers, Tertiary
Consumers, Decomposers

Food Webs
Many interconnected food chains within an
ecosystem
 Can be very complicated

Quick Quiz:
1.
2.
3.
4.
5.
What only eats plants?
Who always starts the food
chain?
Who eats plants AND animals?
Who only eats animals?
How is a Food Web different
from a Food Chain?
Quick Quiz, cont.
6.
7.
8.
9.
10.
Who eats EVERYBODY when they’re
dead?
What do we call producers (like plants)
who make their own food?
What is the other name for consumers?
What is the name for living things in the
environment?
What is the name for non-living things in
the environment?
Matter is recycled
How is matter recycled?
It moves from the producers, to the
consumers, through the food web
Then it is broken down by decomposers
Then it is taken up as nutrients by producers
What is recycled?
Carbon, Nitrogen, Phosphorus, Sulfur
Many more!!!!!!!
What about energy???
Energy moves through the food chain,
from producers to consumers to
decomposers
 Where does the energy come from???
 Is energy recycled?
 What is the “Law of Conservation of
Energy” aka “The First Law of
Thermodynamics”……

Energy Cannot be
Created or
Destroyed!!!
However,
Energy is
NOT recycled…
Answer: it is changed
from one form to
another.
Where does the energy go?
Most of the energy at each trophic level is
used by the living things to conduct their
metabolism, in hunting/killing/consuming
food, and in other life activities
 Not all living material is consumed, ex:
bones, bark, etc. These parts will be
decomposed
 So where does this energy go?

The Law of 10%
At each trophic level, 90% of the available
energy is used, with most of it being “lost”
as heat to the atmosphere.
 Only 10% of the energy at each level is
available to the next trophic level
 So if a producer has 10,000 Calories (or
kilocalories) of energy, how much energy
would each level after that have?

Energy Pyramid
Energy Can also be measured in
Joules (J)
What does this mean for higher
level consumers?
There’s less energy
That means there are lower numbers of
higher level consumers, and higher levels
of producers and lower level consumers
What will happen to an ecosystem if all of
the producers are killed? (Think
deforestation, forest fire, drought, etc)
Symbiosis
Living together
-Two different species

Parasitism


Not symbiotic
Causes harm to host
A tapeworm in a
person or animal
intestines

Mutualism

Both organisms derive mutual benefit
tickbirds and rhinos
Commensalism
Only one member benefits

The other member: no benefit/ no harm
Whale and barnacles
Barnacle: gets place to live/feed.
Whale: no harm/no benefit
