Ecosystems Unit
All living and nonliving things on our
planet are connected.
Key Learning:
How are the living and
nonliving things connected in an ecosystem?
Unit Essential Question:
Ecosystems Unit
Concept: What’s In An Ecosystem?
Lesson Essential Questions:
1. How are population sizes determined?
2. How do you identify what is in an ecosystem?
You will be able to
answer these
questions by the
end this section
Vocabulary
Population
Sampling
Abiotic Factor
Biotic Factor
You should already know what these
words mean. You will be able to use
them in your responses and
discussions throughout the unit
Ecosystems Unit
Investigation #1: Sampling Populations
Natural Selection is a species’ response
to Environmental Stress.
Environmental Stress
is any
factor in the environment that makes it
harder for a species to reproduce or
get what it needs to survive.
Environmental Stress could be…
• Competition from an organism requiring a
similar habitat.
• Climate change
• Predation
• Change in availability or type
of food
• Other factors that would put long
term stress on a species!
Three basic things can happen when
a species is under stress:
1.
Go extinct in that area.
2.
Move to another area (emigrate).
3.
Adapt to survive the stress.
Ecosystems Unit
What the Beak?
Part A
Complete the reading in your packet and
answer the questions when you finish.
Ecosystems Unit
What the Beak?
Part B
You will complete the lab. Follow all of Mr.
Herlihy’s instructions and do not move ahead.
If you miss a step, you will have skewed data
and will not get full credit on the lab.
Ecosystems Unit
Ecosystems Unit
Structure/Function Lab
Ecosystems Unit
Among Organisms
There are three main types :
Predation
Competition
Symbiosis
Competition:
Ecosystems Unit
Food (nutrients), water and
space are usually limiting
factors in a habitat.
Species that occupy similar
niches will have to compete
for these limited resources.
Ecosystems Unit
Organisms have developed
specialized forms,
characteristics and behaviors
that allow them to compete,
these are called adaptations.
Predation:
Ecosystems Unit
An interaction in which one
organism kills and eats another!
The organism that does the
killing is the predator,
the one that is eaten is
the prey! 
Predators
Ecosystems Unit
Have a wide range of specialized
adaptations that allow them to
catch prey.
Think of some predators that you
know, what adaptations do they have
that help them in their niche?
Prey
Ecosystems Unit
Have specialized adaptations to
allow them to survive! 
Such as:
Camouflage- coloring
or body parts that allow them to
blend with surroundings
body markings that make it look like something
more dangerous
Mimicry-
Protective coverings- shell
to catch or eat
Warning colors- bright
or spines that make them hard
colors that warn predators that
they are poisonous
Ecosystems Unit
Symbiosis -
a relationship between populations in which one
or both populations is benefited.
There are 3 main types of
symbiotic relationships:
commensalism
mutualism
parasitism
Ecosystems Unit
Commensalism- a relationship in which
one species is benefited and the other is neither
benefited nor harmed
For instance: barnacles on an
oyster
The barnacle gets a place to
live, the oyster is not harmed
or helped.
Ecosystems Unit
Mutualism
are helped.
- both
species
For instance: oxpecker (also called “tick-pickers”)
and herding animals such as cows or water
buffalo.
The “tick-picker” gets food and protection from
predators. The herd animal gets relief from
parasites.
Ecosystems Unit
Parasitism- one species is
helped, the other is harmed.
For instance: A tick and a dog. The tick gets food, blood from the
dog. The dog is harmed, with too many ticks the dog will become
anemic and will not be as healthy.
Parasites RARELY kill the host. They almost always weaken it
though.
Ecosystems Unit
Energy Flow Through an
Ecosystem
Food Chains, Food Webs, Energy Pyramids
Ecosystems Unit
•Begins with the SUN
•Photosynthesis
6CO2 + 6H2O + sunlight & chlorophyll
C6H12O6 + 6O2
Ecosystems Unit
Organisms that can make
glucose during
photosynthesis are called
PRODUCERS.
Producers use most of the energy
they make for themselves.
Ecosystems Unit
The energy that is not used by
producers can be passed on to organisms
that cannot make their own energy.
Organisms that cannot make their own
energy are called CONSUMERS.
Ecosystems Unit
Consumers that eat producers to get energy:
• Are first order or
primary consumers
• Are herbivores
(plant-eaters)
Ecosystems Unit
Most of the energy the primary
consumer gets from the producer is
used by the consumer.
Some of the energy moves into
the atmosphere as heat.
Ecosystems Unit
Some energy in the primary
consumer is not lost to the
atmosphere or used by the
consumer itself.
This energy is passed on to
another consumer.
Ecosystems Unit
A consumer that eats another
consumer for energy:
• Is called a secondary or
second order consumer
• May be a carnivore or a
herbivore
• May be a predator
• May be a scavenger
Ecosystems Unit
Most of the energy the secondary
consumer gets from the primary
consumer is used by the secondary
consumer.
Some of the energy is lost
as heat, but some energy is
stored and can be passed
on to another consumer.
Ecosystems Unit
A consumer that eats a consumer
that already ate a consumer:
• Is called a third
order or tertiary
consumer
• May be a carnivore
or a herbivore
• May be a predator
• May be a scavenger
Ecosystems Unit
Consumers that eat producers
& other consumers
• Are called omnivores
• Omnivores eat plants
and animals
Ecosystems Unit
The transfer of energy from sun to
producer to primary consumer to
secondary consumer to tertiary
consumer can be shown in a
FOOD CHAIN.
Food Web
Sun
owl
red fox
rat snake
toad
rabbit
corn
field mouse
grass
bacteria
fungi
butterfly
flower
mold
Decomposers break down all dead organisms and wastes from entire
food web
Ecosystems Unit
Another way of showing the transfer of
energy in an ecosystem is the
ENERGY PYRAMID. Energy pyramids show:
• That the amount of available
energy decreases down the
food chain
• It takes a large number of
producers to support a small
number of primary consumers
• It takes a large number of
primary consumers to
support a small number of
secondary consumers
Ecosystems Unit
ECOLOGICAL PYRAMIDS: The concept of a pyramid is useful
to describe the energy (trophic) levels of organisms, the
amount of biomass (the mass of all the living material), and
amount of energy transferred from one trophic level to
another.
Trophic Levels
Tertiary Consumers
Secondary Consumers
Primary Consumers
Producers
Biomass Pyramid
Tertiary Consumer has 10% of the
biomass found in the secondary
consumer level, that’s 0.1 % of the
producer level
Secondary Consumer has 10% of the biomass
found in the primary consumer level, that’s 1
% of the producer level
Primary Consumer level has
10% of the biomass found in the producer level
Producer level has the largest amount of biomass
90% of the materials (biomass) taken in by consumers ends up as waste.
This means that in order to make 1 gram of tertiary consumer biomass,
1000 grams of producer is needed in the beginning!
Energy Pyramid
0.1% of the energy originally
taken in by the plants
1% of the energy originally
taken in by the plants
10% of the energy originally taken in by the plants
100% of the energy originally taken in by the plants