Ecosystems
A Unit Review
What are Ecosystems?
• Groups of living things and the non-living
environment in which they live.
• The people that study ecosystems are called:
“ecologists.”
Let’s look at the living parts of the ecosystem:
Individual: one
Population: group of organisms
of the same species living
in the same place
Community: A community is made up of all the populations that live in the
same area. When thinking about the deer we just looked at, their community
would include:
r
a
b
b
i
t
s
S
q
u
i
r
r
e
l
s
s
n
a
k
e
s
birds
bears
Just to
name a few.
and
Habitat: is the physical space that is used by a population. You can remember that
habitat also means “home.”
For example: when thinking about the deer that we just saw, they might live
in a forest. The forest is also home to those rabbits, snakes, squirrels, bears, and
birds. This is their habitat. It’s where they live. Notice that you don’t see sharks,
giraffes, or polar bears here. The forest is not their habitat.
So, how do all the living things in an ecosystem live together without killing one
Another?
Well, the truth is they do kill each other. They have to – it’s the “circle of life”
Remember Lion King?
We represent this cycles three different ways:
Way 1: Energy Pyramid:
Notice how there is a lot of
grass, but fewer primary
consumers, and even fewer
secondary consumers.
That’s what makes the
pyramid.
Which organisms in the
ecosystem contains the
most energy?
Which organisms in the
ecosystem contains the
least energy?
Contributing Factors=
“What causes?”
What is the contributing factor to
more producers than consumers
In the energy pyramid?
a. There is more energy available to the producers.
b. There is more energy available to the consumers.
Way 2: Food Chain
Way 3: The food web shows how all the
food chains are connected.
What is the main source
Of energy in this food
Web?
What organisms does the
Bird eat for energy?
If the population of birds
Rapidly increased, what
Would be the effect on the
Population of kangaroos?
You’ll need to know lots of definitions in order to understand how energy is transferred
in ecosystems:
1. Energy -
The sun provides
the energy for all
living things on
Earth. The amount
of sunlight an
ecosystem receives
affects the types of
organisms
that live in it.
2. Producers -
Organisms that use
energy from the sun to
make their own food.
That process is called
“photosynthesis.”
3. Consumers – Organisms that get energy by eating other organisms.
a. Herbivores – eat
only plants.
c. Omnivores – eat
both plants and
meat.
b. Carnivores –
eat only
meat.
d. Scavengers – eat dead materials
4. Decomposers –
Get energy by breaking
down nutrients in dead
organisms. This causes
“decay”.
Predator Vs. Prey
Predator – An
organism that
eats other
organisms in
order to live.
Prey – The organism
that is eaten
So what is it called when organisms live
together in ecosystems?
Symbiosis
Mutualism – when
both organisms
benefit
Parasitism – when
only one organism
benefits.
Here’s an example of Symbiotic Relationship that is mutually beneficial:
The ox gets the bugs eaten off of him, and the bird gets lunch!
Here’s an example of a symbiotic relationship this is parasitic.
The flea lives off the dog, but the dog doesn’t benefit. He only gets itchy skin and
maybe even worse.
What happens when animals don’t have long term relationships, but they still share
same habitat?
This means they “compete” or have a contest to see who gets the food, water,
sunlight, or shelter. Ever heard the phrase “survival of the fittest?”
Which one do you think would survive if they needed to run away from a big, mean bear?
Predator –
the animal
that hunts
Prey – the
animal that
gets eaten
Sometime animals share resources:
Owls and hawks eat the same things, only at different times of the day.
Exotic Animals
Animals that are not native to a country, but instead have been
brought to that environment. Pythons are not native to Florida.
Look what this has done to one of Florida’s top predators.
How could this impact the rest of the Everglades Ecosystem?
Biomes – large-scaled ecosystems.
We talked about 3 Terrestrial (Land) and 3 Aquatic (Water):
1.
2.
3.
4.
5.
6.
Tropical rainforest
Temperate Deciduous forest
Grasslands
Estuaries
Oceans
Lakes and Ponds
Rainforest
Estuaries
Oceans
Lakes and Ponds
Whew! – That’s a lot!
Your test is coming up soon!
Make sure you know your stuff!
Good Luck!