Ecosystems
All the living and nonliving things that
interact in a particular area make up an
ecosystem. Organisms live in a specific
place within an ecosystem. Examples of
ecosystems are mountain streams, deep
oceans, dense forests, and deserts. The
place where an organism lives and that
provides the things that it needs is called
its habitat. An organism obtains food,
water, shelter, and other things it needs to live, grow, and reproduce from its habitat. A
single ecosystem may contain many habitats. For example, mushrooms grow in the
damp soil, while termites live under tree trunks, and birds make nests in tree branches.
Organisms live in different habitats because they have different requirements for
survival. You wouldn’t see a penguin in the desert because it does not meet its needs.
An organism interacts with both the living
and nonliving things in its environment. The
living parts of an ecosystem are called biotic
factors. These include grass, plants, worms,
fungi, bacteria, and animals. The nonliving
parts of an ecosystem are called abiotic
factors. Abiotic factors include water,
sunlight, oxygen, temperature, and soil.
Can you name the abiotic and biotic
factors in this ecosystem?
Remember, all living things require water, not
just to carry out their life processes, like
digestion, but also for producers to make food in the process of photosynthesis. These
autotrophs provide the energy for many of the other organisms in same ecosystem.
A species is a group of organisms that are physically
similar and can reproduce with each other to produce fertile
offspring. All the members of one species in a particular area
are referred to as a population. i.e. all the pigeons that live in
New York City. But not all the trees in NYC are a population
because they are not all the same species. There are pines
and maples, and birches, and others.
Different species of trees.
Are they a population?
All the different populations that live together in an area make up a community. To be
a community, they have to interact, meaning they have to use the same resources. For
example, foxes, snakes, and owls can be in the same community because they use the
same forest to hunt the same kind of prey.
The smallest unit of organization is a single
organism or individual, which belongs to a
population of other members of its species. The
population belongs to a community of different
species. The community and abiotic factors together
form an ecosystem. Ecosystems that are similar
across the world are called biomes. Biomes make
up the biosphere, which consists of all the living
organisms on land, in the air, and in the water
The study of how living things interact
with each other and with their
environment is called ecology.
Ecologists, scientists who study
ecology, look at how all the biotic and
abiotic factors in an ecosystem are
related. They study how organisms
react to changes in their environment.
Living things constantly interact with
their surroundings, responding to
changes in the conditions around them.
A picture of this is when a prairie dog sees a hawk overhead and gives a warning bark.
The other prairie dogs hear the bark and respond by hiding in their burrows. Or when the
temperature changes, animals migrate thus changing the food supply.
Draw your own picture and write a caption about something
that you learned in this reading.
Write your caption in the box below.
Name___________________________
Ecosystems
1. What is an ecosystem?
________________________________________________________________________________
2. Give some examples of an ecosystem.
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3. Within an ecosystem, the specific place that a particular organism lives is called its
__________________.
4. True or False? Habitats contain most of what an organism needs to survive.
5. An ecosystem contains ________________ and __________________factors.
6. List some examples of biotic factors. __________________________________________________
7. List some examples of abiotic factors. _________________________________________________
8. What is the basic difference between abiotic and biotic factors? ____________________________
_______________________________________________________________________________.
9. What kind of factor is water? ______________ Besides being used for body processes, why is it
such an important factor for an ecosystem?
___________________________________________________________________________________
___________________________________________________________________________________
10. A group of organisms that are physically similar and reproduce with each other to produce fertile
offspring is called a ____________________.
11. All the members of a species in a particular area are called a(n)___________________________.
12. True or False? All the trees in the Rockies belong to the same population since they are all in the
same area.
13. Different populations sharing the same resources in an ecosystem are called a(n) __________________.
14. The smallest unit of organization is a single __________________ or _____________________.
15. Similar ecosystems across the world, such as the tundra, or rain forests, are called ________________.
16. All living things in the air, on or under the land, and in water, make up the _____________________.
17. The study of how living things interact with each other and their environment is called ________________.
Review: Did you get it??????
1. Complete the diagram above to show the levels of organization in an ecosystem. Start with the
smallest unit.
2.a. Choose one of the ecosystems listed and name three populations commonly found in it.
a forest, a desert, the jungle, or a coral reef
________________________________________________________________________________________
b. Name four abiotic factors in the ecosystem you chose above.
___________________________________________________________________________________
c. Identify two different habitats in the ecosystem you chose. Name one organism found in each habitat.
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