Science 7
Unit 1: Interactions within Ecosystems
Chapter 1: An ecosystem is all the living and non-living
things in a particular place
Section 1.1
Types of Ecosystems
Ecosystems can be described by the types of
organisms and the conditions found there.
4 types of ecosystems in Atlantic Canada are:
1) Oceans & Coastlines
2) Freshwater: Rivers, Lakes, & Ponds
3) Forest
4) Arctic
 Different ecosystems will have different
types of organisms, different conditions and
vary in size (they can be large or small).
 They include the living (biotic) and non-living
(abiotic) things.
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Section 1.2
Abiotic Parts of an Ecosystem
 The non-living parts of the environment.
 Each type of organism is adapted to a
particular set of abiotic conditions.
 Examples of abiotic conditions are:
temperature, sunlight, air, wind, water, soil, and
climate.
 Organisms can only survive in a certain range
of conditions. For example, a salmon can survive
in water between 0°C and 20°C.
 The range of conditions within which an
organism can survive is called the organism’s
range of tolerance.
 Each organism has a different range of
tolerance for each abiotic condition.
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Section 1.3
Biotic Parts of an Ecosystem
 The living parts, or organisms, in the
environment.
 Organisms can be organized in to species,
populations, or communities.
 A species is a group of organisms that can
reproduce among themselves to produce
offspring of the same type (that can also
reproduce successfully).
 A population is an entire group of individuals
of the same species that live together in one
ecosystem at the same time.
 A community is formed when populations
interact.
 Refer to example in text on page 25.
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Organisms may be studied at different levels of
organization in an ecosystem:
Habitat - the organism’s address; where does it
live?
Ex. A moose’s habitat is the boreal forest.
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Niche - the organism’s job; what role does the
organism play in its environment.
- It includes:
 where it lives
 how it obtains food
 how it affects its environment
Ex. A moose lives in the boreal forest, it is a
herbivore (plant eater), it provides a home for
parasites and it provides food for coyotes.
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Interactions in the Environment:
Biotic – Abiotic: Interactions between living things
and non-living things.
Ex. The polar bear and the water.
Abiotic – Abiotic:
Interactions between non-living things and other
non-living things.
Ex. The wind and the temperature.
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Biotic – Biotic:
Interactions between living things and other living
things.
Ex. The lion and the elk.
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