Download Science 10 Chapter 1.2

What type of environments are
these animals adapted for?
What do you notice?
What questions do you have?
Bryce Casavant was suspended after he defied orders
from the province to kill two bear cubs in 2015.
Black bear tranquilized after running loose
in South Vancouver (April 28, 2015)
http://bc.ctvnews.ca/black-bear-tranquilized-after-running-loosein-south-vancouver-1.2348334
Chapter 1.2:
Ecosystems
Today’s objectives…
1. Describe the relationships/interactions
between abiotic and biotic elements
within an ecosystem
Parts of Ecosystems:
• Within biomes are different ecosystems.
– a network of interactions linking biotic factors
(organisms) and abiotic factors (air, water,
light, etc.).
• Ecosystems can be many hectares wide or
take up just the space inside a fallen tree.
• Within
ecosystems are
habitats.
– Where an
organism lives
(bottom of a
rotting log,
between rocks in
tide pools, in a
burrow, etc.)
Abiotic Interactions:
• The abiotic components of ecosystems are just
as important as the organisms that live in them.
Abiotic interactions include the following:
1. Oxygen is produced by green plants and certain
micro-organisms and is used by most other
organisms.
2. Water is essential for all life.
1.
Nutrients like carbon,
nitrogen, and phosphorus are
materials that organisms need
to live and grow.
2. Light is required for
photosynthesis
–
The amount of light in an
ecosystem can vary  forest
canopy versus ground or deep
water versus water surface
1. Soil doesn’t just contain water and
nutrients; it is a home to many plants
and animals.
Ecological Hierarchy:
• Ecology is the study of the
relations of organisms and
its environment and to each
other.
• A species is a group of
closely related organisms
that can reproduce with one
another.
• The biotic interactions can be arranged
into an ecological hierarchy that shows the
order of relationships:
Biotic Interactions in Ecosystems:
• Within an ecosystem, organisms
constantly interact with members of
their species and with other organisms
• Symbiosis is a relationship in which two
different organisms/species live together
in close association.
1. Commensalism
•
One organism benefits while the other
organism is not affected.
Examples:
2. Mutualism
•
•
both organisms benefit from the interaction.
Often in mutualism, both organisms cannot
survive without one another (they are highly
dependant on one another)
Examples:
3. Parasitism
•
•
One organism benefits while the other is
harmed.
The organism that is harmed is call the ‘host’
 host is not usually killed (unintentionally)
Examples:
Other biotic interactions:
(non-symbiotic)
• There are 3 factors that must be
considered in terms of an organism living
in an ecosystem and its chances of
survival:
– Niche, competition, and predation
• Niche refers to the role an organism has
within an ecosystem
– How it fits into the community and how it
contributes to its environment physically,
chemically, and biologically.
• Competition is a harmful interaction
between 2 or more organisms when they
need the same resource (food, territory,
mates, etc.) in the same location at the
same time.
– Competition can limit the size of a population
because an organism needs energy to compete but
also needs energy to grow and reproduce.
– Examples: weeds compete with your flower bed for
space, nutrients, and soil (invasive species often
out-compete native plants/animals)
• Predation is the relationship where one
organism (the predator) kills and
consumes another organism (the prey).
– Predators have adaptations that make them
effective hunters
• good eyesight, sense of smell, or fangs and claws
– Prey can have adaptations that keep them
from being eaten
• Shells, spikes/quills, camouflage, mimicry
• The numbers of predator and prey influence
one another
– The prey population grows when there are fewer predators
– The prey population shrinks when there are many predators
– Vice versa for predator population
Biodiversity:
• Biodiversity is the
variety of all living
species of plants,
animals, and
micro-organisms
• Healthy
ecosystems
generally have
high biodiversity.
• Most biodiversity loss occurs from the loss
of habitat.
– Humans often have a negative impact to
biodiversity by cutting down forests and
building cities
– Efforts being made to lessen human impact
and maintaining biodiversity
• Ecological management programs (aka sustainable
resource management) try to maintain a balance
between human progress and biodiversity.
Homework:
1. Read pages 34 to 48 in textbook
2. Complete 1.2 Worksheet
3. Ch.1 Practice Quiz