Download 1.1 SUSTAINABILITY (Pages 7-20)

1.1 SUSTAINABILITY
• Sustainable ecosystems endure, and
they sustain the organisms that live within
them.
• Matter including nutrients such as
nitrogen, are constantly moving through
Earth’s spheres.
• Human activities that increase the influx
of nutrients into a terrestrial or aquatic
ecosystem can upset the nutrient balance
in the ecosystem.
• Decisions and actions that are taken to
protect the health of ecosystems may
involve international agreements and
court decisions.
The Mystery of Easter Island
• Trees were cut to build
homes and boats for
fishing
• Cut down trees to clear
the land for their crops
• Burn wood for warmth
• Easter Island
• Farming
• Sustainability
What is an ecosystem? List two
examples.
• An ecosystem is all the interacting parts of
a biological community and its
environment
• Examples:
– Coral reef, forests, rainforests, ponds, deserts
What is the two part meaning for
the word “sustain”?
• “Sustain” means to endure and support
Explain what sustainable
ecosystem means.
• Sustainable ecosystem refers to an
ecosystem that is capable of withstanding
pressure and giving support to a variety of
organisms.
Use the map in Figure 1.2 to explain how
ruby-throated hummingbirds are dependent
on more than one ecosystem.
• Ruby-throated hummingbirds live part of
the year in a tropical rain forest, and then
they stop in many ecosystems along the
way as they migrate north in the spring.
• They spend the summer in meadows and
wetlands in Canada.
Do you know any species that depend
on more than one ecosystem?
• Birds fly south during the winter
• Flowers and plants flourish in the spring
and die away as it gets cooler in the fall
• Any other examples?
What are the two parts of an ecosystem?
Define and list four examples for each
one.
Definition:
•BIOTIC PARTS – The
living parts of an
ecosystem
Examples:
•Plants, grass, animals,
micro-organisms,
bacteria, insects
Definition:
•ABIOTIC PARTS – The
non-living parts of an
ecosystem
Examples:
•Water, oxygen, light,
nutrients, soil
Describe how the three types of
biotic interactions work.
SYMBIOSIS
PREDATION
The interaction between members of
two different species that live together
in a close association. An example
would be a mushroom helping trees
absorb water & nutrients from the soil.
One organism consumes another
organism for food (predator vs. prey).
An example would be the river otter
[predator] & fish [prey].
COMPETITION
Two or more organisms compete for
the same resource, such as food, in
the same location at the same time.
An example would be dandelions
competing with grass for the same
resources.
Define the following terms:
• Lithosphere: The hard part of the Earth’s
surface
• Hydrosphere: All the water found on Earth,
including lakes, oceans & ground water
• Atmosphere: The layer of gases above
Earth’s surface
• Biosphere: The regions of Earth where living
organisms exist
The Water Cycle
• As water vapour rises, in the atmosphere, it cools and
condenses (evaporation)
• Clouds form from the condensed water droplets
(condensation)
• Water returns to the lithosphere as precipitation
• Water returns to the Earth & enters biosphere as it is:
– Absorbed by plants & animals
– Erodes rock
– Consumed by organisms
The Carbon Cycle
• Carbon is an essential nutrient for all living things
• CO2 in the air is used by plants and algae to make sugars
(atmosphere  biosphere)
• Organisms break down the sugar to obtain energy for life & growth &
CO2 is released as waste (biosphere  atmosphere)
• Burning fossil fuels releases CO2 into the atmosphere (biosphere 
atmosphere)
• When organisms die, their carbon-containing molecules become part
of the soil as they decay releasing CO2 into the air (biosphere 
lithosphere)
• The remains of dead organisms gradually changes to fossil fuels
(such as coal, gas, oil) which are carbon rich
The Nitrogen Cycle
• Involves converting nitrogen into useable forms
• Nitrogen is needed by plants for photosynthesis
• Nitrogen Fixation is when nitrogen is converted (by soil
bacteria) into ammonium (NH3) or nitrate (NO3)  useable
forms
– It is used by plants and animals and released back into the atmosphere,
and the process repeats
– Decomposed animals and plants release nurtrients into the soil and
through their feces
• Plants absorb nitrates from the soil most of the time and it is
passed on in the food chain as organisms eat one another
• Denitrification change nitrate back to nitrogen
which can be released into the atmosphere for use
again in nitrogen fixation
• Decomposers break down large nitrogen-containing
compounds into smaller ones until they make them
into nitrate for the denitrifying bacteria to work on
The Phosphorus Cycle
• Unlike nitrogen and carbon that’s stored in the atmosphere,
phosphorus is stored in the lithosphere
• When rock is broken down into smaller pieces, phosphorus in
the form of phosphate (PO4) is released into the soil
• PO4 is then absorbed by plants through their roots
• PO4 continues to move through the biosphere as organisms eat
one another
• Bacteria eventually break down dead organisms & waste
releasing phosphate back into the soil & the cycle continues.
• Enters the aquatic ecosystems by leaching or run-off land
List and explain 2 human activities that
can throw off the balance in a sustainable
ecosystem.
• Aquatic ecosystems suffer when a runoff has high amounts of agricultural
fertilizers
• Regular constant drilling of the Earth’s
lithosphere can deplete resources such as
coal, oil and gas
What is eutrophication?
• Eutrophication is a process which nutrient
levels in aquatic ecosystems increase,
leading to an increase in the populations
of primary producers