Key Questions:
1. What is sustainability?
2. How does biodiversity indicate the health of an ecosystem?
3. What natural factors affect the stability of an ecosystem?
4. How do energy and matter flow through ecosystems?
5. How do human activities affect the sustainability of an ecosystem?
6. How can humans in general improve the sustainability of our ecosystems?
Outcomes:




Assess the consequences of human actions on the local, regional, and global climate and
the sustainability of ecosystems.
Investigate the mechanisms that influence Earth’s climate system, including the role
of the natural greenhouse effect.
Examine biodiversity through the analysis of interactions among populations within
communities.
Investigate the role of feedback mechanisms in biogeochemical cycles and in
maintaining stability in ecosystems.
1
Ecology
Habitat
Niche
Biotic
Abiotic
Levels of Ecological Organization
Organism
Population
Community
Ecosystem
Biome
Biosphere
2
Roles in the Ecosystem
Producer
Consumer
Primary
Secondary
Tertiary
Carnivore
Omnivore
Scavenger
Decomposer
3
Energy Flow in the Biosphere:
Autotrophs
Heterotrophs
Trophic Level
1st Trophic
Level
2nd Trophic
Level
3rd Trophic
Level
4th Trophic
Level
Food Chain
Food Web
4
Sun
Role in Food
Chain
Trophic Level
Steps from
the Sun
Grass
Example Food Chain
Mouse
Snake
Falcon
Producers
Primary
Consumers
Secondary
Consumers
Tertiary
Consumers
5
Limits on Energy Transfer – Notes
Energy Transfer between Trophic Levels
Every time energy is transferred between the components of an ecosystem, the amount of energy available to
the next trophic level is ____________.
______________ of the energy captured in photosynthesis is available to the animal that eats the plant
because the ___________ used most of that energy to carry out its life processes
Primary consumers do not ___________ all of a plant meal, some is lost in the feces. Of the remaining energy,
some is lost __________________________ from the chemical transformations of digestion and through
cellular respiration and the animal’s activity.
 _________ of the energy plants receive is stored, and therefore is passed on to the primary
consumers
 _________ of the energy that primary consumers receive is stored and passed on to Secondary
consumers
-the farther up the food chain, the less energy that is available
-this usually limits the number of trophic levels in a food chain to about 5
Thermodynamics is the study of energy transformations
First Law of Thermodynamics: although energy can be changed from one _________ to another, it cannot be
___________________________.
Second Law of Thermodynamics: during any energy transformation, some of the energy is converted into an
___________________, (usually thermal energy) that cannot be passed on.
Human Use of Energy in Ecosystems
- humans are dependent on the
________________ through
ecosystems just like all other living
things.
- we are part of many food chains at
________________________,
dependent on what we are eating.
Think about it: Are we more
efficient when we eat like Herbivores
or Omnivores? Why?
- we also used the energy for fuel for heat (example: burning wood)
- humans have permanently ______________ many ecosystems in order to grow and hunt food.
6
Scientific Models of Energy in the Biosphere
- scientists often construct ______________ to help them understand how living things work.
- models are theoretical descriptions or ___________________ that help us visualize something that has not
been directly observed.
- they provide a pathway for making predictions.
Ecological pyramids – graphs used to represent ________________ flow in food chains and food webs or the
________________ of organisms in a food chain.
- allow ecologists to visualize the relationships in an ecosystem and compare them.
- NOTE: graphs of natural ecosystems may or may not look like a pyramid!
Pyramid of Numbers
A Pyramid of Numbers can be drawn by
_____________ the number of organisms at each
trophic level in an ecosystem. As you move up the
trophic levels, the number of organisms decrease.
-That is why there is a ratio of about __________
grasshoppers to every _____ falcons.
-However something strange can happen with the
number of producers – _____________ producer can support many smaller consumers
Pyramid of Biomass
Biomass is the total ______________ of all the living
material in an ecosystem.
Since organisms store ___________ as organic
molecules, biomass is a measure of stored energy,
as well as the size of organisms at each level.
Pyramid of Energy
A Pyramid of Energy is created by measuring and
graphing the amount of ______________________
at each trophic level.
It allows a ______________ understanding of the
relationships and energy flow at each trophic level.
Large mass and the energy demands of hunting
limits the number of consumers that can be
supported at the top of the pyramid.
7
WATER CYCLE – NOTES
The Zones of the Biosphere
The biosphere is made up of three distinct zones:
1)
(land)
2)
(water)
3)
(air)
The Hydrosphere
Each year as glaciers melt, they release water from melting snow to form
streams,
rivers and lakes. But snow, ice, water in rivers and lakes, and water vapour in the atmosphere make up only a
_______________________ of all the water on Earth.
Most of the water is found in oceans where the water is
so we can’t drink it.
All of the Earth’s water, both fresh and salt, forms what is called the
Water Distribution in the Hydrosphere
Only a very small portion of the hydrosphere consists of fresh water. Most of this fresh water is
in glaciers and in the ice caps around the North and South Poles.
In fact, if all the water in the world were represented by one litre of water, then all the fresh, unfrozen
water in the atmosphere, lakes and rivers would be
With its vast freshwater supplies, Canada is one of the
!
countries in the world.
Our population is just 0.5% of the world total, yet we have almost 10% of the world’s supply of fresh water
8
The Water Cycle
Because so much of the Earth’s surface is covered in water, the weather systems depend greatly on water in
its three
: solid, liquid and gas.
Energy, mostly from the sun, causes water to
(changing from liquid to gas), or ice to
(changing directly from solid to gas) to become water vapour in the air.
also occurs, which is evaporation of water from the leaves of plants.
As the gaseous water rises and the pressure and temperature of the atmosphere decrease, the water vapour
___________________ (changes from gas to liquid), into fog, mist and clouds. If the temperature is low
enough, water vapour may form ice crystals by _______________________ (changing directly from gas to
solid). _______________________ of some kind (rain, hail or snow) - then falls to the ground.
Once water is on the ground it can either run along the surface of the ground as _________________ to
________________ in streams, rivers, lakes, and the oceans (_________________); or it can seep down
through the soil into underground reservoirs of water called ______________ to become
____________________.
Humans and the
Water Cycle
Fresh water is vital
for human
______________.
Throughout human
history, people have
made their
settlements near
sources of
__________ water.
Since a large portion
of the population still
lives
__________________, both near fresh water and on coastlines where fishing provided food, human
populations are still very tied to water.
___________________ on and near large bodies of water greatly affect large numbers of people, and
changes in the amount of water available (__________________________) have a major impact on these
populations. The effects will become greater as the population increases, and as climate change becomes more
______________.
9
CARBON CYCLE – NOTES
1. Explain the following terms:
a. Photosynthesis: (include equation)
b. Cellular respirations: (include equation)
c. Inorganic
d. Organic
10
2. Why are photosynthesis and cellular respiration considered to be “complementary
processes’?
3. Explain the importance of decomposers in the carbon cycle.
4. What are the three main reservoirs for inorganic carbon?
5. What is the main reservoir for organic carbon?
6. Organic carbon usually re-enters the carbon cycle through decomposition of deceased
living things. What two products are the result of deceased living things being buried by
sediment before they decompose?
11
NITROGEN CYCLE – NOTES
Nitrogen fixation
Denitrification
Ammonia
Nitrate
Nitrite
1.
What are the two main uses of nitrogen by living things?
12
2. What provides the majority of nitrates to an ecosystem?
3. Explain the role of decomposers in the nitrogen cycle.
4. How do animals obtain usable nitrogen?
5. Explain why it is a good idea to aerate lawns with respect to nitrogen use?
13
Human Impact on Nutrient Cycles
Carbon Cycle
1.
Burning ‘Fossil Fuels’:
2. Clearing vegetation:
3. Greenhouse Effect:
4. Global Warming:
Permafrost
Icecaps
Ocean & wind
currents
Ecosystems
Extreme
weather
14
Nitrogen Cycle
1.
Agriculture
a.
Nitrogen deficiency:
b. Crop rotation:
c.
Synthetic fertilizer:
2. Water pollution:
3. Fertilizer dependency:
4. Soil Acidification:
5. Fertilizer Burn:
6. Energy Consumption:
15