Transcript 5b. Chap 2- Human Impact TEA Laurier

ASSESSING
HUMAN IMPACTS ON
ECOSYSTEMS
Easter Island Mystery
• Discovered in 1722
• Once were thriving population of people and thick
forests
• The islanders then clear trees for crops, use
wood to move large rock statues, and burn wood
to keep warm
• No forest to support
the island sustainably
• Decline of human and
other populations;
What is Sustainability?
• The ability of populations
of organisms to live,
interact and reproduce
indefinitely in an
environment
Arrange your desk
“Benefits of natural ecosystem &
biodiversity” Cubing activity
• In group of 4, with the provided BIG CUBE
• Use the provided 4-corner placemat
• Each member write down their own thought
after seeing each picture in the cube
Listen for signal to
rotate the cube;
students & placemat
don’t rotate
Benefits of biodiversity and ecosystems
Think/Pair/Share
Food
-Fuel
-Natural resources
-Water
-wetlands purify water
- Regulate climate (temperature, rain)
-Cycle nutrients and decompose waste
-The animals help pollinate crops and disperse
seeds.
-Cultural and recreational opportunities (e.g.
parks, beaches) for our well being.
Biodiversity
= the number and variety of species on
Earth
~ 2 million species identified so far
• To maintain biodiversity, we must use
the resources of an ecosystem in a
sustainable way (Meaning?)
• Sustainable use: of an ecosystem
means using an ecosystem’s resources
in a way that meets our current needs
without compromising the ability of
future generations to meet their needs.
If biodiversity is kept high then the
ecosystem is more sustainable.
Biodiversity Hot spots
Are places of high diversity
Species at risks
“Caption it” activity
Visual + feeling  powerful tool for learning
• Get a few pieces of small paper from Ms.
Pham, tape and marker
• To be done individually
• Rotate around the classroom
• Write a caption for the pictures you see
• Express your feeling and thoughts using
respectful language; initial your writing
SHARE what you came up with
Learning Task
• To actively go through the provided
reading package and answer the
embedded articles.
• If not done in class, please do as HW
• Respond to the exit card at the end and
obtain Ms. Pham’s initial
• Will be taken up next few slides
5 main reasons for the decrease in the variety
of species on Earth
• H = Habitat Change
• I = Invasive Species
• P = Pollution
• O = Overexploitation
• C = Climate Change
HIPOC
HIPOC package
assessment for learning
• NOTE:
• The next couples of slides you do not have
in your reading package
• They are used for assessment of what you
know after the reading on HIPOC
What impact is being implied here?
Habitat Change
What impact is being implied here?
Overexploitation
“Which two factors that
affect biodiversity are
responsible for the possible
extinction of the Bornean
Rhinoceros?”
Answer:
1. Poaching
2. Habitat Loss
What impact is being implied here?
Overexploitation
What impact is being implied here?
Invasive
species
Gray vs. Red
1. List 2 reasons that the Gray Squirrel is such a threat to
the red squirrel.
carrier of squirrel pox and eat 7 times more
than that native red squirrels
2. What strategies is Britain using to solve the problem of
the gray Squirrel?
Allow gray squirrels to be hunted for meals
3. Do you agree with what Britain is doing? Can you
suggest other more humane methods?
What impact is being implied here?
Pollution
What impact is being implied here?
Climate Change
How did human pollution impact the ecosystem?
-Many marine organisms
mistake human plastic
products as food and
consume them.
-They die after eating them as
they cannot digest them.
-Plastic products do not
decompose quickly; they
remain in the environment and
continue harming other
organisms.
http://www.ted.com/talks/capt_charles_moore_on_the_seas_of_plastic?language=en
How did human pollution impact the ecosystem? (Cont)
Causing acid rains
https://www.youtube.com/watch?v=v09KnqiYi-c
Hands-on: Simulate acid rain effect
What you need:
- Vinegar (filled to 3cm depth)
- 1 small test tube
- One 2-cm piece of chalk
• What did you observe?
• What would happen to this
statue if acid rain is falling on
it?
What is an acid?
• A corrosive substance
that have a high amount
of hydrogen ions
• An acid has a pH ranges
from 0 to less than 7
• pH is a measure of how
much hydrogen ions an
acid has.
Acidity Levels
• Acidity is an abiotic factor that is
connected to the chemical environment of
soil and water.
• If the pH of a substance is between 0
and 7 (below 7), it is called acidic. A
lower pH means higher acidity.
• If the pH of a substance is between 7
(higher than 7) and 14, it is called
alkaline (or basic).
• If the pH of a substance is 7, then it is
neutral.
Acid rain pH = 4.2
Clean rain pH = 5.6.
How did human pollution
impact the ecosystem? (Cont)
Causing acid rains
• In Canada, mining and refining
metals, electrical power
generation, automobiles, and
oil and gas operations emit Statue corroded due to acid rain
harmful chemicals made of
nitrogen and sulphur into the
atmosphere. This process is
called emission.
• Acid Rain: rain that contains
acid formed from nitrogen and
sulphur containing substances.
Leafless forest due to acid rain
Ocean acidification- when excess
CO2 dissolved in ocean
• Recall: ocean is a
carbon sink; it
stores CO2
Effects of acid rain on soils, vegetation, lakes,
rivers, and terrestrial and aquatic mammals
• Acid rain is an international problem as pollutant gases
are carried around the globe by wind
-Damages waxy
coating of plant leaves
that protect them
from infection.
-Acidic waters cannot support
life: dissolves shells of
organisms, makes fish eggs too
fragile to survive, and kills off
aquatic plants and animals.
-Reduces plant and tree
growth (increased acidity
towards the right)
-Increases acidity of soil
which decreases the
plants ability to absorb
nutrients from the soil.
-When acid rain
seeps into soil, it
burns the skin of
earthworms.
HW
• Summarize table 3.1 p90 onto your note
• Do Question 1-3 page 94
Sing along