Download BIODIVERSITY THREATS (extra / review)

BIODIVERSITY
THREATS
(extra / review)
Deforestation
● Removal of a forest or a large group of trees from
an area where the land is converted for nonforest use
● Destroys ecosystems, nutrients, soil
● Trees help to remove carbon
dioxide from the atmosphere
less trees will mean more
CO2
● Video - Deforestation
Disturbing Soils
● Deforestation removes topsoil because there are
no plant roots to hold it in place
● Increases frequency of erosion
● Little to no re-growth
without topsoil to
provide nutrients
Wetlands
● Area of land covered by water for part or all of
the year
● 6% of Earths surface is wetland
● 24% of worlds wetlands
are in Canada
● Video – What is a Wetland?
● Importance:
● Store water – reduce flood risk
● Home to thousands of organisms
● 30% of birds in North America stop in
wetlands during
migration
● Plants filter sediment
and pollution from the
water
● Protection:
● Humans once thought
wetlands to be useless
because they could not
be used for farming or building (development)
● Were drained and filled in
● Now their value is known and more efforts are
being made to protect them
● Video - Wetland drainage and flooding
Alien Invasive Species
● Alien Species
● Accidentally or deliberately introduced into a
new ecosystem
● Invasive Species
● Take over habitat of native species
● Human travels have been the main cause of alien
invasive species
● Example: European Green Crab
● Travelled to Bay of Fundy
● Prey on clam, oyster and scallop
● Out-compete lobster
● Severely damaged ecosystem
● Example: Zebra Mussel
● Found in the Great Lakes
● Disturb ecosystem through
feeding
● Also cause trouble for boats,
pipelines and power plants
● Video – Making Invasive Species Work for Us
● Video – Little Things, Big Problems – Invasive
species (plants)
● Video - Invasive Species - Zebra Mussel
Overexploitation
● use or extraction of a resource until
depletion
● can lead to extremely low population
numbers
● examples include overhunting and
overfishing
Overexploitation
Video - Over fishing
●To Do:
●p. 327, #’s 10 & 11
●p. 330, #’s 12 & 14
●Answers
Video – Biodiversity and Health (~30 minutes)
Video - Human activities that threaten biodiversity (12
minutes)
Video – Biodiversity is us (13 minutes)