BIODIVERSITY THREATS (extra / review)
Deforestation Removal of a forest or a large group of trees from an area where the land is converted for non-forest 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)
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)