Download Why Monocultures are Created What?

Monocultures
L.O: to describe the impact of monocultures on biodiversity
Starter: AS BIOL1 recap!
If Mono = one, ?? = Two, ?? = Three, ?? = Six
Do you know any others? (Chemists!)
Definition
The cultivation of a single crop in a given area.
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Why Monocultures are Created
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Why Monocultures are Created
Advantages of monoculture:
• Reduced plant competition for nutrients, space and solar radiation
• Control of undesirable (unprofitable) organisms
• Reduction of costs by limitation of specialized machinery required for arable
operations
• Maximize profit from the growing of high gross margin crops
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Impacts of Monocultures
Paper simulation!
Light Green is Noble Fir
Red is Western Red Cedar
Blue is Vine Maples
Yellow is Western Hemlocks
Orange for White Fir
Pink is Bigleaf Maple
Yellow is Western Dogwood
What?
Why?
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• When a habitat is very diverse with a variety
of different species, it is much healthier and
more ecologically stable.
• One of the reasons for this is that disease
doesn't spread as easily in a diverse
community. If one species gets a disease,
others of its kind are far enough away (due to
the variety of other organisms) that disease is
often stopped at the one or two individuals.
1. What type of competition would be present in the wood? In the
monoculture?
2. Which forest would have more ecological stability? Why?
3. Why didn't the disease spread as fast among the Douglas firs as it
did in the first simulation?
4. Why would you need to use more insecticides in monoculture? Is
this good or bad?
5. Why have farmers been told to plant hedgregrows around their
fields?
6. Extension: Many species can only live/reproduce in 1 type of
forest. The spotted owl is an example - it can only live and
successfully reproduce in old growth forests(big, old cedars,
hemlocks, etc.). If these old growth forests are cut down, it's
unlikely this owl will survive. Environmentalists call it an
"indicator" species." What does this mean? Why be concerned
about 1 species?
Northern Spotted Owl
Northern Spotted Owl
Have a narrow range of ecological tolerance and their
presence or absence indicates the ‘health’ of an ecosystem
Impacts of Monocultures
http://www.bbc.co.uk/learningzone/clips/natural-balance-the-forest-andindustry/4707.html
What?
Why?
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Biodiversity
What is it?
http://www.youtube.com/watch?v=oeQMRlbbI4Q