Transcript 2.1 Populations and Resources (Pages 49-54)

2.1 Populations and Resources
(Pages 49-54)
Homework: Page 55 # 1,3,5,7
Page 47 Activity 2-1; 1-4
Page 52 Activity 2-2; 1-5
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Species – A specific type of organism  Zebras &
water buffalos
Population – A population consists of how many
individuals of ONE species is in one area. For
example, the population of Toronto is 2.6 million
people. This definition ONLY applies to one species
(humans) in one area (Toronto)  5 zebras,
approximately 120 water buffalo
Community – A community is the combination of all
populations in one area. For example, the community
of Toronto is still made up of one area (Toronto), but it
now includes 2.6 million people, 1 million dogs, billions
of insects, millions of squirrels, etc.
Ecosystem –
Key Concepts (Page 55)
• Populations tend to increase exponentially
when there are available resources.
• When resources that are needed by populations
become limited, the carrying capacity of an
ecosystem has been reached.
• Human alteration of an ecosystem, such as
through urban sprawl , often reduce the
carrying capacity of the ecosystem for other
species.
What is population?
• Population is a group of organisms of
one species that lives in the same
place, at the same time, and can
successfully reproduce
3. There are about 25 fish in this image of the
coral reef.
4. After being protected from hunting, the
population of elephants in Kruger National
Park grew exponentially.
5. The turkey population grew exponentially
because many parts of Southern Ontario
became reforested & there was a hunting
community that supported careful
management of hunted species.
6. A limiting factor is a factor that limits the
growth, distribution or amount of a population
in an ecosystem. Three examples are: food,
water & shelter.
7. The size of the population is at an equilibrium
(a balance between opposing forces), or
balance. There is a balance between the # of
individuals added to the population & the # of
individuals that leave or die.
8. As humans alter natural ecosystems, the
carrying capacity may increase for species
that occupy human-altered landscapes, but
often it decreases (ex. urban sprawl).
9. 2 limiting factors:
• Amount of shade – Growth of shade
intolerant plants reduces space for the dace
• The quality of water (habitat) – The decline in
the numbers of dace’s prey due to change in
habitat limits the growth of the dace
10. The Intensification Policy of Ontario
requires that a large percentage of new
development must occur on land within the
boundary of a city (ex. building additional
floors on top of a building).
11. If more houses were being built, there
would be a loss of crops for humans, a loss
of habitat for organisms, a loss of trees to
purify air, etc.
12. Volcanic lava affects ocean species
because the lava may create a toxic living
environment for water animals, contaminate
the water (that can be used for drinking) &
animals that consume the organisms living
in the ocean may start to die as well.