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

• 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.