1. Population Density

2. Density Number of individuals per unit of area Calculation:
Pointe Claire - 1,597.7/km2
Alexandria /km2
Yellowknife /km2
Montreal - 4,439/km2
China - 6,480/km2 
Calculation:
Population Density=
Factors:
Food, water, climate, disasters, disease

3. From latin communitas meaning fellowship
Communities
From latin communitas meaning fellowship

4. Biodiversity Describes the variety of species living in a community
Measures:
Species richness
Number of species
Relative abundance
Number of individuals of a particular species
Biodiversity is high when: relative abundance is similar and when species number is high

5. Interactions - Competition (Rivalry)
interaction between living organisms that seek access to the same resource in their habitat
Intraspecific
Occurs between those of the same species
Interspecific
Occurs between those of different species

6. Interactions - Predation (Robbery)
Interaction between two living organisms in which one feeds on the other
Parasitism is a form of predation
The parasite draws its food from the host by living inside of on its surface
The parasite gains, the host is harmed

7. Interactions - Mutalism (borrowed)
Interaction benefiting both organisms
Example: flowering plants and pollinating species that feed off the nectar
Interaction benefits the plant which reproduce through pollination, pollinators which feed of the flowers

8. Interactions - Commensalism (Sharing a table)
Interaction between two organisms in which one organism benefits from the relationship while the other remains unaffected
Example: birds in human environment. They benefit from the vast availability on our environment, and we are seemingly unaffected (not harmful or beneficial).