Unit 1 Notes:

Populations

Where did we come from?•The processes that individual organisms do to convert and cycle energy and matter throughout an ecosystem.

•Photosynthesis, Cellular Respiration, Food Chains/Webs

Where are we going?

•The processes that impact the ability of groups of organisms to cycle energy and matter throughout an ecosystem.

•Population Changes, Biodiversity, Human Impact, Climate Change

(1) Ecosystem Levels•Organism: 1 living thing.

•Population: A group of the same types of organisms.

•Community: A variety of types of populations living together.

•Ecosystem: A specific environment with unique biotic and abiotic factors.

(2) Population Characteristics•Populations are studied and monitored by 3 characteristics:

•Geographic Distribution:The area/s inhabited by the population.•Density:Number of organisms per unit area within the population’s habitat.•Growth Rate:How fast the population increases or decreases in size over time.

6 July 22, 2012 Footer text here

7 July 22, 2012 Footer text here

(3) Population Size•4 Factors affect the size of a population:•Number of births

•Number of deaths

•Number of organisms entering (immigrating).

•Number of organisms leaving (emigrating).

(4) Population ChangesAnything that alters how the different organisms cycle energy and matter to one another, will cause changes to the

population.

(5) Limiting Factors to Population Size•A Limiting Factor is something that stops a population from continuously growing larger.

•There are 2 Types:•Density Dependent Factors that directly relate to how many organisms there are.

•Density Independent Factors that have no relationship to the number of organisms there are.

(6) Density Dependent Factors•Competition between organisms for resources.

•Predation (organisms being hunted).

•Parasitism (organisms invading other living structures and withdrawing all resources).

•Disease.

(7) Density Independent Factors•Human Disturbances & Activities.

•Climate Change.

•Natural Disasters.

(8) Carrying Capacity•The Carrying Capacity of a population is the largest number of individuals that a given environment can support.

•Limiting Factors determine the carrying capacity of any population.