1 / 24

POPULATIONS

SC STANDARD B-6. 2: Students will demonstrate an understanding of the way populations are affected by density-dependent factors & density-independent factors. POPULATIONS. CN page Topic: Populations EQ: What factors affect population size?. How do Populations Grow?.

calla
Download Presentation

POPULATIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. SC STANDARD B-6. 2: Students will demonstrate an understanding of the way populations are affected by density-dependent factors & density-independent factors. POPULATIONS

  2. CN page • Topic: Populations • EQ: What factors affect population size?

  3. How do Populations Grow? • 3 important characteristics of a population are its : • geographic distribution • density • growth rate

  4. Geographic Distribution • is the range or area where the organism is found

  5. Hooker’s Manzanita • found in maritime chaparrel (threatened habitat due to development) • Central California (Monterrey County)

  6. Franklin’s Bumble Bee • Most restricted geographic distribution of any known bee • Between Pacific coast & Sierra Nevada in Oregon & northern California

  7. Density • population density: the # of individuals per unit area • Density is one of the main characteristics that describes a natural population.

  8. Growth Rate • 3 factors affect population growth: • 1. # of births • 2. # of deaths • 3. # of individuals that immigrate or emmigrate • Immigration: movement of individuals into an area • Emmigration: movement of individuals out of an area

  9. EXPONENTIAL GROWTH • growth pattern in which the individuals in a population reproduce at a constant rate • Under ideal conditions with unlimited resources, a population will grow exponentially

  10. LOGISITIC GROWTH • growth pattern in which a population’s growth rate slows or stops following a period of exponential growth • carrying capacity: largest # of individuals of a population that a given environment can support

  11. Carrying Capacity Graph

  12. Limiting Factors to Growth • In respect to populations a limiting factor is anything that causes population growth to decrease. • Limiting factors are either: • Density-Dependent • Density-Independent

  13. Density-Dependent Limiting Factors • limiting factor that depends on population size • become limiting only when population density reaches a certain level • Include: • 1. competition • 2. predation • 3. parasitism & disease

  14. 1. Competition When populations become crowded members of same or different species compete for food, shelter, mates, space, sunlight

  15. 2. Predation • Predator-Prey relationships mechanism of population control

  16. 3. Parasitism & Disease • Parasites take nourishment from their host  host weakens  does not usually die

  17. Density-Independent Factors • affect all the populations in similar ways, regardless of #’s • Forest fires • Floods • Seasonal cycles • Human interference (clear-cutting, damming river)

  18. Human Population Growth • Population of humans on Earth increases with time

  19. Patterns of Population Growth • Birth rates, death rates, & the age structure of a population help predict why some countries have high growth rates while other countries grow slowly.

  20. The Demographic Transition • the change in a population from high birth & death rates to low birth & death rates

  21. Complete concept map from page 134 of book on page of notebook (landscape)

More Related