1 / 25

Population Ecology

Population Ecology. When we look more closely at a population and it’s dynamics, what do you find?. Characteristics of a Population. Geographic distribution Density Growth rate. 1. Geographic Distribution. The area in which the population lives.

barton
Download Presentation

Population Ecology

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. Population Ecology When we look more closely at a population and it’s dynamics, what do you find?

  2. Characteristics of a Population • Geographic distribution • Density • Growth rate

  3. 1. Geographic Distribution • The area in which the population lives

  4. http://bss.sfsu.edu/holzman/courses/Spring%2005%20projects/RedFoxCasey/RedFox02.jpghttp://bss.sfsu.edu/holzman/courses/Spring%2005%20projects/RedFoxCasey/RedFox02.jpg

  5. 2. Density • Number of individual organisms per unit area • Unit area- square miles, square feet, square inches, etc

  6. http://farm3.static.flickr.com/2273/2201724577_68ffc05639_o.gifhttp://farm3.static.flickr.com/2273/2201724577_68ffc05639_o.gif

  7. 3. Growth Rate • How a population grows over time • Usually they stay the same from year to year • But sometimes can grow higher or lower depending on other things • Affected by 3 things • Number of births • Number of deaths • Immigration and emigration

  8. Birth Rate vs. Death Rate • Population grows when birth rate is higher than death rate • Population falls when birth rate is lower than death rate

  9. http://www.populationaction.org/Publications/Fact_Sheets/FS23/asset_upload_file751_5036.jpghttp://www.populationaction.org/Publications/Fact_Sheets/FS23/asset_upload_file751_5036.jpg

  10. Immigration • Organisms moving into the area or population http://www.nps.gov/npnh/forteachers/images/immigrants_2.jpg

  11. Emigration • Number of organisms moving out of the area or population http://www.bulbman.com/images/exit0005.jpg

  12. http://www.nsc.gov.la/Products/Populationcensus2005/figure%20chapter2/2.6.%20Immigration%20and%20Emigration%20during%20the%20last%2012%20Months%20Prior.JPGhttp://www.nsc.gov.la/Products/Populationcensus2005/figure%20chapter2/2.6.%20Immigration%20and%20Emigration%20during%20the%20last%2012%20Months%20Prior.JPG

  13. Exponential Growth http://www.agen.ufl.edu/~chyn/age2062/lect/lect_27/39_05.GIF

  14. Exponential Growth • Population grows at constant rate • At first growth is slow, then it gets larger and may get to infinity • This ONLY HAPPENS in perfect conditions

  15. Logistic Growth

  16. Logistic Growth • More logical, what really happens • Starts like exponential growth • But resources disappear as they are used and growth slows • Growth stops at carrying capacity

  17. Carrying Capacity • The height the population can reach with the amount of resources in that area

  18. Limiting Factors • Factor that causes growth to decrease • Examples: competition, predation, parasitism and disease, climate extremes, human interference

  19. Density Dependent Factors • Limiting factor that depends on population size • Such as disease: the closer together the organisms live, the more likely they will be to get the disease from another organism

  20. http://img233.imageshack.us/img233/9691/relationshipjp2.gif

  21. Density Independent Factors • Have same affect on all population sizes and densities • Natural disasters, human activity

  22. Human Population • Best population to see all these with • Technology, advances in healthcare, and agriculture have helped the human population to boom

  23. Demography • Study of human populations

  24. http://www.censusscope.org/us/s41/chart_age_graph_1.gif

  25. http://www.census.gov/ipc/www/img/worldpch.gif

More Related