Chapter 17-Biogeography

  1. Biogeography
    study of variation of species composition and diversity among geographical locations
  2. Endemic
    occur no where else on Earth
  3. Global Scale
    entire world
  4. Regional Scale
    • smaller geographical areas in which climate is roughly uniform and species are restricted by dispersal limitations
    • Regional Species Pool: aka gamma diversisty, all species in given region
  5. Landscape
    physical geography of a region
  6. Local Scale
    • essentially equivalent to community
    • alpha diversity: diversity at local scale
  7. Beta diversity
    • connection between local and regional scale of species diversity
    • turnover: told by beta diversity, change in species composition across landscape as one moves from one local community to another
  8. Saturation Point
    limit of species richness for the community
  9. Biogeographical Regions
    • Earth's landmass divided into 6 parts containing distinct biotas that differ markedly in species composition and diversity
    • Neartic- North Am
    • Neotropic- central and South Am
    • Paleartic- Europe, parts of Asia/Africa
    • Ethiopian- Africa
    • Oriental- china, india, southeast Asia
    • Australasian- Austrailia, Indo-pacific, New Zealand
    • correspond roughly to tectonic plates
  10. Gradient of Species
    • species diversity is greatest at equator and decreases towards poles
    • seabirds defy rule
  11. Continental Drift
    sections of Earth's crust that move across Earth's surface due to currents generated by moltened rock mantel
  12. mid-ocean ridges
    • boundary beween tectonic plates
    • seafloor spreading: new crust forcing olates apart
  13. Subduction zones
    • one plate is forced downward under another another
    • associated with earthquake, volcanos, and mountain ranges
  14. Fault
    where 2 plates meet and slide side ways past each other
  15. vicariance
    evolutionary separation of species due to barriers such as those formed by comtinential drift
  16. Hot spots
    areas of high species richness
  17. Species Diversification
    • net increase or decrease of species over time
    • larger land area and steady temperatures leads to higher diversity
    • allows for increase in size of species population decreasing risk of extinction due to chance events and increasing the geographical range of species thus spreading risk over larger area
    • cause less drastic climate condition
    • tropics serve for the cradle of diversity
  18. Productivity Hypothesis
    • species diversity is highest at tropics b/c greatest productiviy occurs there for terrestrial systems
    • promotes larger population size
    • marine organisms have shift b/c higher productivity at poles in aquatic environments
  19. Species-Area Relationship
    species richness increases with the area sampled
  20. Islands
    • smaller the island smaller species diversity
    • islands closer to pop source have higher species diversity
    • equilibruim found b/c of extinction and immigration
  21. Equilibrium Theory of Island Biogeography
    • number of species on an island depends on balance between immigration or dispersal rates and extinction rates
    • occurs b/c competition increase causeing decrease inpopulation size as need same space and resources or predation increases as more consumer species are added to Island
  22. Edge Effects
    potential hazards that effect the edge of forest including harsh environmental conditions, fire hunting, predators, disease, and invasive species
  23. Ecosystem Services
    • produced by natural systems that help sustain human health and well-being
    • ex. drugs and food products made from products that come from Tropical Rainforest plants
Card Set
Chapter 17-Biogeography
chapter 17 terms