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fragmentation_bio_loss

  1. “Any patch of habitat isolated from similar habitat by different, relatively inhospitable terrain…may be considered an island”
    (Simberloff 1974)









    “Any patch of habitat isolated from similar habitat by different, relatively inhospitable terrain…may be considered an island”

    (Simberloff 1974)


    
    “Any patch of habitat isolated from similar habitat by different, relatively inhospitable terrain…may be considered an island”

    (Simberloff 1974)
  2. Differences between habitat islands & oceanic islands:
    • area surrounding habitat island may not be totally inhospitable
    • surrounded by other habitat types (not just ocean)
    • not only sweepstakes arrival


    
  3. Edge Effects
    alteration of “edge” environment due to sharp change from one habitat to another

    • altered environment - sharp change from one habitat to another
    • “edge” may have different microclimate & disturbances than the interior part of the habitat island
  4. Sunlight and Edge effects
    • up to 20 meters into forest
    • depth of edge influence OR edge width
    • sunlight does not penetrate edge into forest
    • forest shades the meadow up to 10 meters
  5. Some common edge effects
    • increased air temperatures
    • lower relative humidity
    • increased soil temperatures
    • increased wind speeds
    • lower soil moisture
    • increased atmospheric deposition
    • more invasive species
    • many more...
  6. habitat fragmentation
    continuous habitat is reduced in size & divided into more pieces

    • continuous habitat is reduced in size & divided into more pieces
    • patch creation
  7. Disturbance patch
    • larger habitat (matrix) interrupted by patches of disturbed habitat
    • (like roads or mudslides)
  8. Regenerational Patch
    successional regrowth after disturbance
  9. Remnant patch
    original habitat surrounded by altered habitat
  10. Environmental patch
    unique environment patch of different community from surrounding matrix
  11. Metapopulations
    • set of seemingly isolated populations of same species in same landscape
    • importance of connectivity between the populations
    • some degree of migration & dispersal
  12. Minimum Viable Population (MVP)
    smallest isolated population having 95-99% chance of remaining extant for 500-1000 years
  13. Minimum Dynamic Area (MDA)
    area of habitat suitable for maintaining the MVP
  14. Top reasons for Biodiversity loss
    • habitat loss
    • exotic species
  15. Exotic Species
    species introduced to a new area by humans, generally by accident

    • direct- outcompete native species (local extinctions)
    • indirect- may change/disrupt ecosystem-level processes
  16. Generalizations about exotic species
    • MOST invasions are NOT successful
    • those that do succeed, do VERY well
    • there tend to be more invasive plants than animals
    • disturbance often facilitates invasion
  17. Global Species
    loss of a species biologically
  18. Trophic Cascades
    loss of prey species leads to extinctions (ecosystem disruption)

    the loss of food for higher predators
  19. local extinction
    • one species dissappears from a portion of its former range
    • (persists in remainder)
  20. Conservation status: Rare
    • a species with a very limited range
    • often this is the natural distribution
Author
kamrunsreno
ID
17295
Card Set
fragmentation_bio_loss
Description
NRES final
Updated

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