extinction’s new face: habitat loss & fragmentation
Post on 18-Jan-2018
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Extinction’s New Face:
Habitat Loss & Fragmentation
What is the evidence of habitat loss?
• Deforestation…
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Deforestation…
• Is it only limited to the Amazon?
How does species abundance relate to habitat size?
• Make predictions• Is there likely to be a relationship?• Why or why not?
What are the impacts of decreasing habitat size?
• We call this habitat fragmentation• Are there likely to be any additional problems,
beyond simple reduction in area?
Over time large blocks of forest (green) are fragmented through a variety of land use activities (after Curtis, 1956) - Cadiz Township, Wisconsin.
Habitat Fragmentation & Edge Effects
Mean alien species richness, summarized by transect position and aspect. Sample size = 7 for each combination of transect and aspect. Redrawn from Brothers and Spingarn 1992). (http://dnr.state.il.us/orep/inrin/ecosys/forests/forstres.htm )
Mean frequency of sample transect segments containing alien species (bottom), summarized by transect position and aspect. Sample size = 7 for each combination of transect and aspect. Redrawn from Brothers and Spingarn (1992). (http://dnr.state.il.us/orep/inrin/ecosys/forests/forstres.htm )
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