Biodiversity is intimately linked with ecosystem function and services
there have been five great extinctions; we may be in the midst of the sixth
-Phase 1: began 100,000 years ago with the spread of humans
-Phase 2: began 10,000 years ago with the dawn of agriculture
-Phase 3: began 250 years ago with scientific and industrial revolutions
-extinctions usually evolve into something else
-large animals most at risk
-over-hunting
-great migrations: migration of one prepares habitat for the next
Threats to Biodiversity:
1. over-exploitation
2. exotic species
3. habitat destruction
4. climate change
5. pollution
6: domino effects
Nature reserve habitats change over time: must manage the matrix
-size matters
-background extinction: rate in historical records
-mass extinctions occur episodically
-anthropogenic extinctions: human-caused
Probable rate of extinction:
-estimate number of species
-estimate rates of habitat loss
-use species-area relationship to estimate loss
estimated loss of 25-50% of world's species by 2100
-habitat loss biggest problem
-then invasives
-then hunting
