Ch. 23 - Global Ecology

Global Ecology

le

7 main direct threats to biodiversity

1. habitat destruction

2. habitat fragmentation

3. habitat degradation/pollution

4. overexploitation

5. global climate change

6. invasive species

Habitat Destruction

disappearance of ecosystems and the native organisms that inhabit them

How much land surface has human activity transformed earth’s land surface.

50-59%

Agricultural expansion

Is the biggest cause of habitat loss/destruction.

edge effects

changes in physical env. within fragments & along forest edges

Due to deforestation historic carbon sinks are becoming:

Carbon “emitters”

Highest conc. of atmospheric gases in:

troposphere

Ozone concentrated in

stratosphere