State of the Planet: Why is there a crisis?

Question 1

Over-Harvesting

Answer 1

Due to human over-hunting, megafauna (large mammals) has become increasingly more extinct in most continents, apart from Africa.
When humans take resources from the environment at a faster rate than they are being produced naturally.
They’re more humans- technology improving, we often take too much e.g. deforestation, over fishing.

Question 2

Invasive/ Introduced Species

Answer 2

Hawaii- mostly introduced species.

Cannibal snails- Hawaii

Question 3

Habitat Change/ Destruction

Answer 3

Humans: urbanisation, farmland- deforestation to make way for cities.
Large knock-on effect on food chains and biodiversity.
If you are in an area with altitudinal zoning, survival is more likely as you do not have to move as far to find suitable climate.

Question 4

Islandisation/ Fragmentation

Answer 4

Islands of undisturbed habitat in a sea of totally disturbed habitat
Might not be enough space to provide food for all the species.
Edges that are vulnerable and interaction with human interference.
Fragment = smaller population = greater vulnerability to…e.g disease, human interaction (easier to wipe out)
Smaller fragments, so smaller gene pool makes inbreeding more likely.

Question 5

Pollution

Answer 5

Some pollution is localised e.g water pollution (oil spills, factory waste discharge)
Some pollution is regional or even GLOBAL :O e.g air pollution (smog, acid rain)
Enhanced greenhouse effect
Climate change puts stress on ecosystems e.g. sea level rise
Climate change allows species to move, however, it’s difficult for them due to urbanisation (humans in the way)
Rate of change is unprecedented- harder for moving away