Transcript Is_conservation_important

Conservation
Learning objectives
You should be able to:

Outline the reasons for the conservation
of animal and plant species, with reference
to economic, ecological, ethical and
aesthetic reasons.
How humans affect nature






We use the environment to our advantage
Increase in number of humans
Using more of Earth’s resources
Our activities affect other species directly or
indirectly
Loss of biodiversity occurs
Extinction may occur.
List 5 extinct species. For each state why
they went extinct
Passenger pigeon
Irish deer
Quagga
Moa
Thylacine
Dodo
Extinction



Extinction occurs when the last living member
of a species dies and the species ceases to
exist.
Are humans causing more extinctions?
Scientists believe that increased human activity
has lead to the extinction of some species –
giant sloth, mammoth – as they were hunted for
food.
Extinctions
Evolution has been punctuated by mass extinctions.
Number of
Marine Animal
Genera
Becoming
Extinct
Millions of Years Ago






There have been 784 extinctions since 1500.
Up to 20% of species alive today could be
extinct by 2030.
1/3 of primate species now face extinction.
Up to half the world’s species could be
extinct by 2100.
Current rate of extinction is 100-1000 x
faster than ‘background’ rate.
Current rate of extinction is as fast as
previous mass extinctions.
We are probably at the beginning of a mass
extinction event, caused this time by
human activity.
How can human activity
affect biodiversity?
Biodiversity is the range of organisms
found.
The extinction of a species reduces
biodiversity.






Hunting – for food.
Killing for protection – insects that are
vectors of disease, or predators.
Killing to remove competitors for food –
pesticides.
Pollution.
Habitat destruction – deforestation,
development, agriculture.
Inadvertent introduction of predators and
competitors.


Natural vegetation is very diverse and is a
habitat for many species.
When humans clear land it removes the
habitat and replaces it with a monoculture.
Why conserve species?

Economic and ecological reasons:


Lose solutions to future problems (we can learn from nature).
Natural ecosystems are valuable to humans:








Regulate atmosphere and climate
Purify and retain water
Form and fertilise soil.
Recycle nutrients.
Detoxify and recycle waste.
Pollinate crops.
Grow wood, food, fuel.
Ethical and aesthetic reasons:


Living organisms have a right to survive the way they are
adapted.
Natural environments are important for our wellbeing and
physical, intellectual and emotional health.