Homework

•Text p.229 red q 1,2,3•Text p.232/3 q 1,2,3,4,5•P.232-3 q1,2,4,5• Interpreting diversity data worksheet•17.2 organic farming

Species diversity and human activitiesAqa book p 229-30

Homework

•Minimum of 1 paper per week done, marked and handed in.

•Ask any questions arising in class please

Starter

•Q4 p.233

Objectives

•What is the influence of deforestation and the impact of agriculture on species diversity?

Influence of humans on species diversity•Make a list of reasons why diversity index

is low in agricultural ecosystems•Do the same for the impact of

deforestation

Now try q 1,2,3,4,5 p.230

Agriculture;•Ecosystem controlled by humans who

select the plants to be grown on the whole•Little resources left for wild plants, so

fewer types of consumers as a result•Herbicides/Pesticides used to kill off wild

plants/animals•Woodland cleared reducing number of

habitats available•Hedgerow cleared reducing number of

habitats available•Diversity index therefore low

Why do agriculture?

•More food can be produced•Food is cheaper to produce so prices are

lower•More development attracting more

business

Deforestation;

•Reduces number of trees so fewer layers of plant available as habitats

•Less shelter and food for consumers•Reduces diversity

Why deforest?

•Wood and land for homes to be built•Use land for agriculture•Reservoirs / hydroelectric schemes•Timber for export•Palm oil plantations (coffee, maize, soya

etc.)

Conservation is the study and protection of biodiversity and natural resources.

It is not just about preserving habitats and species as they are, although this does play a part in conservation.

Instead, it is more about actively and carefully maintaining a balance between ecological needs and human requirements, which are often in direct conflict with each other.

What is conservation?

The biggest threats to biodiversity are all due to the effects of a rapidly increasing human population. They include:

habitat destruction – e.g. deforestation for urban development and agricultural land, global warming, mining and pollution

overexploitation – e.g. whaling, fishing and wildlife trade

competition from introduced species – e.g. grey vs. red squirrels in the UK, the Nile perch vs. cichlid fish in Lake Victoria, Uganda.

Threats to biodiversity

The most recent of these was the Cretaceous–Tertiary Extinction Event 65 million years ago. This resulted in the extinction of about 50% of all species, including the dinosaurs, and paved the way for the rise of mammals.

Extinction has always been an ongoing feature of life on Earth, and is a natural consequence of evolution.

Since life began, there have been at least five mass extinction events – a sharp decrease in the number of species in a relatively short period of time.

Mass extinctions

Conservation status

Conservation: true or false?