Brainstorm List the factors that you think lead to a loss of diversity. Do you think the loss of diversity is the same from country to country? Why / why not?

Learning outcomes You will all be able to: – Identify the factors that lead to a loss of diversity Most of you should be able to: – Discuss the value of tropical forests in contributing to global biodiversity Some of you might be able to: – Explain why tropical rainforests are vulnerable to disturbance.

Natural Hazards tralia-threat-volcanic-eruption cations/fires_natural_role.html Volcanic eruption Natural fire Landslide Avalanche Tsunami Earthquake

Environmental disasters Loss of tropical rainforest Oil Spills

Habitat fragmentation Pollution: (topic 5) Spraying of pesticides Oil spills Factory emissions Fertilizer run-off Toxic chemical in the food chain Climate change Overexploitation North Atlantic Bluefin tuna

Introducing non-native species Japanese Knotweed homepages.abdn.ac.ukl Grey squirrel Black rat (Rattus rattus) Rhododendron

Cane Toad Australia Rabbits Camels Red Fox

Modern Agricultural practices: GM crops Monocultures Pesticides Spread of disease: Bird flu BSE Tuberculosis Domesticated to wild and vice versa

Importance of tropical rainforests Read the article and try to remember as many of the facts as you can… We will have a test!

See how many you can remember… If Amazonia were a country, it would be the largest in the world. More than 20 percent of the world’s is produced in the Amazon Rainforest. More than half of the world's estimated species of plants, animals and insects live in the tropical rainforests. One hectare (2.47 acres) may contain over 750 types of and 1500 species of higher plants. Rainforests once covered of the earth's land surface; now they cover a mere 6% and experts estimate that the last remaining rainforests could be consumed in less than 40 years.

What makes rainforests valuable? Individually on the piece of paper provided write down your ideas. Think about the following factors: – Biodiversity – Climate – Oxygen

Another factor - “Green politics” What do you think “green politics” are? What do you think is the relationship between rainforests and “green politics”?

Rainforests are often called biodiversity hotspots. What is it that makes them so diverse in terms of species? They contain a lot of long-lived species and it has taken thousands of years for them to develop. If they are damaged it will take a long time for them to regenerate. Why?

Read the facts from the National Geographic article “Rain Forest Threats” and relate this to what we have been looking at on the loss and retention of diversity. Using this, write down the factors that make rainforests vulnerable to disappearance. Think about: – The complexity of the ecosystem – Soil nutrients – Human activity

Check learning outcome booklets You should be able to do: – – identify factors that lead to loss of biodiversity – – discuss the perceived vulnerability of tropical rainforests and their relative value in contributing to global biodiversity