HUMAN EFFECT ON ECOSYSTEMS

Are we making things better or worse?

Agriculture: Using pesticides: Advantages: kills pests

to increase crop yield. Disadvantages:

1. Non-biodegradable; may persist in food chain and kill top carnivores.

2. Causes emergence of resistant pests.

3. Non-specific; kills harmful as well as useful organisms.

Biological control The use of the

natural predator of the pest to decrease their numbers to increase the crop yield. This is safer to the environment.

Deforestation Reasons for cutting down rain forests: 1. provide land for

growing crops, building new cities, roads or factories.

2. use wood for making paper, furniture, build houses.

Over-use of inorganic fertilisers. Eutrophication:

Air pollution: Acid rain

Acid rain causes:

Air pollution: nuclear fall out The radioactive particles land onto the ground, contaminate water & enter food chains.If they accumulate in tissues of organisms they may cause cancer or genetic damage.

Household waste

How can we help?

biogas

Biofuel