effect of humans on biodiversity and land use

what do actions such as building houses, roads, using land for crops and dumping of waste do to the land?

Reduces the land available for other organisms

Destroy habitats

Reduce biodiversity

how does land pollution affect biodiversity?

Increase in human population = increase in sewage, if not treated, can pollute soil

Also increase in household waste is thrown into landfill sites, which:

• Takes up room

• Destroys habitats

• means that toxic chemicals can spread into the soil

how does water pollution affect biodiversity?

• Increase in human population = more food is needed

• so farmers add fertilisers to soil to help plants grow healthy and large

• Minerals in the fertiliser are easily washed into waterways (run

off)

• Untreated sewage can also find their way into waterways

what is the process of eutrophication?

• Minerals from fertilisers, such as nitrates, run off into waterways like streams, ponds and lakes.

• This causes the growth of algae and plants

• There is more competition for light , which causes some plants to die.

• Microorganism population increases as they break down more and more dead plants (by external digestion)

• Decomposers use up oxygen during aerobic respiration.

• This causes a decrease in dissolved oxygen levels in the water which cause fish and otheraerobic organisms to die

• They are decomposed by microbes which use up more oxygen.

• Leading to the death of all aerobic aquatic animals.

what is the process of bioaccumulation?

• Toxic chemicals (pesticides, herbicides, from landfills) can also wash into waterways

• Accumulate (build up) in food chains

• Cause the largest carnivores to die or fail to breed

how is acid rain made?

• Burning fossil fuels that contain sulfur releases sulfur dioxide into the atmosphere

• Sulfur dioxide dissolves in rainwater and reacts with oxygen in the air to form sulphuric acid

• This produces acid rain

what are the effects of acid rain?

• kills trees

• makes lakes acidic, killing aquatic plants and animals

what is the greenhouse effect?

• Greenhouse gases allow short wavelength radiation from the Sun to pass through to the Earth, warming it up

• The Earth cools down and re-emits radiation with a longer wavelength (infrared radiation)

• Greenhouse gases absorb this long wavelength radiation, causing the atmosphere to warm up

what are some features which cause the enhanced greenhouse effect?

• Increase in carbon dioxide levels

• Burning fossil fuels

• Deforestation

• Increase in methane production

what are some effects of global warming?

• ice caps melting

• Sea levels rising (leading to flooding of low lying land, causing habitat destruction)

• Change in migration patterns

• Decrease in biodiversity as many organisms won’t be able to cope with changing conditions (may lead to extinction)

what is deforestation for?

• Clear land for buildings and roads

• To grow foods (crops, rice, palm oil) or keep grazing animals like cattle

• To grow crops for fuel (biofuels)

• To obtain timber (for construction, furniture, paper production)

what are peat bogs?

• Peat forms over thousands of years

• It is made of plant material that cannot decay completely due to acidic conditions or a lack of oxygen

• Peat bogs and peat lands (bogs that have dried out) are major carbon sinks

what is peat used for?

• Can be burnt to use as a fuel

• Used by gardeners and horticulturists as compost / fertiliser

what are the effects of peat bod destruction?

• Burning/decaying peat releases carbon dioxide into the atmosphere

• Loss of biodiversity due to loss of habitat

what is a way to conserve peat bogs?

Using ‘peat free’ composts made from bark, garden waste, etc