Biodiversity And The Effect Of Human Interaction On Ecosystems

What is biodiversity?

The variety of all the different species of organisms on earth, or within an ecosystem.

What does a great biodiversity ensure?

The stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment..

What does the future of the human species on Earth rely on?

Us maintaining a good level of biodiversity. Many human activities are reducing biodiversity and only recently have measures been taken to try to stop this reduction.

What does the rapid growth in the human population and an increase in the standard of living mean?

Increasingly more resources are used and more waste is produced. Unless waste and chemical materials are properly handled, more pollution will be caused.

When/where can pollution occur?

• In water, from sewage, fertiliser or toxic chemicals.

• In air, from smoke and acidic gases.

• On land, from landfill and from toxic chemicals.

What does pollution do?

Kills plants and animals which can reduce biodiversity.

How do humans reduce the amount of land available for other animals and plants?

By building, quarrying, farming and dumping waste. The destruction of peat bogs, and other areas of peat to produce garden compost, reduces the area of this habitat and thus the variety of different plant, animal and microorganism species that live there (biodiversity).

What does the decay or burning of the peat do?

It releases carbon dioxide into the atmosphere.

What are peat bogs?

Bogs are areas of land that are acidic and waterlogged. Plants that live in bogs don't fully decay when they die, because there's not enough oxygen. The partly-rotted plants gradually build up to form peat.

So the carbon in the plants is stored in The peat instead of being released into the atmosphere.

However, peat bogs are often drained so that the area can be used as farmland, or the peat is cut up and dried to use as fuel. It's also sold to gardeners as compost. Peat is being used faster than it forms.

What has large-scale deforestation in tropical areas has occurred for?

• To provide land for cattle and rice fields

• To grow crops for biofuels.

What is the temperature of the earth a balance between?

The energy it gets from the sun and the energy it radiates back out into space.

How do gases in the atmosphere act as an isnulating layer?

They absorb most of the energy that would normally be radiated out into space, and re-radiate it in all directions (including back towards the earth), increasing the temperature of the planet.

What are greenhouse gases?

Gases that contribute to the greenhouse effect by absorbing radiation.

What two greenhouse gases have worryingly increasing levels?

Carbon dioxide and methane.

Why is the earth gradually heating up?

Due to increasing levels of greenhouse - global warming.

What is the biological consequence of global warming in terms of sea levels?

• Higher temperatures cause seawater to expand and ice to melt, causing the sea level to rise.

• This is beginning to increase frequency of flooding and if it continues, it could result in the loss of habitat for organisms.

What is the biological consequence of global warming in terms of distribution?

• The distribution of many wild animals and plant species is changing as temperatures increase and rainfall changed in different areas.

• Some species are becoming more widely distributed while others are becoming less distributed.

What is the biological consequence of global warming in terms of migration patterns?

There have been changes in migration patters, e.g; some birds will be migrating further north as more northern areas are getting warmer.

What is the biological consequence of global warming in terms of biodiversity?

Biodiversity could be reduced if some species are unable to survive a chnage in the climate, so become extinct.

What are the programmes scientists and concerned citizens have put in place to reduce the negative effects of humans on ecosystems and biodiversity?

• Breeding programmes for endangered species.

• Protection and regeneration of rare habitats.

• Reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop.

• Reduction of deforestation and carbon dioxide emissions by some governments.

• Recycling resources rather than dumping waste in landfill.