©Getty Images

©Getty Images

Biodiversity is the web of life. It is the variety of living
 things on Earth.

The word is short for 'biological diversity'. Biodiversity includes the many species of all
 living things, from humans, animals, plants and fungi down to the tiniest organism.

An ecosystem is a community of living and non living
things that are inter-connected.

In a healthy ecosystem there is lots of diversity, and everything has its place in it, and every
 living thing in the ecosystem interacts. In an ecosystem, living things all play a part.

The first group of an ecosystem are the producers. Green plants are the producers because they make their own food by photosynthesis, or energy they get from the sun and water in the soil.

Plants are eaten by the the second group, the consumers, which are animals that get their energy from eating producers or from eating animals that do. Consumers are herbivores or carnivores.

The third group are the decomposers, which are animals or plants (for example, fungi) that break down dead animals or plants into organic materials that go into the soil, which enriches it. This is known as a food chain, or to be more accurate, a food web.

Plants make their food by photosynthesis. ©Getty Images

Plants make their food by photosynthesis. ©Getty Images

Why we need biodiversity

Soils are kept healthy, and therefore productive, by microbes, worms, insects and all manner of burrowing animals. They turn decaying plant and animal matter into soil enriching material. Plants grow in soil and put oxygen into the air for us to breathe. Plants, as well as tiny organisms, filter our water. Plants feed us, and from some plants cloth is made that clothes us. Plants feed animals which in turn are used by us, eaten for food or their fleece made into cloth or yarn to clothe us. Medicines are made from plants. Birds and insects spread seeds and pollen which helps plants reproduce.

Biodiversity feeds and clothes us, provides us shelter, clean air and water. It is an essential part of our lives. If we destroy the plants and animals that are part of the biodiversity, then we lose those benefits they provide. There are an estimated 10 to 100 million species of living things on earth. Today, humans are destroying species faster than at other time in earth's history. It has been estimated by scientists that approximately 8 species an hour, 70 000 a year, are being destroyed.

Megabiodiversity

There are 17 countries that are identified as being megadiverse, which means having a great number and variety of native animal and plant species. This group of 17 totals less than 10% of the world's surface, yet has more than 70% of the biological diversity in the world.

The 17 megadiverse countries are: Australia, the Democratic Republic of Congo, Madagascar, South Africa, China, India, Indonesia, Malaysia, Papua New Guinea, the Philippines, Brazil, Colombia, Ecuador, Mexico, Peru, USA, Venezuela.

Thylacine, Australia's wild marsupial dog, is presumed extinct. ©Getty Images

Thylacine, Australia's wild marsupial dog, is presumed extinct. ©Getty Images

Australia is megadiverse because it has more unique species than anywhere else on Earth.

Yet in Australia, 10 out of 144 species of marsupial have become extinct. Three species of emu are extinct. More than 100 species of mammal are endangered or vulnerable.

Nearly half of Australia's forests are gone (and that figure includes three quarters of our rainforests), so that many of the other forms of forest life are badly affected. Less than 1% of our native grasslands remain, so grassland animals are seriously threatened.

Biodiversity 'hotspots'

The endangered northern hairy-nosed wombat is found in a biodiversity hotspot in Queensland ©Getty Images

The endangered northern hairy-nosed wombat is found in a biodiversity hotspot in Queensland ©Getty Images

A biodiversity hotspot is an area that is mostly intact (untouched or damaged) where there are a good number of native species. It is also a place where there are a number of endemic species. Endemic means it is found nowhere else on Earth. Australia has 15 biodiversity hotspots.

What can we do to help our biodiversity?

  • plant native plants or help revegetate bushland areas to attract native birds and animals
  • create a habitat garden: native plants in layers (leaf litter, low plants then taller shrubs then
  • trees), add logs and rocks for lizards and other creatures
  • make a wetlands habitat to attract frogs to your garden
  • plant bird attracting plants in your garden, and add a birdbath
  • remove weeds: they are not native plants and can smother or overtake native habitat

Read more about biodiversity and ecosystems:

Watch a video about ecosystem food webs, and what happens if part of an ecosystem disappears. http://ed101.bu.edu/StudentDoc/Archives/ED101fa09/tje50/Video.html