WHAT IS BIODIVERSITY?
Biodiversity is the variety of life forms: the different plants, animals and micro-organisms, the genes
they contain and the ecosystems they form.
Western Australia is home to some of the most unique biodiversity on earth. Our rich biodiversity
can be attributed to the State's size spanning across a range of geographical, soil and climatic
conditions. Terrestrial ecosystems range from rainforest, savanna woodlands, grasslands,
shrublands, heathlands, tall forests and woodlands. Inland water environments including permanent
and seasonal waterways and wetlands and marine environments including coral reefs, intertidal
mangrove forests, seagrass beds, sandy beaches, coastal salt marshes, rocky shores, algal reefs and
kelp forests.
WHY PROTECT BIODIVERSITY?
Biodiversity is important to humans for many reasons in that it provides many services which we
often take for granted, for example, providing drinkable water, clean air and fertile soils. A loss of
biodiversity; populations, species, or groups of species from an ecosystem can upset its normal
function and disrupt these ecological services.
ECOSYSTEM SERVICES
Biodiversity performs a range of vital functions for humans. Plant ecosystems extract carbon-dioxide
from the atmosphere and produce the oxygen we breathe. Plants also purify our water, control
water tables, stabilise soils, extract excess nutrients and provide habitats for pollinators, seed
dispersers and the predators and parasites that control pests and maintain ecosystem stability. This
is what is referred to as ecosystem services.
Biodiversity provides all of our plant and animal foods and many of the medicines we use.
Maintenance of biodiversity is crucial to the development of new foods, drugs and materials in a
rapidly changing world.
The study of animals enables us to understand our own origins, our biology, ecology and behaviour.
The study of ecosystems provides models for new approaches to meeting our needs, regulating our
impacts and developing sustainable economies.
WESTERN AUSTRALIA'S BIODIVERSITY
Based on its natural richness in endemic plant and amphibian species and the significant threats that
exist to its ecosystems, the Southwest Australia Ecoregion is recognised as one of the planets
‘biodiversity hotspots’. It is one of only five Mediterranean systems to be listed as globally
significant (Myers 1990) and the only Australian hotspot to be recognised globally. 5 of 15 nationally
recognised hotspots are located in south-western Western Australia.
In Western Australia’s North West Shelf, more marine biodiversity has been documented than in any
other region in the world. The Ningaloo Reef is crowded with Indo-Pacific reef species and the
southern waters of the State are rich in endemic species. The transitional zone of central Western
Australia has mixed assemblages of tropical and temperate species and also supports a range of
endemic taxa. Collectively the marine waters off Western Australia are of global biodiversity
significance.
THREATS TO BIODIVERSITY
With increasing world population and consumption, human demand for fresh water and energy are
having unprecedented impacts on our global and local biodiversity. Western Australia is facing
ongoing biodiversity loss and continuing decline.
There are numerous threats to biodiversity, both biological and physical, such that we may be faced
with one of the most significant extinction periods ever experienced. The principal attacks in WA
terrestrial ecosystems have been identified as direct habitat loss from vegetation clearing, changed
fire regimes, plant diseases such as Phytophthora or dieback, salinity, introduced weeds, introduced
feral animals, overgrazing of rangelands and climate change.
In the marine environment; overfishing, bycatch and ecological changes from fishing all pose threats
to marine biodiversity. Knowledge about many species and ecosystems as well as the threats they
are faced with is inadequate.