Chances are you’ve heard of the term ‘biodiversity’. An abbreviation of ‘biological diversity’, the word was originally coined to help communicate the complexity and importance of life on earth in all its forms. Somewhere along the way it lost its meaning – perhaps a victim of overuse, it’s shoehorned into every news article or discussion around the environment, but is rarely explained.

Australia is one of the world’s 17 ‘megadiverse’ countries (a pretty epic title to have), but we’ve also claimed the largest decline in biodiversity of any continent over the last 200 years – not so epic. All this means nothing unless we know what biodiversity is, and what a decline in biodiversity means.

Megadiversity refers to countries with a high number of species, including a high percentage of endemic species. If something is endemic, it means it is only found in a certain location. So animals like the platypus, bilby and koala are all endemic to Australia because they are not found anywhere else. This term isn’t just restricted to countries or continents though. The vibrant Mount Kaputar pink slug is endemic to Mt Kaputar, due to the fact it only occurs along that mountain range. Some species may even be endemic to a single stream, like the Fitzroy Falls Spiny Crayfish! This is why Australia is categorised as one of the worlds 17 ‘megadiverse’ countries – we have loads of species, and heaps of those are only found here, which is really special.

  • What is it?

    A biodiverse ecosystem – rock pool. Photo : Alex Pike
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    A biodiverse ecosystem – rock pool

    Alex Pike

    Biodiversity is defined as the variety of all living organisms on earth, from microscopic viruses and bacteria, fungi and plants, to insects, fish, frogs and mammals, including us – humans! But wait, there’s more. Biodiversity also includes each individual organism, the bigger ecosystems we all live in, and the many interactions that happen within these ecosystems. To put it simply, the term ‘biodiversity’ captures the huge variety of life and all the living processes that take place on our planet. No wonder our eyes glaze over when we hear biodiversity; it’s broad, complex and a lot to take in.

    Thankfully, with a little help from our ecologist friends, this article will break down everything you need to know.

  • The three levels of biodiversity

    Biodiversity is generally explored as three units; genetic diversity, species diversity and ecosystem diversity.

    Brushed-tailed rock-wallaby. Photo: John Spencer/DPIE
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    The adorable and endangered Brushed-tailed rock-wallaby

    John Spencer/DPIE

    Genetic diversity is the variety of genes within a species. Low genetic diversity can lead to genetic defects and may affect a species’ ability to adapt to threats like climate change. Higher genetic diversity means a species is more likely to survive and adapt to changing conditions.

    Take the brush-tailed rock-wallaby. This adorable and endangered marsupial now lives in isolated colonies scattered across NSW, meaning there’s no way for its genetic material to move from one population to another. If several individuals or an entire population is wiped out, then the genetics of that population are lost forever, and the total genetic diversity of the species decreases.

    The good news is we can lend a helping hand in maintaining this genetic diversity. The Saving our Species (SoS) program moves individual brush-tailed rock-wallabies from one colony to another, ensuring the little wallabies are always sharing their genes with each other and maintaining their all important genetic diversity. SoS also runs a captive breeding program, which aims to safeguard the full genetic diversity of the species.

    Emperor gum moth. Photo: Alex Pike
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    Native Australian emperor gum moth found in the Dorrigo Plateau

    Alex Pike


    Species diversity is the variety of different species within an ecosystem, habitat or region. Ecosystems such as the temperate grasslands of south eastern Australia or the ancient Gondwanan rainforests of the Dorrigo plateau are extremely biodiverse, containing many unique species only found in these ecosystems. Some plants and animals in these Gondwana Rainforests have remained unchanged from their ancestors for thousands of years, giving us a glimpse into the past.

    Ecosystem diversity. An ecosystem is a community of living organisms and their physical environment. The variety of ecosystems within a geographical location – like a mountain chain, coral reef, or even an entire continent – is called ecosystem diversity. In NSW alone, there are over 100 threatened ecological communities, from the bloodwood-dominated woodlands of the Duffy’s Forest Ecological Community in the Sydney Basin to the semi-arid grasslands of the Murray Valley Plains.

  • Why does it matter?

    Aerial view of Emily Miller Beach, Murramarang National Park. Photo credit: Melissa Findley/DPIE
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    A sigh of happiness. #southcoast

    Emily Miller Beach

    Murramarang National Park

    Melissa Findley/DPIE

    For starters, biodiversity is crucial to our own survival and quality of life. A healthy and biodiverse environment provides fresh air, clean water and plentiful food. The decline of pollinators such as bees combined with human-made changes to our waterways, for example, affects our agricultural industry and food security. Trees and forests also store carbon and microorganisms help oxygenate our atmosphere, which gives us clean air to breathe.

    Underwater view of a coral reef. Photo Credit : Alex Pike
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    Coral reef

    Alex Pike

    There are economic benefits too. The forestry, agriculture and fishing industries depend on biodiversity for wood, healthy crops and seafood. Plenty of small local economies rely heavily on natural ecosystems, with Australia’s diverse natural assets positioned as major selling points for the tourism industry, including its pristine beaches, stunning mountain ranges, tropical reefs and iconic animal emblems.

    Most countries depend on biodiversity for their cultural heritage. Aboriginal and Torres Strait Islander concepts that connect people to their ‘Country’ and to the environment are an important part of Australia’s identity and history. Biodiversity is an interwoven part of their cultural heritage and beliefs. Even Australia’s post-colonist image centres on the environment, from the exports of Steve Irwin and Crocodile Dundee to the emu and kangaroo on the coat of arms.

  • What’s causing the decline in biodiversity?

    Aerial of air pollution from factories. Pixabay
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    Pollution. ?


    Unfortunately, humans are mostly to blame for the rapid loss of biodiversity we’re seeing across the globe, dubbed the ‘biodiversity crisis’. Pollution, deforestation, poaching and habitat loss are all contributing to this mass extinction of species, which is estimated to be 100 to 1000 times faster than the natural extinction rate.

    Kosciuszko National Park after the 2019-20 fires. Photo credit: Alex Pike/DPIE
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    Huge loss of biodiversity with the 2019-20 fires that tore through Kosciuszko National Park

    Kosciuszko National Park

    Alex Pike/DPIE

    Throw climate change into the mix, which causes many species and ecosystems to experience conditions they aren’t used to, and it doesn’t paint a pretty picture. We can see this decline in biodiversity happening all around us; scientists are watching coral reefs die as sea temperatures increase, and recent bushfires wiped out a staggering amount of wildlife across Australia.

  • What can we do?


    It isn’t all doom and gloom. The good news is that NSW National Parks and Wildlife Service (NPWS) and Saving our Species are working with volunteers, community groups and corporations to protect our valuable biodiversity. 

    Superb parrot (Polytelis swainsonii). Photo Credit : Helen Fallow/DPIE
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    Superb parrot

    Helen Fallow/DPIE (2009)

    The SoS program has provided much-needed funds for the conservation of more than 400 of our threatened species and ecological communities in NSW, through captive breeding and translocation programs, habitat rehabilitation, research and monitoring, community engagement and threat management. The program has seen 4700 trees and shrubs planted for the superb parrot, provided post-fire food drops for mountain pygmy-possums and brush-tailed rock-wallabies, and is working with the Australian Wildlife Conservancy and University of NSW to reintroduce 13 locally extinct mammal species into NSW National Parks reserves. 

    Did you know? NSW National Parks manage over 7.5 million hectares of land across NSW, this includes more than 890 national parks and nature reserves, flora reserves, rainforests, beaches, alpine areas, 4 World Heritage-listed sites, 17 Ramsar wetlands and sites of great cultural and historic significance. These protected areas are vital in conserving biodiversity, and some areas also protect our delicate eco-systems and habitats which are home to many threatened native wildlife.

    You can get involved as well; volunteer in our national parkshelp out the SoS program – donate, volunteer or even become a citizen scientist while learning about our threatened species at the same time!

The best way to learn more about Australia’s biodiversity is by exploring our many amazing national parks and nature reserves. Remember to be mindful of native wildlife and habitat when visiting: stick to the track, keep your distance and leave no trace.

Looking at visiting a park? Before you go, always check for the most updated info on park alerts and closures .