What is biodiversity? Are we losing it? Can we restore it?

‘Biodiversity’ – short for ‘biological diversity’ – describes the vast array and complexity of all living things on the planet, from the millions of microbes in a teaspoon of healthy soil to the majestic Eucalyptus regnans, the tallest of flowering plants.

Biodiversity encompasses all the variability of genes, species and communities that make up ecosystems, and – importantly – the interactions between them and the physical world they (and we) inhabit.

It can help to think of biodiversity as a giant net or web, where the nodes are species and communities, and the threads between them are how they interact.

The more diversity, the bigger and more resilient the web grows.

A praying mantis stands on human hands encrusted with dirt.

There are over 2,400 known species of praying mantis worldwide. Photo: Patrick Corden.

Why is biodiversity so important?

Biodiversity underpins all living things, including us!

Biological diversity acts as a kind of safety net for life on Earth. Genetic diversity, for example, both helps a species reproduce successfully and provides plants and animals with the capacity to evolve and adapt to changes in environments – for example, climate change.

Functional diversity describes how different species perform various roles in an ecosystem and rely on other species fulfilling their functions too. From tiny organisms that decompose litter and create nutrients for plants to use, to canopy trees that shade and shelter other species in and beneath their branches while producing oxygen, holding soil in place, and reticulating water.

A Southern Brown Bandicoot peering between some foliage.

Species that dig and disturb soil, like this Southern Brown Bandicoot, perform important functions as ecosystem engineers.

The more diversity, the more adaptability, the more functionality. Biodiversity, then, is essential to the healthy function of ecosystems and all the goods and services that nature provides.

It supports clean air and water, fertile soils, pollination of crops, climate regulation, food, medicine, and all the basic materials we need to live.

It is also the basis of economies, supporting human, social, intellectual, manufactured and financial capital.

Our bodies, communities, livelihoods and collective wellbeing all depend on the health of our environment – which in turn depends on biodiversity.

Three people stand in tropical dry rainforest. One is pointing up into the canopy and the others are looking in the direction he is pointing.

Like all living things, we depend on a healthy environment for everything. Photo: Tropical Exposure.

Are we losing biodiversity? What is the biodiversity crisis?

Beyond a doubt, we are witnessing an unprecedented decline in biodiversity around the globe.

Biodiversity loss is being driven by factors such as habitat loss (from changes in land and sea use), direct exploitation, climate change, pollution, and invasive species. These pressures are also compounding, weakening species’ resilience to impacts and accelerating global and local extinction.

Take Alpine Ash forests (Eucalyptus delegatensis) in Victoria. Climate change is driving hotter, drier conditions and more frequent and intense bushfires. It takes an Alpine Ash 15-20 years to produce seed – so if these forests burn at shorter intervals, they won’t regenerate without intervention.

So much for the tree itself – but it’s also a keystone species for the forest ecosystem. Without these canopy trees, the forest microclimate disappears, leading to conversion from what was once a complex, tall wet forest to a simpler ecosystem, with local loss of unique plant and animal diversity. The forest’s disappearance also has direct ramifications for carbon storage, Melbourne’s water supplies, timber and alpine tourism.

Alpine Ash forest burnt during the 2019/20 bushfires. Photo: Tom Fairman.

The Alpine Ash story is an illustration of why the word ‘crisis’ is being used in reference to biodiversity loss. The global rate of species extinction is tens to hundreds of times higher than it has averaged over the past 10 million years, and set to accelerate unless urgent action is taken.

Remember the biodiversity web? Mounting pressures are removing nodes and connecting threads, disrupting the way species can adapt and survive, and therefore how ecosystems function – with far-reaching consequences for the environment and for human health and wellbeing.

Due to the complexity of the web and the rate of change that’s occurring, we also can’t predict or fully comprehend the ramifications of these losses. How many missing nodes or threads can the web sustain before it totally collapses?

Let’s not find out.

A young boy digs at the soil while his mother holds a native seedling they are planting.

We can all take immediate practical action to help stop and reverse biodiversity loss. Photo: Harrison Candlin.

What can be done? Can biodiversity be restored?

First, it is of utmost and urgent importance to safeguard what biodiversity remains, by reducing the impact of human activities on the environment and prioritising protection of nature.

At the same time, we must also invest in restoring degraded ecosystems to help tackle biodiversity loss and climate change and rebuild the long-term resilience of our planet.

There’s no time for half measures, so we must make every restoration effort count to the fullest of its potential. There are three components to factor in when restoring biodiversity: area, connectivity and condition.

Aerial view of direct seeding lines with two tractors in action

Protection alone isn’t enough – we need large scale restoration in collaboration with landholders and Traditional Owners. Photo: Jesse Collins.

We need to restore habitat at a large enough scale (area), using a targeted and suitable mix of species to rebuild functional diversity (condition), in ways that connect with other patches of remnant and restored vegetation across landscapes (connectivity).

If maintained over time, areas restored in ways that optimise these three components should have the genetic and functional diversity to be able to adapt and regenerate in a changing climate. Which, in turn, produces quantifiable, valuable benefits for us all.

Greening Australia has set ambitious goals for rebuilding nature to 2030 – including establishing half a billion native plants across Australia and 330,000 hectares of habitat.

This is what we want our contribution to be towards the global and national goal (adopted at COP15) of 30 percent of degraded ecosystems to be under effective restoration by 2030.

A line of Traditional Owners passing trays of seedlings down the chain.

We’re getting our hands dirty planting for biodiversity alongside Traditional Owners and other landholders. What will your contribution be? Photo: Jesse Collins.

How you can help

Valuing the complexity and interconnectedness of nature must be at the core of every decision and everything we do.

As well as reducing their impact, governments, businesses, investors and individuals must shift their mindsets and practices to prioritise protecting and restoring nature – that is, a nature-positive mindset.

  • Governments should leverage their crucial roles as regulators and standard setters. They can establish policies and incentives to reward authentic action towards global biodiversity targets and goals, and provide catalytic funding to support the scale and pace of action that’s required.
  • Businesses can help by assessing, disclosing and addressing their impacts and by implementing sustainable practices to reduce waste and pollution in all its forms. They should go beyond offsets to invest in restoring nature.
  • Landholders such as Traditional Owners and primary producers can help by adopting and championing sustainable practices and working alongside the environmental sector to protect and restore the biodiversity of their land.
  • Individuals can change how they consume to hold businesses and governments to account and to support nature positive enterprises. They can also reduce waste and their impact on the environment through demand – and support biodiversity in their own backyards.

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