We could soon be able to track changes in Australia’s forests in near-real time – using satellites

Collecting data from sensors in remote woodlands has long required arduous treks. What if sensors could transmit data in real time?

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Brendan Choat, CC BY-NC-NDForests and woodlands cover millions of hectares across Australia, from tropical rainforests and temperate eucalypt forests to the vast woodlands and shrublands of the arid interior. They store enormous amounts of carbon, support biodiversity, regulate water supplies and help buffer the impacts of climate change. Yet we know surprisingly little about how these important ecosystems are changing over time.

Australia has world class ecological research sites and monitoring programs. But until now, we haven’t had a coherent, long term national monitoring network able to track the health of forests across the continent.

As a result, it’s hard to answer fundamental questions. Are forests becoming more vulnerable to drought? How quickly do these ecosystems recover after fire? How much carbon is being stored in forests and woodlands and how might that change in the future? Right now, we don’t know.

As climate change loads the dice for more frequent and intense droughts, heatwaves and bushfires in Australia, it’s vital we understand which ecosystems are at most risk, and which have more resilience.

Our new project aims to help fill this gap. We are upgrading thousands of existing solar-powered sensors so they can transmit data close to real time via satellites in low-Earth orbit. If our demonstration project in western New South Wales is successful, it could be expanded across the state – or the entire country.

Why do we need this?

Tracking changes to forests and woodlands in remote parts of Australia has long been a challenge.

Researchers have installed sensors in many areas highly exposed to climate extremes, such as the arid west of NSW.

These sensors measure soil moisture, microclimate, tree growth and plant water stress in near real time.

In many remote locations there’s no practical way to transmit the data continuously. It can be an ordeal to access data from these sensors as it must be done manually. It doesn’t help when they are located far from towns, roads and telecommunications infrastructure. As a result, data is often collected a couple of times a year.

That’s not ideal. It means we don’t have access to the continuous observations needed to detect change as it happens. This data would be particularly valuable after major events such as droughts, heatwaves and bushfires, when ecological conditions can change rapidly.

Without it, we can’t gauge how ecosystems respond to disturbances or recover over time. That makes it harder to judge how they will respond to future climate extremes.

Eyes in the sky – or data from the ground?

When most people think about using satellites to track environmental change, they might picture images taken from space.

These are valuable as a way to track logging or illegal roads, for instance. But photos aren’t enough. We still need to take measurements on the ground.

This is why our project doesn’t rely on satellites as eyes in the sky. Their communication abilities are much more valuable. Satellites in low Earth orbit let sensors continuously transmit data from regions far too remote to have mobile phone coverage.

While satellite communication has existed for decades, newer low-Earth-orbit satellite systems make it possible for small, low-power environmental sensors to transmit data more efficiently and at lower cost than before.

The benefits of near real-time monitoring will go well beyond science. Graziers, land managers, conservation organisations and carbon projects will be able to get early warning if ecosystems are under new strain.

Environmental monitoring has always been difficult in a country as large and sparsely populated as Australia. Satellites offer a practical way to overcome the tyranny of distance.

Scaling up

To make this a reality, researchers (including this article’s authors) at Western Sydney University and UNSW are working with satellite communications company OQ Technology, with support from the NSW Smart Sensing Network.

At present, we are working to expand the network of monitoring plots from the wet sclerophyll forests and rainforests of the Greater Blue Mountains World Heritage Area to the arid woodlands of the far west of NSW.

Climate, rainfall and vegetation differ dramatically across this area. But all ecosystems are feeling increasing pressure from drought, bushfire and extreme heat.

We have installed satellite-enabled sensors at plots in the Blue Mountains and mulga woodlands in western NSW. Our next step is to test how well the sensors communicate with the satellite.

The network includes sensors that measure soil moisture using probes buried in the soil, monitor local weather conditions, track changes in stem growth, and estimate plant water stress

Over time, flows of data from these sensors will build the datasets we need to make better forecasts of future risk.

Better measurements, better decisions

Policymakers, industry and conservationists rely on models and predictions to understand how Australia’s ecosystems are responding to worsening climate change.

But forecasts are only as reliable as the observations used to build and validate them.

Tracking change with satellites and sensors won’t prevent droughts, fires or ecosystem decline. But this approach can help spot emerging threats, improve forecasts and give the evidence needed to make better decisions in an increasingly uncertain future.
Brendan Choat receives research funding from the Australian Research Council, the NSW Smart Sensing Network, the Terrestrial Ecosystem Research Network and the NSW Natural Resources Commission. This project is supported by the NSW Smart Sensing Network and undertaken in collaboration with researchers from UNSW and industry partner OQ Technology. Daniel Falster receives funding from the Australian Research Council.

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