Media Release April 23 2009: Protecting rare species from space

Australian scientists are developing a revolutionary way to monitor changes in biodiversity across vast
tracts of the continent using satellites.

In research for the Desert Knowledge CRC, Dr Ken Clarke of the University of Adelaide has helped
pioneer a new way to watch over biodiversity in the deserts – where some of the nation’s gravest
extinction rates occur – and study what happens to it as the impacts of pests, human activity and climate
change build up.

“The first big challenge is that we don’t even know what species we have in Australia; on-ground
surveys are still finding new plants and animals whose existence we never suspected. If we don’t know
what we have, how can we save it?” Ken asks.

“I believe we have a duty to conserve our nation’s biodiversity – including that which we don’t yet
know about. However, till now, this has been an unrealistic goal for the rangelands, which cover 70 per
cent of the continent. They are simply too vast and there are too few people to cover them by surveying
small plots on the ground.”

One possible answer was to explore the use of satellites to monitor not so much individual species but
rather the overall health and variety of desert ecosystems and vegetation, Ken says.

“You can’t measure biodiversity as such from outer space – but you can measure primary productivity
(or plant growth), which we know is dependent on the amount of water and energy available to sustain
species. We felt that if we could understand what generates biodiversity in the first place, we could then
look for what was putting the sort of pressures on it that cause extinction.”

Using the driest of the Australian deserts, the Stony Plains country extending over 400,000 square
kilometres between Spencer Gulf in South Australia and the NT border as their ‘laboratory’, Ken and
his colleagues began to amass satellite data and link it to field observations of vegetation condition to
build up a picture of the primary productivity of the region.

“Where you see vegetation failing to grow to the potential which the local climate affords it, then you
know it must be under some sort of stress – for example from overgrazing by feral or domesticated
animals.”

The team has been using imagery from the MODIS sensor, flying on two satellites called Terra and
Aqua, which pass above Australia every day. By monitoring the same areas of vegetation every two
weeks, Ken and colleagues have assembled an understanding of how stressed the plants are, or how well
they are doing on the energy and water available to them.

“Our aim is to build a picture of where the pressure on native Australian biodiversity is greatest. Then
on-ground investigation can establish the causes, so that the responsible managers can take action.”

For example, it may be possible for pastoralists to reduce stock numbers and restrict access to watering
points to reduce grazing pressure from both domestic and feral animals, so allowing vegetation and
other biodiversity to recover.

“Manipulating access to water is a powerful technique used by pastoralists in desert regions to manage
grazing pressure and there is evidence pastoralism can help to improve biodiversity values by grazing
more strategically,” he adds.

Conservation and natural resources managers can also respond with programs to control the large
numbers of feral camels, goats, rabbits and other introduced species threatening the desert regions.
The use of satellites to monitor biodiversity is not without scientific controversy. “Obviously you can’t
see small endangered animals from space – but there is quite good evidence that the abundance of native
animals is linked to the health and diversity of the vegetation and, at a landscape scale, that’s what you
want.”

In one way, however, satellites have an advantage, Ken adds. Even experienced biologists miss some of
our more cryptic plants and animals when they carry out a survey – so an on-ground survey does not
provide a true picture of local biodiversity. However, ensuring the overall health of the vegetation at a
regional scale can go a long way towards protecting species we do not even know are there, he says.

“Although we have only tested the concept in the Stony Plains region, the initial results give confidence
that we will be able to develop satellite monitoring into a useful technique for monitoring the health of
Australian biodiversity, especially in the desert regions.

“Given the major pressures which these regions face from climate change, human activity, grazing and
feral animals, it is vital that we develop some sort of early warning system that will enable us to take
timely action if we see part of the landscape suffering and signs of the loss of species richness.

“The Holy Grail of using satellites to do this isn’t quite there yet, but we have made promising progress
in developing it to work as a new tool to help us better care for the enormous expanse of the deserts
which occupy almost three quarters of the Australian landmass.”