Tree death patterns revealed through statistical lens

August 27, 2013 by Aaron Fernandes, Science Network WA
Tree death patterns revealed through statistical lens
The method could be applied on a national scale to identify declining water tables over Australia’s vast geography. Credit: Giles Hardy and George Matusick

New methods of analysing high resolution digital airborne imagery are being trialled in a bid to track water usage in Perth's drying climate.

CSIRO has collected images of large areas of native woodlands using morphological image analysis, and are now applying spatial point process statistics to assess if sudden death among trees is caused by a lack of access to .

Spatial Adrian Baddeley says the research aims to test the effectiveness of spatial point statistics as a method for extracting information from the pictures.

"CSIRO regularly fly planes over woodland areas and take at such a high resolution that you can actually identify individual trees and shrubs," Professor Baddeley says.

"If you take images over successive years, and then compare the photographs, you can spot where trees have died from one year to the next.

"[Currently] there is a concern in Western Australia that as we are taking out of the , we might actually be causing trees to run out."

Using photography, researchers are able to apply spatial point statistics to determine if tree deaths occurred at random or in a particular pattern, which may suggest the causal factor is declining .

"There might be a pattern evident in the images, if you are clever enough with your analysis and studied the same region several times," Prof Baddeley says.

"Our aim is to identify signals that something is going wrong and that water would not be taken from a particular bore.

"Of course, forests are not flat, simple surfaces and the topography, depths of the water, in addition to a range of hydrological and ecological variables make that very difficult to determine."

However researchers say spatial point statistics could play an integral role in sorting through the masses of data collected from airborne imagery.

"This was essentially a test case where we had intensively surveyed forest and were able to try out some new techniques, and we demonstrated that they were successful."

He says the method could be applied on a national scale to identify declining water tables over Australia's vast geography.

"In a healthy eco-system, you expect to see trees evenly scattered all over. If that's true, then it means that just by taking a photograph, and being very clever you can spot that," Prof Baddeley says.

"We could then draw a map that shows which areas of Australia are environmentally stressed."

Explore further: Groundwater research may be forest lifesaver

Related Stories

Following the footprint of invasive trees

July 9, 2013

In Oregon, western juniper trees are expanding their range, pushing out other plant species, reducing sagebrush habitat and livestock forage, and at times fueling catastrophic wildfires. During some of these conflagrations, ...

Recommended for you

Propping up glaciers to avoid cataclysmic sea level rise

September 20, 2018

As global warming outpaces efforts to tame it, scientists have proposed building massive underwater structures to prevent an Antarctic glacier the size of Britain from sliding into the sea and lifting the world's oceans by ...

NASA balloon mission captures electric blue clouds

September 20, 2018

On the cusp of our atmosphere live a thin group of seasonal electric blue clouds. Forming 50 miles above the poles in summer, these clouds are known as noctilucent clouds or polar mesospheric clouds—PMCs. A recent NASA ...

Study tracks Hurricane Harvey stormwater with GPS

September 20, 2018

Hurricane Harvey dumped more than 5 feet (1.5 meters) of water on southeast Texas in late August 2017, making it the wettest recorded hurricane in U.S. history. But after the storm passed, where did all that water go?

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.