Aussie diggers linked to ecosystem decline

September 25, 2013
Aussie diggers linked to ecosystem decline

A new Murdoch University-led study has highlighted the relationship between the loss of Australian digging mammals and ecosystem decline.

Referred to as 'biotic engineers' by researchers, species such as bilbies, bandicoots, potoroos, echidnas and woylies have been highlighted for their impact on and ecosystem functioning.

"Most Australian soils are nutrient-poor and are greatly dependant on external processes to support environmental health," said Associate Professor Trish Fleming.

"Digging mammals play a vital role, creating disturbances in the form of nose pokes, scratchings, shallow and deep digs, long bull-dozing tracts and complex subterranean burrows.

"These interactions lead to soil turnover, nutrient mixing, better breakdown of organic materials, and improved infiltration of water, which decreases surface runoff and erosion.

"For example, in foraging pits created by echidnas is approximately twice as great as in undisturbed soils, and the breaking up of the hard soils allows seeds to find suitable sites for germination."

Professor Fleming said the amount of soil shifted by digging mammals was astonishing. A southern brown bandicoot can excavate over 3.9 tonnes of soil per year, while a woylie will create between 20 and 100 excavations every night.

She said these amounts had to be considered against the fact that over the past 200 years around half of all digging mammals have been declared extinct or have come under conservation threat.

"Australian ecosystems have been undergoing a massive loss of , including higher rates, episodic die-offs and general decline in the number and vitality of plant species," she said.

"Meanwhile, Australia has had a higher record of extinction of over the last 200 years than any other part of the world.

"The role of these animals is largely unrecognised, and research and management targeting of these species need to be undertaken as a matter of some urgency."

'Is the loss of Australian digging mammals contributing to a deterioration in ecosystem function?' has been published in Mammal Review.

Explore further: Dying trees in Southwest set stage for erosion, water loss in Colorado River

More information: onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2907

Related Stories

Digging deeper for soil carbon storage

September 10, 2013

Many surface soils in Western Australia are already storing as much carbon as they can, according to research at The University of Western Australia and in collaboration with the Department of Agriculture and Food WA (DAFWA) ...

Introducing species to change ecosystems is a balancing act

September 25, 2013

Species hold ecosystems in a delicate balance. From time to time humans introduce non-native species to an ecosystem, because they may be needed for domestic work, as pets, for carrying loads or even for killing previously ...

Recommended for you

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.