THE ability of microscopic plants to increase soil carbon and nitrogen levels may hold the secret for land managers in Australia's arid landscape to benefit from bio-sequestration, according to rangeland ecologist Wendy Williams of the University of Queensland.
It is good news for producers who graze livestock on the arid or semi arid rangelands - regions with less than 500mm of rainfall - which form more than 70 percent of Australia's landscape.
"Simple, microscopic plants grow on the soil surface of these areas, generally forming large masses or colonies which are visible on bare soil between plants or on rocks," Ms Williams said.
"These single-celled micro-organisms were once called 'terrestrial blue green algae' and are now more correctly known as cyanobacteria, and well-managed grazing practices can encourage cyanobacterial soil crusts to thrive within their natural environment."
Ms Williams explained that through the process of photosynthesis, cyanobacteria utilises carbon dioxide and converts it into biomass while replacing oxygen back into the atmosphere.
They thrive in harsh environments ranging from the Antarctic to hot deserts and rock surfaces where temperatures exceed 70 deg C.
"Ancient cyanobacteria were so productive that they changed earth's atmosphere from a CO2-rich state to the oxygenated atmosphere that supports life as we know it today," she said.
"Recent research on a global scale shows cyanobacterial soil and rock crusts account for significant amounts of net terrestrial carbon and more than 40 percent of biologically fixed nitrogen.
"This nitrogen is in a form immediately available to plants and is crucial to carbon capture.
"Increasing the terrestrial carbon sink can be tricky, as Australia has limited water and nutrients, however, place cyanobacteria in the picture and the situation appears much more favourable.
"Cyanobacteria are a natural asset in the Australian landscape and in that context are freely available to be used for our benefit - for example, Queensland has abundant cyanobacterial crusts on soil and rocks across the Mulga lands, Channel Country, Gulf Plains and Cape York.
"Based on current calculations Australia-wide, this equates in itself to an estimated net carbon sink of at least 1.7 million tonnes annually."
The Boodjamulla (Lawn Hill) National Park north of Camooweal is in the cyanobacteria spotlight with Ms Williams and Professor Burkhard Budel from the University of Kaiserslautern in Germany leading a team of researchers and technicians to establish a world-first trial on cyanobacterial soil crusts.
The research is a partnership between AgForce North, Century Mine, Boodjamulla National Park and the Australian Geographic Society to ensure ancient cyanobacteria are better understood.
AgForce senior policy advisor Drew Wagner said this type of research was integral to the bio-sequestration debate.
"Opportunities for bio-sequestration play an important role in landholders and scientists being able to further understand the full sequestration potential of our landscape, not just those with compliant forestry regimes," Mr Wagner said.
"Research such as this will further allow the agricultural industry to be part of the carbon solution, not part of the problem, while at the same time providing strong environmental outcomes when coupled with productive capabilities.
"AgForce will continue to support such research while at the same time working with the Australian Government so that opportunities like this are not just recognised domestically, but in the international arena as well."
Ms Williams said Boodjamulla National Park was selected for its widespread presence of naturally occurring soil crusts combined with the facilities needed to service such a project.
With specialised equipment on loan from the University of Kai-serslautern, the researchers can accurately measure how much carbon cyanobacteria sequester on a half-hourly basis.
The project will also calculate how much carbon is accumulated over a year and when peak nitrogen production occurs.
"Data from this research will assist land managers, producers and scientists alike in maximising productivity and preserving or increasing soil carbon and nitrogen levels," Ms Williams explained.
"This research will not just provide interesting figures for statisticians but actual facts on which to base our management decisions.
"Unlocking secrets from these primitive organisms provides us a fascinating window on past climate change events and opens up opportunities for the enhancement of a natural carbon sink.''
She said cyanobacteria could possibly step into a CO2-rich environment and increase their productivity.
"In rangeland soils the answer to this may be critical to increasing plant growth as it is well documented that if nitrogen is limited then carbon uptake by terrestrial vegetation will be reduced," Ms Williams said.
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