Rainforests have been established to be effective for carbon storage as a means of mitigating the effects of climate change but researchers from Deakin University have found that freshwater wetlands or swamps may be up to 50 times more effective for that purpose.
Researchers carried out a study investigating how wetlands could aid against climate change, identifying not only carbon stock levels in south-west Victorian wetlands but the impact as well of restoring wetlands on said stocks. According to Dr. Rebecca Lester, an estuarine and freshwater ecology expert, it is crucial for methods for measuring stocks of carbon to be defined as this will allow for affordable but rapid assessment of large numbers of wetlands.
"The measurement tools will enable natural resource managers and landholders to reliably estimate and enhance their carbon sequestration," she said, adding the tools will help in the global effort to address the effects of climate change.
Preliminary results from their research hinted that wetlands have the ability to absorb up to 33 percent of carbon in soil and yet they take up just around 4 percent of land surface on Earth. Researchers are confident, however, that this kind of storage capacity wetlands have has not been quantified before in earlier studies accounting sources and sinks of carbon around the world. In fact, the work Lester and colleagues did is believed to be the first to quantify sequestration in freshwater wetlands, starting with the ones in Australia.
Sequestration, or biosequestration, is defined as the capture and storage of carbon via biological processes. In Australia, it is considered as the single biggest shot at reducing carbon dioxide emissions.
Lester explained that one of reasons wetlands perform better compared to forests in capturing carbon is in the way organic matter and sediments are collected underwater, resulting in a slower breakdown that lets swamps act like carbon sinks.
Wetlands used to cover up to 10 percent of the land mass but many have been drained and used as farmland, with the buildup of organic matter ideal for growing produce. Researchers warn that, in the future, the agricultural value of wetlands will have to be assessed against the benefit they can bring as carbon sinks.
The research Lester and colleagues have done is part of a larger project involving the University of Arizona, the University of Liverpool and Flinders University aiming to explore the possibility of improving carbon sequestration in wetlands across semi-arid and temperate ecosystems in Mexico, the United States and Australia.