Drought makes peat release far more carbon into the atmosphere and into watercourses than scientists had previously thought, a new study shows.
Once a peat bog dries out, it starts emitting carbon by giving off carbon dioxide gas (CO2) and methane into the atmosphere, and by releasing it into rivers and streams in the form of dissolved organic carbon (DOC).
This loss can carry on for a decade or more, and can continue or accelerate even after the bog is submerged again. And the type of bog habitat that's worst-affected accounts for some 60 per cent of the world's peatlands.
'Our findings on re-wetting were a huge surprise,' says Dr Nathalie Fenner of Bangor University, lead author of the paper, which appears in Nature Geoscience. 'There has been a lot of research on the impact of drought on peatlands but this is the first study that shows it can carry on for years after the drought has ended in a range of peats, but more importantly why - it seems to turbo-charge carbon emissions even once the water table has risen again.'
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