How the secret weapon in the battle against climate change could be the humble pond; Northumbria University research reveals how ponds have an amazing ability to soak up carbon, and are excellent for wildlife too.
Byline: Tony Henderson
The burning of fossil fuels such as coal has been firmly linked to accelerating climate change.
But mining has left a legacy which goes some way to balancing the books, a 25-year experimentby Northumbria University's Mike Jeffries has shown.
It has involved calculating the amount of carbon absorbed by ponds from the atmosphere.
The Associate Professor in Ecology and his students dug a series of small metre-wide ponds in 1994 at Hauxley nature reserve onDruridge Bay in Northumberland. The aim was to monitor, over time, what life colonised the ponds, and how long the process took.
But then Mike realised that because the exact age of the ponds was known, it would be possible to calculate how much carbon had been absorbed in their sediment annually.
"They had accumulated a layer of sediment, dark and rich in organic debris, distinctly different to the underlying clay. We used sediment cores and dug out all of the sediment from some ponds, to measure the organic carbon that had accumulated," said Mike.
The ponds' burial rates for organic carbon ranged from 79 to 247g per square metre per year, with an average of 142g -- much higher than the rates of 2 to 5g attributed to surrounding habitats such as woodland or grassland.
Small ponds occupy a tiny proportion of the UK's land area at 0.0006% compared to grassland at 36%, and 2.3% for ancient woodland.
"But the rate of carbon burial we found would result in ponds burying half as much as the vastly greater expanse of grassland," said Mike. "The ponds locked up carbon at a much faster rate than woodland or grassland. They are really powerful sinks for carbon and are also good for wildlife, which is a lovely bonus."
And he claims that the large number of ponds created by mining subsidence on the coastal plainfrom Ambleto the Tyne and 20 miles inland, is now a special landscape.
"The sheer number of subsidence ponds make it an internationally significant landscape, which also echoes the mining history and economy ofNorthumberland," said Mike.
But generally, ponds are taken for granted, he says.
"We think they're only good for goldfish. Ponds may be the number one habitat for children's minibeast hunts, but we are supposed to grow out of them in adulthood.
"All too often, ponds are missed out of conservation strategies which are instead fixated on larger lakes and rivers. This is a serious omission."
Mike says research has revealed that ponds are biodiversity hotspots in the...
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