The carbon economy

October has experimented with the possibilities of every season. Blue skies and the last of the Red Admirals showing off in the sunshine, boy racers at heart, barely alighting long enough to flaunt their colours before away again, impatient. Then fog leaving the Blakemoor wind farm as stumps propping up the gloom or else we’d all be squashed down into the mud and browning grasses. Now snow, the flakes freezing together in an overnight crust . The blues skies in the photo above are Hauxley Nature Reserve scarcely a week ago. Scott is using a corer to drill out a plug of sediment from the little pond. This pond and twenty nine others were dug out in the Autumn of 1994 to monitor the initial colonisation by invertebrates and plants, then how the various species would respond to changes such as dry years or prolonged flooding. This also means we know how old the ponds are to the day, along with their history. Age and history are not the same thing. The ponds are all eighteen years old but some have had a fraught life of drought and flood. Others are more sedate, a steady progress of clogging by mosses and grass. The ponds are the closest we have to a time machine. We can ask questions of their contemporary nature and know enough to check back how their history may be responsible for this. Scott, Pete and Dave are extracting the plugs of sediment to measure the amount of carbon trapped in the mud since the ponds were dug. Some of the carbon is bound up in the obvious fragments of plant which have drawn carbon dioxide out of the air as they photosynthesise but there are also microscopic algae plus bits of plant fallen in from the land around too. The ponds may be small but the verdant plant growth, much of it trapped in the sediment, may be a powerful trap pulling carbon out of the air and down into the mud.