This story about a tropical peatland in the Congo basin is interesting for lots of reasons.

The peatland is estimated to contain billions of tonnes of carbon which have gradually accumulated as partially decomposed vegetation over the last 10,000 years or so (the Holocene). This is important in the story of the global terrestrial carbon cycle.

However, in the long term the most important contribution this discovery is likely to make is to environmental (and climate) reconstructions. Peat deposits provide one of the most important sources of information on environmental change during the Holocene (the last 12,000 years or so, since the end of the last glacial period). They allow reconstructions of the environment using two key sources of evidence - plant macrofossils (such as seeds, fragments of leaf, bark etc.), and pollen, both of which are well preserved in waterlogged conditions and can often be identified to the level of individual species.

Consequently the layers of peat provide a record of changes in the vegetation of the surrounding region - for example the species composition of the forest, and by extension changes in regional climate (temperature, rainfall) can also be inferred.

However, while we have thousands of pollen and macrofossil reconstructions from the higher latitudes, the conditions required for continual peat accumulation are rarely found in the tropics - the map on this website (http://www.ncdc.noaa.gov/paleo/gpd.html) shows the distribution of American, Asian and African pollen records held by the Global Pollen (European records are stored elsewhere). The map shows just how rare these tropical records are!

Finally, this is also an interesting story about the lengths field-based scientists go to get their data - they may have only been on the peat bog for three weeks but it sounds as though they had a pretty tough time!