Bogs are possibly the finest repository for information of what’s been happening in the environment for the last few thousand years.
The nature of raised bogs is they are acidic and oxygen poor; this makes the perfect pickle recipe for preserving all sorts of material: plants, animals, inorganic particles from the atmosphere, even butter was once preserved in bogs: you name it, it all turns up in the bog sooner or later.
Bogs also grow at a relatively constant rate (Flanders Moss is about 1mm a year). Although Flanders Moss has been growing steadily for 8000 years the average depth on the deeper sections is about 7 metres, you’d think that it should be 8 mtrs, but the peat has been compressed by the weight of the overlying peat and over the centuries bits of Flanders have been hacked off, dug up and nibbled at, by people looking for fuel and farmland.
With this in mind, an intrepid team of Geoscientists (Tim, Dimtri and Morag) from Aberdeen University, went out on to one of the least visited and most pristine parts of Flanders Moss to take some core samples. The intent is to take the core samples back to the lab and analyse the material for plant fossils and anything else that they can find, to build a picture of the changing nature of the moss over time.
Down to about 2 metres, the peat was a browny orange colour with mostly sphagnum moss, lots of cotton grass roots and the occasional heather root. Morag’s job is to look at the species of sphagnum moss (macro fossils) within the core and look at changes in species, which indicate environmental variations over time (palaeo-ecology); that’ll have to be done in the lab with microscopes. The first 2 metres; is the sphagnum peat layer. Below 2 metres; the core starts to change colour and consistency – the peat gets darker with woody material and glimpses of carex sedges, and the peat becomes more of a fen peat.
The browny orange moss peat is from a rain fed raised bog (similar to modern day Flanders Moss), but about 3000 years (the 3000 years is a bit of a guestimate [my guestimate], the layers can be dated really accurately, using C14 radio carbon decay; but not in the field) ago, where the darker peat starts; something different was happening. There was a source of mineral nutrient input, possibly ground water upwelling, or run off from the surrounding land, which created a different habitat.
Just from a cursory look at the peat core, on site, with no analytical instruments, microscopes or anything other than a hand lens; we can see that about 3000 years ago. Flanders Moss, went from something that probably looked something like this:
To something like this:
That’s just in the top 2½ metres
We went down to 3.2 metres, just short of half way down, and found that the fen peat didn’t form a completely continuous layer, but had layers of more sphagnum dominated bog interspersed within the core. After this we ran out of sampling pipes to go any further. Originally the team had only wanted to go down two metres or so, but curiosity about the deeper part of the bog got the better of them.
It will take many months for all the data to be extracted from the core samples, but we await with interest.