Raised Bogs

So before I move on to any more sites, I thought I should take the time to write a full post on how raised bogs are formed. They are an extremely important resource because of their ability to absorb excess water and because they are natural carbon sinks. All those floods we've been suffering the last few years would not have been nearly so bad if the bogs were still in a condition to soak up water, but in order to harvest them for peat, we have installed drains in the bogs to dry them. For studying the past, the bogs have given us the most amazing examples of archaeology, from trackways to boats to depositions. These are all things I'll discuss further in the series, but the real value is that organic material which normally does not survive can be recovered and very precisely dated. The bog allows us to study the climate and ecology of the past too, meaning we can reconstruct very well what the landscape of the past was like.

After the glacial retreat 15,000 years ago, we were left with quite a few shallow lakes in the midlands that had no way to drain. In conditions like this, plant material growing around the lake edge only partially decomposes and eventually forms a layer of dead plant material stretching across the surface of the lake. This is known as fen peat and at this stage in bog formation, it is fed by ground water so it is nutrient rich and of an basic Ph. As this layer grows and thickens, it can no longer reach the ground water and is instead fed by rainwater, creating a nutrient-poor and acidic environment. Plants which prefer this environment start to colonise the bog and, as layers of plant material decompose, it takes the form of a dome.

Sphagnum Moss

Among the plants which thrive in the bog is Sphagnum Moss, also known as the Bog-Builder. This moss can hold up to 20 times it's weight in water and it contributes to the bogs' ability to drain the surrounding landscape. We also find plants such as Bog Rosemary or Cranberries in the wet raised bogs. Because of the lack of nutrients, carnivorous plants are often found in bogs, such as Sundew which preys on insects.

Sundew

On hummocks or in drier bogs, if they have been affected by drainage for instance, we are more likely to find heather or bog cotton. Bog Asphodel is colourfully nicknamed the Bone Breaker because it was believed to affect cattle's bones.

Bog Cotton

On the verges of the bogs, today we often see the conifer plantations, but birch and willow are the trees which we would expect to see in a natural environment. Many of the trackways which archaeologists have uncovered in the bogs are constructed from birch, showing how convenient a resource it was.

The wetlands were used for commercial forestry over the last several decades and this has had a damaging effect on the drainage of the bog and the ability of wetland plants to thrive. Thankfully, projects such as the Raised Bog Restoration Project are attempting to remedy this by preventing the spread of non-native species and reducing the amount of pine forest on the wetlands.