Here at the Humberhead Peatlands we love it when it rains. It’s not just because rain is wet – and wet is good for bogs – it’s because rainwater isn’t just any old water. Rain, hail and snow have two key properties that are key ingredients for bogs like Thorne and Hatfield Moors.
Remember acid rain? We’ve not heard much about it in the last 20 years or so since the air pollution that caused it has thankfully reduced compared to its peak. What you might not know is that all rain is a bit acid – it’s supposed to be, just not as acid that our pollution had made it. This is because carbon dioxide in the atmosphere dissolves in water creating weak carbonic acid. The sphagnum bog mosses and cottongrasses that grow on the bogs need that acidic environment. If that changes then rushes and other species will take over and the habitat will change to swamp or fen.
Rainwater is also different from comfrey or nettle tea. If you grow your own veg you’ll know that water from your rain butt keeps your plants from wilting but it doesn’t help to fertilise them. Rainwater should be pretty free of plant nutrients – although air pollution from transport and agriculture does turn it into a very weak fertiliser. Our precious bog plants are specially adapted to growing in a low nutrient environment. Sundews and Bladderworts are two insectivorous plants that make up for the lack of nutrients by catching their own in the form of insects. If we fertilised a bog, the special plants and mosses would be replaced by other species that aren’t specially adapted, and the entire habitat would change.
Restoring our bogs at Thorne and Hatfield Moors is all about managing water levels. Some areas are too dry – you may see lots of heather, bracken and tall birch trees. The challenge is to slow down the run-off of the precious rainwater so that it can soak into the peat and keep the habitat wet. We can’t pump water onto it from ditches as the water in the ditches has come into contact with the non-peat substrate below the level of the bog. This means that the water is likely to be less acidic and more nutrient-rich than plain old rainwater.
This is a shame, as some of the very low-lying parts of Thorne and Hatfield Moors flood to such an extent that the water drowns out the peatland vegetation that is trying to colonise the bare peat that was left from the process of commercial peat harvesting. To get water from these areas to the parts of the bogs that are too dry would be very difficult to do without changing the rainwater into ditch water.
We live in a quite a dry area of England. Things do seem to be getting a little wetter as our climate is changing – but more of the rain is falling during very wet periods and we’re getting more frequent dry periods. We’d really like our spread out fairly evenly across the year. However, we do have some very good areas of bog that are, of course, entirely fed by rainwater, and these areas show exactly what it is possible to achieve over thousands of acres of our very own Moors.
