Bill Shaw – Ecology and Conservation Land Management Adviser
Ponds are very important habitats for wildlife and used to be an important part of the farmed landscape, providing drinking water for livestock. Ponds are often close by houses, farms and villages – and so provide excellent opportunities to watch a habitat in action.
With the advent of mains water, which could be used to fill drinking troughs, the need for communal ponds declined dramatically and so they tended to be forgotten about or filled in to create more productive land.
A pond that is not cleaned out fairly regularly will naturally fill in with vegetation, become a marsh and then, over time, dry land. This process is called natural succession and, interestingly, if all land in the United Kingdom were left totally untouched nearly all of it would eventually become oak woodland – the climax vegetation.
Anyway, this loss of ponds has not gone un-noticed and there are a number of organisations working to restore ponds and dig new ones where possible e.g. the Freshwater Habitats Trust for one, and the North York Moors National Park for another.
Last year we were approached by some locals in Silpho village in the south east of the Park about their village pond which had dried out. The geology around here is limestone which does not hold water well, so to water livestock here in the past the pond had been dug and then lined with ‘puddled’ clay which held the water. These sort of ponds are called ‘dew ponds’ and, despite their name, they actually rely on rainwater to fill them up. During construction a layer of soot or lime was put under the clay to deter earthworms from burrowing through the clay and riddling the pond with holes!
Parish records showed that the pond had been constructed during the agricultural revolution in about 1800. In 1982 the clay liner had finally given up and the pond had dried out so a plastic liner was installed, but this had failed by 2012 and the pond had totally grown over.
The task for us (official and unofficial Volunteers, and National Park staff) was to remove all the vegetation and install a new plastic liner. This took two days and was very enjoyable, being a good mix of brawn and brain!
The pond will now fill naturally with rainwater and in the spring we’ll bring some suitable native plants in from a nearby pond – plants like water crowfoot, water forget-me-not, water soldier, hornwort, floating sweet grass, marsh marigold, water mint and yellow flag iris. I for one have put money on frogs breeding here this spring!
We’ve now got our eyes on three other ponds fairly close by that we want to reinstate, so creating a local network of watery homes for wildlife.