Nature's double-edged sword
And why ponds are key to wildlife recovery
Listen to the whole interview here.
Professor Carl Sayer of the University College London is hurting. He has been hurting for more than 30 years as he witnesses the damage that is being wittingly and unwittingly done to the natural world.
‘I love the natural world to my core,’ says Carl, who grew up in the rural county of Norfolk on the east coast of the UK.
‘And I’ve been hurting for at least 35 years but I balance that hurt by doing good things. I’m amazed and delighted by nature but I get deeply disturbed when I see bad things happening. That is the double-edged sword I have to live with.’
Carl’s answer, among many, many things, is to set about rehabilitating as many of Norfolk’s historic ponds as he possibly can. Some of the ponds – and there are thousands of them across the county – are in need of restoration. Others are ghost ponds, visible on aerial maps as slightly ‘different’ looking patches of land. The soil could be darker, there could be a different shade to the vegetation growing there, the soils are a different colour. But the ovoid shapes that we can see across the arable landscape are usually a sign that a pond once existed.
The ponds that exist today are often overgrown with scrub and trees, so Carl is leading a project – the Norfolk Ponds Project – to work with volunteers to clear these ponds and allow light back in. The biggest task is to clear the self-set trees that have taken root around the edges of the pond.
Trees have a profound influence on ponds. When they drop their leaves, the water can become completely shaded so there is no light getting in. In addition, the bacterial action on the fallen leaves takes all the oxygen. This dark, oxygen-starved body of water becomes very low in diversity.
Carl refers to the ‘ghastly and the ghostly’ when he refers to ponds. The ghastly are the ponds that are clogged up, the ghostly are just shadows. There are currently 22,000 ponds in Norfolk; before the second world war there were more than 30,000. Most of the missing 8,000 were filled in as part of maximising the land’s output for crops.
Despite being farmed, the lost ponds are not great bits of farmland. For this reason, it has been an easier task for Carl and other pond restoration groups to persuade farmers and landowners to return ponds to their previous state.
One of the most fascinating features connected to restored and resurrected ponds is the revelation of the seed bank. Seeds that have laid dormant for thousands of years can be germinated once they have been allowed to see the light of day. Nearly all the plants that grow back in the first few years after a pond has been cleared are, in Carl’s words, ‘coming back through time.’
‘They are coming back from decades, even millennia ago. Things that are locally or nationally extinct are appearing and that is astonishing. To my mind, this is the most successful form of restoration that we know of in fresh water.
‘Once we restore a pond, we are restoring an entire habitat. Ponds provide a super habitat for all manner of things.’
As a pond develops, the wealth of wildlife becomes quickly apparent. Plants, insects, birds, mammals all start to appear and soon the pond, which can be no more than 10 metres wide or across, will be a vibrant area providing for all manner of wildlife.
Listen to the whole interview with Prof Carl Sayer here