Wednesday, 5 August 2015
Here is one of the Ellington Farm arable field subsidence ponds in September 2013 (left) and this July (right). In 2013 the wide, shallow pool had stayed wet most of the summer, the open water ideal for gulls, and waders to loaf about leaving the water’s edge with a scum line of preened feathers and down. It was ploughed through in the autumn but then left unplanted and soon reverted to its less domesticated state. In 2015 the pond was waterlogged over winter but only as a small central pool and the winter wheat has been drilled, germinated and is fast approaching harvesting. I doubt that any teal or avocets hung around this year. Since 2010 we’ve kept track of when these ponds dry and fill, and their changing areas. The arable field ponds are particularly sensitive to the rainfall of the preceding month, the ponds in amongst wetland mosaics and dune slacks less so, perhaps buffered by a more waterlogged surround.If the pond stays like this the whole lot can be ploughed and planted this autumn, which may be enough to knock it out of the wider pond-scape and banish the wildlife that likes these disturbed, open flashes. The wall of wheat looks likely to advance, unless the weather turns fearsomely wet.
Saturday, 1 August 2015
July has been an unlovely mix of cloudy, clammy days. Nonetheless we have had little sustained rain and the effects are obvious as the Bay’s smaller wetlands dry out. Not a problem in itself, especially with the mosaic of pond types scattered across the landscape. Perhaps a greater threat is the interplay between the weather and other forces, in particular land management. For example this subsidence pond at the south of the Bay at Ellington Farm. These fields are dotted with seasonal ponds, shallow bowls that fill every year, roundels in winter then choked with the ephemeral mayweeds and oraches of disturbed ground in summer. You can see the white splodges of scentless mayweed in bloom. This pond has been the summer hangout of avocets and gulls in recent summers but not this year. The dry weather has allowed the wheat to grow thick and strong a long way into what is normally the pond’s core. It is now a small remnant, forlorn in amongst the crop. The dry ground also means that tractors can plough through, rather than round.
It could be worse, for example this pond.
It’s not there. You can make out the faint curve where it has been but this summer a solid mass of wheat. There are none of the characteristic plants in amongst the phalanx of stalks, only a huddle of pineapple mayweed along the distant hedge line edge.
Pond and their wildlife can cope with drying out, so long as there are refuges to retreat to then re-advance from. However the dry weather has tilted the balance in favour of the intensive cropping. The land use looks to be the greater threat to the pondscape’s survival rather than the dry summer itself. It is a classic threat, a double whammy of drying out and land use intensification. Wildlife can ride out the occasional mishap. But multiple stresses take a toll. The subsidence ponds are having a tough year.