Pond Maintenance Sunday 20th March 2022
Spring time, for amphibians and BCV, means it’s time to look at ponds. This particular pond in Longsight Park, Harwood, was at first inspection thought to be in poor shape: it is surrounded by trees and very well shaded, leaf litter was silting up the pond, and yellow flag iris was spreading out from a patch at the north end. But when we started setting up on this the first warm and sunny task this year we found a decent sized clump of frog spawn, later we also found three large and sheepish looking common frogs who may have had something to do with it. We were happy for all concerned.
ut some of the trees but mostly at the other end of the pond, this will improve things but Ideally de-shading needs to be done at the southern end of the pond that is being shaded out. More sunlight reaching the pond will fuel primary production and let oxygenating aquatic plants to do their work, also frogs and their spawn tend to be happier and develop better in warmer water than they do in the cold and dark.
So, this is where we started work. We took down overhanging branches with either the long named and laboriously long-handled pruning saw, or zipped through them with the energetic long-handled chainsaw, or chainsaw on a stick as it is affectionately known. The results were the same, the branches fell into water and splashed anyone standing too close.
With some of the branches and smaller trees now out of the way we could start dragging stuff out of the water. Three intrepid volunteers braved the silliness of wearing waders and walked hip-deep into the pond. As well as pulling out the dead wood they also used rakes to dredge some of the leaf litter from the murky depths. Leaves falling into ponds do two things, they eventually silt up the pond turning it from a open water into a bog, and secondly they also use up the available oxygen as they decompose. Instead of a thriving pond you end up with a stagnant pool which is no use to anything except things that can live in oxygen poor conditions.
With more light and less sludge our pond was looking a lot better, but there’s still lots we can do to make it a froggy heaven. More plants will be added at a later date, maybe some water fleas as well to nibble their way through the algae. In turn these will be eaten themselves by other pond life that will eventually make this place their home. Circle of life.
All of the trees and branches that were cut down were used to make dead hedges, or linear habitat piles if you want to be PC, near by. In time these may be used as hibernacula for sleepy toads and newts, that is if they can bothered to find the pond in the first place.
Following on from one of the on task conversations that make us such a merry band, blue skies are caused by short wave light being scattered at right angles by atmospheric gases, chiefly nitrogen AND oxygen. Blue light being at the short end of the spectrum is scattered more readily by gas particles because of the gas particle size in comparison to the light’s wavelength (if I’ve read this right.) This is called Rayleigh Scattering after the clever bloke who worked it out; scattering by larger particulate matter is Mie Scattering, in honour of another clever bloke, and can be seen when the observer looks at light closer coming more directly from the Sun. Because of these scientific phenomenon we enjoyed our first blue sky in months and a nice sunset later on bringing to an end a really good task day.