Phase 1 (the messy phase!) of sealing the leaks in the pond has been completed today, with Isobel Clark, Mark Hobbs and Brian Harris doing most of the heavy work.Read More
I understand that native bluebells can sometimes be albinos and therefore have no pigment in their petals. It is more usual to see white bluebells that are hybrids with the Spanish bluebells. To identify native bluebells of what ever colour I look for the following:
- ratio of length of flower to width (4/5 :1 is native, 1/2:1 is Spanish, in between is hybrid)
- droopiness of flower stem (very droopy with flowers seeming to be on one side of the stem is native, upright with flowers all round ( a bit like hyacinth) is Spanish, in between is hybrid)
- colour of pollen ( white/cream is native, blue is Spanish or hybrid)
- width of leaves (less than 0.75 inch is native, 1" or more is Spanish, in between is hybrid)
- how curled back the petals are at the ends (very curled is native, uncurled is Spanish, in between is hybrid)
I find that I need to use most of these indicators to decide which type a particular flower is. On the Commons we have a lot of native ones, mostly well onto the Commons and filling the glades and under the woodland. Nearer to the road there are some hybridswhich I guess have got out of people's gardens where they have Spanish ones. We hope that no-one puts any Spanish ones on the Commons as they are much more successful at reproduction, germinate more easily, grow into bigger clumps more quickly and come to dominate in areas where they are found. It would be such a shame for our native population to die out from competition.
The photo you sent shows, I think, a hybrid bluebell as the bells have a 3:1 ratio, the petals are not very curled and the habit is somewhat upright. The blue bells around it seem to be more native than Spanish but I suspect they are all hybrids. Where did you see these particular ones?
Some people ( including Richard Mabey) seem to think that we should not resist the spread of the Spanish bluebells. He says that plants have moved from place to place over centuries and this is just another one we will have to get used to. Cross-breeding and competition are facts of nature, increasing diversity and a plant's ability to survive. I think he has forgotten that the Spanish bluebells didn't come to Britain on their own but have been imported by us humans so it is not Nature that is making this competition possible, but humans. I'm a bit surprised that he does not think it worth preserving the variety of species that have evolved so far but I think he takes the view now that Nature knows best so let it do whatever happens without interference from us humans. If we followed this advice we would leave the bracken to cover the whole common, not to say the trees, the ponds would fill up with rushes and New Zealand Pygmy Weed, the heather would die out here and many of the wild flowers would disappear under the blanket of dead bracken and dense shade of the woodland. I suspect Richard Mabey would say " What is wrong with that?" . Maybe it all depends whether you are accepting the natural world as it evolves over time or whether you value the wide diversity that it has at the moment. I suppose it may be that we are only holding up the succession to the wild forest that covered the country millennia ago but it seems to me worth trying to preserve the wide diversity of species where we can.
A few years ago we had a couple of working parties digging up some of the hybrids on the Commons verge but we don't have anyone who is keen to lead that at the moment. If you know of anyone who would like to protect the native ones on the Commons from the invasive pollen which undoubtedly is brought in from surrounding hybrids, let me know and we can have another session, perhaps first identifying where the most Spanish ones are and then digging them out. The best thing people can do to stop the spread, without digging them up, is to take the flowers home and put them in a vase to enjoy, thereby stopping the pollen from getting to the natives and stopping the production of seed which can also be spread to other areas by birds and small mammals. I can't say that we have permission to do this on the Commons as most people will have trouble identifying which are which.
The New Zealand Pygmy Weed has disappeared from places where we have had black plastic covering it but, unfortunately, it has now invaded some of the areas where there was no plastic. As far as we know, nothing predates the weed. There is a selective spray but this is only 70% effective. The radical strategy suggested by experts is to pump out the pond and spray to kill everything.
There is no guarantee that it won’t return, however, since birds can bring it in from nearby ponds although it is interesting to note that the dew pond, not far away, shows no sign of it.
It may be that sealing the gabion wall along the roadside, and thereby making the pond deeper, may reduce the NZPW but it is also possible that it may just become the aquatic form, which is just as bad. The benefit of deeper water is two-fold: firstly, any black plastic will be less visible at low water levels and secondly, the Sweetgrass, which otherwise will completely fill the pond, seems to prefer shallow water. Leaving the plastic as a permanent feature while the water depth is so low is not preferred as it is such an eyesore. The Committee agreed to consider the possibility of increasing the water depth by sealing the gabion wall (if possible) and then using submerged black plastic again to shade out the NZPW.
The Sweetgrass is relatively well controlled at the moment but that has largely been down to the black plastic but, now it has been removed, this will allow the Sweetgrass to spread again. We do not now have many volunteers working on the pond and so removing the Sweetgrass by hand, with the black plastic removed, may not halt its advance in the future.
Pond Conservation; the Canal and River Trust; and the Million Pond project will be contacted for advice and possible sources of funding.
Apart from the Pygmy Weed and Sweetgrass problems, the pond is looking good.
A Wildflower walk with Isobel Clark, volunteer with HCCPS, on the stunning Hawridge and Cholesbury Commons in the Hilltop villages of the Chiltern Hills.Read More
An update on the HCCPS Owl and Raptor nesting box conservation project situated on the Hawridge and Cholesbury Commons, in the Chiltern Hills.Read More
FRIDAY 15TH MAY AND SATURDAY 16TH MAY 2015
HCCPS invite you to an exciting wildlife event to take place over two days.
Friday 15th May at 7.30pm
Peter Bygate and David Dennis – our local butterfly and moth experts - will be combining their experience and their slides to give an insight into a range of exotic species from the Indian sub-continent. They will also show us some of the more unusual species to be found closer to home.
Friday 15th May at 10.00pm
Later in the evening, they will set up two moth traps on the commons to attract some of the colourful species that are around at this time of year. Anyone is welcome to join them opposite the Full Moon to see what arrives.
Saturday 16th May at 10.00am
The contents of last night’s moth catch will be identified, photographed and released safely. All ages are welcome to come and see what interesting beasts have been flying on our commons while we were all asleep!
Help clear our commons of rubbish and join us in the Litterblitz.Read More
Stephen and I walked up to Pallett's Pond today to experience the 'darkness' that was promised. The cloud cover was entire and it never seemed to get noticeably darker or colder as it did in 1999, when conditions on the hill at Brill were clear. At 9.40, we did not expect to see anything of the eclipse. At that point, we turned towards the east and a slight break in the clouds revealed a moon traversing a spectral sun, which was veiled by a higher layer of cloud. In 5 seconds or so, it was gone, obscured by the grey clouds.
We walked on to the pond, and on the way back we looked at the work that has been done by James Joliffe on the dew-pond and thought - if only we had a camera and if only the clouds were not so heavy - we could use the open space of water as a mirror to watch the progress of the eclipse. As we got nearer home, the clouds began to evaporate and I ran as fast as possible to get the camera and car keys to get back to the dew-pond. By this time, I realised that we would be too late to get back to the pond, so we took these photographs in our own pond, just before the sun became too bright for the camera.
So, in lieu of the dew-pond, here is our record of part of the event. I will never again travel on the Commons without the camera.