Tuesday, 1 March 2022

February 2022

Thanks to the goodwill of Brien Curran of Ward & Burke, the contractors for the dam safety works, I was given access to the lakeside prominade to complete my 510th monthly standard bird count since August 1985. They have used the lake drawdown pipe in the new dam structure to lower the lake level unprecedently low to allow work on the dam. On Jan 16th the lake level was 0.25 metres lower than it was in the previous four months, and on 28th February it was 0.52 metres lower and still going down. This extra lowering had exposed much rubbish that was previously hiding beneath the surface: old metal structures, concrete and brickwork. The anglers have cleared much of this from around the other sides of the lake, but nothing seems to have been done beside the dam. Work was going on to add a timber face to the top of the sheet piling at the edge of the dam, and to fill behind the top of the piling with concrete. So the top edge was already looking much more tidy. The construction of the new lakeside prominade was far from complete. Looking around the lake, I could spot no place where the lowering had exposed any appreciable amount of the lake bottom sediment. This thoroughly disproves assertions by LB Merton that a much more modest lowering of the lake would expose large amounts of "silt". Essentialy, the lake has retained its designed shape even with a water level appreciably lower than in Brown's original design. The first photo below also shows some work under way in the distance on the northern part of the golf course, now closed for golf. Of course, work on All England's proposals for intensive tennis development should not begin without planning permission, but the nature of the work was not clear. The security fence between the public park and golf course near the Wimbledon Park Road entrance has had extra height added recently.


My bird count didn't add a lot to last month's results, showing that the very considerable lowering of the lake water hadn't affected the water birds appreciably. As in January, there were no cormorants. Whilst the anglers celebrate this, I don't, because it means there are few fish to attract them to the lake. Fish will thrive if they have better cover from predators. Natural cover is best and waterweeds will come with improved water quality. The highlight, however, was two Little egrets feeding at the lakeside of the golf course. This species has been seen only once before, in September 2019, but is increasing in the UK and that probably explains the unprecedented number. Another possibility is that the low water level has exposed a little more shore. Time will tell. Coot numbers have returned to the long-term February average. This suggests, sadly, that water quality may have declined, so compromising waterweed growth. Both Egyptian goose and Greylag numbers remained low. Three of last year's cygnets remain on the lake with their parents. The same resident bird species were singing as in January.

Laurustinus is a garden shrub and one was in flower in the golf course hedgerow beside the perimeter path. This is one of the many species that has arrived there, mainly in the droppings of birds, over the last 100 years. At the northern end of the same hedge a Myobalum plum was in flower and there was just one early Hawthorn flowering further south. This is the season for the Sweet violets, which were flowering on the southern edge of Horse Close Wood. Daffodils, too, were starting, including those planted by the Friends beside the Bowls pavilion, under the veteran Oak and beside the Revelstoke Road entrance. Blackthorns and Snowdrops were flowering along the hedge between the Revelstoke Road car park and Horse Close Wood. Hazel catkins were more or less over and leaf buds breaking. The leafs of Cow parsley, Cuckoo pint and Bluebells are showing in Horse Close Wood. Unfortunately, the heavy use of the area around the Bluebell path during lockdown has damaged many of the Bluebells there. They may recover now that there is lighter use.

The park was closed on 18th February because of Storm Eunice. The storm resulted in many small branches falling off trees in the park. Five larger trees fell, a low number considering the force of the storm and a credit to LB Merton's tree safety monitoring over recent years. Two Leyland cypresses fell across the perimeter path near the north-east corner of the stadium, bringing down two panels of the security fence. Many people have stopped using the path there, but some are braving the very soggy grass of the great field to get past. It would be silly to replace these with Leylands. It's a great pity that parks maintenance has removed many trees and shrubs that have regenerated naturally at the bottom of this hedge, because these would have made sensible provision for such losses. I would plant quick-growing native shrub species. Given the damp soil, shrub willows would make sense. One of the two Balm of Gileard poplars in the south-west corner of Horse Close Wood has fallen over the path that enters the wood from the car park. The path remains passable, but I would suggest removing a short section of trunk to restore level access. The rest of the tree provides valuable habitat and the managment plan would suggest leaving it in place for that reason. Another poplar fell over the path that runs towards the Glade at the other end of the wood. Inspection showed that this tree was rotten at the base. Whilst this one could be cleared away to restore the path, walkers have already made a diversion around the tree. It might make sense to allow the path to remain there, so allowing most of the tree to provide valuable habitat also. The last tree was one of a stand of Leyland cypress growing on the banks of the brook just downstream of the cafe. The remaining Leylands remain undamaged. This is not a very sensible place for large-growing trees because they are planted too close to the brook and they shade it. I would not replace it, awaiting a sensible enhancement of this stretch of the brook. All these fallers brought up subsoil around their roots as they fell, confirming what we knew already, that the soils of the park are predominantly heavy clay loams.


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