Friday, 14 January 2022

January 2022

I struggled to do the monthly bird count on the 12th and lake water sampling on the 16th, because the lakeside promenade was fenced off between the play area and the jetty. 

One of this year's Mute swan goslings was missing, probably seen off by its parents to join a non-breeding flock, as is usual in winter. The 75 Coots were not greatly above the long-term average of 55, so this waterweed eaterseems still to be slowly declining down from its 2015 January peak number of 190, not a good sign for water quality. The 6 Mallards conform with the long-term decline of this species. Egyptian goose and Greylag numbers remain down compared with recent counts. Numbers of both species peak in early Summer, so it will be interesting to see how they shape up then. I suspect culling by the golf course has affected both. In December there were no Great crested grebes and there was just one in January. Cormorants are usually in peak numbers at this time of year, but were missing in both months, also. But there were 5 Cormorants on the 16th, so the indication that fish numbers are low this winter may just be random fluctuations in attendance. Mid winter finds peak numbers of the Pochard which has been increasing in recent years, and the 35 birds was another record count for this species. This species, too, can come and go, as I was unable to show Nick the flock on the 16th. Some resident bird species had begun territorial behaviour. Great spotted woodpeckers were drumming in Ashen Grove and Horse Close Woods and a further bird was calling in the fenced veteran oak by the ex-bowling green. A Ring-necked parakeet was perched in the same oak, so it will be interesting to see whether both species breed there come Spring. The increase of the parakeet seems to be over, the 7 birds seen being substantially lower than in some recent years. Resident birds begin singing in mid-winter: Great and Blue tits, Wrens, Song thrushes and Stock doves were singing. Redwings are winter visitors from places further north and east, occurring mainly between November and March: 6 were feeding on Ivy fruit in Horse Close Wood.

Hazels in the woodlands, hedgerows and on the railway embankment were all showing their winter catkins.

My lake water sampling showed that the lowered water level has not led to any difference in the biota compared with the previous five years. As is usually the case, I found an extra species: the Lake limpet. The longer you look, the more you find. 

Work began on the dam safety project before Christmas. It appears that the lake level was being lowered to enable the works because the brook in the public park carried a more considerable flow than recent rainfall would predict and measurements of lake level showed it to be some 10 cm lower than in recent months on the 12th and 25 cm lower on the 16th. This lowering has revealed several built structures out in the lake near to the dam that have remained invisible before. On the 16th it was observed that work was under way to remove the seats along this eastern part of the prominade. Unfortunately, the access to the works down from Home Park Road has involved depositing large quantities of wood chippings on top of the woodland soil of Ashen Grove Wood, against the advice we gave at the time of the planning application. This material is difficult to remove when access needs are over and acts as a mulch, supressing the growth of woodland ground flora. Sufficient protection could have been achieved with the removable trackway, so obviating this damage. As I expected, the temporary trackway constructed for the outflow construction is over the single plant of Wood Millet. This is a perennial plant, but I suspect it will not recover from this insult. Fortunately, the other ancient woodland indicator plants are more widespread in the wood and some should survive away from the construction area. All this reflects the emphasis on trees in the planning of these works, as if the rest of the flora and seedbank of an ancient wood is of no value. Replacing a few lost trees will not replace the losses to the woodland soil and ground flora. There has been no consultation with park users on the compensatory tree planting, despite the existing voluary programme of tree planting within the public park. We have been careful to take account of the soils of the area and of Capability Brown's original design. It remains to be seen whether the compensatory planting will accord with this existing programme.

The grille that catches debris where the brook goes under the tube line embankment on its way underground to Earlsfield has quite a lot of debris on it. There was also Yellow flag iris rhyzomes caught on rocks in the brook, something not previously noted, so it appears that the works to create the new weir and outfall has involved sending this debris down the pipe. These two things risk blockage of the grille in any storm event, resulting in a significant flood in the public park.

Where the Wood Millet was, now woodchip mulch and trackway

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