29th April 2020

A visit to check on progress with the lake following the ending of a drought with rain over the last two days. In passing I saw two plants of Flax growing under the veteran Oak, an unexpected find. It can be a component of bird seed, but there's no obvous reason for bird seed to be scattered here. It may originate from the "Wildflower meadow" patches in nearby parts of the great field. As an annual species, it's unlikely to persist.

Two days ago, at the end of the drought, water clarity was higher than in any of the previous three years but, today it had declined back down to a more typical late April value. It seems that the rain and cooler temperatures have done this because the rains were not accompanied by a particularly strong wind.

Cuckoo flowers can be seen in the steep grassy slope at the corner of the tennis courts near the white pavilion.

Flax

Water clarity

April 2020

20th April 2020

As the public park is just two minutes from my front door, I'm visiting more often than usual for my daily exercise. So, a few recent observations.

There's at least three Song thrushes singing in and around the public park: one audible from my back garden near to the boundary with Home Park Road housing. Another in and around Ashen Grove Wood. A third on the golf course near Wimbledon Park Road and what may be the same individual within Horse Close Wood.

Lake water quality is shaping up well so far this year. The chart shows water clarity over the last 3 years. This year, clarity declined, as usual, coming to a mimumum in March and, as usual, is now recovering. This recovery correlates with a reduction of the diatoms that cause the murk. The reason for the depleted diatoms is the great abundance of two species of Water flea which are grazing the diatoms down. See my photo of Daphnia longispina, one of those two. The greater water clarity should result in an increase in water weed, but my grab sample shows that there has been little weed growth to date.

If visiting the park, look out for the native Bluebells in Horse Close Wood (and a few can be seen through the fence in the part of Ashen Grove Wood on the golf course).