The bright jewels of winter found thriving in Acton Wood Nature Reserve on the north side of Derwent Reservoir
Fringing the edge of Derwent Reservoir on the North side, are a stand of old willow trees, gnarled, blackened and reaching high into the sky.
(The Heart of Durham Project works in partnership with Northumbrian Water)
In January Durham Wildlife Trust Heart of Durham volunteers have been pollarding these willows. Pollarding is a pruning system involving the removal of the upper branches of a tree to promote a dense head of foliage and branches lower down. Last year the volunteers carried out this work and on patches of willow on the reserve and the results have been impressive. This lush new growth will be beneficial to a variety of birds as willows are host to a wide range of insect species and caterpillars.
As well as pollarding the willows, cut lengths of willow have been planted to create new young trees.
Willow usually is the easiest tree to grow from cuttings, but last year’s plantings failed. January and February 2017 where unnaturally dry and the resrvoir throughout the year was very low allowing sheep to slip around the fences knocking over the whips.
Willow trees fringe the edge of the reservoir, but the nature reserve site consists of a small fir plantation surrounded by majestic veteran oaks and wonderful ancient birch woodland.
Dripping from the branches of all these woodland species are a wide range of lichen and fungi – jewels of colour in a grim January day.
Lichens are very interesting as they are a symbiosis of at least two quite different organisms, a partnership that always involves a fungus, which lives with one or more partners which can do photosynthesis. The photobiont partner may be a green alga and/or a cyanobacterium and these live inside the fungus exchanging nutrients with it. The lichen is a distinct form of life and as a result is very different in shape to its partners.
Tree bark offers lichens a good substrate to grow on, but different trees have bark of different acidity and this will dictate the type of lichens that will colonise. Lichens are sensitive indicators of air quality, with some thriving in areas with high levels of nitrogen compounds, whilst others are only found where there is low air pollution.
Lesley Hodgson, a volunteer with the Heart of Durham Project, took some photographs whilst working in the nature reserve.