We are so pleased to see a Brown Hairstreak. In 2013 a single egg of this endangered butterfly species was found on a Blackthorn bush in Pheasant Field. Part of the vulnerability of these butterflies lies in the interactions of habitat that they require. Blackthorn is the sole food plant of Brown Hairstreak caterpillars and adult females only lay their eggs on younger specimens. Adult males and females congregate to mate on Ash trees and may be seen lower down nectaring on Fleabane, Hemp-Leaved Agrimony and Bramble. With our abundant Blackthorn and Ash, large stocks of Fleabane and Bramble (and a patch of Hemp Agrimony) we felt we could provide a good habitat for the Brown Hairstreak. In January 2015, with the help of the South Downs National Park volunteers, we started managing Blackthorn to provide space for the younger bushes preferred by the female butterflies whilst not allowing it to encroach too much on the main part of the meadow. Last Monday we were sitting in the meadow discussing progress with a ranger from the South Downs NP. We had seen no sign of Brown Hairstreaks. Less than an hour later a female Brown Hairstreak appeared a few feet from where we were. Was she making a point? Perhaps it was that your opinions on habitat depend on who you are. We see a complex interaction of woodland, marginal shrubs, meadow flowers and grasses. The Brown Hairstreak sees all these things as one habitat. We would tend to agree with them.
It is very sad to report the arrival of Chalara Ash Dieback in Lag Wood. The first symptoms are clearly visible, blackening leaves and shoots, often remaining attached to the stem and formerly healthy green stems turning brown and producing little or no leaf. The picture of a recently coppiced Ash stool (taken in early September) shows the classic early signs of the disease. Over time dark lesions will appear where leaves and shoots join larger stems. The disease is an airborne fungus Hymenoscyphus fraxineus (formerly known as Chalara fraxinea) and its tiny mushrooms might be seen on fallen ash twigs and leaves this autumn. Chalara Ash Dieback is known to claim around 90% of Ash trees exposed to it. Many of our recently coppiced Ash stools are already affected, and it is a melancholy sight to see the abundant regrowth we saw in June now blackening with disease in September. Some of our younger un-coppiced Ash trees are also showing signs of the disease.
There is no doubt that Chalara will have a significant impact on the character of Lag Wood. By volume around 35% of this wood is Ash, and Ash makes up nearly half of the canopy. But while it is hardly happy news, there are some glimmers of hope. Many older Ash trees may take several decades to succumb and, unlike Elm, the natural genetic variation in Ash will ensure that a few survive unscathed to create a new generation of resistant trees. The impact on wildlife will be comparatively slow and many of our other trees, Hornbeam, Field Maple, Alder and hopefully Oak, will take full advantage of the opportunities it brings. There is very little that can be done to halt the progress of the disease but we will be looking out for potentially resistant trees and adjusting our coppicing plans accordingly.
Finally, after many false starts, the mud dried out at the end of August and we were able to get a vehicle into our coppice coups and extract some wood. The picture shows the first of many small truck-loads of wood from the trees that we coppiced in March. We think that this is the first time since the 1950s that wood in any quantity has been harvested here.
Most of our wood is not of timber quality and will go for firewood. But we have discussed the development of short-rotation hazel for traditional fences and hurdles, and there might be opportunities to explore with other skilled crafts-people such as musical instrument makers who have expressed an interest, particularly in Alder and Field Maple. Our reasons for coppicing remain the same, to maintain and improve the biodiversity of Lag Wood. But our long term aim is to break-even on the costs of doing it. This goes at least some small way towards establishing that it is feasible to do so. A good day all round.