When Kirstie joined Mark at Shabden Park Farm, she brought with her a passionate interest in butterflies.With Kirstie's links with Butterfly Conservation,
a national conservation society dedicated to saving butterflies,
moths and their habitats, we are managing areas of the farm particularly
for butterflies and moths, and even for individual species. This
is not at the expense of other wildlife, as butterflies and moths,
along with all other living things, can only survive within a sustainable
ecosystem made up of plants, insects, birds and mammals. |
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The Shabden Elm ProjectWhen Dutch Elm disease struck in the early 1970s,
the vast majority of elms in south England were affected and had
died in a matter of two or three years. Many of the insects dependent
on elm were severely affected, especially the White-letter Hairstreak
butterfly, whose caterpillar larvae live off the elm plant. The
White-letter Hairstreak is a small butterfly with a flight which
spirals upwards towards the tree tops. It is distinguished by a
bold white 'W' mark across the under wing and short ‘tails’
to the lower wings. The dark upper wings are seen only in flight
as the butterflies always settle with their wings closed. Adults
are difficult to see because they spend so much time high up in
the tree canopy, although they occasionally come to ground level
to nectar on flowers near elm trees or saplings. |
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Against all expectations the butterfly
has survived in reduced numbers by living off the sucker growth
which many dead elms are able to regenerate. Because of the cyclical
nature of this regrowth, there are years when the butterfly is hardly
seen. Often the good years are followed closely by another wave
of infection.Dutch Elm disease is a fungus which is spread by bark
beetles. These beetles feed in the upper branches of the tree and
introduce the fungal spores to exposed tissue. Once infected the
disease spreads rapidly and unless treated at the early stages the
tree will not survive. In the late 1960s an aggressive strain of
the disease, originating from North America, was imported into this
country via diseased timber. It spread rapidly across southern England,
and by 1977 was estimated to have killed 50% of the elms in the
area. The disease shows no signs of waning in Britain. In summer
2005 it attacked ancient elms in the centre of Brighton resulting
in the felling of 370 prime specimens. Horticulturalists have been
trialling many different elm hybrids in search of an elm tree which
is totally resistant to the fungus. One of the successful hybrids,
named Lutece, is being used by the French government in a massive
planting programme to restore elms to the French landscape. |
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On 16th February 2006, three whips of elm Lutece were planted at Shabden Park Farm as part of a project by the Surrey & SW London branch of Butterfly Conservation. The project has planted 30 whips across South London and Surrey commons and country parks and has recorded the exact location by GPS in order to locate and monitor the young trees. The three young elms at Shabden are within ten metres of each other on the edge of one of the woodland shaws. For the first year I will be keeping a watchful eye on them, especially if we continue to suffer rainfall shortage. Now we seem to have gone straight from a long dry winter to hot dry summer, the whips are surrounded by waist-high brambles and nettles which give the root some shade and shelter. All three are in leaf and are strong and healthy. Hopefully, all three elms will grow to maturity, but they could be grown as coppiced elms if more appropriate, and this would also allow the butterflies to breed. The elm Lutece is in its infancy, but elsewhere, caterpillars of the Comma butterfly and the Grey Dagger moth have been found on young bush elms, so there is a great deal of hope and potential for the White-letter Hairstreaks. |
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Butterfly TransectsThe transect method of monitoring butterfly species involves the establishment of a fixed route across a site. This route is divided into a number of sections, which usually vary in length, habitat type and management. Each week, between April and September, walks are carried out along the transect, where the number of individuals of each butterfly species counted in each section are entered onto a standardised form. This information will then be collated and sent to the County Recorder and to the Research into Farmland Butterflies project coordinator at Butterfly Conservation. |
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