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In a message dated 02/08/2006 14:02:03 GMT Standard Time,
dom@xxxxxxxxxxxxxxxxxx.co.uk writes:
Many are linked to medieval field systems and
some are possibly late Romano British. In short they're old and nearly all
of them appear on 1830-1860 maps but their species rich nature indicates
they're far older. 7 woody species in 10m streches is very common - often
higher and in 100m stretches 7 woody species - easy.
While I accept you're most probably right Dom, I've planted hedges with 7
woody species in less than 10 metres......
If you're trying to apply Hooper's Law then be careful, I've frequently had
people tell me that a hedge must be old cos there are 5 or 6 species. Well
Hooper said his Law wasn't safe to use north of south Derbyshire, (so that's
me
out) and some species are so invasive(?) (I don't like 'invasive' but can't
think of the right word) that they have to be ignored, Elm for one IIRC. I
think Hooper intended you to measure the whole length of the hedge, count
the
species, then divide the species count by the number of 100metre lengths in
the hedge. In a traffic jam once we (me and the crew) worked it out for the
M1
verge, a sort of hedgerow, based on what we could see growing and what we
could recall having seen, and it came out at 35 years old.....
My point was there won't have been that much evolution in a hedge bank when
compared to a woodland edge, and we frequently see creatures and plants
colonising areas quite rapidly after extensive change. Not that I'm saying
that we
don't also see mankind making a complete bollox of something without even
realising we've got something out of which to make a bollox.
Bill.
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