It's funny looking at soil levels around trees, seeing something "abnormal"
and then trying to work
out what has gone on over many years. In the tropics you often find trees and
bamboo clumps growing
well above the surrounding soil level and you wonder whether soil has been
eroded or whether it
accumulates under the tree. I have visited Finland and suggest the following:
i) trees grow a lot more slowly than in southern England - the trees you see
are often a lot older
than trees of the same size in the UK
ii) I expect the trees may not have been huge (?)
iii) there are relatively few storm events and less oceanic storms
iv) if the trees were native they were likely to be Norway Spruce, Birch or
Scots Pine
The combination of these things suggest you might not be comparing like with
like?
However the biggest mystery I have ever seen lies a few miles south of
Peterborough - the Holme Fen
Post
http://en.wikipedia.org/wiki/Holme,_Cambridgeshire
The Holme Fen Post. A cast iron pillar,from the Crystal Palace Exhibition was
erected in 1851 on the
south west edge of Whittlesey Mere. It replaced the wooden posts which had
been erected in 1848 to
indicate peat shrinkage caused by drainage. The post was driven 6.7m through
the peat into buttery
clay until its top was flush with the ground. Within 10 years the ground
level had fallen nearly
1.5m through shrinkage. A second post was erected in 1957 with its top at the
same level as that of
the original post. Plaques fixed to this post show the ground level at
various succeeding dates. As
one stands by the pillar now, on peat which actually quivers underfoot, it is
difficult to realise
that men who watched the last of the mere 120 years ago stood level with its
top which is over 4m
above today's ground level.
If you do a google search for images you will find a few good photos. However
it's the trees that
interest me - have all the roots shrunk as the land has gone down by 4
metres, or did the land
shrink and the trees have grown up much more recently. There are a few oaks
if my memory serves me
right as well as a load of birch.
If you're heading along the A1 it's well worth the detour (probably an hour
is needed as the roads
are not flat) to have a look but you'll probably want a decent map to find it
beside the road in the
middle of the reserve.
Jon Heuch
Tel: 01233 713 466
mob: 07810 610 712
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