Volume 9 - Electric Scotland

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Although
46 ANNALS OF SCOTTISH NATURAL HISTORY
The marshy nature of the ground is only one of the
conditions which have prevented the moor from being naturally
replanted in course of time by the abundant source of
seeds in the old wood, with the prevalent westerly wind to
transport them. The stunted growth of the trees one of
which is seventeen years old and yet only 7 feet high and the
frequency of broken tops and branches testify to the severity
of climatic conditions. Sheep and rabbits nibble the young
leaves ;
and every few years the heather is burnt by the
game-preserver. When all the causes tending towards extermination
are considered, it is surprising that even a few
examples have managed to survive. These favoured few
are mostly in spots which have escaped burning for a
number of years ;
and the best grown specimens have been
sheltered during their earliest years by the long heather
around them.
489 yards from the wood is the greatest distance
at which any Birch trees were found, this is probably
considerably under the distance to which the seeds may be
carried. It might be suggested that a number expressing
more accurately the maximum distance of transportation
would be obtained by measuring the distances of seed-dispersal
of those isolated young Birch trees which are common
on some Highland moors.
The distance of 886 yards (Sio metres) here determined
as within the possible range for the dispersal of Pine
seeds is
very much greater than that of 1 1 5 metres given
by Fliche. In his paper he contrasts the smallness of the
distance to which Pine seeds are carried by the wind with
the greater distances to which animals carry the seed of
Beech (500-600 metres) and Rowan (1400-2100 metres);
but if this new estimate for the Pine is accepted, this contrast
can no longer be regarded as established. It is evident,
from the disparity which exists between the few definite
measurements yet published, that many more cases must
be recorded before we can reach any degree of accuracy on
the subject.