MOSSES AND MOORS
Peat-mosses and their birds--Moorlands--Cotton-grass--Scotch
whisky--Growth of peat-moss--A vegetable pump--Low-lying and
moorland mosses--Eruptions and floods of peat--Colonizing
by heather and Scotch fir--Peat-mosses as museums--Remains
of children and troopers--Irish elk--Story of the plants in
Denmark--Rhododendrons and peat--Uses of peat--Reclaiming the
mosses near Glasgow.
In Great Britain in this present year one finds exceedingly few
places where the influence of man cannot be traced. Over most of the
country, indeed, it is impossible to discover a single acre of land
where Nature has been allowed to go on working at her own sweet will
without interference or restraint.
But near Stirling, between the Lake of Monteith and the sea, there
is a wide, desolate valley which is probably in exactly the same
condition as it was when the Roman legions halted to reconnoitre
before Agricola passed onwards to Perth and Aberdeen.
Indeed, this great peat-moss has been probably in very much the same
condition for some 200,000 years, which is a nice round number to
represent the ages that have passed since the Great Ice Age.
Now, as then, it is inexpressibly dreary and desolate; everywhere
saturated with water, and only to be traversed in dry seasons and
with much agility. Even with the greatest care the pedestrian may
sink to the waist in a hole of black, slimy, peaty water. Moss,
Heather clumps, Sedges, Rushes, and occasionally Cotton-grass, almost
at one dead level, stretch right across from the one side of the huge
valley to the other.
Even grouse are not common. In summer great numbers of gulls lay
their eggs upon the moss. This also is one of the few places in
Britain where great flocks of wild geese can be heard and seen, but
only at a distance.
It is almost impossible to get near them, for the upright neck of
the sentinel cannot be seen by the stalker as he wriggles towards
the flock on his face, until long after the stalker himself has been
plainly visible to the bird.
Of all useless stretches of barren waste, such a moss as this seems
one of the worst. It would, of course, be possible to reclaim it;
probably, fertile fields and rich meadows _could_ be formed over the
whole valley, but it would not pay nowadays. There is so much good
land available in Canada, the United States, and Australia, that this
great stretch of our native country will probably remain as useless
as it was in Agricola's days.
In the Scottish Lowlands and Highlands the moorlands are almost as
desolate. At a height of 1500 to 1600 feet in Southern Scotland there
is nothing to be seen but the undulating lines of hills, all dark
purple with heather or with the peculiar scorched reddish green of
Deer's Hair and dried sedges.
Perhaps on the nearer hills small streams may have cut a whole
series of intersecting ravines in the black peat. They may be six to
ten feet deep, and here and there the bleached white stones which
underlie them are exposed. Now and then the "kuk-kuk-kuk" of an irate
cock grouse, and much too frequently the melancholy squawking
of the curlew, irritates the pedestrian as he stumbles over clumps
of heather, plunges in and out of the mossy holes, or circumvents
impossible peat-haggs.
[Illustration: AN ARCTIC ALPINE PLANT
This is Draba Alpina from Cape Tscheljuskin, and it is drawn the
natural size. The stunted, closely set leaves show the inclement
character of the climate.]
It is indeed a remarkable fact that though these islands support
44,000,000 of inhabitants, including at least 1,000,000 paupers and
unemployed, one-seventh of Ireland and many square miles in Scotland
are still useless peat-bogs!
The Bog of Allen alone covers 238,500 acres, and the peat is
twenty-five feet deep.
In some few places the peat is still used for fuel, and there is
a theory to the effect that peat reek is necessary for the best
kinds of Scotch whisky, but neither grouse nor black-faced sheep,
which live on the young shoots of the heather, employ in at all a
satisfactory way these great stretches of land.
Many attempts have been made to spin the silky threads of the
Cotton-grass which grows abundantly on the Scotch lowlands. It is
neither a grass, nor does it supply cotton, but is called Eriophorum.
It is perhaps the one really beautiful plant to be found on them, for
its waving heads of fine silky-white hairs are exceedingly pretty.
The heather itself gives a splendid red and purple shade, which in
summer and autumn is always changing colour, but it is monotonous.
Neither the little Bog Asphodel with its yellowish flowers, nor red
Drosera, or butter-coloured Butterwort, are particularly beautiful.
After seeing such a country one understands something of the
Cameronian Covenanters who held their conventicles and took refuge
therein.
The manner in which these mosses and moors have developed is most
interesting, and yet difficult to explain.
There are two kinds of peat-mosses, which, although there are many
intermediate types, may be kept apart.
The first, like the one near Stirling, Lochar and Solway Moss, near
Dumfries, and Linwood, near Glasgow, have been formed in low-lying
flat estuarine marshes.
If one refers back to page 210, it will be seen how reeds and rushes
and marsh plants may gradually fill up river backwaters. Eventually a
saturated, marshy meadow is produced.
Then comes the chance of that wonderful moss the peat-moss, or
Sphagnum. It is scarcely possible to appreciate its structure without
the help of a microscope and a good deal of trouble in the way of
imagination.
It is in a small way a sort of vegetable pump which raises water a
few inches or so. Stem and leaves and branches possess little cistern
cells, which act both as capillary tubes raising the water and also
retain it. The stems are upright and develop many branches, so that
they become a close-ranked or serried carpet of upright moss-stems
squeezed together, which floats on the surface of the water. Each
moss-stem is growing upwards and dying off below. In consequence, the
bottom gets filled up by dead mossy pieces, which accumulate there,
while the live moss-carpet remains floating on the surface of the
loathly, black, peaty water.
In many peat-mosses the water gets entirely filled up, but that
does not stop the formation of the peat-moss. It is now resting on
the water-saturated remains of its forefathers, and if water is
abundantly supplied it goes on developing.
Thus in these lowland or estuarine peat-mosses the moss eventually
occupies the water, and goes on growing. After this it develops like
the moorland mosses which cover most of the Lowlands and Highlands
of Scotland. They cover the hills, and it looks exactly as if some
giant had plastered all those hills with a layer of six to ten feet
of black peat from 1250 feet upwards.
The soil would at first be covered by a saturated moss-carpet of
_Sphagnum_ and other mosses. Rainwater falling upon it was all
retained, and very little could get away, for the Sphagnum carpet is
just like a huge sponge soaking up and retaining the water.
But it sometimes happens in these great upland mosses that there
are enormous falls of rain which continue for days. Then the water
collects _under_ the living moss-carpet and over the dead peat.
It may be gathered together in such quantities that the carpet of
living peat above it bursts, and a deluge of peaty water overflows
the surrounding country, destroying and spoiling everything that it
encounters.
The worst of these inundations of black mud that has happened in
recent years was in December, 1896, near Rathmore, where 200 acres of
bog burst and a horrible river of mud overflowed the country for ten
miles. Nine people perished, and enormous destruction was caused.
There have been many other cases. In 1824 Crowhill Bog, near
Keighley, burst; and in 1745, in Lancashire, a space a mile long and
half a mile broad was covered by peaty mud. There was also a case
in 1697, where forty acres of bog at Charleville burst in the same
way.[152]
[152] Miall, _Nature_, Aug., 1898, p. 377.
Attempts have often been made to calculate the rate of growth of such
peat-mosses. A great many of them began to develop on the mud left by
the ice-sheet when the glaciers retreated at the end of the Ice Age.
Those mosses are therefore probably 200,000 years old. Some of our
Scotch mosses are twenty to twenty-five feet in depth, which gives
a foot in 10,000 years. By calculation of the weight of the peat
formed, Aigner made out that a certain moss was 20,600 years old, and
was growing at the rate of two inches in a century.
But in Denmark ten feet has been formed in 250 to 300 years, and
in Switzerland three to four feet of peat-moss has been formed in
twenty-four years.
This shows quite distinctly that there is no regular rate of growth,
and indeed it is obvious that much must depend on the climate, on the
rainfall, on the drainage, and other circumstances.
Sooner or later, however, a limit comes to the growth of the moss.
The surface then becomes gently curved: it is highest in the centre,
and slopes very gently down in every direction to the edges.
What happens next? The first sign is that the surface begins to dry
up, and Heather, with grey Cladonia lichens, begins to grow on the
projecting tufts and tussocks.
Occasionally, if gulls build their nests on such drying-up mosses,
patches of bright green grass appear wherever the gulls are in the
habit of resting. That is due to the lime in their guano.
But under quite natural conditions a much more important and
interesting change begins.
Here and there scattered over the moss, miserable little seedling
Birches and Scotch Firs begin to struggle for life. Of course, if
there are hares and rabbits, or if sheep and cattle are allowed to
graze upon the moss, those firs have no chance whatever. They are
eaten down to the ground.
[Illustration: LAKE DWELLINGS IN EARLY BRITAIN
The Irish elk is the result of the day's sport of these
prehistoric Britons, who lived in houses built on piles actually
in the water, or in peat mosses. Their only boats were rough
dug-out canoes.]
But if allowed to go on growing they would no doubt cover the whole
moss with a wood of Birch and Scotch Fir. In time that wood would by
its roots and its formation of fine leaf-mould so radically alter
the ground that a forest of Oaks might be possible.
It is in fact quite likely that most of our Highland and Scotch hills
were at one time covered by fine forests of Scotch Fir, of which the
_Silva Caledonica_ spoken of by Tacitus was an example.
There is, moreover, evidence to show that this was the case. There
is one strange peculiarity of peat which renders it a most useful
substance to antiquarians.
Anything lost in a peat-moss does not decay away, but remains in a
blackened but still recognizable condition for hundreds of years.
Not long ago a basket containing the bones of a child was found in a
Scotch peat-moss. There is also a story that an English trooper of
the fourteenth or fifteenth century, and his horse, were discovered
in Lochar Moss, near Dumfries. The man's features were traceable at
first, but fell into powder when exposed to the air; but the weapons,
stirrups, etc., were all perfectly preserved. Bones of the extinct
Irish elk have often been found. Not merely so, but the piles of lake
dwellings and the rough dug-out canoes which were used by the early
inhabitants of Britain have been discovered in a great many places.
Coins of Roman, medieval, and modern times have been unearthed, and
indeed there is no doubt that if Britain is still inhabited two
thousand years hence, boots, sardine tins, brass cartridges, clay
pipes, and other characteristic products of our own days, will be
disentombed from the peat by enthusiastic antiquarians, and displayed
in museums to admiring crowds of our descendants.
The reason is quite simple: in peat neither those bacteria which
cause ordinary decomposition, nor worms of any kind, are able to
exist, so that the material does not decay but accumulates, though
it may be blackened by peat, water, and humic acid. It is for this
reason that a peat-moss is such a bad or rather an impossible soil.
Neither roots nor bacteria can thrive in saturated peat; therefore
the flora of a peat-moss is generally confined to the upper surface,
where air and bacteria can reach the roots. Peat-mosses are also the
home of insectivorous plants, which get their nitrogenous food from
the insects which they catch.
In consequence of this preserving effect of peat, it is possible to
trace the entire history of a peat-moss from the very beginning.
Remains of the Dwarf Willow or Polar Birch have been found in
England, showing that those now Arctic plants were then flourishing
in Norfolk. These are generally in the lowest layers of peat-mosses.
Next follow remains of the Birch and Aspen, which would be growing,
as they do in places to-day, on mossy soil where the peat was still
thin. Higher up in the peat one finds remains of Scotch Fir, showing
that at that time regular forests of Scotch Fir existed, e.g. in
Sutherlandshire and on Lochar Moss, where they do not grow at present.
Some hold that the goats, black cattle, and ponies which have been
kept since the Roman occupation at any rate, are responsible for the
destruction of these forests. Others hold that they were killed by a
change of climate. But they certainly existed.
Trunks of Scotch Fir have even been found in peat at 2400 feet in
Yorkshire, and at heights in Scotland which are above all the present
plantations. About this time it seems that the newer Stone Age men
must have been in Switzerland and Denmark, for their remains and
characteristic weapons occur in those countries at the same level in
the mosses as the Scotch Fir.
Still higher in the peat comes the Bog Oak. With it are in Denmark
remains of the Bronze, Iron, and Roman times.
In Denmark the uppermost layers of the peat contain remains of Beech
trees. As this last tree only entered the country in the historic
period, it is not found except in the highest layers of all.
Unfortunately we have not yet obtained in our own country the same
evidence from the peat-bogs as to the history of the flora of
Britain. It is at least probable that it was on very much the same
lines.
Would it be possible to again cover our peat-mosses and moorlands
with forests of Conifers, Pines, Larches, and Spruces? There can
scarcely be any doubt about it: it would be possible, and according
to the best authorities it would even pay to change all land which is
not yielding more than 7s. 6d. an acre into forests of Pines.
One of the curious facts about peat is that though a peat-moss is one
of the worst natural soils, yet broken-up and dried peat is excellent
for Rhododendrons, for Orchids in stoves and greenhouses, and a great
many other plants.
Peat consists of very much the same substances as those that go to
form leaf-mould. But the presence of humic and other acids, and
the saturation with water and consequently the absence of worms,
bacteria, and also of air, make it impossible for plants to grow in a
peat-moss.
Peat-moss due specially to the Cotton-grass rather than the Sphagnum
moss is imported in great quantity from Holland, for use as litter
for horses. We have in this country plenty of peat quite good for
this purpose, but labour is too expensive for our home-grown peat to
compete with the produce of Dutch moors.
But that is by no means all the uses to which peat can be put. It is
interesting to mention a few of them.
1. Peat is used as fuel.
2. Growing Orchids, etc.
3. Litter for poultry, cattle, and horses.
4. Food for cattle, etc., is made by rubbing the peat into small
pieces and saturating with molasses.
5. Paper and a kind of felt can be made of peat.
6. Rugs and carpets can be made of peat-fibre.
7. String and twine.
8. Rough sacks and mats can be made of peat-fibre.
Unfortunately, though all these things can be produced out of
peat-fibre, it has never paid to manufacture them, and there are very
few of the British peat-mosses nowadays where peat is even cut for
fuel.
It seems much more likely that the end of these peat-mosses will be
to become either agricultural land or forest.
Near Glasgow a large area of a useless peat-moss has been reclaimed
and made to yield excellent crops, by using the refuse of the city.
The disposal of such refuse used to be a most troublesome and
expensive process, but now it is turned to good effect.
It was suggested a few years ago that peat, which is not worth
conveyance, should be burnt on the spot, and the energy transmitted
by wires.
That would be quite impossible, in at least four years out of five,
over most of Scotland.