of such decayed vegetable matter, and all who have dug a
garden bed (or seen it dug, but the phenomenon is then less
impressive !) know what a difference there is between the
dark, fertile surface layer and the paler, less fertile sub-soil
where vegetable matter is scanty. The process of decay is
chiefly effected by certain bacteria, which can only thrive
where there is plenty of air and some Hme salts. Therefore
our garden beds are constantly stirred and dug to allow air
to enter, and, if lime salts are deficient, dressings of Ume are
appUed. Thus, the process of decay is not, as we used to
think, spontaneous, it is a phenomenon of life. Anything
118 MOORS AND HEATHS
which destroys or prevents the development of the minute
organisms of the soil, prevents that breaking down of the
parts of the dead plants which is essential for the growth of
most new plants. Peat is in essence partially decomposed
vegetable matter, and it tends to accumulate where the
conditions are unfavourable to the ordinary soil bacteria,
that is, where air and Ume salts are absent. Low tempera-
tures assist its formation, for they also check bacterial
activity ; thus peat is not formed in warm climates. Further,
we do not in the general case get peat over limestone rocks,
because these yield lime salts and are permeable to water,
though there are certain exceptions to this rule, where special
causes intervene. The fact has a good deal of practical
importance, for if you propose to take a hohday in a district
where grouse are rigorously preserved, you will find that it
is advisable to pick out a village in a region where limestone
predominates, if you can, for here there will be few grouse
moors and you will have greater freedom of movement.
This is especially true in the Pennines, for instance, for where
the limestone predominates cattle pastures occur, and only
the bullocks are hkely to resent your taking long tramps
over the hills. But where peat occurs, and therefore heather,
then the watchful gamekeeper lies in wait.
What conditions lead to that absence of oxygen which,
next to a low temperature and the absence of lime salts, is
so potent a factor in peat formation ? The answer is, in
brief, the waterlogging of the surface. Part of the reason
why peat does not generally form over limestone is that in
limestone regions water drains away rapidly and water-
logging does not occur. This may seem absurd when we have
just stated that peat often forms, though in thin layers, over
sand and gravel, surely porous enough formations. Here,
however, a new factor intervenes, for a complicated series
of chemical interchanges often takes place which leads to
the formation of a hard layer called ' moor-pan ' (German
DISTRIBUTION OF PEAT 119
orlstcin), often lying a foot or so below the surface, and
cutting off the surface layer of soil and the surface water
from the porous lower layers. As a result the upper layers
are flooded with stagnant water, and peat forms. In such
cases, if the moor-pan be thoroughly broken up, and the soil
afterwards kept stirred, or trees planted, peat formation
seems to cease. The moor-pan, however, is itself at least
partially due to cUmatic conditions, to the absence of sun-
drying in summer, of prolonged frost in winter.
Another occasional cause of surface-waterlogging is the
presence of a layer of impervious boulder clay, which does
not allow the surface water to drain away. But these and
similar causes do not account for the enormous depths of
peat found in parts of the north-west Highlands of Scotland,
and it seems fairly certain that these owe their origin to
climatic conditions which prevailed at an earUer period than
the present — are thus, in a sense, one of the results of the
Ice Age. On the other hand, there is very httle doubt that
parts at least of the heaths of Germany, of south-eastern
England and possibly even of certain regions in Scotland have
arisen from woodland, largely owing to human mismanagement.
They are Uke the maquis and garigues of the Mediterranean
region, in that they represent areas where man has turned a
very dehcately poised balance definitely against the forest.
In some instances at least, as has been shown in Germany,
scientific forestry can restore the vanished woodland, and
prevent further peat formation, but so far as is known at
present the true ' moors ' of north-western Scotland, with
their heavy, impervious load of peat, represent regions
which are in large part destined meantime to resist human
.efforts at reclamation. If Northern Europe as a whole is
a region which has, owing to the gradual passing away of
the effects of the Ice Age, been becoming through the historic
period progressively better fitted for man's occupation,
these peat-enveloped areas are regions where the amehora-
120 MOORS AND HEATHS
tion has not yet proceeded far enough for his purposes.
But their incapacity for cultivation and in part also even
for afforestation need not mean that they should He unvisited
save by the sportsman ; they are, to some extent, fitted to
be the recreation grounds of the dense industrial populations
further south, to be tourist resorts in the largest sense, and
the singularly close connection which exists between their
vegetation, the physical conditions, and the types of human
occupation which alone are possible, make them admirably
suited for study by the inhabitants of a country where the
vegetation, the modes of life and of soil utiUsation have
largely lost their primitive and * natural ' connection with
the physical conditions.
If we sum up the general facts as regards the distribution
of heaths and moors, we find that within the reach of the
extreme type of oceanic cHmate, the poorer and more porous
soils, especially in the more exposed situations, maintain
under natural conditions a thin kind of woodland which, owing
to human influence, or to slow geological or even cUmatic
change, is liable to disappear and to be replaced by an associa-
tion of plants very tolerant of infertile soil, of which heather
is the more conspicuous member. Among the heather there
often appear seedlings or dwarfed plants of forest-forming
species, such as birch, mountain ash, willow, and so forth.
These, Uke the dwarfed trees of the maquis, or the prostrate
pines of the eastern Alps, represent the last struggle of the
forest against unfavourable conditions. Once the heather
has estabUshed itself, if there be no interference by grazing,
periodic burning or drainage, the tendency is always for it to
increase its hold, partly because its dense felt of roots, by
interfering with the circulation of water, helps to promote
the development of raw humus, which is in its turn inimical
to forest growth (Plate XIV.). The formation of moor-pan
also prevents the re-establishment of forest. But while
it is probable that in some cases mismanagement has done
HEATHEK 121
much to promote the growth of heath, on the other
hand, the succession of plants in the peat bogs of Scot-
land suggests that in the past climatic changes, in the
direction either of a total increase in rainfall, or of increased
uniformity of distribution throughout the year, greatly
promoted the growth of peat, and the present predominance
of heaths and moors there is thus a persistent result of past
conditions rather than of present ones.
We have thus in North-western Europe generally all
transitions from the sandy heath with no peat but a covering
of heather, to the deep peat bog where the heather is more
or less submerged among other plants. The object of the
scientific forester is to save, where he can, wood from degenera-
ting into heath, to re-convert where possible existing heath
into forest, and, as already suggested, probably also to
recognise that in certain locahties the time has not yet come
when his interference is possible.
Let us now look at heaths and moors a httle more closely.
Graebner defines a heath as an open region without conspic-
uous tree growth, where woody vegetation consists for the
most part of shrubs and low bushes, and a continuous grass-
sward is absent. The absence of this sward makes the
grazing poor, the poverty of the soil renders cultivation
usually unprofitable, and cultivation is further rendered
difficult by the frequent presence of peat, which acts like a
poison to most plants.
The predominating plant of the heath is heather (Plate XV.),
a low straggUug shi-ub with characteristic small, evergreen,
closely crowded leaves, and, as we all know, a gorgeous display
of bloom in the flowering season, the splendour of which is apt
to conceal the real poverty of the soil from the casual observer.
Obviously the plant is drought-resisting (a xerophyte), a fact
which may seem curious when we remember that it often
occurs in damp places. The reason is that the acid humus
of the peat makes it very difficult for the plant to absorb
122 MOORS AND HEATHS
water, and therefore it must economise supplies, for these
can only be renewed with great slowness. Further, not
only can heather grow on the poorest of soils, but a rich soil
is fatal. The plant normally takes in water with extreme
slowness, and this absorbed water in natural conditions
contains only an infinitesimal amount of dissolved salts ;
if a stronger solution be presented to the roots, the plant is
soon poisoned.
Another peculiarity of heather as compared with wood-
land plants is its stationary nature. Plants which in summer
make no attempt to economise water, hke those which form
the hardy perennials of our gardens, grow rapidly, but at the
same time speedily exhaust the soil around them. In our
gardens they require constant feeding, and a periodical
' shift ' as the gardeners say ; in nature they often display
adaptations which permit them to tap each year new areas
or layers of soil. Thus many bulbs sink deeper into the soil
as they grow older {e.g. wild hyacinth), and such plants as
Solomon's seal or the perennial sunflowers have creeping
rootstocks, so that next year's stem will not occupy exactly
the same position as this year's one. This does not occur
with heather, for though the individual plants are not long-
lived, the new growths spring from the same region as the
old. No doubt this is because hfe is not so fast as in the
woodland.
During their growing period herbaceous plants take up
food and water rapidly, and soon exhaust their immediate
surroundings ; in the soil also the bacteria efiect rapid
decomposition of organic remains. Not only does the heather
absorb food substances with great slowness, but the peat
contains a large amount of partially decomposed vegetable
matter, capable apparently of supplying the heath plants for
an almost unlimited period. It seems clear also that there
is some form of partnership between the heather and a fungus
of simple structure which thrives in peat, comparable to that
BERRY-BEARING SHRUBS 123
partnership with a bacterium which enables plants of the
peaflower family to enrich instead of impoverishing the soils
in which they hve.
Of the companions of the heather, most have evergreen
leaves, either small with in-rolled edges, Uke those of the
heaths, or tough and leathery like those of bearberry, cow-
berry and so forth. Blaeberry (or bilberry or whortleberry)
is an exception, for its small leaves are deciduous, falling off
in the autumn, at which time they are brightly coloured
and add another tone, if a minor one, to the coloration of
the heath. But its green stems can carry on leaf functions
during the period when the leaves are absent, so that in a
sense it also is ' evergreen.'
In the drier moors of Scotland (that is, in the * heaths ' of
the botanists) the blaeberry is often abundant, though it
does not fruit with the freedom seen on the sunny Alpine
slopes. Its ally the cowberry is also abundant, and presents
an interesting resemblance to the bearberry, which often
covers large areas on the Scottish moors. The resemblance
is of course adaptive, that is the result of the fact that both
plants are suited to similar surroundings. If the fruits are
present it is easy to distinguish the rather pleasant, acid
cowberries from the absolutely tasteless bearberries, with
their large ' wooden ' seeds. If the fruits be absent it is a
pretty Uttle test in accuracy of observation to learn to
distinguish at a glance between the two. The learned (or
the well read !) will reflect that the same difficulty arises
for the stranger in distinguishing between the oHve and
the evergreen oak in the Mediterranean area ; between the
yellow gentian and the lily-Uke Veratrum in Alpine pastures ;
between the leaves of Catalpa and Paulownia in a Mid-
European park, and wall not fail to draw the obvious deduc-
tion. Another example of the same thing is seen on the
moor in the resemblance of the crowberry to a heath, except
where the black berries are present to point the diti'erence.
124 MOORS AND HEATHS
Other frequent plants of heaths are the two common true
heaths, distinguished by their bell-hke flowers from the heather,
which has cleft blooms, the curious petty-whin, the mat-grass
and its allies of the grass family, sedges, club mosses. High-
land cudweed, so oddly reminiscent of the Alpine edelweiss,
tormentil, bedstraw, wintergreen, cowwheat, and the com-
mon milkwort, the last a trying plant for the uninitiated.
It occurs in three colour varieties, blue, white and pink,
and the beginner can rarely shake off the conviction that
these are three separate plants. The writer has a vivid
recollection of a week's botanising, long, long ago, on a
moor in the company of a party zealous but inexperienced.
When each member of a party numbering some four or five had,
with great formaHty and much introductory self-laudation,
presented a specimen of each variety, as an entirely new and
remarkable plant, one began to feel that the milkwort rather
overdid the variabihty. It is, however, a curious and com-
pUcated flower, and has alpine representatives with the
same disconcerting habit as our common British form of
looking like anything, except what one expects a milkwort
to look hke. One Alpine species has been known to be
described in the field by persons who prided themselves on
a certain knowledge of botany as a dwarf broom, a plant
with which milkwort has no connection whatever.
Where the heath merges into wood, juniper is often common,
and bracken may also occur, though as a general rule in
Scotland bracken occurs outside the heather zone. This
is true also of the gorse or whin, common on Enghsh heaths
but in Scotland occurring outside of the dry moors, and being
specially characteristic of the hills built up of basaltic rocks
(whinstone), whence its local name. These regions, however,
suffer from physiological drought no less than the heaths
proper, and gorse shows the usual features of reduced
leaves and a short-lived glory of bloom at the most favour-
able season of its year. In connection with this spring glory
BOG-MOSS 125
it is difficult to resist the temptation to quote the saying
of a Scottish farmer, whose reflections on the subject illus-
trate the type of mind produced by the natural conditions,
no less than the characters of the plant.
He was walking over slopes covered with gorgeous yellow
bloom in the company of a lady who expressed some
appreciation of the sight. The farmer was meditatively
chewing grass, and he glanced round and said seriously —
' Ay, they do say that when Linnaeus first saw the whin in
bloom he went down on his knees and thanked his Maker.'
Then he spat out the grass vigorously, and added — ' I
never thocht anything on't myseF ! ' In other words, he
did not consciously despise it, but its aesthetic aspect had
not occurred to him as a significant fact.
On the true moors, that is, where the peat is very deep,
bog-moss (Sphagnum) mth its long stems loaded with water,
and showing a wonderful range of colour, from pure green
to delicate pinkish-yellow, is common in the wettest parts,
and is a great peat former. Cotton-grass and dwarf sedges
are also abundant, and form the clumps or tussocks on which
the plants of heather and heath are chiefly found. Cran-
berry, cloudberry and bog asphodel with its pale yellow
spikes of bloom are frequent. In places, also, the curious
sundew, with its leaves fringed with bright red insect-catching
hairs, is often common. It generally hves in association with
the wet sphagnum patches, and its difficulty in absorbing
mineral food is compensated for by its fly-catching powers.
The flat pale-green rosettes of butterwort (Piuguicula) also
occur in such places, and the comparatively large deep blue
flowers may be seen rising singly from the centre of the
.rosette. This plant, which is also insectivorous, has beautiful
Alpine representatives, and our common form occurs at
considerable elevations there. Almost any plant of the
' heath ' association may reappear on the typical moors,
but one characteristic of wet patches in both has not yet
126 MOORS AND HEATHS
been mentioned. This is Bog myrtle, a low shrub with
fragrant, resinous leaves, bearing catkins in early spring.
It often occurs in great abundance, and its fragrance, recalUng
that of many Mediterranean plants, is an interesting point.
If we now sum up in brief the contents of the preceding
chapters, we may say that the most characteristic plant
formation of Western Europe is the temperate forest, with
its marked alternation between a drought-resisting, leafless
winter form, and a water-demanding and water-spending
summer form, with abundant and deUcate foliage. At the
sea.ward margin, where the cHmate becomes very equable
and very damp ; at the southern margin, where it becomes
equable as to temperature but dry, especially in summer ;
at the upward margin, where the wind, the great radiation,
the persistency of low winter temperatures, the coldness of
the soil lead to the development of a special type of climate —
in all these three regions the temperate forest is replaced
by a xerophytic type of vegetation, differing greatly in
the three different regions, but showing the same tendency
for arborescent plants to become dwarfed and then finally
to disappear, and for the shrubby or herbaceous plants to
develop various forms of protection against loss of water.
Within the Mediterranean region in the narrow sense the
soil is often very shallow ; within the zone of heaths and moor
it is naturally poor, and tends, especially in the latter, to be
covered or even entirely concealed by a layer of peat, a
substance inimical to the growth of all but a restricted number
of plants. Finally, in the mountain region the soil is generally
shallow, often shifting, but its shallowness is to some extent
compensated for by the rapidity of rock waste, which con-
tinually renews the substances necessary to plant Ufe. In
Western Jiurope the regions best fitted to the cultivation of
plants are first tho.se favoured parts of the Mediterranean
region, where the soil is deeper than usual and is fertile,
THE CHANGING EARTH 127
for here the high temperatures promote plant growth, and
then the loess regions of the forest area, and the plains within
the forest area from which the woods have been cleared.
Had we taken the Europe of the geography books instead
of the Europe of our own definition, we should have been
obUged to add another great plant formation to those already
considered, that of the steppe, but this we regard as outside
our scope here.
In studying any one of the formations described above
the tourist should not confine himself to picking out the
more obvious adaptations — interesting though this occupa-
tion is. Even more important is the fact that all the forma-
tions, especially near the margins of their natural habitat,
are in a state of constant flux, due in large part to the wearing
down or building up of the surface by the ordinary agents
of geological change. It is along the lines of natural weakness,
as it were, that man intercalates his cultivated plants and
domestic animals, and it is one of the most important con-
tributions of modern botany to geographical science that it
is emphasising the changeableness of the plant covering,
the ebb and flow of plant hfe with changes in the physical
conditions. Thus to the older geological conception of change,
so admirably expressed by Tennyson in the well-known
stanza, a part of which we have placed at the head of Chapter
VII., we have to add the newer botanical one, that forest and
moor and grassland shift and change also, chasing one another
Uke clouds across the summer sky.
References. For the German heaths the most comprehensive
book is Graebner's Die Heide Norddeutschlands, with very copious
references, in Engler u. Drude's Vegetation der Erde. The moors and
heaths of the British Isles are considered fully in Types of British
Vegetation, edited by A. G. Tansley, also with references, and those
specially interested in Scottish moors, should consult the recent volumes
of the Scottish Geographical Magazine, in which a number of papers on
the subject have appeared.
CHAPTER XI
THE EARTH AND MAN
' Necessity ! thou mother of the world.'
In the preceding chapters, when considering the natural
plant formations, we have seen that only in hmited regions,
and often only to a small extent, do these persist unaltered.
Everywhere man has affected the original vegetation, de-
stroying here, adding new plants there ; acting sometimes
directly, and sometimes indirectly, as by draining the land,
by involuntary soil destruction, by soil improvement, and
so forth. But while some of these effects are involuntary,
or due to unforeseen circumstances, by far the most important
are the result of dehberate intention. Everywhere man has
sought to make room for his cultivated plants and his domesti-
cated animals, and this has involved wholesale modification
of the original formations, which in some instances, as we have
seen, can now only be traced with difficulty. The cultivated
plants consist in part of native plants improved by human
care, but retaining the adaptations which fit them for the
chmate of their habitat (c/. the ohve of the Mediter-
ranean region) ; in part also of introduced plants, brought
from parts of the world having some cHmatic affinities with
the districts where they are now grown (cf. the potato, now
so widely grown in North-Western Europe, but a native of
the cool, moist chmate of the slopes of the Andes). As
successful cultivated plants must of necessity show such
fitness for the climatic and other conditions under which
they are grown, we find that, to a certain extent, the diversity
128
MEDITERRANEAN CULTIVATION 129
of the natural plant formations of Western Europe is reflected
in the diversity of the cultivated plants of the different climatic
regions, and their characteristics in those of the latter.
For example, in the Mediterranean region the short-lived
herbaceous and bulbous plants of the maquis are replaced
on cultivated ground by such cereals and other annual crops
as can grow without any great heat, but demand moisture.
Such crops occupy the surface for the cooler but rainy half
of the year, and are reaped in spring. In summer, save where
irrigation is possible, land utilisation takes the form chiefly
of a kind of gardening, fruit-bearing trees, especially the vine,
the ohve, the Citrus fruits, and so forth, being extensively
cultivated, and being so arranged that they afford a succession
of crops. Thus the peaches and apricots and similar fruits
ripen in August ; the grapes and chestnuts in September or
October ; the ohves in November. Often the short-Uved
cereal crops occupy the same ground as the trees, and the
traveller will not fail to note that the corn, or the vegetables,
or the forage crops like lupin and lucerne, growing among the
trees of the ohve grove is the equivalent, from the point
of view of physiological botany, of the anemones, the bell
hyacinths, and the cyclamens seen among the wild evergreen
oaks.
Obviously then again, except where irrigation is possible,
while water-demanding plants can be grown in the Mediter-
ranean area in the cooler season, perennial plants must be
those capable of resisting the drought of summer, and plants
which demand at once much heat and much moisture, Uke
rice and sugar-cane, cannot be grown unless water is arti-
ficially supphed.
Further, as rich pasture does not exist within the Mediter-
ranean region proper, save at great elevations, and pasture