THE VEGETATION OF
KINTYRE
H Ferguson
Part One
What is the vegetation of Kintyre like? and what
is it due to? These are the questions with which this article deals very
briefly and very generally.
Climax Vegetation(1)
Climate is the primary factor determining the type of
vegetation. Western Europe has a wet temperate climate with cold winters
and warm summers, and the climax vegetation for this climatic region is Deciduous
Forest. This is the case in Kintyre; and, though much modified by local factors
and human interference, there are residual areas of indigenous forest in
Kintyre. In prehistoric times undoubtedly much of Kintyre was clothed with
forests of this kind.
Wind is a potent factor affecting vegetation, and the Atlantic gales whch hit the west and south-west coasts of Kintyre blast everything but ground vegetation. It is unlikely that forests ever grew in these areas, and, as it is obvious to see, even planted trees need protection from these gales to survive. Trees bent away from the prevailing wind, and with their foliage and branches blasted off above protective cliffs and walls can be seen along west road and at Machrihanish (e.g. Lossit plantation.)
Barren rocks and peat bogs, which occur along the middle of Kintyre and at the south-west corner do not offer soil conditions amenable to deciduous trees, at least in their natural conditions; and such areas do not support, and would not have supported, the climax vegetation.
(1) "Climax Vegetation" is the type of vegetation which develops in
particular climatic conditions, unimpeded by other factors.
Thus, residual forests are to be found on uncultivated
land along West Loch Tarbert and at various places along the east side of
the peninsula, which,in both cases, are sheltered from the westerly gales.
These forests consist mainly of Oak and Birch, with Alder in the wetter parts.
The Oak-Birch association is characteristic of the poor acid soils of these
areas, derived mainly from mica schist. In the southern part of Kintyre,
where agricultural conditions are better, there is now little or no indigenous
forest, practically all of it having been cleared for farming in early times.
It is not always easy to distinguish between planted and natural woodlands,
but, where the latter do occur in south and south-east Kintyre, Ash and Beech
are often more dominant than Oak. This reflects the less acid and more permeable
soils associated with the geological formations of these areas. Hazel, rather
than Alder tends to be the valley bottom tree in these areas, again because
of better drainage. Sycamore, which is probably the most widely distributed
tree in Kintyre, has little significance as a constituent of vegetation.
It is a recent incomer into Britain, having arrived in the middle ages: and
it appears to adapt to a wide range of conditions.
Other Climax Types.
Considering the mildness of our winters compared with
those of the British east coast, and of the European main land it is surprising
that the indigenous vegetation has virtually none of the constituents of
the Lusitanican type of vegetation. This is characterised by evergreen trees
and shrubs, and occurs along the Atlantic fringe of Portugal, Spain and Ireland.
Typical plants are the Strawberry Tree (Arbutas unedo), Tree Heaths, Cherry
Laurel, etc. Although some of these are natives of Western Ireland, they
do not occur here. However, the success of introduced species proves that
the climate is well adapted to this evergreen type of vegetation. Apart from
the Strawberry Tree, the common Rhododendron, and the Laurels, which are
natives of Europe, Escallonias, Fuchsias, Hebes, and several others flourish.
These all come from climatically similar regions, principally in Chile and
New Zealand - mild (mainly frost free), maritime temperate regions. This
vegetation is not sub-tropical, as it is sometimes euphemistically described.
The latitudes concerned are round 450 against our 550; this difference being
a measure of the warming effect of the Gulf Stream on our coasts. At the
other end of the climatic scale, there is also little evidence in the indigenous
flora of Kintyre of the coniferous forests, which are the characteristic
vegetation of Northern Europe. There are a few indigenous Scots Pines here
and there, and these may indicate greater occurrence of this conifer in the
past. There is no doubt that conifers such as Spruce and Larch, with their
tolerance of cold, preference for acid soils, and shallow root systems are
well adapted to much of the higher, poorer land unattractive to deciduous
trees. Recent successful plantings of these conifers amply confirm this.
The absence of these two extreme types of vegetation from Kintyre, despite its suitability for them, is thought to be due to their relative remoteness when Britain was being re-colonised after the ice age. The degeneration of much of the higher land into peat bogs has also made it difficult for coniferous trees to establish themselves.
Modifications of the Climax Vegetation.
So far we have dealt with the "climatic climax" vegetation which Kintyre does, or could, support. What about its modifications? These fall into two categories - those due to natural differences in topography and soil, and those resulting from human interference.
Coastal Vegetation.
The effect of wind along the south and west coastal areas has already been mentioned. The gales along these coasts permit only of low growing vegetation, consisting of short grasses and low growing herbs, often creeping close to the ground. Only where there is some shelter can upright herbs and low growing trees, such as willows be found.
Along the coast line in all parts of Kintyre there is a strand vegetation consisting of salt tolerant or salt loving plants such as Thrift (Armeria vulgaris), Stonecrop (sedum spp.), Sea Purslane (Honckenya peploides), Orache (Atriplex spp.), etc. Sand dunes occur in places and the vegetation on these is always entirely dominated by Marram Grass (Psamma arenaria). This grass serves a useful purpose in fixing the dunes, which it does by virtue of its deep system of roots and underground stems.
Salt marsh vegetation, as distinct from strand vegetation, occurs only to a very small extent in Kintyre as the kind of tidal flats which encourage it are rare and small.
We are not dealing with Algae, which grow below the tide line, but there is one "flowering plant" which grows permanently in sea water, and occurs In Kintyre. This is the Sea Grass (Zosters). There are two species (Z. marina and Z. nana), and one or other occurs at places along the sea coast, e.g. West Loch Tarbert and The Dhorlin, in low water pools.
Upland and Interior Vegetation.
Turning to the upland and interior vegetation, it is necessary to mention very briefly some of the geological features of Kintyre. Practically all the northern, and the far south-western, parts of the peninsula are mica schist, and this outcrops in the highest land, and constitutes most of the cliffs along the coast. At intermediate elevations and less steep topography it is often overlaid with boulder clay (a glacial deposit). Both schist and clay are relatively impermeable, and the soils arising naturally from them are poorly drained. Impeded drainage over a long period results in peat formation, and so, on the higher plateaux lands in Kintyre there are extensive peat deposits of varying depth. It should be noted that the essential factor in peat formation is impeded drainage and not either altitude or geological formation, as illustrated by the Durry Moss.
Moorlands.
These formations give rise to moorland, which occupies much of the higher land, and a little of the lower, in Kintyre. Moorland vegetation is characterised by heathers (both Calluna and Erica), together with an association of grasses, sedges, and rushes; and various mosses and small herbs. Grasses, sedges, and rushes are difficult for a non-specialist to identify, but there are more obvious indicator plants.
Variations in moorland depend on its wetness - from dry (heath) to very wet (bog). The former is characterised by Bell Heather (Erica cinerea), and the latter by Cross-leaved Heath (Erica Tetralix). The latter is not usually dominant, and, apart from the unspectacular grasses and sedges, other constituents of the wet moorland association are Bog Myrtle (Myrica. Gale), Cotton Grass (Eriophorum), which is a sedge, Sphagnum Moss, and Bog Asphodel (Narthecium ossifragum). Except in the wettest moorland the ordinary Heather or Ling (Calluna vulgaris) is usually dominant, and apart from Bell Heather (E. cinerea) and certain grasses, Blaeberry (Vacciniun Myrtillus), Tormentil (Potentilla Tormentilla), and Bedstraw (Galium saxatile) are noticeable constituents.
It will be appreciated that the composition of moorland and other forms of "natural" vegetation is modified by sheep and cattle grazing. Burning also affects the moorland, reducing the total dominance of the heather.
Amongst the interesting, though less spectacular moorland plants are our main insectivorous plants - the Sundew (Drosera) and the Butterwort (Pinguicula). These are to be found in the wetter moorland. Both are small plants: Sundew is difficult to spot, but Butterwort is easy to find because of its yellowish green leaves and pretty purple flower.
Another Interesting moorland plant which has been recorded in Kintyre is Dryas octopetala. This an alpine species which is usually confined to the higher mountains in Britain, and its occurrence in Kintyre is surprising as the hills here are not really high enough to support an "alpine" vegetation. Dryas has been recorded (authentically) as occurring near the Mull, but I have not seen it myself, or know of any recent confirmation of its occurrence there. It is a lime loving plant, and there are outcrops of limestone in the vicinity where it has been recorded. Incidentally, several other plants which characterise the vegetation of the higher mountains elsewhere in Scotland are infrequent, rare or absent in Kintyre.
Green Hills.
Except for Beinn Ghuilean and the main south-western part of the peninsula, which are mica schist, the rocks and deposits in the vicinity of Campheltown, Southend and Machrihanish are mostly geologically younger than the schists. These include scattered outcrops of limestone (the "Loch Tay limestone") to the north of Campbeltown, and the much more recent "calciferous" lavas and sandstones to the south and east of Machrihanish. These types of calcareous rock, like limestone anywhere, are alkaline in reaction, and form soils of low acidity, relatively high calcium content and high permeability. These factors have an obvious effect on the vegetation, the calcium content being the most critical in this respect. The low acidity discourages heathers and other moorland plants, and, with the calcium, encourages an association of short grasses, such as Sheep's Fescue (Festuca ovina). This results in green grassy hills rather than brown heather ones. These green hills are obvious in the areas concerned. Knock Scalbert is an example, and the contrast between it and Beinn Ghuilean is striking.
It is interesting that Water Cress (Nasturtium officionale) is a lime loving plant, and occurs only where springs and streams are associated with calcareous strata. In this connection, it is noteworthy that calciferous soils in Kintyre are characterised by absence of acid loving plants rather than the positive presence of lime loving species.
The Loch Tay limestone, which is of the same geological age as the mica schist and is associated with it, occurs in a few small outcrops elsewhere in Kintyre, e.g. near Clachan, and usually shows its effect on the vegetation.
Other geologically younger rocks (conglomerates, sand stones, basalt, porphyrite etc.) south and west of Campbeltown, though less acid and more permeable than the schists, produce soils which are acid enough to maintain the usual type of natural heath or moorland vegetation. They are, course, overlaid by surface deposits in many places, and are generally agriculturally developed. They tend to encourage Ash and Beech as forest trees, and Whins (Ulex europaeus) as well as Heather on hills and heaths.
Part Two next month
No 5 Spring 1979
Page 2: Janet and Marie Morrison's 1993 Trip to Scotland - Part 1
Page 3: David Whitehead's Genealogy Special - Part Two
Page 4: John and Mary Morrison of Rocky River - The First Part
Page 5: Bracken - A Weed of Great Antiquity
Page 6: The Vegetation of Kintyre - Part One
Page 7: The Cistercian Abbey of Saddell, Kintyre - Introduction By A.I.B. Stewart
Page 8: By Hill and Shore - Part 2
Page 9: An Unusual Visitor // To: The Editor, The Kintyre Magazine