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Suffolk Natural History, Vol. 34 HEATHLAND FLORA - I T ISN'T JUST BRACKEN, HEATHER A N D BIRCH. LYNNE FARRELL
Many people think of heathland as consisting largely of heather, often with scattered scrub, generally birch, gorse, pine or willow, with some patches of bracken. Examples of these communities can be found on many of our heathland National Nature Reserves and SSSIs. For instance - Heath and Reach, on the Herts/Bucks border, the Quantocks, Somerset, Muir of Dinnet, Aberdeenshire, Minsmere, Suffolk, Cow Bridge, Hartland Moor and Trigon in Dorset, RAF Bamham and Lakenheath in Breckland, and, nearer to here, Purdis and Sutton Heaths, and Barnhamcross Common. In my view heathland is not a blasted landscape or a waste of space. It is quite acceptable to have some of the area supporting bracken and scrub, and a managed heathland might have about 30% of those non-heathland elements. In fact, if you look closely and really get down to it heathland is a diverse habitat, particularly on the coast where the maritime influence is apparent, and also where grazing still exists. It is often a mosaic of types, and the juxtaposition of wet and dry areas gives rise to a varied structure and a variety of species, e.g. Powlers's Piece, Devon. Lower plants also enrich the scene, and lichens especially often grow in heathland areas. The following examples serve to illustrate the variety of heathlands throughout Britain, each has its own characteristics, providing us with some of the best examples in Europe, and indeed, in the world, as heathland is a restricted habitat. In the Breckland of East Anglia are the grassy heaths on well-drained soils and with a variable pH. There are many species of botanical interest, for example, Medicago varia on the flowery verges of Foxhole Heath or, if you are searching for larger specimens, the Black Poplars (Populus nigra ssp. betulifolia) on Cavenham Heath. The Spiked Speedwell (Veronica spicata) can be found on the grassy turf at Newmarket. But it is when you really get down to it that the little gems are discovered, such as Spring Whitlow-grass, (Erophila verna) at Weeting Heath, Norfolk, and at Maidscross Hill, Suffolk. Other tiny plants include the three rare, annual speedwells - Veronica verna, V. praecox, and V. triphyllos (see plate 2); Mossy Stonecrop (Crassula tillaea), Suffocated Clover (Trifolium suffocatum) and Buckshorn Plantain (Plantago coronopus). Some plants are as small as rabbit droppings - Perennial Knawel (Scleranthus perennis ssp. perennis) and indeed are dependant on close grazing by rabbits to keep the competition at bay and provide open, bare patches into which they can seed and spread. Moonwort, (Botrychium lunaria), and the Breckland Catchfly (Silene otites) are also part of the local flora, although the latter is nationally rare and restricted to the Breckland. Although we tend to concentrate on vascular plants when we talk about the flora of an area, lower plants are just as an important part of the Community and can even dominate a site e.g. Wangford Warren, Suffolk (see plate 1). The moss Rhytidium rugosum is essentially a dune species, but can be found on the sandy soils in the Breckland. Fungi also play their part in the ecosystem e.g. Shaggy Parasol (Lepiota sp.). Grasses such as the restricted Drooping Brome (Anisantha tectorum), and Breckland Foxtail, (Phleum phleoides) should not
Trans. Suffolk Nat. Soc. 34 (1998)
HEATHLAND - A WASTE OF SPACE?
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be overlooked. Journeying further south to Dorset we find wet and dry heaths, and, because of their central position in southern England, they support species of both eastern and western distributions, such as Bristie Bent (Agrostis curtisii), Marsh Gentian (Gentiana pneumonanthe) and Dorset Heath (Erica ciliaris). Species of the wetter patches include Marsh Clubmoss (Lycopodiella inundata) and White-beaked Sedge (Rhynchospora alba). Normally fire and water do not mix, but the Marsh Gentian is peculiar in its requirements in that it is actually associated with the open patches in damp heathland maintained by periodic fires, which also aid germination. Travelling south and west we reach the specialised heaths of the Lizard peninsula in Cornwall, where the Cornish Heath (Erica vagans) dominates the Serpentine areas, although once again, many of the rarities are tiny - Fringed Rupturewort (Herniaria ciliolata), Land Quillwort (Isoetes histrix) and Dwarf Rush (Juncus capitatus). The golden liehen Teloschistes adds colour to the scene. In Wales there are examples of wet heath or 'rhos', where there are frequent changes from wet to dry conditions and in topography, resulting in mixed fen communities in intimate association with the ericaceous species, and in transitions from lowland to upland heath. Pillwort (Pilularia globulifera) and Yellow Centaury (Cicendia filiformis) are to be found usually lurking in the wet depressions on old trackways. Going 'north of the border' to Scotland, fine examples of Bilberry (Vaccinium myrtillus) heath occur in Fife at Lochmill Loch, and in Speyside Alpine Bearberry (Arctostaphyllos uva-ursi) heath, which is generally considered to be an upland type sometimes occurring at lower altitudes, is found, often along roadsides where disturbance has taken place, or on the shallower, stony soils. Liehen heath is more frequent - one of the best examples that exists is at Cuthill links, Sutherland, although the new road bridge across the Dornoch Firth now dissects the site. In Britain we have some of the best and most extensive remaining areas of coastal and maritime heath. In some areas only narrow strips remain along the coastline, but in the far north and east such as Caithness, Sutherland, Orkney and Shetland wider strips occur and whole islands may survive as wind-pruned heath. The Spring Squill (Scilla verna) and the endemic Scottish Primrose (Primula scotica) are amongst the more colourful flowers. On the northernmost islands of Fair Isle and Shetland such is the influence of the climate that patterned ground and patterned heath - mainly heather bushes formed into crescents, wind stripes and terraces - is the norm, rather than a continuous turf. Take a fresh and closer look at heathland, and you will find that there is more than meets the eye and a diversity that reflects the ränge of biogeographical conditions that exist in the British Isles. These examples also illustrate the widest ränge of heathland types in Europe. Lynne Farrell, SNH, Argyll & Stirling Area, 1 Kilmory Estate, Kilmory,
Trans. Suffolk Nat. Soc. 34
(1998)
Plate 1: Liehen heath at Wangford Warren S W T Reserve, 1988 (p. 22).
Plate 2: Three rare Breckland Speedwells, A: Fingered Speedwell (Veronica triphyllos L.); B: Breckland Speedwell (V. praecox All.); C: Spring Speedwell (V. verna L.) (p. 22 & p. 106).