Dounreay Site Restoration Ltd

Habitat

Woodland

Small areas of planted coniferous woodland are present, including the dense single-species stand of maturing Norway spruce on the south-eastern perimeter of Dounreay and mixed woodland by Loch Achbuiligan to the south of the site.

Tree species at Loch Achbuuiligan include Scots pine, Norway spruce, pendulous birch, downy birch, common sallow and eared sallow. Natural regeneration here is providing a varied age structure.

Newer coniferous plantations are present in fields to the south east of the Dounreay entrance off the A836. A ground flora is generally absent from the denser stands of conifers. The woodlands, however, provide a significant local habitat for a number of bird species

Scrub

An area of dense and scattered gorse between Loch Achbuiligan and the main A386 road provides the only significant scrub habitat. It provides habitat for finches and other small passerine birds including yellowhammer, whinchat, robin and wren. Gorse is present elsewhere but is limited to rather sparse "hedge" lines or occasional scattered individuals along a small number of field boundaries.

Grasslands

There is a wide range of grassland types, the majority of which have been agriculturally improved by past, or ongoing, management, including the addition of artificial fertilisers, possibly herbicides, mowing and re-seeding.

Species diversity in most of these grasslands is relatively low though in some wet grasslands a currently low-intensity management regime allows a greater range of flowering plants to be expressed.

Apparently un-improved and relatively species-rich grasslands are limited to small areas of verge by the old runways to the north-east of Dounreay and some adjacent field headlands.

North of the spruce stand are two fields of wet, probably semi-improved, rushy pastures with matt grass and a small marshy area in the northern corner supporting sedges, cotton grasses and marsh marigold, relict species of the wet grass-heath from which these pastures were claimed. Wet grasslands dominated by Yorkshire fog are typical along the landward edge of the coastal heath communities.

Common tall herb species such as thistles, docks, nettle and hogweed occur in a few sites within Dounreay,

Heathland and mire

Coastal heathland probably represents the original vegetation type, maintained by soil and climatic conditions, and probably lightly grazed, which existed before land-use changes associated with modern farming and other developments.

Towards the coast, black bog rush predominates locally with cotton grasses, ling and cross-leaved heath. This grades into a clear maritime grass-heath community towards the cliffs where numerous blue flowers of spring squill appear with the grasses, sedges and heathers. Two nationally scarce plants are recorded in the coastal heath, small adder's-tongue fern and Scottish primrose.

Five sedge species are present including flea sedge, wet-heath species such as ling, cross-leaved heath and purple moor-grass, and a number of herbs of wet grassland such as sneezewort, both common and greater birdsfoot trefoil, angelica, grass-of-parnassus, lesser spearwort, cuckoo flower and devilsbit scabious.

Dounreay Burn or Mill Lade

The unmanaged vegetation along the roadside verge and stream banks of Mill Lade comprises a tall coarse-grass/tall herb association with much meadowsweet and reed canary grass. This is intermixed, lower down the banks, with streamside emergents including patches of water mint, marsh marigold, water forget-me-not and the non-native monkeyflower.

Loch Achbuiligan

The communities around the loch show a range of classic types associated with shallow Scottish lochs on peat substrates including bottle sedge swamp, bogbean-water horsetail, bottle sedge-marsh, cinquefoil fen, and purple moorgrass-tormentil mire, angelica subcommunity.

Coastal

Dwarf shrubs typical of the maritime heath give way to a grass-dominated community along the cliff edge.

Sedges and herbs such as spring squill, devilsbit scabious, tormentil and eyebright are common to both zones. The latter, however, has an additional varied array of colourful flowering plants typical of both base-rich substrates and conditions subjected to sea spray, e.g. thrift, sea campion, sea plantain, scurvy grass, birdsfoot trefoil, kidney vetch, dog violet, primrose, Scottish primrose and thyme.

Communities in the cliff crevices include species such as sea pearlwort, roseroot, Scots lovage, sea milkwort and sea mayweed. The nationally uncommon salt-marsh grass Puccinellia distans var. borealis grows in crevices on the rock faces.

The sandy shore by Dounreay Castle supports a distinctive community that includes the nationally uncommon oyster plant, Mertensia maritima, which grows in the mobile sand above the strand line along the whole length of the shore. Sea mayweed is a frequent associate. Behind this zone towards the land, the lower lying section of shore adjacent to the Castle support a cover of sea sandwort with red fescue, sea campion and scurvy grass. In addition, there are single species stands of lyme grass by the Castle and marram just to the east of the entrance gate, both typical sand-dune species.

The more stable grasslands around the Castle are formed from a sward of Yorkshire fog with red fescue, couch-grass, much red bartsia, silverweed and locally taller stands of nettle, goosegrass, thistles and docks.

Eastwards from the castle, the steep slopes at the landward edge of the bay are in places formed from made ground. Here, marram is absent and these stretches support a disturbed-ground flora of typical species such as thistles, nettles, docks, sow thistles, coltsfoot, groundsel, mayweed and Yorkshire fog.

Disturbed ground

Disturbed ground communities with a typical array of ruderal plants (docks, thistles, sow thistles, groundsel, scentless mayweed, coltsfoot with grasses such as Yorkshire fog, annual meadow grass and creeping bent) occur in a number of areas within the Dounreay complex, and outside along the cliffs where made ground exists. In the arable fields beyond the site, a typical array of common arable weeds can occur, e.g. shepherds purse, sticky mouse-ear, pineapple mayweed, corn spurry, common hemp-nettle, common persicaria and black-grass.