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Condition (NatureScot)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| F1 | Coastal Geomorphology of Scotland | Favourable | — | 2017-03-20 |
Climate exposure
This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.
Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.
Geology & landscape
Landscape processes: Coastal, Fluvial, Periglacial
Description
BALTA Balta SSSI occupies a low, north-west facing basin on Balta, the small island at the mouth of Balta Sound to the east of the island of Unst. The SSSI is the most complete machair system in Shetland. It consists of an area of blown sand extending across the island from a small bay on the western side of the island, through a low col to the eastern sea cliffs. Dunes are absent and the complex thus represents an example of a beach-machair continuum. Aeolianite (blown sand cemented by calcite deposited from sub-surface water) is present and provides a base-level for wind erosion in places. A combination of rill dissection by running water, severe wind deflation and a high rabbit population has reduced the machair to a highly dissected state in the past, making it an ideal research area for studying the processes of machair erosion.
Plant communities
A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream
Potamogeton natans community
Show 20 indicator speciesSchoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa
A14 — Fast flowing river and stream
Myriophyllum alterniflorum community
Show 15 indicator speciesIsolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina
A17 — Chalk river and stream, Fast flowing river and stream
Ranunculus penicillatus ssp. pseudofluitans community
Show 11 indicator speciesBerula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans
A18 — Fast flowing river and stream
Ranunculus fluitans community
Show 12 indicator speciesFontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea
SD8 — Machair sand dune, Sand dune
Festuca rubra-Galium verum fixed dune grassland
Show 113 indicator speciesSalix repens, Rosa spinosissima, Carex arenaria, Carex caryophyllea, Carex flacca, Luzula campestris, Plagiomnium rostratum, Plagiomnium undulatum, Ditrichum flexicaule, Brachythecium albicans, Calliergonell cuspidatum, Climacium dendroides, Entodon concinnus, Homalothecium lutescens, Hylocomium splendens, Hypnum cupressiforme, Kindbergia praelonga, Pleurozium schreberi, Pseudoscleropodium purum, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Thuidium delicatulum, Thuidium tamariscinum, Syntrichia ruraliformis, Lophocolea bidentata, Cladonia rangiformis, Odontites verna, Peltigera canina, Peltigera rufescens, Angelica sylvestris, Daucus carota, Heracleum sphondylium, Achillea millefolium, Bellis perennis, Centaurea nigra, Cirsium arvense, Cirsium vulgare, Crepis capillaris, Hypochaeris radicata, Jacobaea vulgaris, Leucanthemum vulgare, Pilosella officinarum, Scorzoneroides autumnalis, Sonchus oleraceus, Taraxacum officianalis, Myosotis arvensis, Myosotis ramosissima, Campanula rotundifolia, Succisa pratensis, Cerastium arvense, Cerastium diffusum, Cerastium fontanum, Cerastium semidecandrum, Sedum acre, Equisetum arvense, Anthyllis vulneraria, Astragalus danicus, Lotus corniculatus, Medicago lupulina, Ononis repens, Trifolium campestre, Trifolium pratense, Trifolium repens, Vicia cracca, Vicia lathyroides, Gentianella amarella, Eriodium cicutarium, Thymus praecox, Linum catharticum, Dactylorhiza viridis, Neottia ovata, Euphrasia officinalis, Rhinanthus minor, Plantago coronopus, Plantago lanceolata, Plantago major, Plantago maritima, Veronica arvensis, Veronica chamaedrys, Polygala vulgaris, Rumex acetosa, Rumex acetosella, Primula veris, Primula vulgaris, Ranunculus acris, Ranunculus bulbosus, Ranunculus repens, Thalictrum minus, Potentilla anserina, Galium verum, Viola riviniana, Viola tricolor, Agrostis capillaris, Agrostis stolonifera, Aira praecox, Ammophila arenaria, Anthoxanthum odoratum, Arrhenatherum elatius, Avenula pubescens, Cynosurus cristatus, Dactylis glomerata, Elytrigia atherica, Elytrigia juncea, Elytrigia repens, Festuca ovina, Festuca rubra, Holcus lanatus, Koeleria macrantha, Leymus arenarius, Lolium perenne, Poa pratensis, Poa trivialis, Trisetum flavescens