The term 'wetlands' can cover a vast array of habitats. They are considered by international conventions to include areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt.
Areas of standing open water of all sizes occur in the region, from large lochs such as the Dee to small ponds. The most important type, in relation to biodiversity, is mesotrophic lochs. These sites have an intermediate nutrient status, have the highest diversity of large plants and contain many nationally scarce and rare aquatic plants such as Pillwort Pillularia globifera and Slender Naiad Najas flexilis. Examples include Loch Kindar and Milton Loch.
Rivers and streams are dynamic systems which in their natural state are continually changing their form, though there are few in the whole of the UK that have not been significantly modified by man. There are eleven main rivers in Dumfries and Galloway, from the River Esk in the east to the Luce in the west. Of the regions watercourses, 75% are designated salmonid waters (capable of supporting salmon and/or trout). Rivers consist of a mosaic of features, which support a diverse range of plants and animals. Shingle beds and sand bars are important habitats for invertebrates. In addition, riparian trees along riverbanks support a great number of woodland birds. Otters Lutra lutra are widely distributed throughout the regions river network and Sparling (Smelt) Osmerus eperlanus migrate to spawn on the River Cree.
Fen, carr, marsh, swamp and reedbeds are widespread, but fragmented, habitats. Fens tend to be clustered in Galloway. The Wood of Cree RSPB reserve is one of the best examples of hydroserial bog/fen development in Scotland. Vegetation, such as the nationally scarce Elongated Sedge Carex elongate, provides essential cover for mammals, such as Water Shrew Neomys fodiens and Water Vole Arvicola terrestris. Fens are also important for bats, migratory and breeding birds, due to the emergent insects found in this habitat. In Dumfries and Galloway, both coastal and freshwater reedbeds can be found, although there are few large reedbeds. Nationally it is amongst the most important habitats for birds, including the Marsh Harrier Circus aeruginosus which occasionally breed in the region. It also provides habitat for a range of specialised invertebrates.
Hare's-tail Cotton Grass
There is a significant proportion of the UK's raised bog area in Dumfries and Galloway, including examples along the Solway and the Cree. This habitat has suffered in the past due to peat extraction, conversion to forestry and lowered water levels. Primary bog, which have remained relatively undisturbed, are rich in Sphagnum communities and support characteristic species such as Bog Rosemary Andromeda polifolia, Cranberry Vaccinium oxycoccos and sundews. The Large Heath Coenonympha tullia butterfly is strongly associated with raised bogs which provide abundant sources of both the larval foodplant Hare's-tail Cottongrass Eriophorum vaginatum and the adults favoured nectar plant Cross-leaved Heath Erica tetralix.
Silver flowe NNR
A second type of bog habitat in the region is blanket bog, which occurs at altitudes from 70 metres above sea level, such as the Wigtownshire mosses, to nearly 700 metres on Merrick Kells and Moffat Hills. It is characteristic of the wettest areas in the UK. A number of wading birds species, such as Curlew Numerius arquata and Dunlin Calidris alpina, are associated with this habitat, as are rare dragonflies like the Azure Hawker Aeshna caerulea. It can also be important for Black Grouse Tetrao tetrix whose young feed on Cotton Grass Eriophorum vaginatum.
Coastal and floodplain grazing marsh in Dumfries and Galloway is mostly found in river floodplains, with an excellent example along the Bladnoch. Most of these areas are intensively farmed, reducing the area of habitat. It is important for breeding waders and wintering wildfowl, particularly geese, and is a key hunting territory for species like the Barn Owl Tyto alba. It is also rich in plant species, such as Holy Grass Hierochloe oderata and supports many invertebrates.
The Local Biodiversity Action Plan identifies ten priority wetland habitats:
- River Headwaters
- Lowland Rivers and Backwaters
- Exposed River Shingle
- Eutrophic Lochs
- Mesotrophic Lochs
- Oligotrophic Lochs
- Upland Springs and Flushes