Covering about 4,000 km2 (1500 miles2), the Flow Country is a large, rolling expanse of blanket bog found in Caithness and Sutherland in Scotland. The property
encompasses an exceptionally wide range of vegetation and surface pattern types, including numerous pool systems. These features are usually rare and localised but here they are widespread and a high proportion of the ground remains undisturbed. The range of mire types varies from those of the lowland Caithness plain in the east, with their continental affinities, through to those of the mountainous oceanic west. Extensive areas of active blanket bog, where bog moss Sphagnum and other bog species ensure continuing peat accumulation, occur in intimate association with a range of open water, wet heath, grassland and fen communities. This provides the diversity of habitats necessary to support a wide range of wetland and moorland species. Of particular importance are the birds, many of which are typically northern species found here towards the southern limit of their range. These include red-throated diver, black-throated diver, golden plover, greenshank, golden eagle, merlin and short-eared owl.
The Flow Country is also unusual in that it provides an extensive area of wild land and solitude on an otherwise highly developed and densely populated island. As wild areas such as these are typically mountainous, the associated blanket bog tends to be relatively fragmented and confined to the gentler slopes. As such, large, continuous areas such as the Flow Country are exceptional.
Blanket bog is a globally rare habitat, perhaps extending to some 10m ha. It is confined to the most oceanic areas of mid-high latitudes (45 – 60 degrees). This site represents around 1.5% of the global blanket bog resource.
Although no site could represent the full range of species and forms occurring throughout the global range, this site does demonstrate some remarkable diversity in response to altitude and longitude over relatively small distances. The whole area experiences an extremely oceanic climate, but within this there is a strong east-west gradient reflected in the floristic composition. Overlain on this gradient is geological and topographical variation resulting in additional species and structural diversity. This is particularly well expressed in the range of patterns of pool systems. Although analogous patterns appear on peatlands elsewhere in the world, nowhere else does such variety occur on blanket bog or over such short distances.
Thus, although distinguished from other examples, this site captures the essence of the habitat in a way which few, if any, other sites could.
In addition to the extent, continuity and diversity of peatland habitats, the size and composition of the bird population contributes to the outstanding international importance of this site. Raptors, waterfowl and waders are particularly abundant and diverse for this habitat and for many of these this is a stronghold set against declines elsewhere and predicted restrictions on range in response to climate change.
Another important aspect of the Flow Country is the history and continuity of scientific research into the habitat, its species and its supporting processes. Not only did its study contribute to some early ideas on the development, form and function of blanket bog, it is now a key site in developing our understanding of a wide range of peatland issues, from the ecology of individual species and changes in their population over time, to greenhouse gas fluxes and the role of such habitats in climate change mitigation.
(Text courtesy of UNESCO)