United Kingdom Biosffer Dyfi Biosphere Ecological characteristics: • Dyfi is a glaciated catchment of predominantly hill land with thin, acidic soils developed on lower Pa- laeozoic sedimentary strata; • Broadleaf woodlands, typically sessile oak or ash do- minated, are a feature of the valley slopes and its ma- ny tributaries, although conifer plantations now domi- nate large areas; • The bryophyte, lichen and fern communities of the shady, damp valley woods are particularly notable, with large numbers of Atlantic species; • Several areas of upland moorland occur, comprising mixtures of acid grassland, blanket bog and dwarf shrub heath, often contiguous with larger upland areas © Biosffer Dyfi Biosphere BR and supporting important bird populations. • The Dyfi is a classic bar-built estuary, and one of the Declaration date: 1977 foremost examples of a drying, sandy, nutrient-poor Surface area: 1,589 ha estuary. Important populations of migratory fish, birds Administrative division: Ceredigion, Gwynedd and Po- and otter occur along with extensive areas of salt- wys, Wales, UK marsh (Atlantic salt meadow); • The spit dune system of Ynyslas is an actively accre- Human activities: ting system with good representation of dune commu- nity succession including marram fore-dunes and hu- Pastoral farming and forestry; mid dune slacks. Tourism and outdoor recreation; • The estuarine raised mire of Cors fochno is one of the Sustainable living and technology development; largest and best preserved active raised bogs in UK. It Natural resource re-habilitation, management and monito- is a key site for climate-related research and supports ring; important assemblages of lower plants, invertebrates Environmental education and interpretation; and birds. Cultural development Protection classifications: The greater part of the estuarine unit, and core area lies within Dyfi SSSI (sites of special scientific interest) and National Nature Reserve. Additional areas of SSSI occur within the Dyfi river cat- chment, part of which is also within Snowdonia National Park.. © Biosffer Dyfi Biosphere BR Contact information: Ecodyfi, Ty Bro Ddyfi, 52 Heol Maengwyn, Machynlleth, Powys, Wales SY20 8DT. Email: [email protected] Email: [email protected] .