Table 1.

Classification of broad habitats used for the risk register based on the classification used in the UK National Ecosystem Assessment. For some analyses, these habitat classifications may be too broad and so have been subdivided into meaningful habitat units

Broad habitat type	Component habitats	Scope
Mountains, moorlands and heaths	Blanket bog	Rainfall‐fed bog in upland environments
	Mountains, moorlands and upland heaths	Upland heath, montane habitats and associated wetlands (flushes, fens). Also includes rock and scree habitats such as limestone pavements
	Lowland heath	Lowland habitats dominated by heather family or dwarf gorse species
Semi‐natural grasslands	Semi‐natural grasslands	All grasslands unimproved for agricultural purposes. This includes a range of grassland types
Enclosed farmland	Enclosed farmland	Arable, horticultural land and improved grassland as well as associated boundary features, for example hedgerows
Woodlands	Woodlands	Includes broadleaved and coniferous woodlands both natural woods and planted (wet woodland is included here)
Freshwaters	Standing open waters	Lakes and ponds (reservoirs and canals are considered to be manmade and therefore out of scope)
	Rivers and streams	Streams and rivers down to the tidal limit
	Groundwaters	Aquifers and significant quantities of below‐ground water
	Wetlands	Lowland fens, raised bogs, swamps, reedbeds and floodplain wetlands
Urban	Urban	The natural environment elements of built up areas, for example parks, gardens, towpaths, urban trees, sustainable urban drainage systems
Coastal margins	Coastal dunes and sandy shores	Dune systems and the upper zone of sandy shores
	Saltmarsh	The upper zone of vegetated intertidal habitat – transition into other intertidal habitats
	Transitional and coastal waters	Estuaries, coastal lagoons and other near‐shore waters
Marinea	Intertidal rock	Bedrock, boulders and cobbles which occur in the intertidal zone – colonized by mussels/barnacles and seaweeds depending on exposure
	Intertidal sediment	Shingle (mobile cobbles and pebbles), gravel, sand and mud in the intertidal zone
	Subtidal rock	Bedrock, boulders and cobbles in the subtidal zone colonized by seaweeds (infralittoral zone) or animal communities (circalittoral zone)
	Shallow subtidal sediment	Shingle (mobile cobbles and pebbles), gravel, sand and mud in the subtidal zone
	Deep sea bed	The sea bed beyond the continental shelf break
	Pelagic water column	The water column of shallow or deep sea; beyond the coastal waters

^aThe marine ‘land‐use type’ is based on EUNIS habitat classification and proposals for Marine Strategy Framework Directive reporting. These could be amalgamated to give: intertidal, subtidal, deep sea bed and pelagic.