Accounting for Nature: Assessing habitats in the UK countryside
Appendix A: Broad Habitat Definitions

Chapter 3 Enclosed farmland – Arable and Horticultural, Improved and Neutral Grasslands

Arable and Horticultural

Includes all arable crops such as different types of cereal and vegetable crops, together with orchards and more specialist operations such as market gardening and commercial flower growing. Freshly ploughed land, fallow areas, short-term set-aside and annual grass leys¹are also included in this category.

Improved Grassland

Improved Grassland occurs on fertile soils and is characterised by the dominance of a few fast-growing species, such as rye-grass and white clover. These grasslands are typically used for grazing and silage, but they can also be managed for recreational purposes. They are often intensively managed using fertiliser and weed control treatments, and may also be ploughed as part of the normal rotation of arable crops but if so, they are only included in this Broad Habitat type if they are more than one year old.

Neutral Grassland

Neutral Grasslands are found on soils that are neither very acid nor alkaline. They support different types of vegetation communities compared to Acid and Calcareous Grasslands described in Chapter 6 in that they do not contain calcifuge (‘lime-avoiding’) plants which are found on acid soils, or calcicole (lime-loving) plants which are found on calcareous soils. Unimproved or semi-improved Neutral Grasslands may be managed as hay meadows, pastures or for silage. They differ from Improved Grassland in that they are less fertile and contain a wider range of herb and grass species. Usually the cover of rye grass is less than about 25%.

Chapter 4 Boundary and Linear Features

Boundary and Linear Features

This habitat includes a diverse range of linearly arranged landscape features such as hedgerows, lines of trees (whether they are part of a hedgerow or not), walls, stone and earth banks, grass strips and dry ditches². These features may occur separately or in combinations forming multi-element boundaries. This habitat type also includes some of the built components of the rural landscape, including roads, tracks and railways. The narrow strips of semi-natural vegetation along verges or cuttings are also included³.

Chapter 5 Woodlands

Broadleaved, Mixed and Yew Woodland

This form of woodland is dominated by trees that are more than 5 m high when mature, which form a distinct, although sometimes open, canopy with a cover of greater than 20%⁴. It includes stands of native broadleaved trees (such as oak, ash and beech), non-native broadleaved trees (such as sycamore and horse-chestnut), and yew trees, where the percentage cover of these trees in the stand exceeds 20%⁴ of the total cover of the trees present. Scrub vegetation, where the woody component tends to be mainly shrubs (usually less than 5 m high), is included if the cover of woody species is greater than 30%.

Coniferous Woodland

Coniferous Woodland is dominated by trees that are more than 5 m high when mature, which form a distinct, although sometimes open, canopy which has a cover of greater than 20%⁵. It includes stands of both native conifers (Scots pine but not yew) and non-native conifers (such as larch and Sitka spruce) where the percentage cover of these trees in the stand exceeds 80%⁶of the total cover of the trees present. Recently felled woodland is also included in this category if there is a clear intention to return the area to Coniferous Woodland.

Comment on mixed woodland

Many areas of woodland contain both broadleaved and coniferous trees. There is not a separate Broad Habitat for mixed woodland. Instead where mixtures occur they are assigned to the Broadleaved, Mixed and Yew Broad Habitat if the proportion of conifers is less than 80%⁷. However, the separation of coniferous from Broadleaved, Mixed and Yew habitat is applied at a stand or sub-compartment level within large woodlands to avoid areas that are predominantly coniferous being treated as mixed because they are part of a larger wood, of which 20%⁵consists of pure broadleaved trees. Therefore, most areas of mixed woodland that are assigned to the Broadleaved, Mixed and Yew Broad Habitat would normally have much more than 20%⁸broadleaved or yew trees.

Chapter 6 Mountain, Moor, Heath and Down

Acid Grassland

Vegetation dominated by grasses and herbs on a range of lime-deficient soils which have been derived from acidic bedrock or from superficial deposits such as sands and gravels. They characteristically include a range of calcifuge or ‘lime-avoiding’ plants.

Dwarf Shrub Heath

Dwarf Shrub Heath comprises vegetation that has a greater than 25% cover of plant species from the heath family or dwarf gorse species. It generally occurs on well-drained, nutrient-poor, acid soils.

Fen, Marsh and Swamp

This habitat occurs on ground that is permanently, seasonally or periodically waterlogged as a result of ground water or surface run-off. It can occur on peat, peaty soils, or mineral soils. It covers a wide range of wetland vegetation, including fens, flushes, marshy grasslands, rush-pastures, swamps and reedbeds⁹.

Bog

Wetlands that support vegetation that is usually peat-forming and which receive mineral nutrients principally from precipitation rather than ground water. Where bogs have not been modified by surface drying and aeration or heavy grazing the vegetation is dominated by plants tolerant of acid conditions, such as bog-mosses, cotton-grass and cross-leaved heath. Purple moor-grass or hare’s-tail cotton-grass can become dominant on modified bogs.

Calcareous Grassland

Vegetation dominated by grasses and herbs on shallow, well-drained soils, which are alkaline, as a result of the weathering of chalk, limestone or other types of base-rich rock. They characteristically include a range of calcicoles or ‘lime-loving’ plants¹⁰.

Bracken

Stands of vegetation greater than 0.25 ha in extent which are dominated by a continuous canopy cover (>95% cover) of bracken (Pteridium aquilinum) at the height of the growing season.

Montane

Vegetation types that occur exclusively above the former natural tree-line on mountains¹¹. It includes prostrate dwarf shrub heath, snow-bed communities, sedge and rush heaths, and moss heaths. They contain species which are characteristic of the arctic and alpine regions and the vegetation is often ‘wind-clipped’ or prostrate.

Inland Rock

Habitat types that occur on both natural and artificial exposed rock surfaces, such as inland cliffs, caves, screes and limestone pavements, as well as various forms of excavations and waste tips, such as quarries and quarry waste.

Chapter 7 Rivers, Streams, and Standing Waters

Standing Waters and Canals

This Broad Habitat category includes lakes, meres and pools, as well as man-made water bodies such as reservoirs, canals, ponds, gravel pits and water-filled ditches¹². A variety of vegetation types can be found associated with Standing Water, including aquatic vegetation (which may be free-floating or rooted in the sediments at the bottom of open water), and vegetation which is found in the shallower water of the margins.

Rivers and Streams

This category includes rivers and streams from bank top to bank top; where there are no distinctive banks or banks are never overtopped, it includes the extent of the mean annual flood. This includes the channel that may support aquatic vegetation and water fringe vegetation.

Chapter 8 Developed Land in Rural Areas

Built-up and Gardens

Covers urban and rural settlements, farm buildings, caravan parks and other man-made built structures such as industrial estates, retail parks, waste and derelict ground, urban parkland and urban transport infrastructure¹³. It also includes domestic gardens and allotments.

1 CS2000 includes annual grass leys under Improved Grassland.
2 CS2000 does not distinguish between wet and dry ditches (because only one visit is made during the year).
3 CS2000 also includes fences and associated vegetation.
4 CS2000 uses a percentage cover of 25%, not 20%
5 CS2000 uses a percentage cover of 25%, not 20%
6 CS2000 uses a percentage cover of 75%, not 80%
7 CS2000 uses a percentage cover of 75%, not 80%
8 CS2000 uses a percentage cover of 25%, not 20%
9 CS2000 includes areas of high rush (Juncus spp.) cover in this category, irrespective of associated species.
10 CS2000 may have under-recorded Northern limestone grasslands because they may be dominated by species that are not calcicoles.
11 In CS2000, the zone was defined by recognising a threshold annual accumulated temperature of 2,000°C, to delimit those areas with a montane climate (mostly in Scotland).
12 CS2000 is likely to record an under-estimate because some areas of small, closely adjacent water bodies in Scotland were necessarily mapped as single units.
13 CS2000 includes all transport infrastructure in this category, whether urban or rural.