Grassland

Plant communities dominated by grasses can develop in a wide range of environmental conditions but the largest tracts tend to develop on shallow soils and in the more exposed locations, where tree growth can be inhibited. There are no steppe grasslands in the UK, but much of Breckland has close to a continental climate and what little is left of natural and seminatural habitats there tends to be dominated by grasslands and grass-heath of various types. Elsewhere, grassland habitats develop naturally on coastal dunes, exposed clifftops and on shallow chalky and acid soils. Natural grasslands tend to be relatively species-rich, especially on chalky soils (less so on acid soils) but can become impoverished if nutrification is increased as typically a handful of more agressive species tend to become dominant. This is often the case with roadside grasslands, while artifically created grasslands such as rye-grass leys often consist of a monoculture or with just one or two uncommon associates.

This section covers grass-dominated communities from dry grasslands on shallow, chalky soils, through artifically managed grasslands to communites that develop in wetter floodplain soils along river valleys and around the coast.

1. Calcareous Grasslands

Grassland on shallow soils over a calcareous substrate are particularly species-rich and, in East Anglia, these habitats are centred around the chalky soils of Breckland, south and west through the Newmarket area and into South Cambridgeshire, from where they continue down into the chalklands of southern England. In Breckland, the climate serves to create suitable conditions for these habitats to develop, while particularly good examples of these communities elsewhere can often be found where ancient, man-made earthworks create the chalky conditions near the surface that are required. Thus, ancient mounds, hill forts and raised dykes have particularly good communities, while a modern-day version of the habitat is created by the steep banks of railways and main roads, such as the A14 near Newmarket. Chalky outcrops near Ipswich and in North-west Norfolk provide other areas of similar habitat.

Livestock grazing is often integral to maintaining these semi-natural grasslands, while the close-cropped turf produced by Rabbits can be particularly productive for plants. All of this grazing helps to suppress the growth of potentially aggressive grass species, as well as preventing succession from grassland to scrub. Typical calcareous communities on shallow soils are rich in fine-leaved grasses and have good populations of Common Bird's-foot Trefoil, Kidney-vetch, Salad Burnet, Common Rock-rose, Lady's Bedstraw, Hoary Plantain, Wild Thyme, Rough Hawkbit, Small scabious and such specialities as Squinancywort, Autumn Gentian, Spotted Cat's-ear, Western Bastard-toadflax and various eyebrights as well as good orchid communities. In Breckland, the continental-type climate produces even more specialised plant communities which include a number of rare species, such as Spanish Catchfly, Breckland Thyme, Maiden Pink and Spiked Speedwell.

Where the grass is less often grazed and grows longer - such as along roadsides and in scrubby habitats, species such as Tufted Vetch, Red Clover, Common Agrimony, Perforate St. John's-wort, Slender and Greater Knapweeds, Oxeye Daisy, Field Scabious, Yarrow and Wild Parsnip become part of the plant communities.


Typical Breckland Calcareous Grassland in summer with a mass of Common Kidney-vetch dominating the scene.	Breckland grasslands can vary subtly in a mosaic of plant communities even within relatively small area. Here, Oxeye Daisy is an important species in the community.

Ancient mounds and earthworks can become important sites for calcareous grassland communities, such as here at the Iron Age Warham Fort, Norfolk.	Sheep and Rabbit grazing keep the grass very short at Warham, which produces a tight sward full of short, perennial species, such as Squinancywort, Large Time and Rough Hawkbit.

An important feature of calcareous grasslands are the nest mounds of meadow ants, which provide growing opportunities for a variety of plants. Large Thyme, Field Mouse-ear, Lady's Bedstraw and Common Rock-rose seem particularly to favour the summits of these small hills.	Plant communities subject to less grazing grow taller and are favoured by a different suite of Plants, such as Common Restharrow, Perforate St. John's-wort, Greater Knapweed, Yarrow and Field Scabious.

Some Typical Species

Common Twayblade

Common Spotted Orchid

Common Bird's-foot-trefoil

Perforate St John's-wort

Common Carline Thistle

Common Burnet-saxifrage

Common Parsnip

Common Carrot

Species to Look Out For

Chalk Fragrant Orchid

Man Orchid

Heath Sedge

Purple-stem Cat's-tail

Lesser Meadow-rue

Purple Milk-vetch

Common Horseshoe Vetch

Sand Lucerne

Hairy Violet

Long-stalked Crane's-bill

Western Bastard-toadflax

Places to Visit

Branhamcross Common, Norfolk/Suffolk

Cranwich Camp, Norfolk

Devil's Ditch, Suffolk/Cambs

Foulden Common, Norfolk

Narborough Railway Line, Norfolk

Warham Fort, Norfolk

2. Wet Heaths

Wetter areas of ground can develop on acidic soils where there are springs or seepages or where there might be an underlying area of less pervious soil. Small areas can appear in lower-lying sections of sand dune comlexes and are known as dune slacks, while larger areas of wet heath develop along valley bottoms and give way at the wettest sections to valley mire and bog communities. Typically there is a seemless gradient from dry heath, through wet heath to valley mire and bogs and defining precise lines is not always possible.

As with dry heath, plant communities can be rather species-poor, becoming more species-rich in even wetter, valley mire or bog communities and members of the heather family tend to dominate. Both Common and Bell Heather can tolerate wetter ground, but the key indicator of damper conditions is the presence of Cross-leaved Heath, while Purple Moor-grass tends to replace Wavy Hair-grass. Other species such as Heath Rush, Tormentil and Heath Spotted Orchid appear, while rarities include Petty Whin, Marsh Gentian, White Beak-sedge and Common Deergrass. Scrubby patches are generally thin and low and may include Downy Birch and Eared and Creeping Willows.


Naturally sloping ground at Dersingham Bog creates a full set of heathland communities, from coniferous woodland, through dry heath and wet heath to valley mire and bog.	Wet heath gives way to valley mire, with stands of Cross-leaved Heath and sphagnum appearing on the tussock bases of Purple Moor-grass. In wetter areas the land transitions to valley mire and Sharp-leaved Rush becomes more frequent. patchy scrub includes Eared and Creeping Willows, while Marsh Helleborne and Heath Spotted Orchid can form good colonies.

Pale pink flowers of Cross-leaved Heath and the bright green stems of White Beak-sedge, the latter a very rare plant in East Anglia.	A gradient of heath habitats in coastal dunes, from dry lichen heath through tussocky heather to wet heath dominated by Purple Moor-grass and tussocks of European Royal Fern.