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.
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| 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. |
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| 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 Thyme and Rough Hawkbit. |
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| 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. |
2. Dry Acid Grasslands
Grasslands on acidic soils tend to be typical of upland regions in northern and western Britain, where they develop on soils over a bedrock of sandstone or granite. Lowland acid grasslands are much rarer in the UK and only occur in any quantity in the Hampshire/Dorset area and in East Anglia's Breckland. In the latter, these grasslands have developed where wind blown sands and glacial gravels have been deposited over the underlying chalk. At one time, Breckland had large areas of mobile sand dune systems, but these are now all gone (largely due to conifer planting) except for some tiny remnants on protected sites. Smaller but still interesting areas of dry acid grassland can also be found scattered through the Suffolk Sandlings and south into North-east Essex, while similar habitats can develop in coastal areas where there are extensive sand dune systems.
As with dry heath, plant communities can be rather species-poor on acid soils when compared with those on areas of higher pH and this can be further exacerbated by over grazing with sheep, though appropriate grazing can be beneficial by preventing scrub encroachment. However, the scarcity of these habitats in East Anglia means that they do provide an extra layer of diversity to the overall landscape of the region. Dry acid grasslands are usually overwhelmingly dominated by Common Bent, Common Sheep's Fescue and a non-clumping form of Yorkshire-fog. At the interface of these grasslands and heather-dominated heaths, there are usually stands of Wavy hair-grass. Where openings in the vegetation occur (often through Rabbit diggings or mole activity), some of Breckland's classic scarcities find a niche, such as Annual Knawel, Mossy Stonecrop and various small clovers. In very dry and exposed places, communities dominated by terrestrial lichens can develop; with the lichens being slow-growing and brittle, such areas are fragile and the very best locations are often closed to general access but may be visited on occasion.
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| Grassland on acidic soils, such as here at Weeting, can appear rather uninspiring at first, being largely dominated by a small handful of common grass species. | Scattered areas of dry acid grassland can be found close to the coast, especially in the northern Suffolk Sandlings and along Norfolk's Holt-Cromer ridge. In the latter area, outcrops of glacial till and morain often have good colonies of Common Kidney-vetch and hold perhaps the best population of Yarrow Broomrape in the UK. |
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| Extensive tracts of Common Bent are a regular feature of dry acid grassland and at flowering time, masses of fine, pinkish-purple flowerheads can dominate. | Sheep's Sorrel can form extensive colonies in short-cropped acid grasslands, often colouring the ground in various shades of rusts, reds and oranges. |
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| Churchyards can often preserve interesting patches of acid grassland in areas where such habitat has otherwise been lost. Field Mouse-ear and Germander Speedwell can form attractive patches of colour in spring is such places. |
| Some Typical Species
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Species to Look Out For
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Places to Visit
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3. Mesotrophic Grasslands
This group covers grasslands that are found on neutral soils and includes the majority of grasslands found in river valleys and on the boulder clays that cover the bulk of the region's interior, away from Breckland and the Fens. Such grasslands can be very species-rich with plants and include hay meadows and areas typically recognised as 'wildflower meadows'. Most tracts of mesotrophic grassland exist as remnants of former, much larger blocks, the bulk having disappeared under the plough during and after the agricultural revolution and later agricultural improvements. Those that remain on farmland are often just lucky quirks of fate and many are now protected in various ways, while churchyards and village greens are also a rich source of relict mesotrophic grasslands. Roadside verges provide another source of remnant mesotrophic grassland and many species typical of these communities have strongholds on protected roadside verges. In East Anglia, Norfolk seems to have suffered most heavily in the loss of its grasslands, except on the boulder clays in the south of the county, but Suffolk and North Essex have fared better.
Good mesotrophic grasslands can be the most species-rich plant communities in our region. The grasses are highly variable in this group, ranging from the rather species-poor banks beside main roads that are dominated by tall False Oat-grass, to remarkably rich, ancient meadows and pasture. A floral extravaganza might start in early spring with a show of Primroses, followed by Cowslips and an ever wider range of species as summer progresses. The exact mix varies from site to site, according to soil quality and moisture content, but often involves a range of orchid species, especially Green-winged, Pyramidal and Early Marsh Orchids and Common Twayblade, as well as some extreme rarities like Frog Orchid. Other rare species include Common Adder's-tongue, Meadow Saffron, Snake's-head Fritillary, Dyer's Greenweed and Pepper-saxifrage. In Breckland, the last remaining Field Wormwood plants can be found on small tracts of dry mesotrophic grassland, while the wettest sites can hold a range of plant species that grade into rush pasture and fen communities and may include Common Fleabane, Great Willowherb, Great Burnet and Parsley Water-dropwort among others.
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| Mesotrophic grassland being used for cattle grazing in a valley bottom meadow. Grazing or cutting for hay is essential for controlling more aggressive plant species and maintaining a mixed community, but over-grazing can overly favour buttercups (as here), which are poisonous and avoided by livestock and in extreme cases, over-grazing can lead to species-poor grasslands dominated by Creeping Thistle, Common Nettle and similar strong-growing species. | Village greens can harbour good mesotrophic grassland communites if managed sympathetically. Some of the finest stands of orchids and Cowslips in our region occur in such locations. |
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| Grassland communities can be at their most diverse in managed mesotrophic grasslands and often include Yorkshire-fog, Cock's-foot, various bromes and fescues, Meadow Foxtail and Crested Dog's-tail. | Wink's Meadow is a classic example of a protected and well-managed mesotrophic grassland with a fine colony of Green-winged Orchids along with many other scarce and declining plant species. |
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| In wetter areas, careful management can still produce species-rich plant communities, often with fen species starting to appear, such as Marsh Thistle, Great Burnet and Parsley Water-dropwort. | Perhaps the most celebrated valley bottom mesotrophic grasslands are those that contain colonies of Snake's-head Fritillaries. It seems likely, given the evidence, that this is not a native species in the UK, but it makes an impressive sight when growing en masse and, either way, serves as a great banner species to ensure protection of rare, wet meadows in southern England. |
4. Rush Pastures
In a national sense, rush pasture communities mostly form in upland areas and represent a gradient between drier grassland and wetland habitats. In East Anglia's lowland plant communities, I have used rush pasture to define areas that tend to be managed largely by grazing and form an interface between wet grassland and fen communities. In many cases, these habitats developed along valley bottoms that once would have been too wet to manage or farm, but which have been ditched and drained over time. As an intergrade, clear boundaries between rush pasture and neighbouring communities don't exist and usually are represented by a mosaic of communities, defined by the amount of inundation by water that the land gets. Rush pasture can often arise from over-grazing; this is because cattle favour grasses over rushes and it is very common to see extensive stands of tussocky Soft Rush developing in damp meadows where the grazing is particularly intensive. Such pasture often also has large quantities of Common Nettle and either Creeping or Marsh Thistle depending on water levels. Soft Rush doesn't do well with regular cutting, so areas that are mown rather than grazed tend to develop into more species-rich fen habitats with the creeping rushes taking over from the clump-forming species.
Rush pastures are rather species-poor, with a handful of strong-growing species dominating and excluding more specialist species. However, wetter depressions within the pasture can often offer up openings for a few other species to get a toe hold, such as Greater Pond Sedge, Floating Sweet-grass, Reed Canary-grass, Marsh Woundwort and Purple Loosestrife in something of a species-poor, wetland fen-type community.
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| Rush pasture forms in valley bottoms where the habitat is mostly used for cattle-grazing and forms something of a quintessential British scene. | In some wet pastures, Soft Rush can become dominant and forms major stands of tussocky vegetation, usually growing amongst carpets of Creeping Bent. |
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| Towards the coast, rush pasture can be extensive at the upper edges of marshland, where saltwater creep doesn't quite reach into the soil. Old, silted up ditch systems and wetter hollows can hold stands of Reed Canary-grass, which forms distinctive, pale patches in the landscape, such as here along the field margin. | Because they are typically not mown, rush pastures can develop qantities of dead material which is apparent particularly during the winter. Build up of this thatch can eventually aid drying out of the land and allow scrub to develop. |
| Some Typical Species
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Species to Look Out For
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Places to Visit |
5. Coastal and Floodplain Grazing Marshes
East Anglia has large areas of coastal grazing marsh associated particularly with Broadland and Fenland as well as further south along the estuaries of East Suffolk and North-east Essex. Much of this land has been acquired as grazing marsh by the construction of coastal sea walls and draining of saltmarsh. Originally, these lands would have been part of a continuum of habitats and plant communities, grading from dry grassland to saltmarsh but now tend to be rather uniform in appearance but for ditches and linear hollows, the latter often the remnants of old saltmarsh creeks. Despite this, coastal grazed lands often form an interface with wetlands and such wetter areas are covered under Wetland Plant Communities.
These are generally rather species-poor habitats, dominated by a handful of grasses and rushes, but certain features in the landscape can provide localised habitat for other species. Bare earth can develop due to seasonal inundation by fresh or salt water and these patches are often colonised by a variety of annuals such as goosefoots, oraches and the introduced Yellow Buttonweed. Where cattle trampling poaches the ground around gateways or water troughs, another range of annuals can develop and may even include Mousetail.
These are often difficult habitats to visit, since most grazing marshes are private, have limited access due to the presence of ditches and often have livestock on them. With this in mind, the list of places to visit includes ones where public footpaths give access to at least some of the plant communities.
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| Coastal grazing marsh is generally species-poor for plants but it covers such extensive tracts of land in East Anglia that it provides important areas for wildlife. Heavily grazed areas are dominated by grasses but may also develop ranker stands of nettle and thistles, while low spots that regularly flood can hold annual plant communities. | Areas that are drier and less regularly grazed, such as river flood banks, can develop a ranker, taller plant community, often dominated by False Oat-grass and umbellifers such as Hemlock, Common Hogweed, Alexanders and Cow Parsley. |
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| Freshwater floodplains further inland along valley bottoms are typically more species-rich than those closer to the coast. Large stands of buttercups can occur, while wetland species such as Cuckooflower and Ragged-Robin are frequently found. | Perhaps the greatest limiting factor to plant establishment in floodplain and coastal areas is inundation during winter storms. At the coast in particular, saltwater inundation is a serious limiting factor to plant growth and is likely to increase with current levels of climate change. |
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| Grazing marshes in smaller side valleys and away from the larger expanses of low-lying ground can be part of a more complex mosaic of grassland, wetland and scrub. | Gateways on grazing marshes are easily poached by livestock, producing different growing conditions and different suite of plants, typically annuals that favour the more open ground. |
| Some Typical Species
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Species to Look Out For
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Places to Visit
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