Acid Grassland a nationally important habitat in London Acid Grassland? What is In the UK there are many Lowland acid grassland develops on kinds of grassland, each with low-nutrient, acidic soils (pH 4 to 5.5) different characteristic overlying acidic rocks or on the free- e v e e species of grasses, wild R Lowland Acid draining, gravelly and sandy soils found l e g i flowers and other wildlife. N Grassland in many parts of London. It often © is an important habitat for These differences depend on occurs as an integral part of lowland nature conservation throughout factors like the nature of the heath landscapes, commons and the Greater London area. soil, altitude and land-use; parklands. Grazing (or cutting) is needed both now and in the past. to prevent invasion by scrub and trees. Areas of infertile soil, unsuitable for growing crops, were often used by our ancestors as common grazing land, The supporting a mixture of heath main picture and acid grassland rich in shows acid OTHER GRASSLAND grassland in Bushy wildlife. Park with well- TYPES developed ant hills. Other types of grassland in A diversity of grasses London that are also Today, some of these areas and wild flowers, such important for wildlife e v as germander speedwell e e remain as commons and R (blue) and heath conservation include the l e g i parklands, but the vast majority bedstraw (white), ‘chalk grassland’ found on N can be seen in © Chalk grassland have been developed, converted spring. alkaline (high pH) soils or on into sports pitches and other soils of medium pH, amenity grasslands, or they wildflower-rich ‘neutral grassland’. When either have been neglected and these grasslands or acid allowed to develop into scrub t grassland are degraded by t e l w and woodland. nutrient enrichment or bad e H n a management, so-called ‘rank’ J © The few remaining areas of grassland develops. The Neutral grassland heath and acid grassland in delicate fine grasses and wild flowers are replaced by London are now under serious coarse grasses like threat – we need everyone to cocksfoot, rye grass, common understand and support efforts couch, Yorkshire fog and e other plants like thistles, v to conserve this precious e e R l common nettle, dock, broad- e g habitat for the future. i leaved plantain and rosebay N Rank grassland © willowherb. Main photo © Nigel Reeve. Insets © Piers Eley and Why is Acid Grassland important? Nigel Reeve Wimbledon Common and Putney Heath (main picture) is a Site of Special Scientific Interest which supports the most extensive area of wet heathland in Greater London, with important areas of dry heath and acid grassland. Acid grassland is a nationally important habitat Acid grassland species you may see G Lowland Acid Grassland is a include (clockwise from above): mat grass, UK Biodiversity Action Plan wavy hair grass, heath speedwell and Essex habitat and as such is a top skipper butterfly priority for wildlife conservation nationally. G Several plant, invertebrate and bird species found in acid grassland are protected under the Wildlife and Countryside Act 1981. G In England and Wales there are 271 Sites of Special Scientific Interest (SSSIs) that Acid grasslands are have this habitat as a principal important in London reason for notification. G G A number of Special Areas of In London there are an estimated 1,300 Conservation (SAC) are hectares of lowland acid grassland, which contributes about 4% to the national resource. designated under the G European Habitats Directive. The acid grasslands of Greater London, south These include Epping Forest, Essex and north west Kent are an important Wimbledon Common and home for a distinctive community of insects and Insects in spiders – many of which are nationally scarce. Richmond Park, all of which the Thames Terrace Invertebrates group include the bee-wolf wasp This community is collectively known as the include substantial areas of (above left) and many solitary bees London’s acid grasslands. and wasps. The bee above is feeding ‘Thames Terrace Invertebrates’. on mouse-ear-hawkweed Introducing the plants of Acid Grassland foot d’s If you look closely, you will see that acid Bir grassland contains a diversity of fine- leaved grasses. These include common bent, red and sheep’s fescues, mat grass and others.Alongside the grasses grow wild flowers like sheep’s sorrel, heath bedstraw, tormentil, harebell, bird’s foot, common stork’s-bill, heath milkwort and bird’s foot trefoil. w tra ds be th ea Nationally scarce plants H found in London’s acid grassland include clustered clover, upright chickweed and autumn squill. Heath milkwort In areas that are less Harebell well drained, you will see tussocky grasses, along with a range of sedges and rushes. On the soil surface you may find a range of mosses and lichens. Acid grasslands are also important for l i t their fungi, in particular various n e m r coloured waxcaps (below) – but o T e v e conditions are rarely good enough e Waxcap fungi R l e g i for these in the N © d a London area. e r p s s i h t n Grasses and rushes, like dense-headed heath woodrush (left) are o s o t typical of acid grassland. However, a huge range of tiny, yet o h p spectacularly beautiful, wild flowers thrives in the acid grassland l l A habitat. If you look carefully, you will often be rewarded by finding delicate blooms like those on these pages. © Nigel Reeve acid grassland habitat acid grassland to adds gorse Dwarf Habitat ideal structur better jobofmaintainingan Grazing animalsdoamuch insects. nectar for as pollenand shelter aswell patches ofscrub acid grassland, toour isaseriousthreat trees scruband by Although invasion spiders andreptiles. arangeofinsects, for good inthesun,up quickly whichis important warm becausethey very soilare Patches ofbare to theground. close smallandgrow generally are that thegrassesandflowers The infertile acidicsoilmeans and bare areas. and bare ofplantheights patchwork cr helps tocontr trampling andbrowsing machines.Theirof mowing to thehabitat–pr andvaluablediversity structure andheather,gorse add restore grasslands restore andhelp to inthevegetation structure scrub and bracken,that control create grazers hardy are Highland cattle(right) eates anatural e ol scruband occasional structure than theuse , including o viding © Nigel Reeve lizard (right) lizard common for patch warm-up welcoming a providing earth (below), exposed the have Rabbits Common green grasshopper Common green © S u s a n n e B la n k e m e y e r Roger Key/English Nature © Nigel Reeve © Nigel Reeve with here W olf spider ggs Meadow brown (top left) and small copper (top right) butterflies, the bee-wolf wasp (below left) and many species of tiny solitary bee are What animals might I see? among acid grassland’s residents. A huge array of animals can be found in acid grassland... G Small mammals such as shrews, mice and voles (above right) forage in dense grass. G Common lizards may bask in sun- warmed patches of bare soil. G Kestrels (top left) and tawny owls (left) hunt many of these creatures as prey. G The large range of invertebrates attracts many other birds such as the green G Characteristic butterflies include the small woodpecker, meadow heath, meadow brown, small copper, small, p s a w pipit and skylark. large and Essex skippers. f l o w - e e b t G p e G The Thames Terrace Invertebrates include c x e In undisturbed areas, e v e many species of burrowing bees and wasps. e R meadow ants create l e g i The red-banded sand wasp is a flagship species N e t distinctive mounds (ant i © a s for acid grassland in London. The mining bee o W t e o k h i hills) among the grass p Andrena florea M l l and the bee-wolf wasp are A © (right). endangered and nationally scarce species found in London’s acid grassland. What can we do to conserve it? The conservation of acid Ideally acid grassland is maintained skylarks, meadow pipits and others. grassland depends on appropriate by carefully-managed low-intensity It is generally best to delay cutting management and the co-operation grazing with livestock; usually hardy for as long as possible into the of visitors to the sites. Neglect breeds of cattle, sheep or ponies. autumn, although the availability of allows the habitat to become However, if grazing is really the appropriate machinery and wet invaded by scrub and woodland impractical, as it is in some urban weather may mean that timing has so that it loses its special wildlife areas, a programme of cutting and to be flexible.Whenever the cut value.The addition of nutrients by scrub control is necessary. occurs, it is best to remove all the fertilisers, dog-fouling or from cuttings to avoid putting the atmospheric pollution from The time of cutting is also nutrients back into the soil. vehicles, are all very damaging; as important. A summer cut may Sometimes an acid grassland or is the use of lime either to remove food from some insect heath in poor condition requires ‘improve’ the grassland or in species at a critical time. Cutting radical treatment such as major stone chippings used in car parks before the end of July may also scrub clearance, or the removal of and paths.Tree planting, even just affect ground nesting birds like an area of secondary woodland. one tree in the wrong place, will increase shade and can cause Scraping a living significant destruction of this for wildlife vulnerable habitat. One effective remedial treatment is to scrape off An important aim of grassland an area of nutrient-enriched topsoil and either remove it, bury it or pile it into a bank.