There are many types of grassland: amenity grassland (lawns and recreational fields), grassland habitats (including acid, magnesium and chalk downland grasslands), agricultural pasture, waste (grass) lands and common land. Historically, in the UK, areas of land with thin, sandy soils (unsuitable for cultivation) in urban or peri-urban settings have typically been left unmanaged and, instead, been used for informal recreation and grazing. Many such areas have gained legal protection as common land, and many have developed interesting ranges of habitats including heathland and rough grassland.
Frequently, up to a third of the area of a town or city may be grassland. Of this, about two-thirds is closely mown amenity grassland used primarily for recreation. Such amenity grasslands generally consist of few species, compounded by quality fertile or fertilised soil and a management regime that discourages either structural or species diversity. Given the diversity of habitats that are associated with urban greenspaces and the diversity of the types of grassland that can be successfully established in such settings, grasslands offer a very versatile and practical means of expanding the social and economic benefits offered by greenspace.
The maintenance of amenity grasslands is surprisingly high, forcing many local authorities and land-owners to seek cheaper management protocols or regimes. Allowing grassland habitats in urban settings for the provision of native or naturalised grasses and flowering plants offers several advantages:
- Plant diversity attracts insects (including butterflies and bees), arthropods (from spiders to millipedes), birds and mammals.
- Opportunities for education and recreation abound.
- Even small plots of wildflower planting can change the atmosphere of a setting - the creation of a wildflower meadow as part of an urban greenspace can bring a little piece of countryside into the town.
- The reduced-intensity management needed for rough grasslands and urban commons makes them a cost-effective alternative to closely mown amenity grassland.
- Where flowering species flourish, a changing palate of colour is added to the urban environment throughout the seasons.
- Involving the local community in managing the site, for example in mowing or grazing regimes, encourages personal investment in the site.
Where recreation and tidy appearance are priorities in an urban greenspace, long grasses have been replaced with traditional, short, regularly mown grass. Tall grasslands and wildflowers may not be appropriate and can often be seen as unsightly and unattractive both before and after flowering. Others see tall grasses as a fire risk; and others as a dog latrine or a focal point for littering.
But there are benefits of tall grasslands that merit their wider consideration.
- Biodiversity - while short grasslands attract birds and invertebrates of grassland and open habitation, tall grasslands will also tend to include nectar-rich plants, in turn attracting hoverflies, butterflies, moths and bees. The habitat will also be more likely to support small mammals and even reptiles.
- Social benefit - tall grasslands are particularly attractive to young children, stimulating the imagination and natural play, educating with respect to insects and other invertebrates associated with the habitat, and introducing them to wild habitats.
- Economic sustainability - the management regime for grassland varies according to the specific habitat to be created (or maintained) and the objectives associated with it. The management regime for tall grasslands and wildflower meadows is less intensive than for closely mown grasslands, so they can be a cost-effective alternative.
Public acceptance of grasslands other than monotonous and barren amenity grassland can be fostered through community engagement, education and carefully balanced design. For example, the use of colourful wildflowers and bulbs that provide a changing splash of colour through spring, summer and autumn can stimulate interest through visual appeal. Maintaining closely mown grass along edges and paths, and cutting wide meandering pathways through the tall grasses, will improve aesthetic appeal and encourage people to wander in and out of the meadows. Signs to explain the interest and importance of tall grass and meadowlands, including interpretation of the habitat’s biodiversity, may stimulate interest.
The biodiversity of urban greenspace can be increased by tall grassland and wildflower meadows. In particular, biodiversity can be increased by:
- A shift in habitat type from closely mown grassland to rough, tall or flowering grassland, or shrub land
- Changing the cutting regime to convert to flowering lawns for at least a period of the year, to stimulate species and structural diversity
- Removing turf and/or topsoil through stripping or soil inversion, and laying a meadow seed mix on the reduced-nutrient sub-soil
- Cutting in rotation so that there is always some long grass somewhere in the greenspace
- Not cutting for at least one season, to reveal what species are naturally present
- Encouraging nutrient-stripping of the soil by using a sow-grow-mow regime, removing the cuttings with each mow
- Seeking specialist advice.
Rough grassland and wildflower meadows are suited to a grazing management regime. Grazing plays a key role in maintaining species richness by limiting the ability of competitive species to achieve dominance, and influencing the proportion of competitors (stress-tolerators). A high proportion of grassland species are perennials. The removal of plant biomass by a hay harvest or by grazing maintains floristic diversity by reducing nutrient recycling and subsequently suppressing soil fertility. Grazing can be selective towards rare or local livestock breeds, and thus play a role in rejuvenating rural economies and promoting traditional rural skills. Grazing animals also provide a fascinating educational resource.
Jeskyns Community Woodland
Grazing as a means of managing grassland habitats is being adopted by the Jeskyns Community Woodland, a greenspace to the south-east of Gravesend. The careful management of grazing and stocking density at Jeskyns should minimise the requirement for chemical pesticide and fertiliser application.
Natural browsers control the sward differently as a result of their browsing preferences (e.g. cattle, sheep, deer, rabbits and hares). Cattle remove more biomass than sheep and are more indiscriminate browsers, generally leaving a longer sward that retains many fecund flowering heads. Sheep, with smaller mouths and more mobile lips, select and reject vegetation from lower levels in the grassland profile. Sheep lower and tighten the sward and discourage weedy species from establishing in open areas. Tight grazing also allows light to reach ground-hugging rosettes of many grassland herbs such as yellow rattle.
Grazing animals stimulate diversity within a grassland habitat through non-uniform (patchy) browsing, if stocked at appropriate densities. The result is that some areas are closely cropped, while other patches are of taller, ungrazed vegetation, creating a structurally diverse sward that benefits floristic and invertebrate diversity. Grazing also removes plant material more gradually than mechanical cutting, giving more mobile invertebrates a chance to move to other areas within the grassland.
Forest Research has been establishing vegetation on brownfield sites for over 40 years, and uses this expertise along with ongoing research to provide consultancy and research services to the Forestry Commission and external clients for a wide range of habitats and vegetation types.
Forest Research Best Practice Guidance
Hutchings, T., Sinnett, D. and Doick, K. (2006). Soil Sampling Derelict, Underused and Neglected Land prior to Greenspace Establishment (PDF-956K). Best Practice Guidance for Land Regeneration, BPG Note 1. Farnham, UK: Forest Research.
Sinnett, D. (2006). Maximising Biodiversity (PDF-289K). Best Practice Guidance for Land Regeneration, BPG Note 9. Farnham, UK: Forest Research.
Agate, E. (2002). The Urban Handbook, 2nd edn. Doncaster: British Trust for Conservation Volunteers.
Ash, H.J., Bennett, R. and Scott, R. (1992). Flowers in the Grass. Sheffield: English Nature (now Natural England).
Luscombe, G. and Scott. R. (1994). Wildflowers Work. Liverpool: Landlife.
Fresh Start (Defra).
Butterflies Under Threat Team (1986). The Management of Chalk Grassland for Butterflies. Peterborough: Joint Nature Conservation Committee.
Crofts, A. and Jefferson, R.G., eds (1999). The Lowland Grassland Management Handbook. English Nature/The Wildlife Trusts.