(syn: Open Mosaic Habitats on Post Industrial Land)
The habitat comprises mosaics of bare ground with, typically, very early pioneer communities on skeletal substrates, more established open grasslands, usually dominated by fine leaved grasses with many herbs, areas of bare ground, scrub and patches of other habitats such as heathland, swamp, ephemeral pools and inundation grasslands. High quality examples may be characterised as unmanaged flower-rich grasslands with sparsely vegetated areas developed on poor soils/substrates.
Invertebrate faunas can be species-rich and may include many uncommon species, such as dingy skipper and grayling. Exotic plants provide for an extended flowering season and, with the floristic and structural diversity of the habitat mosaic, contribute to the value of the habitat for invertebrates.
Some areas are important for birds such as little ringed plover, as well as more widespread, but UK BAP priority species, including skylark and grey partridge. The habitat provides secure breeding and feeding areas commonly absent from land under agricultural management.
Identification & Mapping
This habitat requires all of the following criteria to be met*:
- The area of open mosaic habitat is at least 0.25ha in size
- Known history of disturbance at the site or evidence that soil has been removed or severely modified by previous use(s) of the site. Extraneous materials/substrates such as industrial spoil may have been added.
- The site contains some vegetation. This will comprise early successional communities consisting mainly of stress-tolerant species (e.g. indicative of low nutrient status or drought). Early successional communities are composed of annuals, mosses/liverworts, lichens, ruderals, inundation species, open grassland, flower-rich grassland, heathland
- The site contains unvegetated, loose bare substrate and pools may be present
- The site shows spatial variation, forming a mosaic of one or more of the early successional communities as detailed above plus bare substrate, within 0.25ha.
When mapping the habitat, areas of scrub, wet flush or more lush vegetation should be included as part of the habitat’s structural diversity, unless these elements take the habitat outside of the definition. In places brownfield sites have been landscaped/planted with trees, but still retain areas of brownfield habitat. Estimates of tree cover should apply to each individual habitat area rather than the entire land parcel.
Later successional stages on brownfield land may become important as semi-natural habitats such as lowland heath and neutral or calcareous grassland in their own right, and conform to those definitions. We are not concerned with these stages within this definition.
There is currently no condition assessment designed for this habitat.
*UKBAP (2010) Priority Habitat Definition: Open Mosaic Habitats on Previously Developed Land