Open Mosaic Habitats on Previously Developed Land

Habitat Description

Previously developed land includes redundant urban land which once served a use, such as industry, housing, extractive industry, landfill, or transportation (railway lines) but has now become derelict, allowing natural processes, once again, to take place.

  Post-industrial and urban sites often hold diverse and sometimes unusual species assemblages and demonstrate dynamic ecological processes, particularly for invertebrates Buglife reports that brownfield sites have as many associated Red Data Book and Nationally Scarce invertebrate species as ancient woodland. Post-industrial habitats are often, but not always, associated with urban areas. Most previously developed habitats occur within the principal towns of Northampton, Corby and Kettering. The existence of these mosaics of habitat is essential to the survival of many species, both those specific to this type of habitat and to those moving between patches of other habitat. Brownfield sites also provide a refuge for species that would be associated with other habitats, e.g. species rich grasslands, was it not for man's influence on the environment.

Current UK Status and Trends

Declining due to infill development pressure. 

Estimated Current Northants Resource

Unknown but anticipated being concentrated in Northampton, Corby and Kettering. 

Progress Towards BAP Targets 2002-2007

Awaiting update  

Main Issues and Threats

  • Development pressure due to historical lack of recognition and the consequently poor history of recording on many urban and post-industrial sites.
  • Built development is concentrated in urban areas in order to protect the countryside: The current national target for housing is that 60% of all new housing should be on previously developed land. Unfortunately this has led to the loss of valuable habitats and green space in urban areas.
  • Local communities have a strong desire to 'clean-up' previously developed sites, whereas untidiness is more valuable for biodiversity.
  • Mismanagement of brownfield sites by 'green washing' importation of topsoil, seeding of grassland, and planting of trees can be devastating to their already rich biodiversity.

General Strategies

  • Protect these sites through good use of planning conditions and use Section 106 agreements or conditions to secure funding for long-term management.
  • Ensure that green infrastructure is integral in new development schemes.
  • Refine the Wildlife Sites designation criteria to allow previously developed land to be designated.
  • Identify and survey previously developed sites that may have a high biodiversity value (particularly invertebrates).
  • Educate conservationists, local authorities and local people about the value of naturally recolonised habitats.
  • Ensure suitable restoration schemes are put in place once industrial use (e.g. landfill or quarrying) of a site ceases.
  • Specific target areas are Northampton, Corby and Kettering.

Lead Partner

The Wildlife Trust

Associated National Priority Species

  • Annual knawel
  • Broom moth
  • Brown hare
  • Caraway
  • Common lizard
  • Dark spinach (moth)
  • Dingy skipper (butterfly)
  • Four-spotted moth
  • Garden tiger (moth)
  • Ghost moth
  • Grass snake
  • Grizzled skipper (butterfly)
  • Hedge rustic (moth)
  • Red star-thistle
  • Rosy rustic (moth)
  • Shaded broad-bar (moth)
  • Sky lark
  • Slow worm
  • Small heath (butterfly)
  • The cinnabar (moth)
  • The lackey (moth)

Specific Management Required for Associated Species


Northamptonshire Status

Management Prescriptions

Key Sites

Annual knawel


Prefers sandy areas such as disused sand pits.


Dingy skipper


Common bird's foot trefoil is the main food plant. This is required in a sparse sward, with areas of open ground, taller vegetation for shelter and roosting, in a sunny sheltered position (Butterfly Conservation, 2008).

Twywell Hills and Dales Country Park.

Grizzled skipper


Requires at least one of the main food plants (Rosaceae family) growing among short vegetation (< 10cm), with patches of bare ground, taller vegetation and scrub or woodland edges (Butterfly Conservation, 2008).

Twywell Hills and Dales Country Park.


Target Code

Target Type

Target Description

Target Units

Northants Baseline Resource



Unit Cost £

Total Cost £


Identify Extent

Identify all areas that meet the definition for this habitat through desk study and site visits by 2012.







Maintain extent

Based on the results of surveys, calculate the extent of this habitat and ensure no net loss.



No Net Loss




Action Code

Action Description

Lead Partner

Support Partner(s)

Related Target


By 2010 carry out a desk study to identify potential sites that meet the BAP habitat description.

The Wildlife Trust




By 2013 carry out a general and floristic survey of all areas of previously developed land that may meet the LBAP description.

The Wildlife Trust

University of Northampton (PhD students)



Carry out invertebrate surveys on all sites meeting the LBAP habitat description by 2015.

Diptera Group, The Wildlife Trust




Assess the surveyed sites against Local Wildlife Site criteria within 6 months of survey date and designate where appropriate.

The Wildlife Trust




Produce a guidance document for planners and developers regarding the value of open mosaic habitats on previously developed land by 2015.

The Wildlife Trust, Buglife




Ensure that suitable restoration schemes are put in place once industrial use of sites such as landfill sites and quarries ceases.


The Wildlife Trust