Open Mosaic
Any piece of vegetated land of at least 0.25ha, which has been altered by human activity. Also referred to as brownfield, they can be extremely varied, from former industrial estates to quarries, spoil heaps, disused railway lines, landfill sites and disused airfields.
Unvegetated areas, loose bare substrate and pools may be present with spatial variation, forming a mosaic of early successional communities
Importance for wildlife
They can have as many rare invertebrate species as ancient woodlands, and many act as important ‘reservoirs’ of wildlife. Cycles of disturbance and abandonment combined with low-nutrient soils give rise to a wide variety of habitats, patterns of water temporarily ebbing and flowing and a mini-ark of plant species. Many invertebrates have complex life-cycle needs so they often require two or more habitats close to each other – a ‘mosaic’ of habitats rather than miles and miles of the same.
Important associated species
Birds
Dunnock, Starling, Song Thrush, House Sparrow, Herring Gull, Swift*
Mammals
Common Pipistrelle*, Soprano Pipistrelle, Hedgehog
Reptiles and Amphibians
Great Crested Newt, Common Toad, Common Lizard, Slow-worm
Bees and Wasps
Weevil Hunting Wasp, Five-banded Tailed Digger Wasp
Beetles
Necklace Ground Beetle, Stag Beetle
Butterflies
Wall
Moths
Goat Moth, Four-spotted Moth
Mosses and Liverworts
Thatch Moss, Chalk Screw Moss
Plants
Broad-leaved Cudweed, Red Hemp-Nettle, Annual Knawel, Fine-leaved Sandwort
*Suffolk Priority species
**Priority - Research Only. Common and widespread but rapidly declining
Factors affecting habitat in Suffolk
- Despite a growing acknowledgement of the biodiversity value of wildlife-rich brownfields, many local authorities still consider them a priority for development. Loss of habitat clusters is likely to negatively impact wildlife populations as key sites are lost.
- ’Greening’ is a growing issue, with brownfields being inappropriately restored or remediated for use as public open space. This can involve adding nutrient-rich topsoil and seeding with grass species, alongside tree planting and introducing intense management such as grass cutting. resulting in the loss of early successional habitat features.
- Neglect of sites can lead to scrub encroachment and the eventual loss of open habitats.
Habitat management advice
- Some sites will require management to prevent site succession to scrub or woodland, and the loss of open habitats, the management of brownfields differs from traditional conservation management.
- Avoid rigid management schemes; management should ideally be undertaken in a relatively reactionary manner based on rotational disturbance in response to site monitoring during the early years of management being introduced.
- Management should be rotational, with only parts of a site managed in a single year to maintain a mosaic, avoiding using a single technique site-wide in a single year. This is essential to retain a habitat mosaic and prevent the homogenisation of a site.
Vision for Suffolk
- Improve knowledge of extent and quality of open mosaic habitats.
- Maintain the existing extent of open mosaic habitats to ensure no net loss.
- Re-create open mosaic habitats as opportunities arise.
- Encourage the restoration and improvement of degraded open mosaic habitats.
Where to find further information
- Buglife – advice on managing BAP habitats
- JNCC – Habitat Description (pdf)
- MAGIC website – interactive mapping information, including designations
- Natural Environment White Paper June 2011 – The Natural Choice: securing the value of nature (pdf)
- Suffolk Wildlife Trust – Habitats Explorer
- The Planner - The value of restoring nature to brownfield sites
Images:
- Derelict ex-military base by Emma Aldous
- Swifts by Neil Rolph (Flickr)
- Hedgehogs by Natural England (Flickr)
- Common toad by Neil Rolph (Flickr)
