Download OPEN MOSAIC HABITATS ON PREVIOUSLY DEVELOPED LAND

OPEN MOSAIC HABITATS ON PREVIOUSLY
DEVELOPED LAND (UK BAP PRIORITY
HABITAT)
Summary
This priority habitat consists of a patchwork of bare, previously disturbed ground and
vegetated areas which can be in the process of changing from one vegetation type to
another. Typical of this habitat are areas of grassland, tall ruderal plant species, damp
areas, patches of scrub and invasive species, both native and non-native. The previous
disturbance is often industrial, such as mining, although the habitat can include old quarries
or building sites, areas of spoil from old coal mines, disused railway lines and urban
brownfield land.
The vegetation is mostly kept at a pioneer or early successional stage because the soils can
be low in organic matter or contaminated. Some of the best sites can exist for several
decades, supporting areas of scrub in addition to species rich grassland and freshwater
habitats. The vegetation is often in a state of flux changing from one type to another.
This habitat is particularly good for invertebrates, potentially having as many associated Red
Data Book (RDB) and Nationally Scarce invertebrate species as ancient woodlands (Jones,
2003).
What is it?
The Open mosaic habitats on previously developed land (OMHPDL) priority habitat consists
of a patchwork of bare, previously disturbed ground and stands of vegetation.
Although OMHPDL is associated with brownfield sites, only a small proportion of brownfield
sites support good examples of this priority habitat.
Macadam et.al.(2013) review the most important component features for biodiversity and
which are characteristic of the best examples of OMHPDL. Key features described are:
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Bare ground
Species rich grassland
Tall ruderal plants
Scrub
Shelter (although not a habitat, this is a feature of OMHPDL particularly important for
invertebrates)
South facing slopes and banks (of soil and/or rubble)
Seasonal ponds and damp areas
Many of the plant species are tolerant of drought and nutrient-poor conditions, in some ways
reminiscent of coastal habitats. The land in these places has a known history of disturbance
such as industrial use, and it is clear that soil has been removed or severely modified and in
some places there is an added cover of extraneous material such as mine spoil.
The grassland or heath vegetation is at a pioneer or early successional stage. The soils can
vary from dry to wet, very acidic to very alkaline, and can be deficient in nitrogen or
phosphate, impede the vegetation from developing to more mature successional stages,
even where left alone for many years. In this respect the habitat differs markedly from
almost all others in the lowland areas where it is most commonly found.
The grassland components of this habitat vary from species-poor, open swards of fineleaved grasses such as red fescue Festuca rubra, wavy hair-grass Deschampsia flexuosa
and mat-grass Nardus stricta, typically with some mosses such as Ceratodon purpureus, to
more colourful herb-rich swards including species such as black knapweed Centaurea nigra,
cat’s-ear Hypochoeris radicata and red clover Trifolium pratense. The heaths typically have
abundant ling Calluna vulgaris, but bilberry Vaccinium myrtillus may also be present. Nonnative plant species can be common. Many of the plant communities cannot be clearly
assigned to NVC communities. This is partly because of the presence of non-native species
but also because in these early successional stages of colonisation chance is evidently a
significant factor affecting the establishment and spread of particular species so that the
species composition can be unusual in NVC terms.
In some places scrub or even young woodland has developed, typically including willows
especially goat willow Salix caprea, birch Betula spp., ash Fraxinus excelsior, elder
Sambucus nigra and sycamore Acer pseudoplatanus, but even here the species
composition can still show floristic peculiarities attributable to the soil types and early
successional stage, and can therefore give a poor fit to NVC woodland and scrub
communities.
In a study of Open mosaic habitats on previously developed land in Great Britain, Riding et
al. (2010) identified a list of vascular plants characteristic of this habitat in Great Britain.
Whilst this was found to be useful in the Central Belt of Scotland, Macadam et al (2013)
identified that the plant list did not adequately reflect the regional variations within Scotland.
For example species such as hard rush Juncus inflexus, meadow salsify Tragopogon
pratensis) and Oxford ragwort Senecio squalidus are scarce in northern Scotland.
As the composition of plant species across OMHPDL sites is varied a typical plant species
list may not always be suitable for widespread use. An alternative more general vascular
plant list is suggested by Macadam et.al. (2013) to identify OMHPDL across Scotland.
The vegetation of OMHPDL in Scotland consists of mixtures of the following species:
mugwort Artemisia vulgaris, Centaurea nigra, common centaury Centaurium erythraea,
common mouse-ear Cerastium fontanum, viper’s bugloss Echium vulgare, eyebright species
Euphrasia spp., wild strawberry Fragaria vesca, cranesbill species Geranium spp., St. John’s
wort Hypericum perforatum, cat’s ear Hypochoeris radicata, oxeye daisy Leucanthmum
vulgare, common toadflax Linaria vulgaris, fairy flax Linum catharticum, pineappleweed
Matricaria discoidea, black medick Medicago lupulina, forget-me-not species Myosotis spp.,
red bartsia Odontites vernus, ribwort plantain Plantago lanceolata, buttercup species
Ranunculus spp., mignonette species Reseda spp., red campion Silene dioica, clovers and
related species Trifolium spp., mayweed species Tripleurospermum spp., coltsfoot Tussilago
farfara, umbellifer species Umbelliferae, speedwell species Veronica spp., vetches Vicia
spp..
In addition a wide range of lower plants are associated with this habitat including the mosses
Polytrichum commune, P. piliferum, Ceratodon purpureus, Bryum capillare, Pohlia nutans,
Calliergonella cuspidata, Kindbergia praelonga, Brachythecium rutabulum, Hypnum
cupressiforme and Rhytidiadelphus squarrosus.
Some native plant species, including broad-leaved dock Rumex obtusifolius, nettle Urtica
dioica, common ragwort Senecio jacobaea and bramble Rubus fruticsosus can become
dominant on some OMHPDL sites but these can often be important for a range of
invertebrate species and are an important element of the overall habitat mosaic.
Pools (including temporary ones), ditches and associated patches of wetland vegetation may
also be present.
With the variation in vegetation cover and structure, in addition to invertebrates this habitat
can be valuable for birds. Some breeding birds benefit from the lack of disturbance
compared with that in more managed habitats.
How do I recognise it?
Riding et al. (2010) list five criteria that must all be met for a site to qualify as OMHPDL:

be at least 0.25 hectares 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 a)
annuals or b) mosses/liverworts or c) lichens or d) ruderals or e) inundation species
or f) open grassland or g) flower-rich grassland or h) heathland.

The site contains un-vegetated, 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 plus bare substrate, within 0.25 ha.
Differentiation from other Priority Habitats
Areas around old mine workings with soils rich in heavy metals and supporting vegetation of
a metalliferous nature should be classed as the Calaminarian grasslands priority habitat,
even though in terms of their thin, poor soils and patchy vegetation they may have much in
common with the Open mosaic habitats on previously developed land priority habitat.
Some of the vegetation can be similar to that found in other priority habitats, for example
CG10 (Upland calcareous grassland and Lowland calcareous grassland), U1 (Lowland dry
acid grassland) and MG5 (Lowland meadows). However, the typical floristic peculiarities,
owing to its early successional stage of development, and the mosaics of this vegetation with
bare, previously disturbed ground, should distinguish it from other priority habitats.
Definition in relation to other habitat and legislative classifications
Classification
NVC
Phase 1
UKBAP Broad Habitat
Habitats Directive
Annex 1
SNH SSSI Habitat Features
Habitat types belonging to this UK BAP priority habitat
The Open mosaic habitats on previously developed land
priority habitat is not defined by any NVC communities, but
can include examples of CG10, MG1-2, MG5, MG9-11,
MG13, H9, OV19, OV21-22, OV24-28, U1-2, U4, W6 and
W21-24.
This priority habitat belongs within the Phase 1 habitat type I2
Artificial rock exposure and waste.
Forms part of the UK BAP Broad Habitat type - Inland rock
Does not include or belong within any Habitats Directive
Annex I types
Does not include or belong within any SSSI habitat features
Where is it?
This priority habitat occurs on thin, poor soils on ground which has previously been very
disturbed as a result of human activity such as industrial use. The soils can be wet or dry,
acid or alkaline and are commonly poor in nitrogen or phosphate. The topography has
typically been altered considerably by previous human use and can include features such as
coal bings.
As this habitat is most common in lowland areas the surrounding habitats are mainly urban,
enclosed farmland or woodland.
Although in Scotland it is most common in the more densely populated central and southern
lowlands, some of the largest areas can be found at discrete sites in rural areas around the
coast associated with industrial activity. The habitat is under-surveyed in Scotland, but can
be identified using remote assessment (Riding et. al. 2010). This methodology has been
trialled in Scotland using aerial imagery (Macadam 2010 a, b. Macadam et. al. 2013, and
Macadam 2014 (in preparation)). Ground truthing of remote assessment proved that it can
be effective at identifying OMHPDL (Macadam et. al. 2013).
What is special about it?
This priority habitat can be of importance in being one of the less managed habitats in
otherwise urban and intensively managed lowland landscapes. Some species of special
conservation status recorded in this priority habitat in Scotland are listed below.
Group
amphibians
amphibians
bees
beetles
Com mon
nam e
great crested
new t
common
toad
a solitary
bee
a ground
UK BAP
priority
list
EC
Habitats
Directive
Annex II
Scottish
Biodiversity
List
Triturus cristatus
y
y
y
y
Bufo bufo
y
y
y
Latin nam e
Andrena ruficrus
Amara praetermissa
y
Red
Data
List
y
y
Wildlife and
Country-side
Act (1981)
Group
birds
birds
birds
birds
birds
birds
flow ering
plants
flow ering
plants
flow ering
plants
mammals
mosses
reptiles
reptiles
Com mon
nam e
beetle
tree sparrow
common
linnet
grey
partridge
house
sparrow
common
starling
cuckoo
purple
rampingfumitory
basil thyme
annual
knaw el
hedgehog
flamingo
moss
slow -worm
common
lizard
Latin nam e
UK BAP
priority
list
EC
Habitats
Directive
Annex II
Scottish
Biodiversity
List
Red
Data
List
Wildlife and
Country-side
Act (1981)
Passer montanus
y
y
Carduelis cannabina
y
y
Perdix perdix
y
y
Passer domesticus
y
y
Sturnus vulgaris
y
y
Cuculus canorus
y
y
Fumaria purpurea
y
y
Clinopodium acinos
y
y
y
Scleranthus annuus
y
y
y
Erinaceus europaeus
y
Tortula cernua
y
Anguis fragilis
y
y
y
Zootoca vivipara
y
y
y
y
y
The importance of this habitat for invertebrates is highlighted by the fact that at least 194
invertebrate species of conservation importance, including 50 RDB and 131 Nationally
Scarce species have been recorded from brownfield sites in the UK. This includes 50% of
rare solitary bees and wasps and 35% of rare ground beetles (Bodsworth et al. 2005). An
assessment of four brownfield sites in the Inner Forth area (Currie and Bairner 2013) noted
37 invertebrate species of local or very local/unevaluated distribution. In their study of 14
OMHPDL sites in Falkirk, Bairner and Macadam (2011) found numerous rare and notable
invertebrates, including the locally scarce leafhopper Scleroracus plutonius, the Nationally
Scarce (Notable B) ground beetle Amara praetermissa and the Red Data Book 3 solitary bee
Andrena ruficrus.
How do we manage it?
This priority habitat has been heavily modified in the past by industrial or other human
activities, and one of its characteristics in its current (post-disturbance) state is the lack of
deliberate ongoing land management. However, to maintain biodiversity value, some sites
require periodic management, such as scrub or non-native invasive species removal to
revert the habitat to prior successional states (Buglife 2013). Examples are at Roughcastle,
Falkirk and Carron works also in Falkirk – the latter of which has also been declared a Local
Nature Reserve by Falkirk Council.
In general, OMHPDL is usually unmanaged. Some human activity may continue in the way
of recreational use such as walking, cycling, motorcycling etc. This may have a noticeable
effect on parts of a site but does not appear to be a major factor affecting the habitat on a
large scale.
These sites are generally not deliberately grazed by domestic stock, but can be accessible
to deer (mainly roe deer) and rabbits which may graze or browse some of the vegetation.
Some sites may be subject to landscaping in order to tidy them up visually. Such
management can result in uniform, species-poor grass swards and can be detrimental to the
ecological interest of the habitat.
Areas of OMHPDL are a category of green space within urban environments and contribute
to integrated habitat networks. The latter is particularly important in areas where there is a
shortage of semi-natural vegetation. Macadam et.al. (2013) provides suggestions as to how
to strategically approach redevelopment of areas supporting OMHPDL.
References, links and further reading
Averis, A., Averis, B., Birks, J., Horsfield, D., Thompson, D., & Yeo, M. 2004. An Illustrated
Guide to British Upland Vegetation. Peterborough, JNCC http://jncc.defra.gov.uk/page-2463
Ellis, N.E. and Munro, K. 2004. A preliminary review of the distribution and extent of
BAP priority habitats across Scotland. Scottish Natural Heritage Commissioned Report
No.044 (ROAME No. F00NA02).
http://www.snh.org.uk/pdfs/publications/commissioned_reports/F00NA02.pdf
Rodwell, J.S. ed. 1991 et seq.. British Plant Communities. 5 volumes: Vol. 1 (1991) Woodlands and Scrub; Vol. 2 (1991) - Mires and Heaths; Vol. 3 (1992) - Grasslands and
montane communities; Vol. 4 (1995) - Aquatic communities, swamps and tall-herb fens.
Cambridge, Cambridge University Press.
Rodwell, J.S., Dring, J.C., Averis, A.B.G., Proctor, M.C.F., Malloch, A.J.C., Schaminee,
J.H.J. & Dargie, T.C.D. 1998. Review of coverage of the National Vegetation Classification.
Joint Nature Conservation Committee contract report F76-01-170. Coordinated by the Unit of
Vegetation Science, Lancaster University.
UK BAP 2008. http://jncc.defra.gov.uk/pdf/UKBAP_BAPHabitats-40-OMH-2010.pdf
Usher, M.B., Bain, C. and Kerr, A. eds. 2000. Action for Scotland's Biodiversity. Scottish
Biodiversity Group. Edinburgh, The Scottish Executive and The Stationery Office.
Bairner, S. and C. Macadam 2011. Brownfield Biodiversity in Falkirk. Forth Naturalist and
Historian 34: 5-22
Bodsworth, E., Shepherd, P. and Plant, C. 2005. Exotic plant species on brownfield land:
their value to invertebrates of nature conservation importance. English Nature Resources
Report No. 650. Peterborough, English Nature.
Buglife, 2012. Scottish Invertebrate Habitat Management: Brownfields. Buglife, The
Invertebrate Conservation Trust.
Currie, N. and S. Bairner 2013. An assessment of invertebrate biodiversity at four brownfield
sites in the Inner Forth area. Buglife, Peterborough.
Jones, R.A. 2003. The 2001 Presidential Address – Part 2. A celebration of urban
entomology. British Journal of Entomology and Natural History 16: 109-121.
Macadam, C., Bairner, S. and Cathrine, C. 2013. Open mosaic habitats on previously
developed land: survey and recommendations for habitat planning and management in
Scotland. Scottish Natural Heritage Commissioned Report No. 606
http://www.snh.org.uk/pdfs/publications/commissioned_reports/606.pdf
Riding, A., Critchley, N., Wilson, L. and Parker, J. 2010. Definition and mapping of open
mosaic habitats on previously developed land: Phase 1. Defra Research Report WC0722.
London, Department for Environment Food and Rural Affairs.
Buglife, Managing priority habitats https://www.buglife.org.uk/advice-andpublications/managing-priority-habitats-invertebrates
Buglife case study, Roughcastle, Falkirk
http://www.buglife.org.uk/sites/default/files/Roughcastle,%20Falkirk.pdf
Common Standards Monitoring guidance http://www.jncc.gov.uk/page-2199
Countryside Survey http://www.countrysidesurvey.org.uk
National Biodiversity Network (NBN) Gateway https://data.nbn.org.uk/
Scottish Government website – information about agricultural grants, subsidies and services:
http://www.scotland.gov.uk/Topics/farmingrural/Agriculture/grants/A-Z/Intro
Scottish Natural Heritage website: http://www.snh.gov.uk/
UKBAP information on JNCC website: http://jncc.defra.gov.uk/default.aspx?page=5155