Urban Biodiversity: Successes and Challanges: Brownfields: oases of urban biodiversity

2012·3.9 MB·English

by  Craig R Macadam

REFERENCES sites have since been reclaimed by nature through
Buckingham, S. (2005). Women (re)construct the plot; natural succession.
the rcgen(d)eration of urban food growing. Area,
37, 2, 171-179. This rich industrial heritage ofScotland has resulted in
Foley. C. (2004). The Allotment Handbook. New over 10,000 hectares of land being listed as vacant or
Holland, London. derelict. These brownfield sites can be incredibly
Gilbert, O.L. (1991). The Ecology’ ofUrban Habitats. important for biodiversity, often supporting nationally
Chapman & Hall, London. important populations of rare and endangered
Marshall, T. (2009). Rural gardens, allotments and invertebrates, alongside other wildlife such as birds,
biodiversity. British Wildlife, 21,2, 85-95. reptiles, plants and lichens. With the loss of natural
Smith, R. M., Warren, P. H., Thompson, K. & Gaston, habitats in the wider countryside through agricultural
K. J. (2006a). Urban domestic gardens (VI): intensification and development, wild areas within the
environmental correlates of invertebrate species urban environment have become crucial to the survival
richness. Biodiversity’ and Consen>ation, 15, 2415- ofmany increasingly threatened species in the UK. As
2438. a result Open Mosaic Habitat on Previously Developed
Smith, R. M., Gaston, K. J., Warren, P. H. & Land (OMHPDL) was recently included as a UKBAP
Thompson, K. (2006b). Urban domestic gardens priority habitat.
(VIII): environmental correlates of invertebrate
abundance. Biodiversity and Consen’ation, 15, Brownfields are any site that have been altered by
2515-2545. human activity and are currently not fully in use
(CABE, 2006). They tend to be concentrated in urban
and former industrial landscapes but also include
quaiTies, spoil heaps, old railway lines and disused
Urban Biodiversity: Successes and airfields (Allan et al. 1997; Bodsworth et al. 2005;
Whitehouse, 2008; Riding et al. 2010). Brownfield
Challanges: Brownfields: oases of
sites provide linkages or ‘stepping stones’ between
urban biodiversity more natural areas of habitat and facilitate the
movement and mixing of individuals in a less
Craig R. Macadam' and Suzanne Z. Bairner“ favourable urban setting. Lack of management of
brownfields often creates an open mosaic of habitats
‘Buglife-The Invertebrate Conservation Trust, such as species rich grassland, bare ground and early
Balallan House, 24 Allan Park, Stirling, FK8 2QG successional habitats (Key, 2000; Bodsworth et al.
^ BTCV Scotland Natural Talent Apprentice 2005; Harvey et al. 2008). This, combined with a low
nutrient content ofthe soil which prevents fast growing
species becoming dominant, provides a continuity of
E-mail: craig.macadam(^buglife.org.uk
resources for invertebrates throughout the season
(Harvey et al. 2008). In addition, a mosaic of habitats
provides a home for a wide range ofspecies and allows
ABSTRACT
many to complete their life cycles within the same site
Despite their potential to support biodiversity, a strong (Bodsworth et al. 2005).
negative public image has been attached to brownfield
sites, with the conservation of these sites therefore It has long been recognised that brownfields may have
lagging behind other habitats. The inclusion of ‘Open as many associated Red Data Book (RDB) and
Mosaic Habitats on Previously Developed Land
(OMHPDL)’ as a UK Biodiversity Action Plan Nationally Scarce invertebrate species as ancient
woodlands (Jones, 2003). At least 194 invertebrate
(UKBAP) priority habitat has however resulted in a species of conseiwation importance, including 50 red
renewed focus on brownfields as important wildlife data book and 131 nationally scarce species, have been
habitats. The experiences of Buglife - The recorded from brownfield sites in the UK. This
Invertebrate Conservation Trust in both the Thames includes 50% ofrare solitary bees and wasps and 35%
Gateway and central Scotland have shown that of rare ground beetles (Bodsworth et al. 2005).
bUrKowBnAfiPelpdriosriitteys scpaenciessu,ppsoormtemoafnwyhircahrea,rescbaerccoemianngd sBpreocwinefs.ieldFsoralesoxasmupplpeo,rtthae sluaictek ooff UmKanBaAgPemeprnitoriotny
increasingly reliant on such sites as their natural
brownfield sites often provides a secure area for
habitats come underthreat. breeding birds such as skylark (Alauda an’ensis) and
INTRODUCTION grey partridge (Perdix perdi.x), that are often absent
from land under agricultural management. Many
The industrial revolution starting in the eighteenth features identified at long abandoned industrial sites
century transfonned the scenes of our towns and
can no longer be found in the managed and over-
countiyside. Central Scotland was at the heart of this fanned wider countiyside or even in over-tidied parks
revolution and many heavy engineering works and iron
(Bodsworth et al. 2005). Loss of natural habitat is
founders were based there. With the demise of these causing many species, including bumblebees, beetles,
industries across the country, their fomier premises butterflies and reptiles, to become increasingly reliant
have been left derelict. Many of these ex-industrial
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on brownfield sites. Scotland, the National Planning Framework aims to
bring ‘vacant and derelict land’ back into productive
Despite their potential to support biodiversity a strong use for housing, for economic purposes and to create
negative public image has been attached to brownfields attractive environments however there is potential for
due to lack ofmanagement and a perceived untidiness this vision to conflict with the conservation of Open
and they are increasingly threatened by development Mosaic Habitats on Previously Developed Land
OMHPDL I
and landscaping (Key, 2000; Riding et al. 2010). and urban biodiversity.
Restoration ofpost-industrial sites into greenspace can
destroy much of the existing wildlife interest through BROWNFIELDS AND BUGLIFE
the importation of large quantities of topsoil and tree Buglife was one ofthe first conservation organisations
planting. Site restoration can also result in the loss of to highlight the ongoing loss of brownfield habitats -
particular niches at brownfields which will have a and the serious consequences ofthis for biodiversity - j
knock on effect on the wildlife found at that site and has been working to conserve brownfield wildlife
(Bodsworth et al. 2005). For example, the loss ofbare since 2004. Buglife’s flagship ‘All of a Buzz in the
ground at a site will affect themiophilic (warmth- Thames Gateway’ project in southem England has
loving) invertebrate species such as spiders and ground mapped and assessed the biodiversity of over 1,000
beetles as well as species such as mining bees and brownfield sites. This study has identified that although
solitary wasps that nest in the ground (Key, 2000; as many as a third ofall brownfield sites support high
English Nature, 2005; Whitchousc, 2008). levels of biodiversity - in many cases significantly
-
higher than surrounding ‘greenfield’ agricultural land
In 2007 Open Mosaic Habitat on Previously Developed many ofthese sites are being lost to development as a
Land was added to the list of priority habitats in the result ofgovernment targets fornew housing.
UK Biodiversity Action Plan (Maddock, 2008). To fit
the UKBAP criteria for OMHPDL the site must be Brownfield sites in the Thames Gateway are very
li
over 0.25 hectares in size and have a known history of important for the brown-banded carder bee (Bombiis
I
disturbance (Table 1). In addition, there must also be a Inimi/is) and the shrill carder bee {Bomhiis sylvarum). J:
mosaic of vegetation on the site comprised of early The East Thames conddor with its large areas ofopen
successional communities and un-vegetated bare areas. flower rich brownfield grasslands is home to the most |
|
important remaining metapopulations of these
Criteria bumblebees.
[i
1
1. The area of open mosaic habitat is at least 0.25
The streaked bombardier beetle {Brachiinis sclopeta)
ha in size. I
2. Known history of disturbance at the site or was thought to be extinct in Britain but was :!
evidenee that soil has been removed or severely rediscovered in 2005 on a brownfield site in London
modified by previous use(s) of the site. (Jones, 2006). The site is cuirently being developed
for housing and as mitigation around 65 beetles have j
Extraneous materials/substratcs such as industrial
spoil may have been added. been translocated to a nearby site. Invertebrate |
3. The site contains some vegetation. This will translocations typically have a low success rate, j
comprise early successional communities particularly with species with complex life histories as i'
consisting mainly of stress tolerant species (e.g. is the case with the streaked bombardier. It is therefore
highly unlikely that this mitigation will save this
indicative of low nutrient status or drought).
Early successional eommunities are composed of species at this site and it may well become permanently S
extinct in Britain.
a) annuals or b) mosses/livei'worts or c) lichens
or d) ruderals or e) inundation species or f) open
The distinguished jumping spider (Sitticiis
grassland or g) flower rich grassland or h) [|
distinguendus) was discovered during surveys in 2005
heathland. I
4. Tsuhbestrastiteeancdopnotoailnssmauyn-bveegperteasetnetd., loose bare astpeWceisest Tihsurroonclky Makrnsohwens (Hfarrovmey,oneteal.o,t2h0e0r5).sitTehi-s |
5. The site shows spatial variation, fonning a dSewvaenlsocpommenbte pMraorpsoshaelss.wheTrhee istities atthrWeeastetneTdhubiyrorcek-
mosaic of one or more of the early successional
csuobmsmturantiet,iweisthai)n-0.h2)5ahbao.ve (criterion 3) plus bare ccauriTepnatrlkyinhgaswphliacnhn,ingifpdeenvneilsospieodn,fowrowualrdehdoeusstirnogy atnhde 5||
habitat ofthis species.
Table 1. Open mosaic habitat on previously developed THE SCOTTISH EXPERIENCE
land definition and criteria (Riding etal. 2010). \
Evidence suggests that this issue is as pressing in
j
Scotland as elsewhere. In September 2010 Buglife
The conservation ofbrownfield sites has lagged behind launched a new project ‘All of a Buzz Scotland’ as a |
other important habitats for plants and wildlife. The j
response to this challenge. This project follows in the
term brownfield was first used by the go%vernment in successful footsteps ofwork completed in the Thames |
1998 when they set a national target of60 ofall new Gateway. The first phase ofthis project assessed 1,522 j
housing developments to be located on brownfield land sites listed as ‘derelict’ on the Scottish Vacant and
(Bodsworth et al. 2005; Riding et al. 2010). In
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Derelict Land Register and identified 393 sites that had Surveys of brownfield sites in Falkirk commenced in
the potential to satisfy the UKBAP criteria for May 2010, with the majority of field work carried out
OMHPDL. The assessment of these sites followed a between June to October 2010 and March to June
remote assessment methodology using aerial 2011. Samples of teiTCStrial invertebrates were
photography to identify features typical of OMHPDL collected using pitfall traps, sweep nets and/or pan
(Macadam, 2011). traps. When collected each sample was labelled with
site name, collection method and date and stored in
It was noted during this initial assessment that some of 70% alcohol. Samples were first sorted into different
the aerial photography was up to 12 years old and the invertebrate orders and then identified to family, genus
sites identified as potentially fitting the criteria for or species by close examination under a high power
OMHPDL may no longer qualify as a priority site due microscope with reference to taxonomic books and
to re-development or succession during the intervening keys. Most groups were identified to species, however
period. The next phase of this project is therefore to in the Diptera, Myriapoda, Acari, Collcmbola and
ground-truth the results from the initial assessment to Mollusca a lower taxonomic precision was used in
ensure that we can have confidence in the findings. some cases.
Advice and infonnation on how to assess a site for the
presence of OMHPDL to ensure that Local/Planning Of the invertebrate species collected during survey
Authorities and Government Agencies can identify work 75 have not been recorded from the Falkirk area
areas ofOMHPDL on ‘new’ sites in the future will also before. A number of these species are common and
be prepared. Future phases ofthe project will promote widespread in Britain including the green tiger beetle
the management of brownfield sites for biodiversity {Cicindela campesths) and violet ground beetle
and provide guidance on tools for mitigation in (Carabus violaceus), the field digger wasp (Mellinns
developments such as green and living roofs, and off- an>ensis) and maiTam spider (Tihellus mariti/niis).
site habitat creation. Results show that 44 of the 72 species of beetle
The ‘All of a Buzz in Scotland’ project will produce recorded during survey work have not been recorded in
much-needed evidence and support for planners and Falkirk before. The reason why there are no records for
developers, enabling them to plan and implement many species, particularly beetles, may be due to the
developments in an environmentally sustainable way. lack of a local biological records centre for the area,
It will also promote more natural habitats, native plant although there are relatively few active entomologists
species, and a ‘less tidy’ approach to land management in the area.
both within developments and in the wider urban
landscape. The diversity of invertebrate species collected clearly
shows the importance ofbrownfields in Falkirk. As an
FALKIRK’S BROWNFIELDS example, the brownfield at CaiTon Works (Forge Dam)
Buglife has recently undertaken a more detailed is particularly important due to the high diversity of
investigation ofthe invertebrate diversity ofbrownfield plants and wildlife, especially the invertebrates that
sites in the Falkirk area (Baimer and Macadam, 2011). were recorded. Four invertebrate species collected at
An assessment ofthe habitat on each ofthe 76 sites in this site are considered rare or scarce in Scotland:
the Scottish Vacant and Derelict Land Register for • The comb-footed spider Anelosimus vittatus
Falkirk was undertaken during May 2010. Details of (Theridiidae) is widespread and common in
each site were recorded using Buglife’s brownfield England and Wales although there are only a few
habitat assessment fonn and included current activity, records in Scotland.
the vegetation type, plant species diversity and • The hobo spider Tegenaria agrestis (Agelenidae)
abundance. Photographs were taken on each site for is a brownfield specialist and was previously only
future reference. Potential invertebrate species known from five locations in Scotland (Bo’ness,
diversity was estimated as low, medium or high for Grangemouth, two locations in Edinburgh and
each site based on plant abundance and plant species near Dingwall in the Highlands).
diversity on the site as well as the presence ofa mosaic • The Nationally Scarce (Notable B) ground beetle
of habitats, including bare ground, scrub and mixed Amara praetermissa (Carabidae) was recorded in
grassland and herbs. Bo’ness in the 1980s and during field work three
individuals were collected from Can'on Works.
From the sites on the register, 19 were chosen as being This represents only the second record of this
important forinvertebrates. species in Scotland.
Invertebrate survey work was undertaken on 14 of • The rare (RDB3) solitary bee Andrena ruficrus
these sites. The remaining sites from the register (Andreninae) has previously not been recorded
OMHPDL
fitting the criteria were visited for from Falkirk.
assessment purposes but no invertebrate survey work
was possible due to access restrictions. In addition CONCLUSIONS
invertebrate surveys were also undertaken at two other Open mosaic habitats with vaiying stages of natural
sites which are not on the vacant and derelict land succession are scarce in the over-managed and fanned
register, but have been previously recognised as fitting countryside. In an urban setting brownfields can be
the criteria forOMHPDL. used as ‘stepping stones’ to allow movement and
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mixing ofanimals and plants across an area (Macadam, ACKNOWLEDGEMENTS
2011). Due to natural succession at these sites, Buglife would like to thank Scottish Natural Heritage
brownfields arc transitory habitats and if left un- and the Central Scotland Green Network for funding
managed they have a typical lifespan of between 15 the first phase ofthe ‘All ofa Buzz Scotland’ project.
and 20 years (Key, 2000; Bodsworth et al. 2005). This We would also like to thank BTCV for the opportunity
is not necessarily a problem as new 'brownfield’ sites to host aNatural Talent apprentice.
are always being created. The transitoiy nature of
these sites means that the extent of this habitat will REFERENCES
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for biodiversity can not only deliver suitable habitat for biodiversity in Falkirk. Forth Naturalist and
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