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Ecological Scoping Report 2009 Portswood Community Wildlife Garden The following document comprises an ecological scoping report for the proposed re-development of the former Portswood Diagnostic Unit. The re-development would entail a conversion to a local community wildlife area which would maximise the ecological potential and biodiversity of the site. The community wildlife area would provide an aesthetically pleasing space that would be easy to maintain and accessible for all residents from the surrounding area to enjoy. Toru Tsuzaki Ecologist Report No: PCG001

NBSP Community Group - Porposal for a wildlife garden

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NBSP Community Group - Final Proposal that was submitted to Southampton City Council

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Page 1: NBSP Community Group - Porposal for a wildlife garden

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The following document comprises an ecological scoping report for the

proposed re-development of the former Portswood Diagnostic Unit.

The re-development would entail a conversion to a local community

wildlife area which would maximise the ecological potential and

biodiversity of the site. The community wildlife area would provide an

aesthetically pleasing space that would be easy to maintain and

accessible for all residents from the surrounding area to enjoy.

Toru Tsuzaki

Ecologist

Report No: PCG001

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Contents

Introduction................................................................................................................................3

Background.................................................................................................................................3

Aims and Objectives....................................................................................................................4

Description of Site.......................................................................................................................4

Baseline Conditions.....................................................................................................................4

Conservation Designations..........................................................................................................5

Outline Design.............................................................................................................................6

Natural Pond...............................................................................................................................6

Hedge and Fencing......................................................................................................................7

Protected Hornbeam trees (Western border)..............................................................................8

Planted Orchard (North eastern corner) ......................................................................................8

Barbeque area (North western corner)........................................................................................9

Semi-natural grassland and wild flower area ...............................................................................9

Footpaths..................................................................................................................................10

Other Environmental Considerations.........................................................................................10

Conclusion ................................................................................................................................11

Potential Issues .........................................................................................................................11

Reference .................................................................................................................................12

Appendix 1................................................................................................................................13

Appendix 2................................................................................................................................14

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Introduction

Background

Toru Tsuzaki was invited by Mr R. Persaud of Portswood Community Group on the 24th

October 2009 to design and advise on the creation of a community wildlife area on the

former site of the Portswood Diagnostic Unit, Brickfield Road, Portswood, and

Southampton. The site location is presented in Figure 1

Figure 1: Aerial photograph of the site showing its current condition

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Aims and Objectives

The aim of this report is to suggest ecological improvements to the site that could be pursued

with the view to improving community amenities and providing an education resource which

would benefit the local educational establishment.

Description of Site

A site walkover was conducted on the 27th

October 2009. The site consisted of approximately

2600 square meter of rank grassland. The site is bordered on three sides by a mixture of

bramble, shrub and trees, beyond these by roads. The southern part of the site is bordered by

fencing that backs onto residential properties.

A small area in the north-east corner of the site is covered in an asphalt surface, which was in

good condition. The site appears undeveloped since the removal of the diagnostic centre,

leaving no obvious evidence of any structural drainage systems such as a soakaway.

The site is surrounded by residential development mainly of Victorian terrace housing. At the

western side of the site there is a primary and pre-school development (Portswood primary

school, Somerset Road).

The site was formally a diagnostic unit which consisted of prefabricated units that were not a

permanent fixture to the site. The only evidence of these units is in the form of a concrete

foundation which occupies a 500 m2 area in the north east corner of the site.

The site has been regularly used for fly tipping. Southampton Council however, has recently

cleared the area of fly tipped material in September, 2009. Furthermore, there did not appear to

be any obvious contamination across the site during the geomorphological survey (Bureau

Veritas, 2007).

Baseline Conditions

Ecological baseline surveys were carried out by Ecology and Planning and Research (EPR) to

assess the wildlife value of the site. The site was evaluated as having a low to negligible value for

wildlife other than a population of slow worm (Anquis fragilis). However, due to the sub-optimal

time of year that the initial survey was undertaken it was not possible to ascertain a fully

informed evaluation. A further targeted reptile and botanical survey was carried out in May and

June 2007. The only species of reptile found was a “good population” of slow worm.

The Ecological consultants ECOSA were contracted to capture and translocate the slow worm in

accordance with the recommendations of EPR in their final mitigation strategy report. This work

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was completed in September/October 2008 and slow worm were translocated to Manor Farm

Country Park to the east of the city.

An addendum to the Ecological Survey was prepared in August 2007 assessing the possible

presence of great crested newt (Triturus cristatus). It was concluded that they are likely to be

absent and subsequently this was confirmed when none were found when the site was

surveyed. The grassland was assessed as having limited ecological value with low botanical

diversity.

Since post war clearance of the site, several trees have been planted and a group of three

hornbeam (Carpinus betulus) on the Somerset Road frontage have been recently subject to a

Tree Protection Order – The Southampton (Portswood Primary School) Tree Protection Order

2007. These are the only trees that are required to be retained on site. However, there may be

other trees on site which can be retained such as the beech (Fagus sylvatica) hedge or at least

some of it, along the Northcote Road/Brickfield Road frontage might also be incorporated as a

retained feature.

Conservation Designations

Southern Hampshire is one of the most bio-diverse counties in the UK. Britain's most valuable

wildlife habitats are designated as Sites of Special Scientific Interest (SSSIs) and protected by

law, they cover 14.5% of the county, about twice the national average. A further 8.7% of

Hampshire is covered by Sites of Importance for Nature Conservation (SINCs) (Hants 2009).

Outside of these specifically recognised areas much of Hampshire's rural landscape, and many

urban areas, are also rich in biodiversity.

However, many wildlife areas have been replaced by the built environment or become degraded

through changes in land management, and many species have declined or disappeared.

The study area is surrounded by valuable conservation sites, such as the internationally

important River Itchen Special Area of Conservation (SAC) (2km south), Southampton Common

SSSI (1.5Km west) and Itchen Valley Nature Reserve (2Km east).

In response to commitments outlined by the Rio Convention on Biological Diversity, the UK

Biodiversity Action Plan (UK BAP) was created. The plan outlines action for many species and

habitats of conservation importance or concern at the national level and can be viewed at

www.ukbap.org.uk.

In addition to having national priorities and targets, action for biodiversity is also taken at a local

level. The local biodiversity action plan (LBAP) for Hampshire’s has local priorities for wildlife

that are of conservation concern or importance. A list of these species and habitats can be

viewed at http://www.ukbap.org.uk/lbap.aspx?ID=451.

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Hedgehog (Erinaceous europaeus) listed as a UKBAP priority species could potentially benefit

from the proposed community wildlife area.

In addition species listed in the LBAP list that could also potentially benefit include great crested

newt, Pipistrelle bat (Pipistrellus pipistrellus), bumblebees (Bombus spp), butterflies and moths

(Rhopalocera and Heterocera).

Outline Design

The following sections comprise the design for improving the ecological value of the site by

creating habitat to encourage local wildlife.

The outline design is included in Appendix A.

Natural Pond

A pond would be constructed at the southern corner of the wildlife area. The pond is designed

to be approximately 50 square meters. The ground is predominantly clay (Bureau Veritas, 2007)

which would negate the use of a pond liner. The margins are to be of shallow depth to

accommodate marginal macrophytes of native variants such as water mint (Mentha aquatica)

and water forget-me-not (Myosoitis scorpioides) which are ideal marginal plants for newts to lay

their eggs. No rushes or reeds should be planted here to avoid mono-speciation of the pond.

The deeper section of the pool can be planted with native oxygen providers such as Hornwort

(Ceratophyllum demersum) and water starwort (Callitriche hermaphroditica). Traditional

oxygenators such as Canadian pondweed (Elodea canadensis) and curly waterweed

(Lagarosiphon major) should be not be introduced to the pond as they are non-native and will

quickly take over the pond. It is important that these plants are not added to avoid expenditure

on maintenance and extensive management during growth seasons. For a full list of plant

species that can be added to the pond see appendix 2.

The pond will have two wooden platforms from which the local education authority could utilise

as pond dipping areas. The surrounding vegetation around the pond (approx. 1m) will remain

untouched providing valuable refuges for amphibians and reptiles and aid in the colonisation of

the pond. Spoil material from the pond can be used to level out other areas of the community

wildlife area negating the need for removal of material from the site. Any trees which may need

removing can be cut into smaller pieces which can be put around the pond to form suitable

reptile hibernaculum.

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Figure 2: A natural pond

Hedge and Fencing

The hedges and fencing surrounding the site will be left in similar condition. Avoiding panel

fencing, would allow organisms to travel through the border with little hindrance. Extra planting

of brambles throughout the borders would provide extra fruit for birds and habitat for

terrestrial invertebrate. The grass within the first 4m border will remain unmowed to form a

rank grassland fringe, which will provide suitable refuges for insects, amphibians, reptiles, small

mammals. The rank grass borders will also provide cover allowing them to move around the site.

Figure 3: Bramble hedging with unmanaged vegetation border

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Protected Hornbeam trees (Western border)

The three hornbeam trees to the west of the site will remain through the tree preservation

order (CBA Trees, 2007). The trees are well established and further improvements can be made

by the installation of bat and bird nest boxes. Bats in particular need a range of roosting sites,

for resting during the daytime in summer, hibernation during winter and as maternity sites.

Providing sites for bats could potentially benefit one of the species listed in the Hampshire LBAP.

Figure 4: Bat boxes on an old oak tree

Planted Orchard (North eastern corner)

The east side of the wildlife area would be planted with orchard cultivar fruit trees including

apples, pears, cherrys and plums, many of which are now becoming rare throughout the UK.

The common apple (Malus domestica) is easy growing and comes in many varieties which

provide a stable crop year after year.

Worcester Black pear (Pyrus communis var Black Worcester) has been around since the 1960s

however the loss of English orchards since 1970s has seen a gradual decline in the species.

Wild Cherry (Prunus avium) is edible from the tree and is fairly hardy species. Attracting bird life

during the autumn and many insects drawn by the sweet juices during the summer.

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Plums (Prunus domestica ssp domestica) are fairly hardy and tolerant of a wide range of

environmental conditions.

Figure 5: Orchard with a variety of fruit trees

The individual species of tree will provide a yield of fruit at different times of year and

depending on the varieties different fruits will be available through spring to autumn.

Additionally the public can pick the fruit and the wildlife will benefit, attracting insects and wild

birds. During the winter the bare trees can be used to hang bird feeders from which would

attract over-wintering birds and squirrels.

Any pruning or material removed from the tree during maintenance can be placed around the

pond area or in distinct piles away from the public barbeque corner. These would generally be

used as hibernacula for reptiles and small mammals during the winter and cover for birds. The

tree cuttings will also provide a nutrient source for saprophytes such as fungus and species of

invertebrate.

Barbeque area (North western corner)

The original scope suggested a barbecue area to the north western corner of the site . This

would provide an area for the public to rest and to enjoy the wildlife area.

Semi-natural grassland and wild flower area

Semi natural grassland will be maintained for the majority of the year in the southern half of the

wildlife area. Depending on the species present the grassland would benefit from the sewing of

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a wild meadow mix of plant seeds that are of local provenance and prefer a pH of neutral to

alkaline. Bureau Veritas (2007) found pH at the site to be between the levels of 7.1 and 7.8. This

would bring in much needed wildflower/ rough meadows which will help sustain moths,

butterflies, bumblebees which are all species in decline due to habitat loss. This habiat is also

important for slow worm, which have been previously found on site (ECOSA, 2008a; ECOSA,

2008b), other reptiles which would use these areas as a refuge along with the habit piles during

the evening.

Figure 6: Semi natural grassland with a high diversity of plants from ribwort to buttercup

Footpaths

There would be one footpath across the site running from west to east which would be

comprised of concrete or asphalt surface. This would provide a convenient path for the public to

negotiate the wildlife area. Another pathway would run from the south west to the centre of

the park and will consist of a mown lawn pathway to allow passage of organisms to various

areas of the wildlife area.

Other Environmental Considerations

• Hibernaculum would be constructed from chopped wood and brash from any trees

felled on site. Wood from other sites can also be used to create hibernation areas for

amphibians, reptiles and small mammals such as hedgehog. The dead wood piles would

also provide habitat for fungus and wood boring insects.

• A survey of the grasses and flowers could be undertaken during the year to assess the

already existing flora therefore targeting specific species which would be beneficial for

insects and therefore promoting diversity.

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Conclusion

This environmental report highlights the opportunity to improve the ecological potential of the

site through sensible and low maintenance design of the wildlife area. The following section

highlights the benefits of such a wildlife area design and such they include:

• improve the conservation value of the area, through increased bio-diversity and

encourage LBAP targets to be reached;

• improving the public perception of wildlife and nature conservation;

• low expenditure of capital to maintain site;

• low carbon footprint design;

• can be used as an educational resource to promote ecology to the younger generation;

and

• Easily accessible for the public and a sensible public amenity which can be enjoyed by all

generations.

Potential Issues

A previous report by Bureau Veritas (2007) highlighted heavy metal contamination at this site

which may be residual from former use of the site. This may need thorough investigation before

commencing any work highlighted in this report;

If high value conservation species such as bats and great crested newts start to occupy the area

this may impact on local planning and potentially impact property values through restrictions;

May require residents to have greater vigilance on the site to ensure that fly tipping and

dumping does not occur again; and

Suitability of the site with regards to ground contamination and an underground watercourse is

still ongoing as of Dec 2009. This is due to be verified in early 2010.

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Reference

Bureau Vista (2007) Former Portswood Diagnostic Unit, Borehole/Ground Site Investigation

Report, Southampton City Council, Report No. LSOX0353/AJC/R1/REV0

CBA Trees (2007) Former Portswood Diagnostic Unit, Tree Survey Report, Southampton City

Council, Report No. CBA6715

ECOSA (2008a) Portswood, Slow Worm Population Assessment and Mitigation Strategy, EPR,

Draft Report – September 2008

ECOSA (2008b) Portswood Primary School, Report on Reptile Translocation, Final Report -

December 2008

UKBAP (2009) Local Biodiversity Action Plan for Hampshire

http://www.hampshirebiodiversity.org.uk/hampshire%20BAP.html [accessed Nov 2009]

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Appendix 1: Site map with proposed ecological improvements

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Appendix 2: Native plants associated with ponds, marginal and boggy grounds

Boggy Area around the pond

Bird's Foot Trefoil, Greater Lotus pedunculatus

Great Burnet Sanguisorba officinalis

Meadow Buttercup Ranunculus acris

Brooklime Veronica beccabunga

Cuckoo Flower (Lady's Smock) Cardamine pratensis

Fleabane Pulicaria dysenterica

Hemp Agrimony Eupatorium cannabinum

Purple Loosestrife Lythrum salicaria

Yellow Loosestrife Lysimachia vulgaris

Marsh Marigold Caltha palustris

Meadowsweet Filipendula ulmaria

Pendulous Sedge Carex pendula

Greater Pond Sedge Carex riparia

Ragged Robin Lychnis flos-cucul

Water Forget-me-Not Myosotis scorpoides

Water Mint Mentha aquatica

Marginals

Creeping Jenny Lysimachia nummularia

Water Figwort Scrophularia auriculata

Gypsywort Lycopus europaeus

Marsh St John's Wort

Square Stalked St John's Wort

Hypericum elodes

Hypericum tetrapterum

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Pendulous Sedge Carex pendula

Pennyroyal Mentha pulegium

Yellow Flag Iris Iris pseudoacorus

Brooklime Veronica beccabunga

Purple Loosetrife Lythrum salicaria

Marsh Marigold Caltha palustris

Water Forget-me-not Myosotis scorpoides

Water Mint Mentha aquatica

Oxygenators

Rigid Hornwort Ceratophyllum demersum

Water Starwort Callitriche hermaphroditica

Water Violet Hottonia palustris

Marsh Pennywort Hydrocotyle vulgaris

Ivy Leaved Water Crowfoot Ranunculus hederaceous

Mare's Tail Hippuris vulgaris