JANUARY 2019
INTRODUCTION
The purpose of this report is to assess the potential impact on biodiversity of proposals to develop a building for the storage of equipment on a small area of land within the Memorial Woodlands site.
METHODS
Extended Phase 1 Surveys, covering vegetation types and plant species, birds and badgers, were carried out on 4th December 2018 and 28th January 2019. Habitat value for other protected species was assessed; in particular the potential of trees around the site for roosting bats was checked using binoculars where necessary.
Data previously provided by Bristol Regional Environmental Records Centre (BRERC), who provided details of designated sites, protected species and notable species recorded within 1km of the survey site, was consulted.
A number of previous surveys have been carried out at Memorial Woodlands. These include a survey of the whole site, carried out in 2012, and surveys of areas to the south and east of the current survey site, carried out in 2015, 2017 and 2018. Data from these surveys were also used to inform this report.
SURVEY RESULTS
Site Description
The survey site largely consists of bare, muddy ground, with a fringe of tall rough grassland and areas of ruderal vegetation on spoil mounds. There are hedges to the north-east and south-west of the site and an area of plantation woodland to the west. Neither the application site nor any adjacent area has any nature conservation designation.
The 2012 survey found species-poor unmanaged grassland here.
Vegetation
Much of the area is unvegetated.
Fringes of tall grassland on the margins of the site are dominated by false oat-grass (Arrhenatherum elatius), perennial rye-grass (Lolium perenne) and creeping bent (Agrostis stolonifera). Other grass species here are timothy (Phleum pratense), rough-stalked meadow-grass (Poa trivialis), Yorkshire fog (Holcus lanatus) and cocksfoot (Dactylis glomerata). The only herb species recorded here were creeping buttercup (Ranunculus repens), curled dock (Rumex crispus), common chickweed (Stellaria media), goosegrass (Galium aparine) and creeping thistle (Cirsium arvense).
Spoil mounds in the western part of the area have ruderal vegetation with creeping bent and rough-stalked meadow-grass, and herb species including common burdock (Arctium minus), stinging nettle (Urtica dioica), teasel (Dipsacus fullonum), spear thistle (Cirsium arvense), charlock (Sinapis arvensis) and goosegrass.
The hedge to the north-east of the site is c4m wide and c5m wide, with semi-mature pedunculate oak (Quercus robur) and immature ash (Fraxinus excelsior) trees. Other woody species in the hedge are hawthorn (Crataegus monogyna), blackthorn (Prunus spinosa), elder (Sambucus nigra) and bramble (Rubus fruticosus agg). All of these species occur in a 30m length of the hedge. There is a hedge bank, and ground flora species include greater stitchwort (Stellaria holostea), red campion (Silene dioica), dog’s mercury (Mercurialis perennis) and wood false-brome (Brachypodium sylvaticum). A ditch runs alongside the hedge; it does not hold water and no wetland species were recorded here.
The hedge to the south-east is c7m tall and c4m wide with three semi-mature pedunculate oak trees. Other woody species are ash, hawthorn, field maple (Acer campestre), english elm (Ulmus procera), dogwood (Cornus sanguinea), blackthorn and bramble. All of these species occur in a 30m length. There is a hedge bank, and ground flora species include hart’s-tongue fern (Phyllitis scolopendrium), male fern (Dryopteris filix-mas), soft shield-fern (Polysytichum setiferum) and red campion. A ditch runs alongside the hedge; it does not hold water; hemlock water-dropwort (Oenanthe crocata) and angelica (Angelica sylvestris) were recorded here.
The woodland to the north-west is a plantation, with mixed native species dominated by ash and pedunculate oak. The understorey is dominated by bramble, with smaller quantities of other species including hawthorn and elder (Sambucus nigra). The ground flora is dominated by ivy (Hedera helix), with species present in smaller quantity including cow parsley (Anthriscus sylvestris), cuckoo-pint (Arum maculatum) and hedge woundwort (Stachys sylvatica).
Birds
No birds were present on the site itself. The following were seen in adjacent areas.
Hedge to north-east: Blackbird, blue tit, great tit, robin and song thrush.
Hedge to south-east: Blackbird, chaffinch, dunnock, fieldfare, redwing and woodpigeon.
Woodland to north-west: Blackbird, blue tit, buzzard, chaffinch, dunnock, goldfinch, great tit, long-tailed tit, magpie, redwing and woodpigeon.
Protected Species
Badger is present on the wider Memorial Woodlands site, but no evidence of badger activity was seen on or around the application site.
A reptile survey was carried out in 2017 on land approximately 25m to the east; no reptiles or amphibians were recorded during this survey.
Further details are given in the Assessment section below.
ASSESSMENT
The nature conservation value of the various habitats on the site has been assessed in order to determine whether they are of nature conservation value in a national, regional, or county context, are of either high or low value in a local context, or are of minimal nature conservation value. The assessment has used standard ecological criteria, including diversity, rarity, fragility and recreatability. Reference has been made to suitable guidance, including the UK Biodiversity Action Plan and South Gloucestershire BAPs and the 1997 Hedgerow Regulations. The value of groups not surveyed, such as most invertebrates, has been assessed using information gathered on the nature and structure of the habitats present.
The timing of the survey means that breeding birds, invertebrates and hedgerow ground flora could not be fully surveyed. This has been taken into account in assessing the site.
Habitats
Most of the application site currently lacks vegetation. When it was surveyed previously, in 2012, it had species-poor grassland. This grassland lacked any species indicative of unimproved grassland, or otherwise of nature conservation significance, and all of the species recorded here are common and widespread. This continues to be true of the rough grassland on the fringes of the site, and of the ruderal vegetation on the spoil mounds. No features that suggest significant value for invertebrates are present.
The application site is of minimal nature conservation value.
Both of the hedges surveyed are moderately diverse in woody species, and include semi-mature trees. The ground flora of both hedges includes species indicative of ecological continuity. Both hedges qualify as Important Hedges under the 1997 Hedgerow Regulations. Diversity is added by the presence of hedge banks and dry ditches. The hedges form part of a wider network of hedges, and contribute to ecological connectivity across the surrounding area.
Both hedges are of high nature conservation value in a local context.
The plantation woodland is of recent origin and therefore lacks features associated with ancient woodland. It is, however, dominated by native species and has the potential to develop further ecological value as it matures. The diversity of birds recorded here is good, although all of the species are widespread and common. The woodland lacks any feature indicative of significant value for invertebrates.
The woodland is of nature conservation value in a local context.
Protected Species
No signs of badger activity were seen around the survey site.
The site is largely unvegetated, and therefore unsuitable for reptiles and as a terrestrial habitat for amphibians. A 2017 survey of apparently more suitable habitat within 30m of the site did not find either reptiles or amphibians. There are no records of great crested newt in the surrounding area.
Two of the oak trees in the hedge to the south-east have low to moderate potential for roosting bats, in the form of dense growths of ivy and crevices behind loose bark. The hedges and the woodland edge are likely to be used by foraging and commuting bats; other parts of the site do not have potential for bats.
The site is not of potential value for any other protected species.
IMPACTS
The proposed development involves the construction of a portal framed storage building, with a footprint of 15m x 25m, in order to store equipment used for management of the wider site. Vehicular access to the building will be through a former gateway at the south-eastern end of the north-eastern hedge.
There are no potential impacts, either direct or indirect, on any designated site.
The area that will be affected by the building currently consists of unvegetated soil, and previously supported species-poor grassland. The area is of minimal nature conservation value and construction of the building will not have any significant ecological impact.
The former gateway that will be used for vehicular access is overgrown with bramble, hawthorn, blackthorn and old man’s-beard (Clematis vitalba), which have colonised the gateway in the last twenty years. The loss of this vegetation will have a very minor adverse impact. The effect on connectivity will be very minor, as taller shrubs to either side of the entrance will maintain a good degree of connectivity across the breach. Mitigation will be required to avoid potential impacts on nesting birds when the entrance is created.
There will be no impacts on protected species. The building will not be lit, and the foraging opportunities provided by the hedges and the woodland edge will remain.
There are no other potential impacts on protected species.
The hedges are potentially vulnerable to adverse impacts arising from incidental damage during construction.
MITIGATION
Due to the low level of potential impacts there are few requirements for mitigation.
In order to prevent the destruction of active birds’ nests, which are protected by law, any removal of woody vegetation including bramble should take place during the period 1st September to 28th February. If this is not possible then the area should be checked by an ecologist before works commence. If active nests are found then works in the area (as defined by the ecologist) should cease until a further check has shown the area to be free of active nests.
Hedges and trees around the working area should be protected during construction works in order to avoid incidental damage. Where plants have to be cut back, for instance where the access point is formed, then they should be cut back using sharp hand tools to leave a clean wound.
