Introduction
Geographic Frame of Reference
Designated Sites and Features
Designated sites
Tree Preservation Orders TPOs
Important Hedgerows (England and Wales only)
Biodiversity Value
Valuing Habitats
Valuing Species
Potential value
Secondary or Supporting Value
Social Value
Economic Value
Legal Issues
Legally protected sites and species
Injurious and legally controlled weeds
Multi-functional Features
3.1 This chapter provides guidance on how to assign values to ecological features and resources, including those that have been designated for their nature conservation interest.
3.2 The Guidelines encourage an approach to valuation that involves teasing apart the different values that can be attached to ecological features. The values that are identified are biodiversity value, social/community value and economic value. Legal protection needs to be considered separately from value. Features that are important for social/community or economic reasons should be identified as part of the assessment of the socio-economic or community effects of a project. The impacts on these features should be assessed by the ecologist but the significance of the impacts will then be determined by the socio-economic/community specialist.
3.3 The value that is attached to an ecological resource influences:
3.4 Guidance on EcIA tends to set out categories of ecological or nature conservation value that relate to a geographical framework (e.g. international, local) together with examples of the ecological features or resources that qualify for each category. It is generally straightforward to evaluate designated sites against these categories (e.g. SSSIs or ASSIs are of national importance); although for sites of local value these may not be predetermined. The same problem often applies to evaluating habitats and species (although there are exceptions, e.g. recognised ways of defining internationally/nationally important populations of waterfowl).
3.5 Attempts were made during the development of the new Guidelines to define how habitats and species could be assigned to different levels of value. However, such definitions proved to be unworkable in that they cannot accommodate all of the factors that should influence the definition of value, for example in relation to the size or conservation status of species populations or, for habitats, their quality. Furthermore, the value of a species population or a habitat area may change depending on whether it is being assessed, for example, in the south of England or the north of Scotland. Consequently, tabulated boundaries between different categories of value become difficult to define with precision.
3.6 The Guidelines therefore propose an approach to valuing features that involves professional judgement based on available guidance and information, together with advice from experts who know the locality of the project and/or the distribution and status of the species or features that are being considered. The remainder of this chapter summarises key considerations to take into account when applying professional judgement to assign values to ecological features and resources.
3.7 The value or potential value of an ecological resource or feature should be determined within a defined geographical context. It is recommended that the following frame of reference be used (or be adapted to meet local circumstances):
3.8 In some EIAs (or other integrated assessments), the ecologist may be required to use other approaches to assigning levels of value (in order to be consistent across different technical subjects). In such cases, it is often helpful for the prescribed terms to be translated into the geographical scale that is set out above, so that the legal and policy consequences of any significant impact can be clearly understood by all ecologists. This is illustrated in the Transport Analysis Guidance example on the web.
3.9 Some sites have already been assigned a level of nature conservation value through designation, a list of which can be found on the Protected Sites Designations Directory32 The reasons for this designation need to be taken into account in EcIA. Key published guidance on selecting designated sites is included in Box 10.
Box 10: Key guidance on selecting designated sites
3.10 The World Heritage Convention40 (WH) (adopted by UNESCO in 1972) was ratified by the UK in 1984. The Convention provides for the identification, protection, conservation and presentation of cultural and natural sites of ‘outstanding universal value’, and requires a WH List to be established under the management of an inter-governmental WH Committee. World Heritage Sites (WHS) that are included in this List may therefore be of international importance for their biodiversity. Some WHS may be designated for their other natural attributes or cultural heritage with no direct implications for their biodiversity value. Where this is the case, their biodiversity value should be determined on the basis of any other designations or attributes. However, sites designated by UNESCO as Biosphere Reserves (e.g. Braunton Burrows, North Norfolk Coast, Dyfi estuary, Beinn Eighe) are of international importance for the conservation of biodiversity41.
3.11 Internationally important sites include: SACs, SPAs and Ramsar sites. Candidate SACs, potential SPAs and proposed Ramsar sites should be given the same consideration as designated sites.
3.12 Nationally important sites are designated as SSSIs in England, Scotland and Wales or as ASSIs in Northern Ireland. They may also be designated as National Nature Reserves.
3.13 Local Authorities and The Wildlife Trusts have designated sites that are recognised as of importance at regional/county, district/borough, etc. levels. Whilst a variety of terms are used to describe these sites, they are now generally referred to collectively as Local Sites42.
3.14 Where a feature has value at more than one level, its overriding value is that of the highest level. For example, a site designated both as an SPA for internationally important features and as an SSSI for nationally importance features should be considered as being internationally important. The features for which the site has been designated at each level may differ and should be valued accordingly. Features of the site that are not the reasons for its designation(s) should be assessed and valued according to their intrinsic value.
3.15 It is possible that ecologists undertaking EcIAs may identify areas that are not currently designated, but that they consider would meet the criteria for designation in a particular geographical context. Conversely, there may be occasions when a site is no longer considered to meet the criteria for designation. Where the latter relates to nationally designated sites (i.e. SSSIs, ASSIs), it is important to remember that, unless a site is formally 'denotified', the designation still applies and the Government has legal and policy obligations to ensure the site is restored to favourable condition. In the case of non-statutory sites, the potential to recreate the lost interest must be taken into consideration (paragraphs 3.40 - 3.42). In both sets of circumstances, ecologists should explain their rationale fully in the EcIA and if possible discuss their conclusions with the relevant designating authority. If it is agreed by the relevant designating authority that the site merits a different designation, this should be reflected in the assessment. If agreement cannot be reached, the issues must be explained fully in the EcIA. Where there is doubt, a conservative approach should be taken and the current designated value used.
3.16 TPOs can be applied to all types of trees, including hedgerow trees, but not to hedges, bushes or shrubs. A TPO can be applied to one or more trees, an area of trees, or woodland. TPOs are used by Local Planning Authorities (LPAs) to protect selected trees and woodlands if their removal would have a significant impact on the local environment and its enjoyment by the public. LPAs are advised to develop ways of assessing the ‘amenity value’ of trees in a structured and consistent way, taking into account the following key criteria43:
3.17 These amenity-related criteria do not incorporate any specific consideration of ecological value. The ecological value of trees with TPOs should therefore be assessed independently of their designation, using the criteria that are discussed later in this chapter for use in relation to other habitats/habitat features, or within the context of the value of any species that they support. The legal issues relating to TPOs are often addressed in landscape and visual assessments, but ecologists should be aware of the legal protection that they provide. Scotland44 and Wales45 have separate guidance.
3.18 The Hedgerows Regulations 199746 provide arrangements for LPAs in England and Wales to protect important hedgerows by controlling their removal through a system of notification. To be 'important', as defined under the Regulations, all or part of the hedgerow must have existed for 30 years or more, and meet at least one of the criteria in Part II of Schedule 1, which is divided into 'Archaeology and history' and 'Wildlife and landscape'. The Hedgerow Survey Handbook47 is available from Defra and is on the English Nature website.
3.19 The removal of any hedgerow to which the Regulations apply is permitted if it is required for carrying out development for which planning permission has been granted (and in other circumstances as set out under Regulation 6). Thus the notification system does not apply to many of the situations in which EcIAs are carried out. Nevertheless, the Handbook and the Regulations can be useful for valuing hedgerows within the context of EcIAs (the appendices contain 'standard' blank field survey forms as well as a form for a Hedgerow Regulations survey).
3.20 There are various characteristics that can be used to identify ecological resources or features likely to be important in terms of biodiversity. These include:
3.21 Consultation, especially with local specialists, can be crucial for identifying less obvious important resources and features.
3.22 The relative ecological importance of different ecological features and resources in the landscape may also change in response to changing conditions. For example, climate change could increase the need for large-scale habitat networks that are designed to facilitate movement of species through the landscape to colonise suitable areas.
3.23 The following sections explain in more detail how the relative value and importance of ecological resources and features can be determined.
3.24 The value of areas of habitat and plant communities should be measured against published selection criteria where available. For example, Annex III of the EC Habitats Directive sets out the criteria for selecting sites eligible for identification as sites of Community importance and designation as SAC. The Guidelines for the selection of biological SSSIs48 set out criteria for habitats or plant communities to be designated as being of national importance. Some Local Authorities and Wildlife Trusts have prepared criteria for the selection of Local Sites. Where areas of a habitat or plant communities do not meet the necessary criteria for designation at a specific level, the ecologist may consider the local context if appropriate, but should take into account potential value (paragraphs 3.38 - 3.40).
3.25 Habitat Action Plans (HAPs) have been developed for numerous habitats as part of the UK Biodiversity Action Plan (BAP) and of other BAPs, (e.g. local BAPs and organisational BAPs such as that produced by British Waterways for the inland waterway network). Those habitats considered to be particularly vulnerable are identified as 'priority habitats'. The statutory basis for priority species and habitats listed in the UK BAP is explained in Box 11.
Box 11: The statutory basis for the definition of priority species and habitats
The statutory basis for species and habitats listed in BAPs is currently provided by Section 74 of the Countryside and Rights of Way (CRoW) Act 2000 in England and Wales, but this will be superseded by Section 41 of the Natural Environment and Rural Communities (NERC) Act 200649. The NERC Act 2006 requires the respective Secretaries of State for England and Wales to publish lists of the living organisms and types of habitat, which in their opinion are of principal importance for the purpose of conserving biodiversity. Before publishing any list the Secretaries of State must consult Natural England and the Countryside Council for Wales as to the living organisms or types of habitat to be included in the list.
The habitats and species in Section 74 are those that the Secretary of State, following consultation with English Nature, considers are of principal importance for the conservation of biological diversity in England50, in accordance with the 1992 UN Convention on Biological Diversity51. HAPs and SAPs under the UK Biodiversity Action Plan are already in place or under preparation for all the listed habitats and species. The Biodiversity Strategy for England52 sets out the means, by which the Government will comply with its duty under Section 74 and to take steps, or promote the taking of steps by others, to further the conservation of the listed habitats and species, including through the continued implementation of the Action Plans.
The Section 74 List for Wales53 is published and differs from the England list in that it omits species that are extinct in Wales, or have never occurred, and adds a few distinctively Welsh ones.
Scotland’s Biodiversity: It’s in Your Hands sets out a strategy for the conservation and enhancement of biodiversity in Scotland54. The Scottish Biodiversity List55 is a list of species and habitats considered to be of principal importance for the purpose of biodiversity conservation in Scotland.
The Wildlife (Northern Ireland) Order 1985 is currently under review. It is proposed to include a statutory requirement for government departments and public bodies to further the conservation of biodiversity and for the Department of Environment to publish and regularly review a list of priority habitats and species considered to be of importance for biodiversity conservation.
3.26 The purpose of HAPs is to guide conservation action for the habitats concerned. That a HAP has been prepared should simply reflect the fact that the habitat concerned is in a sub-optimal state (and hence that action is required). It does not imply - and was never intended to imply - any specific level of value for the habitat. The value of any area of habitat covered by a HAP should therefore be determined on the basis of its intrinsic characteristics using the same approach as with other habitats.
3.27 The only exception to this should be where a HAP states that all areas of a particular habitat should be protected, as is often the case for priority habitats. In such cases, ecologists may decide that it is appropriate to treat applicable areas as being important at the level of the BAP in question. For example, if a county BAP identifies an action to protect all areas of a particular habitat (where there is no similar recommendation in the UK, national or regional BAP), each area could be considered to be of county importance. It should be noted that some BAPs do not qualify their recommendations about specific habitats, for example in relation to the size of habitat areas. Some interpretation may be needed to avoid obvious anomalies, for example, it may be inappropriate to classify a small patch of reedbed within a gravel pit as of county importance just because a county BAP action proposes the protection of all reedbeds.
3.28 BAPs are also useful in that they identify current factors causing loss and decline of particular habitats, e.g. pollution, fragmentation, etc. They can flag up important development types/impact types that should be considered in EcIAs.
3.29 Ancient woodlands are '...valuable for the diversity of species and for the longevity of the woodland habitat...' (PPS9). Ecologists may consider them to be important at a specified geographic level even if they are not designated at this level. It may be appropriate to adopt a similar approach for other habitats that cannot be restored or created within a reasonable time frame.
3.30 Other sources of assistance in valuing habitats may include Natural Area Profiles (England) Natural Heritage Futures: National Assessments (Scotland), development plans (structure and local) and descriptions of National Parks and Environmentally Sensitive Areas (ESAs).
3.31 This part of the guidance deals with species that need to be assessed because they are of biodiversity value rather than because they are legally protected (although some species may fit in both categories). Legally protected species are discussed in paragraphs 3.52 - 3.55. There are also legal requirements relating to notifiable weeds and species that are controlled through legislation for public health and commercial reasons. Issues relating to injurious/controlled species are discussed in paragraphs 3.56 - 3.59.
3.32 In assigning value to a species, it is necessary to consider its distribution56, 57 and status, including a consideration of trends based on available historical records. A non-mobile species can generally be assumed to occur regularly on a site, even after just one recent reliable record. However, records over a longer period, for example five years, may be needed for mobile species. The occurrence of species that are not typical of the habitat from which they have been recorded should be investigated in greater detail. It will be necessary to discuss the period over which data are needed with the relevant country conservation agency if there is a likelihood of there being an impact on a population or group of national or international importance.
3.33 The valuation of populations should make use of any relevant published evaluation criteria. For example, there are established criteria for defining nationally and internationally important populations of waterfowl58.
3.34 Rarity is an important consideration because of its relationship with threat and vulnerability. Some species are inherently rare, so it is necessary to look at rarity in the context of status. A species that is rare and declining may be assigned a higher level of importance than one that is rare but known to be stable. Other rarity-related evaluation criteria include the need to protect populations where the UK holds a large or significant proportion of an international species, e.g. a European population.
3.35 There are numerous species whose populations are in decline throughout the UK; many of those for which the decline is most serious, 'priority species' are the subject of Species Action Plans (SAPs) in the UK BAP. Other species are the subject of action plans in sub-national BAPs. The purpose of SAPs is to guide conservation action for the species concerned. As with habitats, the existence of a SAP should reflect the fact that the population of the species is in a sub-optimal state. It does not imply - and was never intended to imply - any specific level of value for the species. The value of the population of a species covered by a SAP should therefore be determined using the same approach as with other species
3.36 Other than in this context, the main application of a BAP in EcIA is in the context of guiding the development of proposals for habitat creation/enhancement. As for habitats, SAPs can be useful in identifying development types/impact types that should be considered for particular species.
3.37 Inclusion of species in lists of declining species (e.g. the list of Birds of Conservation Concern59) is not in itself a sufficient criterion for assigning a level of value to the species concerned. This is because such lists include species in decline for a number of different reasons and ecological value can vary between listed species.
3.38 Defra has a Public Service Agreement (PSA) target to have at least 95% of the SSSI area in recovering or favourable condition by 2010. The Scottish Executive has a published target of bringing 80% of the SSSI area into assured management arrangements by March 2006 and also to bring 80% of SSSI special features into favourable condition by March 2008. CCW has a 'Programme for Rationalising and Implementing Statutory Site Management' (PRISM), which is designed to help achieve by 2013 the target of 95% of SAC and 85% of SSSI features in 'favourable conservation status'. EHS is committed to ensuring that 95% of the features underlying the designation of its important wildlife sites are in, or approaching, favourable conservation condition by 2013 The existence of these targets means that the 'favourable condition' of a SSSI/ASSI should generally be the benchmark against which impacts are assessed. The main exception is likely to be where the statutory conservation agency agrees that it is not reasonable to expect that the favourable condition target can realistically be achieved without the developer’s intervention.
3.39 The EC Habitats Directive 1992 Article 2(2) states ‘Measures taken pursuant to this Directive shall be designed to maintain or restore, at favourable conservation status, natural habitats and species of wild fauna and flora of Community interest’. Article 3(1) states ‘A coherent European ecological network of special areas of conservation shall be set up… this network, composed of sites hosting the natural habitat types listed in Annex I and habitats of the species listed in Annex II, shall enable the natural habitat types and the species' habitats concerned to be maintained or, where appropriate, restored at a favourable conservation status in their natural range’. Therefore, consideration of potential value in respect of habitats/species on Annexes I/II is important in the selection of SACs in order to achieve favourable conservation status for those species or habitats. This also therefore applies to consideration of any potential impacts upon such sites. .
3.40 Potential value is also addressed in some BAPs. If a particular area of land is subject to a HAP, with existing detailed plans for enhancement or habitat creation and an associated delivery mechanism, and if the chance of failure is low, then it may be appropriate to value the site as if the intended resource already existed. There is already precedent for this approach in planning case law. In England, this principle has been further strengthened by the publication of PPS9, which includes the requirement for Regional Spatial Strategies to include policies to conserve and enhance biodiversity at the regional and sub regional levels and for Local Development Frameworks to: 'identify any areas or sites for the restoration or creation of new priority habitats which contribute to regional targets, and support this restoration or creation through appropriate policies'.
3.41 Some features that are currently of no particular ecological interest in themselves may nevertheless perform an ecological function, e.g. because they act as a buffer against negative impacts, or because they enable in some other way the effective conservation of a more valuable feature. For example, an area of scrub may be included in a calcareous grassland SSSI to act as a buffer from agricultural spraying on adjoining farmland. In this instance, the scrub performs an important ecological function in protecting a feature of national importance.
3.42 It is also relevant to note that Article 10 of the Habitat Directive refers to 'Member States shall endeavour, where they consider it necessary, in their land-use planning and development policies and, in particular, with a view to improving the ecological coherence of the Natura 2000 network, to encourage the management of features of the landscape which are of major importance for wild fauna and flora. Such features are those which, by virtue of their linear and continuous structure (such as rivers with their banks or the traditional systems for marking field boundaries) or their function as stepping stones (such as ponds or small woods), are essential for the migration, dispersal and genetic exchange of wild species.'
3.43 People derive benefits from biodiversity in various ways, including:
3.44 The extent to which a site and its wildlife provide a resource that people use or enjoy often informs the designation of Local Sites by Local Authorities, The Wildlife Trusts and others. In such cases, the social value that is attached to a site may be defined on the basis of the level of importance at which the site has been designated (e.g. county, district, etc.). In other circumstances, it may be necessary to make a judgement about the value of the site based on other criteria, such as the extent to which the site is used by local people and others and the availability of other accessible green space in the vicinity. Collis and Tyldesley (1993)60 also deal with these issues.
3.45 It should be noted that even where designation systems reflect social values, they may not have involved a comprehensive survey of the social value of all green spaces within the relevant area. As a result, an EcIA, EIA or other social/environmental studies may identify previously unrecognised (and un-designated) sites of social importance.
3.46 The social effects of a project that might affect a Local Site that has been designated partly for social reasons are often neglected in EcIAs, as no one member of the team feels able to fully address the issues. Effects on socially valued species (e.g. the population of bluebells in the example above) are even more likely to be neglected. To avoid this situation, it may be useful to separate 'social values' from those specifically related to the conservation of biodiversity in order to ensure that all potentially significant values are recognised. Wherever possible, subjective judgements about social value should be supported by comment from the Local Authority or even surveys of opinion by local residents if the issue is sufficiently critical.
3.47 Having identified the socially important sites/species, the ecologist should carry out the assessment of how the ecology of these sites/species might be affected by the project. Ideally, a sociologist would then make the assessment of the social consequences of the ecological changes. Information about social impacts can then be considered alongside biodiversity impacts in developing mitigation/compensation/enhancement measures, in determining the significance of impacts and, ultimately, in the decision-making process. The LANDMAP26system in Wales is an example of how such an assessment can be undertaken.
3.48 Economic implications may result from impacts on certain ecological features and resources that are financially valuable, for example:
3.49 Ecologists should be proactive in identifying situations where specialist economic input might be required. This will ensure that economic implications of ecological change are properly included in an assessment. Ecologists and economists may need to work together to identify economically important resources. The ecologist will be responsible for describing the ecological changes resulting from the project, which the economist will use to assess the economic impacts in qualitative or, preferably, quantitative terms.
3.50 Any economic appraisal should be open to consultation as soon as possible, with the methodology presented transparently so that stakeholders can give a view on the values assigned.
3.51 Criteria relating to economic value typically reflect considerations such as the contribution to the economy derived from the ecological resource, e.g. the number of jobs that are supported. These need to be considered in relation to direct 'upstream' and 'downstream' economic activities. This would normally be done in the context of values adopted in the wider socio-economic assessment. Guidance on this subject is beyond the scope of this document.
3.52 The EC Habitats Directive Annex II lists animal and plant species of Community interest whose conservation requires the designation of SACs and Annex IV lists animal and plant species of Community interest in need of strict protection. The EC Birds Directive Article 4(1) states ‘…species mentioned in Annex I shall be the subject of special conservation measures concerning their habitat…member states shall classify...the most suitable…as special protection areas...’ and Article 4(2) ‘…take similar measures for regularly occurring migratory species not listed in Annex I…’ There is also a requirement under Article 4(4) that member states ‘...take appropriate steps to avoid pollution or deterioration of habitats...outside these protection areas…' Other species are protected under Schedules 1, 5 and 8 of the Wildlife and Countryside Act 1981 (as amended) and the Wildlife (Northern Ireland) Order 1985, and the Nature Conservation (Scotland) Act 2004. This national legislation also provides the legal framework for the notification of SSSIs and ASSIs.
3.53 Other legislation that is relevant to EcIA includes the Protection of Badgers Act 1992, the Wild Mammals (Protection) Act 1996 and the Hedgerow Regulations 1997.
3.54 Some mechanisms for legal protection or designation indicate what type of information is required to address ecological impacts (e.g. sites protected under the EC Habitats Directive). In all cases, legal and other guidance should be followed to determine whether a project will cause any contravention of legal status or protection, or have a significant effect on the integrity of a system, resource or feature.
3.55 The approach described in paragraphs 3.20 et seq should be used to evaluate the biodiversity value of a feature in order to provide advice on the policy implications of any impacts. In addition to this approach, EcIA must demonstrate how the project being considered will be taken forward such that the legal requirements will be met. It should be noted that for some projects, features may be of insufficient biodiversity, social or economic value to merit assessment within an EcIA (e.g. because they are below the defined threshold for biodiversity value) other than the need to consider them within the context of the relevant legislation. Examples of this might include species that are common in some parts of the UK, such as kingfisher, which is listed in Schedule 1 of the Wildlife and Countryside Act 1981 (as amended), and badger (in the context of the Protection of Badgers Act 1992). More generally, this will apply to foxes and other common mammals (in the context of the Wild Mammals (Protection) Act 1996).
3.56 Some species are legally identified as 'injurious weeds', or are controlled by the Wildlife and Countryside Act 1981 (e.g. Japanese knotweed, giant hogweed) and under the Wildlife (Northern Ireland) Order 1985. These must be controlled, chiefly for public health and commercial reasons.
3.57 Five weed species are identified as injurious in the Weeds Act 1959 (common ragwort, broad-leaved dock, curled dock, creeping thistle, spear thistle). The Secretary of State may serve an enforcement notice on the occupier of land on which injurious weeds are growing requiring the occupier to take action to prevent their spread. The Defra website has a colour guide 'Identification of Injurious Weeds'61. The Ragwort Control Act 2003 (England and Wales) amends the Weeds Act; the related code of practice on how to prevent the spread of common ragwort62 contains useful advice, including the identification of risk in order to prioritise control measures.
3.58 A small number of plant species are legally controlled in Great Britain by the Wildlife and Countryside Act 1981 and in Northern Ireland by the Wildlife (Northern Ireland) Order 1985 (this list of plants is longer). The two plants that are most frequently encountered in EcIA are Japanese knotweed and giant hogweed. It is illegal to plant or to cause these plants to grow in the wild, and legal disposal methods for vegetation and soil subject to clearance from a site must be used. Guidance is available from the Environment Agency in respect of dealing with Japanese knotweed and with both these species as well as other invasive plant species not subject to legal controls including 'Guidelines on the control of invasive plants in or near fresh water'63 and a 'code of practice for the management, destruction and disposal of Japanese knotweed'64 (for more information and factsheets on invasive species, see the EA web page65 and Scotland has a horticulture code of practice 'Helping to prevent the spread of invasive non-native species'66.
3.59 The presence of such species may be assessed as being an ecological, social or commercial disbenefit, although they may have some ecological merit. Advice should be provided on the legal consequences of their presence and the ecological impacts assessed in this context.
3.60 Some habitats or species may have biodiversity, social and economic value. In this instance, the impact of a project on all three aspects should be assessed separately before an integrated assessment is carried out.
Copyright © IEEM 2006 | Last updated 26-06-06