Background

Proposed scheme

Transport Scotland is upgrading approximately 6.5km road from Pitlochry to Killiecrankie to dual carriageway (Project 4) as part of a wider programme to improve the A9 between Peth and Inverness.

Transport Scotland is looking to better capture environmental outcomes within decision making and is fully committed to the protection and enhancement of the natural environment for transport projects. It is thought that Environmental Impact Assessment (EIA) processes could be supported by additional assessments to:

  • Better identify the value of environmental mitigation and enhancement of schemes.
  • Shift approaches from the traditional identification of adverse impacts to include scheme benefits and associated value.

A natural capital approach has been identified as a potential approach to support the above and capture the true value of Transport Scotland schemes. A retrospective natural capital assessment, focussing on the preferred option as assessed within the Environmental Statement, has been conducted for Project 4.

A retrospective study allows for a natural capital assessment of a scheme which has already been subject to scrutiny by stakeholders (including the public) through the consenting process.

This assessment will enable Transport Scotland to consider the benefits of adopting a natural capital approach in the future.

Natural Capital

Natural Capital is ‘the sum of our ecosystems, species, freshwater, land, soils, minerals, our air and our seas’ (Defra, 2018).

Nature provides direct and indirect benefits to people individually and to wider society (known as ecosystem services). Some of these benefits are less obvious than others, but they exist none the less and are important. Applying natural capital approaches ensures that the benefits nature brings are not overlooked and can be protected and enhanced. Natural capital assets provide us with food, clean air and water, fuel, protection from hazards, recreation, physical and mental health benefits and much more.

In 2016 it was estimated that the partial value of natural capital in the UK was near to £1 trillion - (UK natural capital accounts, 2018).

An example of a natural capital asset could be woodland. The ecosystem services that we might associate with woodland include carbon storage, cooling, shading and timber for example. When assessing the benefits and values associated with natural capital and ecosystem services, a logic chain approach (as developed by Natural England) can be used, shown below in Figure 1‑1.

Figure 1-1 shows an example of a natural capital asset, in this case woodland. The key aspects that determine a natural capital asset’s ability to provide ecosystem services are quantity (the extent of habitat or land cover), quality and location. In this example, a woodland provides global climate regulation through carbon sequestration. The total estimated benefit of this ecosystem service provided by UK woodland is 18.6 million tonnes of carbon sequestered per year, which is valued at £1,168 million per year.

Figure 1-1: Logic Chain example (global climate regulation by woodland) used for assessing natural capital assets
Figure 1-1: Logic Chain example (global climate regulation by woodland) used for assessing natural capital assets

Ecosystem services

Ecosystem Services are the direct and indirect benefits that ecosystems provide for human wellbeing and quality of life, and include provisioning, regulating, cultural and supporting services (NatureScot, 2020. Ecosystem services – nature’s benefit).

Provisioning services: Tangible products that can be obtained from ecosystems that meet human needs.

Regulating services: Ecological processes that regulate and reduce pollution and other adverse effects.

Cultural services: Environmental settings that enable cultural interaction and activity.

Supporting services: These do not produce outputs for final consumption or production, but are essential for the functioning of provisioning, regulating and cultural services, which do provide outputs. This distinction is made to avoid the double counting of services and to recognise the contribution that supporting services make without assessing or valuing them. Examples include soil formation, where a final benefit could be crop production, for example.

Ecosystem services considered for this project were based upon the Eco-Metric approach, now known as The Environmental Benefits from Nature (EBN) tool and include:

  • Food production
  • Wood production
  • Fish production
  • Water supply
  • Flood regulation
  • Erosion protection
  • Water quality regulation
  • Carbon storage
  • Air quality regulation
  • Cooling and shading
  • Noise reduction
  • Pollination
  • Pest control
  • Recreation
  • Aesthetic value
  • Education
  • Interaction with nature
  • Sense of place

For this study, the following ecosystem services were considered priorities by stakeholders in the Environmental Steering Group comprised of Historic Environment Scotland (HES), Perth & Kinross Council, Scottish Environment Protection Agency (SEPA), Scottish National Heritage (now NatureScot), Highland Council and the Cairngorms National Park Authority:

    • Global Climate regulation

 

  • Wild species diversity
  • Air quality regulation
  • Water quality regulation
  • Landscape and aesthetic value
  • Scientific and knowledge values
  • Soil quality regulation
  • Noise regulation
  • Hazard regulation

These ecosystem services are slightly different to those assessed within the Eco-metric/The Environmental Benefits from Nature tool, yet still reflect industry best practice such as the Natural England’s Natural Capital Indicators: For Defining and Measuring Change in Natural Capital.

It should be noted that as the project developed, it was agreed that ‘wild species diversity’ i.e. ‘biodiversity’ would be considered independently of other ecosystem services, with the link between the two being defined more clearly i.e. biodiversity enhances natural capital asset quality and therefore the provision of ecosystem services.

Habitat types in Scotland

A habitat is an ecological or environmental area that is inhabited by a particular animal or plant species (UK National Ecosystem Assessment) and different habitats can deliver differing ecosystem services. Scotland comprises of seven broad habitat types, which are:

  • Coastal
  • Inland surface waters
  • Mires, bogs and fens
  • Grassland
  • Heathland
  • Woodland
  • Agriculture and cultivated
  • Urban Environments

Definitions for each of the broad habit types present across the study area for this project are provided below, as defined by the European Nature Information System (EUNIS). The Phase I habitat survey did not identify any specific habitats which are typically associated with the urban environment (such as gardens or allotments for example). The Eco-metric/EBN tools do not identify any ecosystem service provision associated with ‘sealed surface and buildings, which were found to be present across the study area. Furthermore, wider urban environments are captured under the assessment of ‘cultivated’ land wherein the benefits of assets such as open green space is assessed. As a result, the urban environment is not assessed further, with relevant elements contained within other broad habitats.

Inland surface waters

Non-coastal, above-ground, open, fresh or brackish waterbodies (e.g. rivers, streams, lakes and pools, springs), including their littoral zones.

Grassland

Non-coastal land which is dry or only seasonally wet (with the water table at or above ground level for less than half of the year) with greater than 30% vegetation cover. The vegetation is dominated by grasses and other non-woody plants, including mosses, macrolichens, ferns, sedges and herbs.

Heathland

Non-coastal land which is dry or only seasonally inundated (with the water table at or above ground level for less than half of the year) with greater than 30% vegetation cover. The vegetation is dominated by shrubs or dwarf shrubs of species that typically do not exceed 5m maximum height. Includes shrub orchards, vineyards, hedges (which may have occasional tall trees).

Woodland

Woodland and recently cleared or burnt land where the dominant vegetation is, or was until very recently, trees with a canopy cover of at least 10%. Includes lines of trees, coppices, regularly tilled tree nurseries, tree-crop plantations and fruit and nut tree orchards.

Agriculture and Cultivated

Habitats maintained solely by frequent tilling or arising from recent abandonment of previously tilled ground such as arable land and gardens.

Natural Capital in Scotland

In 2015, the partial asset value of Scottish natural capital was estimated to be £291 billion.

The Natural Capital Asset Index (NCAI) tracks the capacity of Scotland’s terrestrial ecosystems to provide benefits through an assessment of quantity and quality information. In 2014 the NCAI completed a backcasting exercise, which aimed to understand the long-term trends of natural capital in Scotland. It found that natural capital had been in decline since 1950 and efforts to recover Scotland’s natural capital had a long way to go.

Since then, the NCAI has found that Scotland’s natural capital is in an ‘increasing’ state, with a 2% increase between 2016 and 2019. This means that the potential for Scotland’s habitats to deliver ecosystem services has improved.

Although the NCAI states that all broad habitat types are increasing, there are declines in some components, such as quality of designated woodlands and upland bird populations. Figure 1‑2 reflects the changes in potential ecosystem service provision from Scotland's habitats during 2000-2018.

As described in text above.
Figure 1 2: NCAI 2000 to 2018 by type of habitat (from Scotland's NCAI)

The £1 Billion Challenge was launched in 2020 by SEPA and the Scottish Wildlife Trust to develop innovative investment and funding models to protect and restore vulnerable ecosystems.

Decorative illustrated scene to promote the £1 Billion challenge

 

As a result of such initiatives, the need for natural capital assessment is growing, with a renewed focus on the natural environment. Scotland’s draft fourth National Planning Framework (NPF4) includes Policy 3: Nature Crisis, which focuses on supporting biodiversity. The draft wording states that ’proposals for local development should only be supported if they include appropriate measures to enhance biodiversity’. However, no standardised method for considering positive effects for biodiversity is currently suggested.

Further, the draft NPF4 Policy 3 expands its focus on biodiversity to also consider ecosystem services, stating that:

Design should take into account the need to reverse biodiversity loss [and] safeguard the services that the natural environment provides
Development proposals which integrate nature-based solutions and deliver positive effects for biodiversity should be supported

Natural capital drivers/pressures and risks

Drivers/pressures are high-level trends/competing requirements which could have an impact on natural capital.

Risks are specific impacts of drivers/pressures which can have direct impact on ecosystem service provision.

Natural capital assets and the associated provision of ecosystem services can be compromised because of environmental trends and competing societal factors.

Figure 1‑3 presents the natural capital drivers/pressures and risks for the A9 Project 4 Scheme as identified by stakeholders in the Environmental Steering Group.

Figure 1 3: Drivers/pressures and risks for the A9 Project 4 Scheme

Climate change

  • Increased frequency and severity of natural hazards
  • Deterioration of peatland which stores carbon yet can act as a carbon source if degraded

Biodiversity loss

  • Changes in habitat & species distribution, composition and quality

Development/Changing use of sea and land

  • Impacts on the historic environment (i.e. listed buildings)
  • Loss of habitat and increased flood risk to habitats
  • Reduction in slope stability through removal of trees
  • Fragmentation of habitats (reducing biodiversity and creating risks to road users from wildlife crossing roads)

Land Management Change

  • Disturbance to archaeological sites and monuments, potential for soil erosion and changes in water levels affecting archaeological deposits
  • Felling of maturing plantations coupled with climate change increases risk of loss of slope stability
  • Drainage of peatlands to increase grazing potential and heather growth for sporting estates increases risks of deterioration of peatlands

Pollution

  • Air pollution
  • Changing water quality
  • Noise and light pollution
  • The above elements leading to biodiversity loss

Invasive non-native species and direct exploitation of organisms

  • Changes in habitat & species distribution, composition and quality
  • Increased need for pest management

Indirect drivers – Such as consequences of social disconnect with nature

  • Exploitation of nature resulting in over-use and/or mis-management which undermines ecosystem service provision
  • Impacts of climate change, pollution and invasive, non-native species are not managed

Natural Capital Opportunities

Through effective management of natural capital assets, opportunities for enhancements are possible. Figure 1‑4 displays natural capital opportunities identified for the A9 Project 4 Scheme, as highlighted by the Environmental Steering Group.

Figure 1 4: Natural Capital Opportunities for the A9 Project 4 Scheme
  • Habitat creation and connectivity (extension of semi-natural habitats) - NatureScot
  • Use of woodland planting and further habitat creation to stabilise slopes - NatureScot
  • Opportunity to address historic habitat fragmentation from A9 via habitat crossings - Natural England
  • Improved access and interpretation of historic assets (not in replacement of avoidance measures) - NatureScot

Areas to note

A core set of tasks were required for the retrospective natural capital assessment, which are set out in the methodology (Section 2 of this document).

However, the scope of the assessment was expanded to include several additional pilot studies, which have added value to how future natural capital assessments (beyond those completed by Transport Scotland) are undertaken.

Additional pilot studies included:

  • Ancient Woodland pilot: Supporting technical note to provide an assessment of ancient woodland across the study area and implications for the existing retrospective natural capital assessment.
  • Historic Environment and Natural Capital pilot: A pilot looking at the integration of the historic environment within natural capital assessments, through collaboration with HES.
  • Habitat Connectivity pilot: Supporting technical note to provide an assessment of habitat connectivity across the study area and implications for the existing retrospective natural capital assessment.
  • Detailed Quantification of Ecosystem Service Flows and Valuation: A pilot quantifying the positive and negative impacts to the flow of ecosystem services from natural capital assets in monetary and non-monetary terms.

A step-by-step approach was undertaken for the retrospective natural capital assessment, with each of the core tasks (outlined in Section 2 of this document) informing the next and building upon the previous. Technical notes were then produced for core tasks Two to Six. Typical reporting for a natural capital assessment would not follow this approach; however, one of the purposes of the assessment is to raise awareness and understanding of natural capital approaches across Transport Scotland team members, and therefore it was beneficial to document each stage of the process. It should be noted that as the retrospective natural capital assessment developed, methodologies also evolved (owing to data availability, development of pilot projects etc.) meaning the content of certain tasks was superseded. Where this is the case, this is noted in the assessment outcomes.

The proposed scheme has already been subject to scrutiny by stakeholders (including the public) through the consenting process. Nonetheless, the natural capital assessment has included engagement with stakeholders included within the Environmental Steering Group. Other stakeholders, such as Forestry and Land Scotland, have also been engaged when considered appropriate throughout the assessment. Stakeholder engagement has been invaluable to this retrospective natural capital assessment and has helped define additional pilot projects which will alter the way natural capital assessments are undertaken in the future across the UK. Stakeholders included:

Purpose of document

This summary document aims to provide a non-technical overview of the retrospective natural capital assessment for the A9 Dualling Programme: Pitlochry to Killiecrankie (Project 4), to:

  • introduce natural capital and applications for Transport Scotland schemes
  • summarise the outcomes of the retrospective natural capital assessment
  • share the outcomes of the assessment across a wider group, and
  • report on a single set of outcomes (allowing the impacts of the additional pilot projects on the core scope of works to be included)

This document includes the following sections:

  • Section 1 - Background
  • Section 2 - Methodology
  • Section 3 - Outcomes
  • Section 4 - Conclusion