Biodiversity Programme Advisory Group - sub group EH and I indicator: recommendations

5. Annex 1

5.1 Biodiversity PAG Sub-Group – November 2024

5.1.1 Developing an approach to measuring Ecosystem Integrity and Health for statutory Nature Restoration Targets

5.1.2 Background

The Scottish Government is intending to introduce statutory nature restoration targets within the forthcoming Natural Environment Bill. The targets are seen as a key mechanism for delivering on the overarching vision of the Scottish Biodiversity Strategy to halt biodiversity decline by 2030 and restore and regenerate biodiversity by 2045.

The targets have been developed with input, advice and recommendations from the Biodiversity Programme Advisory Group (PAG). Thus far, the PAG has recommended 7 topics that targets should cover and scoped potential available indicators to represent those topics. Of the seven topics identified by the PAG, three have indicators that are largely available and ready to be used with some minor development (Habitats, species and enhancing conditions for nature), two have part indicator coverage but need more development work to be used (ecosystem integrity and health, and citizens and society) and two require new indicator development (investment in nature and positive outcomes in public sector policy).

It is likely that biodiversity policy will recommend that the target topics on Ecosystem integrity and health, habitats, species, enhancing conditions for nature and citizens and society benefitting, contributing and understanding nature are taken forward. Work needs to therefore be undertaken to further develop indicator options for the two target topics where gaps have been identified: Ecosystem integrity and health, and citizens and society benefitting, contributing and understanding nature.

The indicator development for the Citizens and society target topic will be taken forward by the biodiversity policy unit, with review by the PAG (TBC). It has been agreed that the PAG will further explore options for the Ecosystem integrity and health indicators.

This paper sets out the basis for the PAG sub-group on recommending Ecosystem Integrity and Health indicators.

5.1.3 Ecosystem integrity and health as a target topic

Ecosystem integrity is a measure of the completeness and functionality of an ecosystem and its ecological processes, and the resilience of the ecosystem in response to human pressures. The Convention on Biological Diversity states that an ecosystem has integrity when: “… dominant ecological characteristics (e.g. elements of composition, structure, function, and ecological processes) occur within their natural ranges of variation and can withstand and recover from most perturbations”. It is recommended that the CBD definition is followed to align with the Global Biodiversity Framework Targets.

During the PAG workshops to define the target topics to be recommended for inclusion in the NE Bill, the PAG included Ecosystem integrity and health as a target topic on the basis that it can be used as a high-level target topic that is scalable, able to cover a wide array of factors relating to the overall ‘health’ of biodiversity and can be applied to ‘modified’ or productive ecosystems. It will allow us to assess whether we have met the key text in the vision of the SBS that states: “Our natural environment, our habitats, ecosystems and species, will be diverse, thriving, resilient and adapting to climate change”. Ecosystem integrity also makes a direct connection to provision of ecosystem services – and so highlights that high integrity ecosystems deliver healthy air, water and soils for society, and hence sustain us.

5.1.4 The PAG indicator recommendation for Ecosystem integrity and health

In the full PAG workshop a long list of indicators was provided to the group ahead of the workshop. The PAG agreed that no one indicator on the long list is fully able to represent ecosystem integrity and health at the scale needed. Ecosystem integrity and health indicators should cover the structural, compositional and functional aspects of all of the ecosystems in Scotland.

The full group discussion and recommendations centred on different conceptual options for indicator ‘sets’ for this target topic that needed to be explored further, these are:

• Developing/enhancing/adopting current and proposed specific ecosystem health indicators.

There are a number of options for specific ecosystem health indicators that were discussed at the PAG workshop including: expanding the Delivering Healthy Ecosystems indicator to be more comprehensive than just protected areas, the Ecosystem red list and the services provided by ecosystems indicators. The NS SAC review of the PAG recommendations also highlighted other specific indicators such as the Biodiversity Intactness Index and the Species Habitat Index. Additional indicator development may also be needed that covers ecosystem functionality and integrity that is representative for the whole of Scotland. Using soil (terrestrial) and the sea bed (marine) as a basis for this was put forward as an option by the PAG. But as yet, we do not have an indicator that fully covers these.

• A systems based indicator set to represent integrity and health.

This approach would provide an assessment of the balance of flows (nutrients, carbon, soil/sediment etc) in and out of ecosystems as an indicator of their overall integrity and health. It would use indicators that align with the enhancing environmental condition for nature target topic such as river water quality, the Scottish Nitrogen Balance Sheet, contaminant levels in coastal water, the emissions inventory (not included in the long list) and soil erosion.

• A meta-indicator of all indicators for target topics on habitats, species and enhancing conditions for nature

An alternative type of meta-indicator would be to include the indicators set out for the habitats and species target topic in addition to the enhancing conditions for nature indicators. This would mean that no separate indicator is used or developed for this target topic but instead ecosystem integrity and health is determined by habitats, species and environmental condition indicators.

5.1.5 PAG sub-group on ecosystem integrity and health

A task and finish style sub-group of the PAG has been established to explore the ecosystem integrity and health indicator options further. The primary objective of the group is to make a final recommendation to the Scottish Government Biodiversity Policy unit on which is the preferred conceptual approach and associated indicator(s) to represent the Ecosystem Integrity and Health target topic.

The group are asked to consider two questions in meeting this objective:

1. Which of the conceptual indicator set options suggested by the full PAG is recommended to be taken forward?

2. For the selected option, which indicators are recommended to be used for setting targets against?

The PAG sub group consists of:

Professor Rob Brooker

Dr Phil Boulcott

Professor Anne Magurran

Dr Rosalind Bryce

Professor Davy McCracken

Professor Des Thompson

Professor Mathew Williams

Dr Clive Mitchell

Colleagues from NatureScot will also be included in the sub-group to provide technical input to the discussion.