Highlands Rewilding aims to be one of the world’s most impactful accelerators of Nature-based Solutions, and its Bunloit Estate is designed to be a beacon of hope against the twin crises of climate change and biodiversity loss.

NatureMetrics worked with Highlands Rewilding on a three-month feasibility study funded through Innovate UK’s Sustainable Innovation Fund. The study mapped soil fungi and soil fauna across the 511-hectare estate. Delivered with Ecosulis as part of the CreditNATURE project, the pilot showed how soil eDNA can set a robust biological baseline. Restoration progress can then be measured against that baseline and future interventions planned with confidence.

To show that its restoration and rewilding work was delivering, Highlands Rewilding needed detailed biodiversity metrics that could be repeated every year. Those metrics had to track recovery against both biodiversity and carbon sequestration goals.

Soil biodiversity is directly linked to ecosystem function, which makes it a critical part of natural capital and a powerful indicator of ecosystem health. The team needed a cost-effective method that could capture community-level data across all of the estate’s representative habitats. eDNA was identified as the most efficient way to establish that baseline.

The CreditNATURE project brought together a range of cutting-edge technologies to build a data-driven platform for issuing carbon, biodiversity and rewilding (ecosystem recovery) credits.

Using NatureMetrics soil eDNA kits, the Highlands Rewilding team collected 40 samples across the full range of the estate’s habitats. We extracted and sequenced the DNA for fungi and soil fauna to characterise the communities present. From the resulting species lists we generated diversity metrics. These let us compare habitats and test how soil life related to soil carbon, nitrogen and pH.

Across the 40 samples, we detected 1,168 fungal operational taxonomic units (OTUs) and 352 faunal OTUs. The number of samples per habitat was small, but the analysis still showed clear patterns:

• Peatlands and grasslands supported the highest and most distinct soil biodiversity on the estate.
• Coniferous woodlands had the lowest richness and diversity of both soil fauna and fungi.
• Two fungal taxa matched sequences of near-threatened species on the IUCN Red List, even though neither species has known records in Scotland. These detections highlight areas for targeted follow-up surveys.
• Fungal and faunal communities were significantly associated with soil organic carbon and total nitrogen, but not with pH.

A multi-habitat baseline for long-term recovery

• A benchmark for rewilding success: The data gives Highlands Rewilding a baseline of soil communities. The impact of restoration and rewilding can be measured against it over time.
• Better-informed land management: Bunloit’s estate managers now know which habitats hold the richest soil life, so they can plan restoration with more confidence.
• Challenging assumptions about peat bogs: Soil fauna was most diverse in the peat bog habitat, which is often seen as having low biodiversity value. Its communities were also highly distinct, which strengthens the case for restoring peatland.
• Linking biodiversity and carbon: Soil communities were strongly associated with soil organic carbon. That supports the CreditNATURE vision of credits backed by data.
• On the global stage: NatureMetrics presented the Bunloit findings at COP26 in Glasgow, and the two organisations plan to keep working together on long-term monitoring at the estate.