Individual trees on aerial imagery and canopy height model. Credit University of Cambridge
New research from the Centre for Landscape Regeneration has mapped millions of trees across the Cairngorms, revealing extensive natural woodland regeneration following landscape-scale changes in deer management.
A new study led by researchers at the University of Cambridge has used airborne laser scanning and AI-supported analysis to map more than six million individual trees across 569 km² of the Cairngorms.
The research provides one of the most detailed pictures yet of woodland regeneration at a landscape scale, showing that young native trees are naturally establishing across large areas of land within the Cairngorms Connect partnership.
The study, Tracking and modelling native woodland expansion in the Scottish Highlands using LiDAR, was led by researchers from the University of Cambridge’s Centre for Landscape Regeneration (CLR), including Dr David Coomes and Dr Aland Chan, with colleagues in Computer Science and Technology. The research was carried out in collaboration with Cairngorms Connect and RSPB Scotland.
Mapping millions of regenerating trees
The team used airborne LiDAR (Light Detection and Ranging) data collected from an aircraft flying around 600 metres above the ground. The technology uses laser pulses to build highly detailed three-dimensional maps of vegetation and terrain.
Using a new AI-supported approach, the researchers were able to identify more than six million individual trees across the survey area and estimate the height of each tree.
Of these, around 2.65 million trees — just over 40% of those mapped — were under five metres tall, providing a detailed picture of ongoing woodland regeneration.
Most young trees were found close to existing woodland, where seeds are more likely to reach suitable sites. However, some regenerating trees were found more than half a kilometre from the nearest forest edge, demonstrating the potential for woodland to expand naturally across the landscape.
The research also found that the type of habitat influenced regeneration. Young trees were less common in boggy areas than in drier heathland.
The ability to map regenerating trees so precisely, at such a huge scale, is a breakthrough for monitoring nature restoration at a landscape scale.
It means we can effectively map young trees, assess whether restoration targets are being met, and inform future restoration work.
Dr Aland Chan
Centre for Landscape Regeneration
Evidence of woodland recovery
The Cairngorms have experienced centuries of woodland decline, with Scotland’s native forests reduced to a small fraction of their former extent.
Cairngorms Connect brings together neighbouring land managers across around 60,000 hectares, with a 200-year vision for restoring habitats, species and ecological processes. A central element of this work is enabling native woodland to regenerate naturally.
The new study found that more than 5,235 hectares of previously open land within the study area now supports young woodland, defined as land containing more than 100 trees per hectare.
The researchers found that this expansion has largely occurred through natural regeneration, with planting concentrated in areas where natural seed sources are not available.
The findings provide a new way to assess how woodland is responding to changes in land management and to track regeneration over large areas.
A new tool for monitoring nature recovery
Traditional monitoring of woodland regeneration can require extensive fieldwork by researchers, land managers and volunteers. The new LiDAR-based approach offers a way to complement these surveys by providing detailed, landscape-scale information on where trees are establishing and how they are developing.
The same approach could also help monitor other changes across large landscapes, including the impacts of wildfire — an increasingly important consideration as climate change alters fire risk and severity.
This approach could provide an important tool for monitoring woodland expansion as more landowners across Scotland seek to restore native forests.
Dr Pip Gullett
Cairngorms Connect
The research also connects with the wider University of Cambridge Tessera project, an AI foundation model designed to help analyse patterns in Earth observation data and make satellite-based monitoring of environmental change more accessible.
With the Scottish Government now funding a nationwide LiDAR survey, the researchers hope that approaches such as this could contribute to monitoring woodland recovery and wider nature restoration across Scotland and the UK.
Research supporting landscape-scale restoration
The study demonstrates how combining remote sensing, AI and field observations can provide new insights into ecological change at scales that would be difficult to monitor through ground surveys alone.
For the Centre for Landscape Regeneration, it also highlights the value of developing practical methods for measuring whether restoration is delivering the changes taking place on the ground.
The research was funded by the Natural Environment Research Council (NERC) and the Endangered Landscapes and Seascapes Programme (ELSP), with support from Tarides SAS, and was undertaken in collaboration with Cairngorms Connect and RSPB Scotland.
The paper, Tracking and modelling native woodland expansion in the Scottish Highlands using LiDAR, is published in the Journal of Applied Ecology.
Reference: S. Thapa & A. Chan et al., Tracking and modelling native woodland expansion in the Scottish Highlands using LiDAR, Journal of Applied Ecology, September 2026. DOI: 10.1111/1365-2664.70561
Link to publication: https://www.repository.cam.ac.uk/items/39eff908-614b-4e65-836b-3a5304052c22
This article was adapted from an original media release prepared by the University of Cambridge.