Unlocking the secrets of ancient trees with RIEGL Terrestrial LiDAR

The SCATTER project (Scanning Ancient Trees with Terrestrial LiDAR) employs a novel LiDAR based approach to assess ancient oaks, raise awareness about their legal status, and provide new insights for their conservation.

Leading the efforts to study and conserve these natural icons are Professor Mat Disney and Dr. Cecilia Chavana-Bryant at UCL, along with Dr. Phil Wilkes at Kew. Funded by the Woodland Trust, they have used LiDAR to capture the unique structural complexity of 40 ancient oaks, offering insights into their growth patterns and ecological importance.

LiDAR is a new tool for this kind of work and allows the creation of extremely detailed 3D models of these individual and vulnerable trees. The SCATTER team is also collaborating with the UK’s Ancient Tree Forum to explore the potential of LiDAR as a practical tool for arboricultural assessments of ancient trees.

Left: Dr. Cecilia Chavana-Bryant (UCL, left) and Dr. Phil Wilkes (Kew, right). Centre: Scanning inside an ancient oak. Images: C. Chavana-Bryant, UCL. Right: The Curley Oak, Llanvair Discsoed, Wales.

The SCATTER project provides new insights into ancient oaks by enabling researchers to quantify the extreme shapes these trees can take. These structural extremes reveal information about the environment and life history of each tree.

Understanding how these trees have survived is crucial, as they are particularly vulnerable and lack substantial legal protection. The Woodland Trust in the UK is campaigning to grant these trees a similar status to buildings, which enjoy much greater legal protection despite often being much younger. Part of this effort involves identifying potential ancient trees of the future and helping to protect them for generations to come.

The Majesty Oak, Kent, scanned by the SCATTER team with its RIEGL VZ-400i TLS (this link takes you to the 3D model developed from this scan). Image SCATTER team.

Both UCL and RBG Kew teams have deployed RIEGL LiDAR over several years as part of their ongoing research to document and understand the behaviour of trees at both individual and forest levels.

Other results from accurate 3D mapping of trees and forests have revealed much more information about above-ground biomass, such as the size of our trees and, by extension, the amount of carbon they contain.

Utilizing the features of RIEGL laser scanners, including full waveform and multitarget responses, has enabled the creation of more accurate 3D models of the trees, enhancing our understanding of these aspects. The teams have deployed RIEGL VZ-400 and VZ-400i terrestrial laser scanners throughout their many years of research, with the SCATTER project specifically utilizing the VZ-400i.

The SCATTER team scanning the Capon tree, said to be one of the last survivors of the ancient Jed Forest on the Scottish borders. Credit: Dr Cecilia Chavana Bryant

The UCL team began using terrestrial LiDAR for this type of work over a decade ago and have pioneered the use of TLS in estimating forest structure and function for some of the world's largest and oldest trees. The tools and workflows they and their colleagues have developed using their RIEGL equipment have been adopted by numerous groups worldwide interested in measuring forests.

The VZ-400i 3D Laser Scanning System is one of a number of instruments from RIEGL that have been employed to create 3D models of ancient trees in Britain including the 300 year-old Niel Gow's Oak in Perthshire, Scotland. Photo: Tree of the Year / Charles Dundas

The SCATTER 3D digital models provide an open-access legacy resource to help us study and safeguard these trees for generations to come. The original LiDAR data can be accessed on ZENODO: https://zenodo.org/records/116... and the 3D models are available on Sketchfab https://sketchfab.com/SCATTER....

Story Source: RIEGL