The Global Terrestrial Laser Scanning (TLS) Network is a network of researchers using ground-based lasers to produce 3D data on forest structure and dynamics. Terrestrial laser scanning works by emitting laser pulses and generating a 3D point cloud from the way that these laser pulses are reflected back. TLS was first used in forests to measure tree height and diameter, and has subsequently been developed for more complex forest and ecosystem monitoring . The Global TLS Network website shows where TLS research is taking place, and provides information about the conditions of research sites and the availability of open data.

Wytham, Oxfordshire, United Kingdom

TLS and Carbon

Wytham Woods TLS 2022

3D TLS data from Wytham Woods, showing the top of the canopy and some individual trees. Image source: Calders et al. (2022). Retrieved 1 June 2023, from https://doi.org/10.1002/2688-8319.12197

More recent work (Calders et al. 2022) uses TLS to help evaluate existing models for estimating tree biomass, which is important for calculating potential carbon sequestration. Using TLS data, Calders and colleagues suggest that biomass – and, relatedly, carbon stocks – in temperate forests like Wytham Woods may be higher than often-used allometric models estimate. These kind of measurements – not only what they measure but also how and where they are made – can have significant implications for an increasingly quantified approach to forest carbon (and its valuing) in the context of climate change.

Wytham, Oxfordshire, United Kingdom

Virtual 3D TLS Forests

A group of researchers (Calders et al. 2018) made a virtual 3D model of one hectare of Wytham Woods, a mixed deciduous forest managed by the University of Oxford that has been used for ecological research since the 1940s. Using terrestrial laser scanning and open-source software, they explore how remote sensing measurements can contribute to understandings of the biophysical properties of forests.

Wytham Woods TLS

A point cloud of one hectare of Wytham Woods, generated through terrestrial laser scanning (TLS). Image source: Calders et al. (2018). Retrieved 1 June 2023, from https://doi.org/10.3390/rs10060933

Researcher Kim Calders also made an animated video of a virtual walk through Wytham Woods, using TLS data. In the animation we move through the trees , not confined to the places where humans could walk, and we also see structures and devices that facilitate research in the forest, such as scaffolded walkways and measuring devices. Whose perspective(s) are we seeing the woods through, and what is revealed and obscured in the environment through this virtual 3D model?

smart forests radio