UCL Department of Geography


Surveying remote and not-so-remote forests

12 October 2018

Pioneering work by UCL Geography staff and students

Surveying remote and not-so-remote forests

Dr Mat Disney reports on the activities of his research group over the summer:

The lidar research team have been busy over the summer on field expeditions to remote and not-so-remote forests and publishing various new studies, some with our students to the fore.

London's forest

Wanxin Yang and Oliver Baines presented their dissertation research at the UK's NERC National Centre for Earth Observation MSc Remote Sensing and Environmental Mapping annual meeting, in Birmingham in early September.

Wanxin’s poster showcased her work estimating the density of wood in trees in the UCL quad, and Bloomsbury. Wood density, needed to convert tree size and volume into measures of carbon stocks, is hard to measure and Wanxin's work suggests a route for doing this more easily.

Oliver presented his work mapping London’s urban forests, using satellite data to extend earlier estimates of tree size and cover. This shows that the Greater London area has more than 9 million trees and nearly 25% canopy cover, more than previously estimated. Oliver showed that 74% of the Greater London area meets the UN-FAO definition of a forest, yet urban areas are explicitly excluded from these assessments.

Oliver's presentation won the Remote Sensing and Photogrammetry Society President's Prize for the best talk of the conference (not just the best student presentation!).

Trees of distinction

Meanwhile, Phil Wilkes, Andy Burt, PhD student Matheus Boni Vicari, and colleagues from Oxford, Belgium, Malaysia and Brazil have been measuring trees of unusual size and shape as part of a project to understand what controls tree form and how this relates to function.

The team scanned some of the tallest trees in the tropics, including a magnificent dipterocarps of nearly 100m. in Sabah, Borneo, before moving to Australia, capturing an amazing curtain fig tree, in Yungaburra, northern Queensland. The team are developing new ways to collect very detailed close-range measurements of branches, using a combination of lidar and photogrammetry.

Finally, Andy and Matheus are returning to the Caxiuanã site in NE Amazon, first visited by the team in 2014. They are harvesting several trees in a logging area and weighing them piece by piece to help validate the lidar measurements.

Mat has also been presenting the team’s results, firstly at a meeting in Paris organised by the European Space Agency bringing together scientists who are developing and using new satellite measurements of forests.

More recently Mat was at the ForestSAT 2018 conference, held jointly by the University of Maryland and the NASA Godard Space Flight Centre, where he helped organize a session on laser scanning of forests and presented some of the team’s most recent work.