Professor Crystal Schaaf Monitors Forest Health, Climate Change Impact at Harvard Forest

Colleen Locke | October 06, 2017
The colors in this 3D scan of the upper branches of trees relate to height. UMass Boston scientists took measurements 100 feet up in the air from a bucket lift nicknamed

The colors in this 3D scan of the upper branches of trees relate to height. UMass Boston scientists took measurements 100 feet up in the air from a bucket lift nicknamed "Buckey" to produce this image.

Schaaf Serving as a Bullard Fellow at Harvard Forest During the 2017-2018 Academic Year

Professor of Remote Sensing Crystal Schaaf and her students in UMass Boston’s School for the Environment have teamed with Harvard Forest, Boston University, and researchers from around the world to develop new ways of measuring the biomass of trees. These measurements help researchers understand how the workings of the forest ecosystem and the impact of climate change without damaging forests.

In August, ecologists, foresters, and remote sensing scientists from the U.S., Australia, the UK, and Canada came together at Harvard Forest in Petersham, northeast of Amherst, to compare methods of scanning and modeling forest biomass. The National Science Foundation funded the research.

The team used laser scanners to analyze trees from multiple angles and produce a set of points (also called a “point cloud”) in three-dimensional space. Researchers use these points to model the shape, structure, and volumes of the trees.

By combining scans from multiple angles around a tree, laser scanners produce a set of points (a point cloud) in 3D space.

Francesco Peri, the research engineer for the School for the Environment, designed UMass Boston’s 3D laser scanner, the Compact Biomass LIDAR (CBL). Schaaf’s team used the CBL to create digital models of hemlock, oak, pine, and maple trees. After all teams were finished scanning the trees, foresters from Michigan State University, Virginia Tech, the University of Maine, and Harvard Forest felled 20 trees and carefully measured and weighed them, creating manual models of tree structure and biomass. 

“There are very few locations in the world where it has been possible to compare LIDAR estimates of forest structure and biomass with destructively sampled measures,” Schaaf said.  

This fall, LIDAR scientists are comparing their digital tree models to the foresters’ data. If digital models are accurate enough, researchers will no longer have to fell trees to measure them accurately.

3D scan of Memorial Woodshed

The digital measurement work is just one of several recent projects involving one of UMass Boston’s most in-demand professors.

Schaaf is serving as a Bullard Fellow at Harvard Forest during the 2017-2018 academic year, studying new methods and techniques to monitor forest health and structural changes in New England forests.

She has teamed with 2016-2017 Bullard Scholar David Buckley Borden, an artist based in Cambridge, on Borden’s art-science collaboration Hemlock Hospice. Borden worked with Schaaf and student Peter Boucher to develop a 3D image of his Memorial Woodshed. The exhibition opens tomorrow, Saturday, October 7 in Harvard Forest. The opening reception is from noon to 4.

She is also featured in the third-grade curriculum in Boston Public Schools. Schaaf is a “Massachusetts Portrait” in a lesson called “New England.” The text explains Schaaf’s study of the ways changes in the forest affect Earth’s climate, and highlights her role as a member of NASA’s science team.

“I’m delighted to think that third graders are learning about my research with NASA,” Schaaf said. “I hope it encourages them to think about science and what we can learn from satellite imagery of the Earth.”

About UMass Boston
The University of Massachusetts Boston is deeply rooted in the city's history, yet poised to address the challenges of the future. Recognized for innovative research, metropolitan Boston’s public university offers its diverse student population both an intimate learning environment and the rich experience of a great American city. UMass Boston’s 11 colleges and graduate schools serve nearly 17,000 students while engaging local and global constituents through academic programs, research centers, and public service. To learn more, visit

Tags: crystal schaaf , lidar , school for the environment

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