PHOENIX — It was about 6:30 a.m. when a towering saguaro fell and a group chat lit up. Lidar scanners — the same technology that lets self-driving cars build 3D maps — had been capturing the day-by-day life of the giant cactus for six months. The machines recorded the cactus as it swelled with water, tilted and ultimately toppled in the Sonoran Desert in February 2024.
The WhatsApp thread included researchers, technicians and artists who had been scanning the plant as part of a yearslong art-and-data project commissioned by the Desert Botanical Garden in Phoenix, said Laura Spalding Best, the garden’s senior director of exhibits. “It was so emotional and meaningful for everybody,” she said. “There was excitement, but it was also super sorrowful. You see it deteriorating, but it’s still giving life to everything around it.”
That footage is part of Framerate: Desert Pulse, an exhibition at the garden created with London-based ScanLAB Projects. The installation stitches together detailed 3D scans of Arizona’s desert landscape — saguaros and other cacti like prickly pear, ocotillo and cholla — and projects them across giant outdoor screens and an immersive indoor room with screens on walls, floor and ceiling. A booming soundtrack by Pascal Wyse, built largely from desert materials such as saguaro spines, underscores the imagery. The effect is both a celebration of the Sonoran Desert and a cautionary look at human impacts, said ScanLAB co-founder Matthew Shaw.
The scans don’t only show plants. They captured a housing development sprouting on the desert’s edge, a dairy farm full of cattle, and crowds at Chase Field on Diamondbacks opening day. “You have things like a Target [parking lot] and the landfill site, which hopefully question some of the slightly less sustainable things that we do as a species,” Shaw said.
The science behind the art
Technicians used lidar to fire millions of laser pulses into the landscape. “They reflect off every surface they come into contact with and create a perfect 3D model of the space,” Shaw said. The team repeated that process every day for a year, producing scans that captured saguaros expanding after rain, branches and pads moving in the wind, sand shifted by animals and people, pebbles shifting, weeds sprouting and dying, and cactus blooms opening and closing.
Those scans produce billions of data points — what the team calls “digital dust.” Because the project was data-driven, the garden now has unprecedented records of daily growth and change that scientists can use for conservation work, Best said. “We now have incredible records of growth that you would never get from going onto the same field site every day,” she added.
Kim McCue, vice president and chief research officer at the garden, said the scans already revealed unexpected behavior. She observed sun-sensitive agaves folding and unfolding their rosette leaves over days. “(We had) no idea that agaves would be doing that,” McCue said. She wonders whether the leaf movements serve an adaptive purpose, perhaps protecting the plant from heat.
That kind of detailed, time-series information could eventually inform better conservation strategies — though sorting through the volume of data will take time. There is precedent: ScanLAB’s earlier work helped produce a scientific paper on coastal erosion in England, information useful for protecting coastal infrastructure.
A fallen saguaro’s second life
The fallen saguaro became a pivotal case study. After it toppled, the team continued scanning it for six months, documenting how the dead column nourished surrounding wildlife and slowly decomposed back into the landscape. Shaw noted that lidar’s reflections can indicate moisture levels beneath a plant’s skin, which might reveal how water content changes as a cactus declines. That could be valuable for understanding why some giants fail.
Those post-fall scans, combined with the larger dataset, could help scientists investigate factors that lead to saguaro mortality and how to shield them from threats. The project’s rich, daily records offer a new window into desert dynamics — from plant physiology to human-driven landscape change — and create a resource that, according to McCue, is “bound only by our imagination” in how it might be used for research and conservation.