Students in Spain bring the biodiversity of the tree canopy down to the ground.

By Zach Mortice

In 2022, a group of 18 students at the Institute for Advanced Architecture of Catalonia (IAAC) had the rare experience of designing and building their own school’s research facility. Rising 30 feet above a hillside site amid the dense forest canopy of Barcelona’s Collserola Natural Park, the Forest Lab for Observational Research and Analysis (FLORA) is a mass timber observation tower that will allow students to observe and catalog the park’s biodiversity, specifically the organisms that make their home in the forest canopy.

Pablo Herraiz, one of the students in the IAAC’s Master in Advanced Ecological Buildings and Biocities program, says he was amazed by how much of the ground-level ecosystem—especially insects—he recognized in the treetops. “I’ve begun to believe that many of the species we assume are restricted to the ground in fact have just fallen from their habitat or are commuting back and forth,” he says. It was an example of “a larger interdependency [among] the trees to the rest of the surrounding environment.”

Treetops as the Magic Middle

The project was conceived by IAAC codirector Daniel Ibañez and cofounder Vicente Guallart, and inspired by the work of the tree canopy biologist Margaret Lowman, who posits the treetops as the interface between the ground and the atmosphere, and a zone that contains half of Earth’s species. “Her theory is that the changes you see in the flora and fauna within the canopy are very telling of climate change,” Ibañez says. Lowman pioneered the use of treetop walkways and suspension bridges to study canopy biodiversity. FLORA’s elegantly shrouded wood-framing and asymmetrical apertures to the canopy beyond mark it as a distinctive evolution of Lowman’s canopy infrastructure.

Students were responsible for designing every aspect of FLORA, “sourcing the materials, transforming them, prototyping them, assembling them, [and] testing it,” Ibañez says, adding that all of the wood for the tower came from the site. “Our material ecology of the project is less than [1,600 feet].” Because Collserola Natural Park is a biodiversity hot spot in an intensely urbanized area, the 70 pine trees that were cut for the mass timber tower were harvested so that gaps in the forest would allow other trees to flourish. To better grasp how canopy ecologies varied from tree species to tree species, students also sited FLORA so that it would be close to four different types of trees endemic to the area: pine, elm, and two kinds of oak.

Inside the tower is a microscope as well as video cameras, an infrared camera, and microphones, powered by rooftop solar panels. The experience in FLORA is less about technology, however, and more about access to the canopy, Herraiz says. “You go in there and you shake a branch, and you analyze what falls out,” he says. “You understand that there’s a whole ecosystem. I had no idea that the canopy had that level of ecological diversity.”