Environment · Ordinary People
Paula Uzcátegui counted close to 86,000 frailejones from the air, then went back to see which ones lived
Páramo de Berlín, Colombia
A wildfire tore through 317 hectares of Colombian páramo, and counting what was left of its signature plant, one by one, was close to impossible with fieldwork alone, so a student who had studied both biology and systems engineering built the census out of drone images.
The person and the place
Paula Uzcátegui was in her eighth semester of systems engineering at the Universidad Industrial de Santander, with two years of biology already behind her, looking for a thesis project that would use both halves of that education. The Páramo de Berlín sits an hour and a half from Bucaramanga, at around 3,600 meters above sea level.
The problem they cared about
On January 22, 2024, a fire burned for almost five days and took 317 hectares of the páramo, a figure the regional environmental authority put on the record. Frailejones are the plant the whole ecosystem is built around. When Björn Reu's research group reached the site six days later, the rest of the vegetation was gone and many frailejones were still standing, central leaves intact, and within days some had even begun to flower. Nobody knew how many had come through. The usual way to find out was to count small plots and extrapolate out to the rest, and a full plant-by-plant count across 83 burned hectares was close to impossible with fieldwork alone.
The agency moment
Reu's group had the drones and the flight experience. What it did not have was anyone who could make the images give up a number. Uzcátegui took an object-detection model that already existed, cut the drone maps into pieces, and labeled around 12,000 frailejones by hand until the model could find one from above on its own. Hoover Fabián Rueda Chacón, from the university's systems engineering school, is the one who explains what the model learned to key on: the rosette a frailejón makes when you look straight down at it. Cristian Mateo Jaimes Prada flew the surveys, in air thin enough to make the drone labor, with wind, fog, and short battery life squeezing each flight into a narrow window.
What changed, with evidence
"En el área grande, de 83 hectáreas, detectamos cerca de 86 000 frailejones con un diámetro mayor a 20 centímetros," Uzcátegui told Mongabay Latam: close to 86,000 plants wider than 20 centimeters, counted individually rather than estimated from a sample. Then, back at the páramo at the end of 2024, the team saw what it had not expected. Frailejones that survived the fire and flowered were dying months afterward. So the team brought in the drone's multispectral sensor and scored every plant the model had found on the balance between the red light it absorbed and the near-infrared it reflected, with a threshold dividing living from dead, and Uzcátegui walked out to plants with a phone and a GPS to check the answer against the ground. The estimate came back at about 30% dead in the year after the fire. "Los frailejones no se murieron por completo por el incendio, murieron tiempo después," Reu said. Andreina Ortiz López, working the same burn from ground level, compared plots inside and outside it and found the number of species already close to matching, with the ground cover still catching up. The 30% is an estimate with a margin of error, and in comparable Andean páramos frailejones go on dying as long as two years out, so one year is a reading and not a final count. The model was trained on a single species, Espeletia standleyana, and Rueda Chacón expects it to carry over, with retraining on a smaller set of images as the worst case. More flights need funding, and the group is hoping to go after it through calls for proposals.
The move worth copying
Uzcátegui did not pick between the biology and the engineering, and the census exists because she refused to. The method is cheap enough to run on one flight a year, which is Reu's plan: photograph it again, count again, and watch how a páramo comes back. Know someone whose two unrelated skills turned out to be one skill? Feed the scout at goodinprogress.org.
"Estaba todo completamente negro, chamuscado. Solamente se veían los tallos de los frailejones" ("It was all completely black, scorched. You could only see the stalks of the frailejones.") — Paula Uzcátegui, Mongabay Latam
Sources
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Curated by Good in Progress from the public record.
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