ProPopulus Team
Assessing the health of a poplar plantation without physically setting foot on the ground is now a reality, thanks to a groundbreaking study conducted at the Ponferrada Campus of the University of León.
Through the use of satellite imagery, biophysical modelling and artificial intelligence algorithms, a team of researchers has succeeded in identifying early signs of diseases such as leaf rust, as well as water stress, in poplar stands.
This advance represents a milestone in applied forest remote sensing and opens up new opportunities for more efficient, sustainable and climate-resilient ecosystem management.
From Ponferrada to Europe: Research with impact
The study, recently published in the International Journal of Applied Earth Observation and Geoinformation, was led by Erika García and Flor Álvarez Taboada, researchers at the Applied Geotechnologies Research Group (GEAT) of the University of León. It forms part of an ongoing research initiative launched in 2024 in collaboration with the European Commission’s Joint Research Centre (JRC).
“Our goal was to demonstrate that it’s possible to assess the physiological state of poplar plantations using freely available satellite imagery, such as Sentinel‑2 data from the Copernicus programme,” explains Álvarez Taboada. “We’re not just looking for visible symptoms—we want to detect early signs of stress before they’re noticeable to the naked eye,” adds Erika García.
Seeing the invisible: chlorophyll, carotenoids and water
The system relies on the PROSAIL model, which simulates how sunlight interacts with vegetation based on its biophysical traits. Building on this model, the team processed hundreds of Sentinel‑2 images using machine learning algorithms—including neural networks and random forests—to estimate chlorophyll, carotenoid, and water content in the leaves of poplar trees.
These three compounds are essential for evaluating plant health: chlorophyll reflects photosynthetic capacity; carotenoids signal stress response; and water content indicates hydration status. “This combination allows us to detect early-stage Melampsora spp. rust infections and initial drought stress—even when trees appear healthy,” says García.
The results are striking: the system achieved 89.5% accuracy in identifying rust, with chlorophyll emerging as the most influential variable (21%), followed by carotenoids (16%) and leaf water content (11%).
An international collaboration with practical vision
The project brought together experts from Wageningen University (Netherlands), the Centre for Agro-Food Research and Technology of Aragon (CITA) with support from the CSIC, and the Spanish company Bosques y Ríos, specialised in sustainable forest management.
“This collaboration allowed us to compare our results against the ANGERS foliar database, a global reference for plant optical properties, and validate them with field data,” explains Álvarez Taboada. The method is not only scientifically sound but also scalable and applicable to other forest species—making it useful across diverse regions and ecosystems.
Moreover, by leveraging open-access Copernicus data, the system avoids the need for expensive sensors or drone flights, making it accessible to both public and private forest managers.
Climate change and forest health: the role of poplar
The ability to monitor tree physiology on a large scale is especially valuable in the context of climate change, where heatwaves, droughts and pests are putting forest resilience to the test.
Beyond its economic role in the timber and pulp industries, poplar contributes significantly to riparian restoration, carbon storage and biodiversity. Detecting the first signs of decline allows for timely treatments, reducing losses and improving planning for rotations and replanting.
“Our aim is not to replace on-the-ground monitoring, but to complement it and help prioritise where and when to act,” García clarifies. “Instead of walking hectares of forest, managers can receive early satellite alerts and intervene with surgical precision.”
Toward smarter forestry
This research, rooted in the region of El Bierzo, represents a step forward toward smart forestry—a model that combines scientific knowledge with digital tools to build a more resilient and sustainable future for forests.
As Flor Álvarez Taboada puts it: “Satellites no longer tell us just how much forest cover there is—they tell us how that forest is doing. That’s a paradigm shift.”
From orbit, poplars now have a new ally to stay healthy and continue delivering their full environmental, social and economic value.