Research

Our research concerns the use of remote sensing and computer modeling to observe, monitor and simulate forest ecosystems as they are influenced by humans and their environment.

Forests are structurally complex, dynamic organisms which interact with their environment (air temperature, CO2, wind, solar radiation, humidity) to assimilate carbon and grow. Forests contribute to human well-being by reviving a sense of connection with the natural world, and they are under increasing pressure globally as land is converted to other uses.

Our research program focuses on three sets of studies:

Canopy structure, light and function

This set of studies investigates links between canopy structure, reflectance and function, in terms of light interception, photosynthesis and evaporation. It integrates the development of physically based phytometrical methods using ground-based lidar data to describe the 3D geometry of forest canopies, with physically based models to enable the study of links between canopy structure, light reflectance and interception, and canopy-level gas exchanges.

The research is highly interdisciplinary and involves integrating lidar remote sensing, field work, algorithm development for data processing, and biophysical modeling. The main objective is to improve leaf-to-canopy scaling schemes within terrestrial biosphere models (TBMs).

Selected publications

PAR NIR
Radiation absorbed by leaves (green) and wood (brown), in W m−2, in a 3D model of the Pasoh Forest Reserve canopy, Malaysia, built from ground lidar. Top: photosynthetically active radiation (PAR). Bottom: near-infrared radiation (NIR).

Forest microclimate and canopy fluxes

This axis develops multilayer canopy models that simulate how forests exchange CO2, heat and water with the atmosphere, layer by layer from the forest floor to the top of the canopy. Our CanVeg2 model combines radiative transfer, heat storage and turbulent transport. Evaluated over long time series at five broadleaf forest sites with contrasting canopy structures, its CO2 and latent heat fluxes closely match eddy covariance measurements.

The model also estimates canopy properties that are nearly impossible to measure directly, such as the temperature of leaves and stems at each height in the canopy. Woody stems absorb a large share of near-infrared radiation in dense forests, store it as heat during the day and release it at night. We added this absorption to CanVeg2 in a way that is efficient enough for routine microclimate simulations, and tested it against a 3D ray-tracing model built from ground lidar and against tower measurements of albedo in four broadleaf forests.

Selected publications

Sunlit leaf temperatures in a 3D model of the Morgan Monroe forest, Indiana, USA, on the warmest day of the 2012 drought, from 11h to 17h. Colors show temperature from 30 to 45 °C.

Monitoring forest disturbances from space

This axis uses satellite time series to map how forests change. It began with near-real-time deforestation detection in Malaysia and Indonesia, combining Google Earth Engine and 30 m imagery from three sensors. This work was done in partnership with private firms, to help industries reach their impact-reduction goals with continuous information on land use change.

Recent work by our students has focused on Canada’s boreal forest. Pauline Perbet used deep learning on Landsat time series to detect and classify disturbances, including partial and progressive ones, produced maps of insect disturbances across Canadian forests since 1985, and tracked biomass recovery after different types of disturbance. Omid Reisi Gahrouei mapped windthrow with Sentinel-2 imagery and classified tree species at large scale by combining PRISMA hyperspectral and lidar data. Xichun Zhou mapped the extent and severity of tree mortality and defoliation caused by the spruce budworm.

Selected publications

Map of Canada showing the latest forest disturbances: wildfire in red, harvesting in green, windthrow in orange, pest outbreaks in purple, and pest followed by harvesting in yellow. Six regional close-ups, labelled a to f, show pest disturbances over a base map, with aerial survey outlines as dashed lines.
Latest disturbances in Canadian forests from 1985 to 2024, mapped from Landsat time series, with regional examples (a to f) and aerial survey outlines (dashed). Click to enlarge. Figure 8 from Perbet et al. (2025), Scientific Data. Base map data © OpenStreetMap contributors.

See all our work on the publications page, or find out how to join the lab.