Background Spatial variation in key leaf optical traits controlled by light environment and species

Remote Sensing acquires optical data across space and time. We then want to interpret the data in terms of spatial and temporal variation in plant functional or biochemical traits. In a recent paper (Atherton et al. 2017, see publications) we investigated the background spatial variation in key optical properties/traits like the photochemical reflectance index or the shape and intensity of the leaf chlorophyll fluorescence spectra and  the factors that control it. We found that both the light environment within plant canopies and the species generate background spatial variability in the above optical traits which needs consideration when interpreting remotely sensed data.


New Lab Member

Anu Riikonen has recently joined our Lab. She just finished her PhD studies and will help us coordinating the project “Cost-effective methods for tracking large scale vegetation physiology (see projects)”.  We will certainly benefit from her expertise with field ecophysiological measurements and stakeholder interaction.

Welcome Anu!

By the way, Anu will also give a hand with the website so it probably start to look gradually better 🙂


The Optics of Photosynthesis Lab gets Key Funding from the Academy of Finland

Cost-effective methods for tracking large scale vegetation physiology: Participatory phase and pilot experiments

Society faces the challenge of an increasing population that concentrates in urban areas. Food production needs to be increased following sustainability criteria for optimal use of water, fertilizers and pesticides. Air pollution and human stress are an increasing problem in urban areas which could be also improved through detailed management and expansion of urban forests and parks. These challenges require new and cost-effective tools to track the health status of vegetation.

With the advent of unmanned aerial vehicles (UAVs) and hyperspectral imaging systems it might be now possible to acquire detailed information on vegetation health and physiological status anywhere and anytime. In this project we will evaluate the potential of advanced optical indices (emission of chlorophyll fluorescence and other fine variations in vegetation reflectance) to monitor vegetation health using UAVs. We will conduct pilot campaigns both in city parks as well as in farms. Stakeholders include: the City of Helsinki,  the Finnish Geospatial Institute, the Natural Resources Institute of Finland, as well as private partners from the hyperspectral sensor industry and agricultural sectors.

See more details in the Section PROJECTS

Apply now to join our Lab!

We have an open PhD-student position to join our Lab. Application deadline is 8th April 2016.

The new team member will study the factors that control the variation in leaf optical traits across space, time and species as part of our FLUOSYNTHESIS project.

Further details and instructions of how to apply from this link:


Check our new paper in Remote Sensing of Environment!

Chlorophyll fluorescence and the Photochemical Reflectance Index (PRI) are related to rapid time-scale adjustments in the photosynthetic machinery. However the relationship between photosynthetic rate and these measurements has not been fully elucidated, even at the leaf scale. We conducted leaf level modelling and measurements of the dynamics of spectral chlorophyll fluorescence and the PRI, and showed that these measurements can be combined to estimate photosynthetic efficiency parameters. We  recommend future strategies to scale to the canopy and landscape (you can find a PDF in our “Publications” section).

Thanks to the University of Helsinki Funds and the Academy of Finland for support!


EUROSPEC Review paper out in Biogeosciences!

Our Review “EUROSPEC: At the interface between Remote Sensing and CO2 flux measurements in Europe” has been recently published in Biogeosciences (See publications for a pdf copy).

In this review we contextualize and describe the main accompishments of EUROSPEC COST Action and describe the background of in situ long-term spectral measurements and their main tradeoffs. We also discuss the potential of in situ spectral measurements towards connecting CO2 flux data and satellite remote sensing data at the global scale (you can find a PDF in our “Publications” section).

Thanks to COST!