Possible approaches to remote sensing of photosynthetic activity

Remote sensing of photosynthesis by fluorosensing and related techniques is a complementary approach to gas exchange and circulation models that helps to monitor accurately the spatial and temporal changes in biosphere primary production. Although important advances have been made in the fields of fluorosensing during the past ten years, a comprehensive review of the different techniques available and their scope is lacking. The aim of the present review is to examine the emerging techniques in order to evaluate their potential for application at different integration levels, from leaf canopy, and from ground measurements to satellite detection. It is also intended to highlight the actual limitations and the necessary preparatory steps towards a space mission. Finally, the information that could be obtained from satellite measurements will be reviewed.