Research project SR/00/322 (Research action SR)
CONTEXT AND OBJECTIVES
BACKGROUND: Isoprenoids represent an important class of Biogenic Volatile Organic Compounds (BVOCs). Among plant BVOCs, isoprenoids form the most abundant class, with isoprene representing about half of the total BVOCs emitted globally. The presence of BVOCs - and in particular of isoprene - alters the cycle NO-NO2-O3 responsible for O3 formation & degradation leading to the formation of other secondary pollutants such as peroxyacyl nitrates (PAN’s) and particulate matter.
OVERALL AIM: In the HYPI project we link isoprene flux measurements at the leaf and canopy levels to hyperspectral vegetation indices. We aim to demonstrate whether hyperspectral vegetation indices offer the possibility for an improved estimation of the spatial and temporal variability of isoprene emissions of ecosystems.
The specific scientific objectives of HYPI are:
- To investigate -at the leaf and canopy levels - the relationships of isoprene emissions with light use efficiency (LUE);
- To investigate - at the leaf and canopy levels - the relationship of isoprene emissions with PRI, as a good estimator of LUE at the leaf and ca levels;
- To investigate the relationships of isoprene emissions with hyperspectral observations in order to identify new vegetation indices offering a good predictive capability. We design the potential approach for the incorporation of PRI and/or the newly developed vegetation indices into a global emission model (e.g. MEGAN).
METHODOLOGY
An experimental set-up, integrated over two organizational levels (leaf and canopy) will be developed. Simultaneous measurements of these reflectance and isoprenoid emissions will be conducted at the leaf and the canopy levels. Collected data will be the basis for running and validating radiative transfer (RT) models.
EXPECTED SCIENTIFIC RESULTS
The overall anticipated outcome of the project will be a novel demonstration of the remote sensing methodology to assess the isoprene emissions from terrestrial ecosystems. This will allow for an improved quantification and understanding of their variability. The developed methodology might need further testing and validation after this project, but at least HYPI will establish a solid scientific basis for further development. The scientific result of HYPI will be a thorough knowledge of the correlation between the hyperspectral vegetation indices and the isoprene emissions at different scales (i.e. leaf and canopy) as well as the suggestion of a future strategy for improvement of an existing model to predict emissions.
EXPECTED PRODUCTS AND SERVICES
HYPI project will provide hyperspectral, VOCs and water and carbon fluxes data for the season 2016 for the experimental field site at Lochristi.
