Exploring Copernicus Expansion Missions for Advancing the MRV of European Forests Entering Nature Markets

EU-Forest Observations for Carbon Market Integrity using Sentinels

(EU-FOCIS)

The aim of the EU-FOCIS project is to develop and demonstrate a forest health and carbon (above-ground) monitoring product for Europe, using ESA open-source satellites, to support voluntary (and compliance) market investment in forest carbon initiatives. There are currently no operational AGB/carbon data products available across Europe at the fine spatial and high temporal resolution appropriate for continuous monitoring of VCM project inventory.

The EU-FOCIS product will combine two EO data streams:

1) Spatially and temporally explicit estimates of terrestrial vegetation GPP (gross primary productivity) derived from ESA Copernicus Sentinel-2 MSI, and future CHIME and LSTM expansion satellite missions; and

2) Ground measurements of AGB made with terrestrial laser scanning at individual tree level that will be used to parameterise and test new empirical models of forest AGB.

Gross Primary Productivity

Expansion Mission GPP Product Description

Gross Primary Productivity (GPP) represents the total amount of carbon assimilated by terrestrial vegetation through photosynthesis and is a key regulator of the global carbon cycle. The Expansion Mission GPP product (EM-GPP) estimates GPP using a light use efficiency (LUE) approach that integrates light availability and photosynthetic efficiency factors.

EM-GPP calculation approach: The EM-GPP product is calculated as the product of photosynthetically active radiation (PAR), fraction of PAR absorbed by canopy photosynthetic pigments, and the photosynthetic pathway (i.e., C₃ and C₄) maximum quantum yield adjusted by environmental limiting factors.
Data sources and generation process: EM-GPP product uses representations of the Copernicus Hyperspectral Imaging Mission for the Environment (CHIME) - like data derived from EnMAP / PRISMA / Sentinel-2 data and the Copernicus Land Surface Temperature Monitoring (LSTM)-like data derived from ECOSTRESS / Sentinel-3 data, along with along with PAR data from ECMWF reanalysis data, to generate canopy-level GPP maps.

Terrestrial Laser Scanning

Terrestrial laser scanner (TLS) data are the best way to provide non-destructive estimates of aboveground biomass in forests. The EU-FOCIS team have collected TLS data at a number of sites, spanning a range of age and forest types. UK field work was conducted at Elveden and Blenheim Estates, Monks Wood, Burwell, Monks Wood and Epping Forest as well as Evo in Finland.

The TLS data have been processed using a state-of-the art processing chain developed for the project, which extracts the point clouds of individual trees from a whole stand and then fits cylinders around the point cloud of each tree. This results in so-called quantitative structural models (QSMs) that enable us to estimate the volume of wood in each tree, from which we can infer the biomass of each tree and then the whole plot. This allows the upscaling of biomass to satellite observations over the same sites.

We have also implemented the UK's Woodland Carbon Code (WCC) approach to estimating carbon for these trees, using the TLS data to measure the tree size and shape. We can then use these size measurements to derive the belowground (root) biomass, using the WCC's scaling estimates.

In this way the EU-FOCIS team have been able to provide independent estimates of above- and below-ground biomass for each tree and each plot.