|Paper title||ESA Forest Carbon Monitoring project – How to improve the usability of Earth Observation based approaches for users’ evolving requirements in forest biomass monitoring|
|Form of presentation||Poster|
Forests are essential in maintaining healthy ecosystem interaction on Earth. Forests cover around 30% of the world’s land area (FAO 2020), are estimated to contain over 500 Pg of above ground live biomass (Santoro et al. 2021) and represent a net sink of −7.6 ± 49 GtCO2e yr−1 (Harris et al. 2021). This makes them a crucial asset in the fight against climate change. Reliable information on forest biomass and carbon fluxes are needed to meet the reporting requirements of national and international policies and commitments like the Paris Agreement on Climate Change and the United Nations’ Sustainable Development Goals (Herold et al. 2019).
The Forest Carbon Monitoring project (https://www.forestcarbonplatform.org/) for the European Space Agency is developing Earth Observation (EO) based user-centric approaches for forest carbon monitoring. Different stakeholders have a common challenge to monitor forest biomass, but specific requirements vary between users. Policy-makers need information to make better decisions; public organizations need information for national and international level reporting. Companies require means to respond to increasing monitoring requirements, and tools for carbon trading. To support forestry stakeholders in these requirements, the project aims to develop a prototype of a monitoring platform which offers:
• A selection of statistically robust monitoring approaches designed for accurate forest biomass and carbon monitoring for varying large and small area requirements.
• Cloud processing capabilities, unleashing the potential of the increased volumes of high-resolution satellite data and other large datasets for forest biomass and carbon monitoring
In this presentation, we will give an overview of the project’s status, first results and further development. We will specifically highlight the research efforts to be undertaken in this project to improve usability of Earth Observation (EO) in meeting the varying user needs in forest biomass and carbon monitoring. The project started with an extensive review of policy needs and users’ technical, methodological and data requirements. Project user partners were interviewed for detailed requirements. This information was reflected against the current state-of-the-art of EO based forest carbon monitoring methods to identify the potential and limitations of EO based forest biomass monitoring. During the first year of the project, different approaches for data processing, biomass estimation and uncertainty assessment have been tested and evaluated. During the second year of the project, three different types of demonstrations will be conducted and validated:
• Local level demo designed to meet private company and other small area requirements.
• Provincial to national level demo aimed primarily at administrative agencies, often using National Forest Inventory (NFI) based approaches.
• Continental level demo, aiming to meet the needs of international organizations and other communities requiring continental level information.
The underlying policy and user requirements analysis including user interviews highlighted the variety of requirements that forestry stakeholders have towards forest monitoring in general and with a focus on biomass carbon. The needs could be coarsely grouped according to the three different types of demonstrations. Particularly the private companies with smaller interest areas need basic forest structural variables (e.g. basal area, diameter, height, volume) as much, or even more, than forest biomass and carbon data. These basic forest variables support their forest management decisions, but also allow biomass or carbon flux estimation when required. Public and international users, on the other hand, are more specific in their requirements regarding the variables or interest, as they are defined by the policy reporting requirements. For the national level organizations, existing approaches are heavily based on NFI field data, and any supporting EO based approaches need to be able to complement the existing monitoring systems in a productive manner. All users raised the importance of reliable and accurate monitoring and reporting of changes in forest biomass.
Due to the large amount of research conducted on the increased volume and variety of high spatial resolution EO data (see e.g. Miettinen et al. 2021), combined with processing capabilities enabled by cloud processing environments, the scientific readiness for EO based forest biomass monitoring is rising fast to the level required meet the user requirements. However, not all of the approaches are ready for operational use and should be further developed. Particular attention needs to be given to the fact that in operational circumstances the available datasets and monitoring conditions are rarely optimal, affecting the quality and consistency of the outputs. Key research issues that need more investigation to properly respond to the user requirements include:
• In an operational system responding to user needs, robust and transparent uncertainty assessment approaches and validation procedures are crucial. Reference data availability is rarely optimal in operational setting, requiring development of several uncertainty monitoring approaches validation procedures to be applied according to available datasets.
• In direct growing stock volume and biomass estimation, further development is needed on utilization of multi-temporal and multi-sensor datasets, combined with improved model calibrations. Approaches such as developed by Santoro et al. (2021) have proven useful for global level analyses, improved pixel level accuracies would enable derivation of reliable results for smaller interest areas and comparison between two time steps of mapping.
• For basic forest structural variable estimation, the availability and suitability of field reference measurements is a crucial issue and better integration with NFI data should be sought. Further improvements are also pursued e.g. from combined use of optical and radar datasets, as well as utilization of variable-specific estimation methods.
• A key feature of the platform to be developed in this project is integration of ecosystem simulation models into the system. The calibration of these models for different tree species and site conditions is still a significant knowledge gap even for European and particularly for global application. By means of data assimilation, the utilization of a modelling framework allows also to integrate multiple data sources for forest monitoring, enabling set-up of a continuously updating monitoring system. This is a major area of development in the long run for forest biomass and carbon monitoring.
The main results achieved in each of the research areas listed above will be reported in the presentation. Overall, the required knowledge on what needs to be done to set up the planned Forest Carbon Monitoring platform exists. However, the research currently conducted in the above listed topics aims to improve the reliability, usability and integration of EO based approaches to such a level that would enable wider onboarding of EO based approaches for forest biomass and carbon monitoring by forestry stakeholders. Although this project focuses on biomass and carbon monitoring, a forest monitoring platform should ultimately have a broader focus than carbon and cover effects of climate change, biodiversity, health, damages, invasive alien species, forest management, and the biomass use.
FAO (2020) The State of the World's Forests 2020: In brief – Forests, biodiversity and people. Rome: FAO & UNEP. doi: 10.4060/ca8985en. ISBN 978-92-5-132707-4.
Harris, N.L., Gibbs, D.A., Baccini, A. et al. (202) Global maps of twenty-first century forest carbon fluxes. Nature Climate Change 11, 234-240. doi: 10.1038/s41558-020-00976-6.
Herold, M., Carter, S., Avitabile, V. et al. (2019) The Role and Need for Space‑Based Forest Biomass‑Related Measurements in Environmental Management and Policy. Surveys in Geophysics 40: 757–778. doi: 10.1007/s10712-019-09510-6.
Miettinen, J., Rauste, Y., Gomez, S., et al. (2021) Compendium of Research and Development Needs for Implementation of European Sustainable Forest Management Copernicus Capacity; Version 2. Available at: https://www.reddcopernicus.info/wp-content/uploads/2021/06/REDDCopernicus_RD_Needs_SFM_V2.pdf
Santoro, M., Cartus, O., Carvalhais, N. et al. (2021) The global forest above-ground biomass pool for 2010 estimated from high-resolution satellite observations. Earth System Science Data 13: 3927–3950. doi: 10.5194/essd-13-3927-2021