Forest Biomass Reference System from Tree-by-Tree Inventory Data

Challenge

With no credible path to keeping global heating within 1.5 degrees without healthy forests, humanity needs to know exactly where forest biomass carbon is, whether forests’ vital functions are changing, and what their future holds. Verifiable and consistent measurement of forest carbon stocks and fluxes supports nature-based solutions, enabling communities to quantify the ecosystem services of their lands. Space agencies have made enormous investments in mapping forest biomass across continents to support climate science and carbon markets. However, satellites do not measure biomass directly; they measure proxies for biomass, which undermines confidence in space-based carbon estimates.

Solution

Since 2018, the CEOS community has made efforts to create a global Forest Biomass System as an equitable and sustainably funded system of recurrent site-based measurements. This system will serve as a lasting interface between Earth Observation (EO) agencies and ground-based tree-by-tree measurement initiatives. This infrastructure is designed to become a common good for the entire EO community. The GEO-TREES initiative will be the world’s first ground-based, open-access, equitably developed forest biomass reference system, designed to make global satellite-based forest carbon assessments actionable.

Intended Socioeconomic and Environmental Impact

The GEO-TREES initiative is a win-win, as site partners benefit from funding for data acquisition and capacity building, as well as increased visibility. Existing networks benefit from continuity in funding streams and contribute to data security. Finally, the Earth observation community gains free access to ground-based data on forest structure (height, biomass) on a continuous and long-term basis. Partners are fully engaged and involved in every step of the project. Only with strong representation of partners, particularly from the Global South, along with fair compensation for their work and investment in their institutions and skills, can science capacity be advanced. This is essential for the long-term sustainability of GEO-TREES.

Objectives for 2025–2030

In the pilot phase of GEO-TREES, we have built the infrastructure and governance and successfully raised funds from a diverse range of donors. For the 2025–2030 phase, we plan to ramp up the operational activities of GEO-TREES to up to 60 sites worldwide, with a focus on tropical forests, where ground reference data are most lacking. We will also consolidate data processing streams to ensure that ground measurements deliver the maximum Return on Investment by providing the required confidence in data products. The four pillars of GEO-TREES for the 2025–2030 phase will be:

Partnerships & Engagement:

GEO-TREES collaborates with ecological and botanical specialists worldwide to generate high-quality ground measurements. Partners are fully engaged and involved in every step of the project, with funding ensured to foster science and technology advancements in partner countries.

Innovative Technologies:

GEO-TREES builds on preexisting forest research sites, benefiting from the field experience of on-site teams and forming part on long-term research efforts. Supported forest biomass reference sites will represent the various environmental and anthropogenic dimensions of forests globally. Ground measurements involve four integrated sets of measurements: forest inventory plots with high-quality botanical identification, airborne laser scanning, terrestrial laser scanning, and climate monitoring.

Long-term Commitment:

Forest carbon and biomass are highly dynamic across space and time. Maintaining current and accurate estimates of carbon and biomass stocks requires continued long-term measurements. Long-term measurements also ensure the continued engagement and participation of partners throughout the system.

Open-access Data:

GEO-TREES is committed to equitably produced, fully funded, and openly shared global forest biomass reference measurements. High-quality, high-resolution maps of the world’s forests, developed through Earth Observation missions in partnership with GEO-TREES, will be made openly accessible to all.

How We Work

The core team is structured around the Executive Board. Its composition reflects the expertise required for implementing GEO-TREES, including two Directors and two representatives from each of the three founding partner networks: ForestGEO, ForestPlots.net, and TmFO. Additionally, a Scientific Advisory Board represents the GEO-TREES scientific community and provides advice and insights on the overall GEO-TREES strategy. The Scientific Advisory Board is structured around three Technical Implementation Groups, which oversee data acquisition, quality assessment, and quality control (QA/QC) for (1) tree inventories, (2) airborne laser scanning, and (3) terrestrial laser scanning.