New publication in Ecological Modelling

The ESA BIOMASS mission offers a unique opportunity: for the first time, we will obtain a near-global P-band radar view of forest height and structure at hectare scales – essentially a consistent forest-height map for almost the entire planet. Together with the BIOMASS CCI AGB product, this height information enables new approaches for estimating above-ground biomass (AGB) and thus forest carbon.

A common assumption behind many AGB estimation approaches is that forest height can approximate biomass everywhere in ‘the same way’, using simple height-to-biomass allometries with parameters α (structure) and β (forest type, growing conditions). However, experience and real-world data show that this relationship is anything but constant across regions, spatial scales and disturbance histories.

In their new paper in Ecological Modelling “Are locally trained allometric functions of forest aboveground biomass universal across spatial scales and forest disturbance scenarios?”, Benedikt Hartweg, Leonard Schulz, Andreas Huth, Konstantinos Papathanassiou, and Lukas Lehnert tested this assumption using FORMIND, an individual-based forest model. We simulated tropical forests near Manaus (Brazil) under disturbance scenarios such as fire and logging, derived forest-height metrics and fitted allometries at different spatial scales (20–200 m).

Key results

• There is no universal height–biomass relationship,
• α and β change with scale, structure and disturbance,
• using a single global “taller = heavier” formula causes systematic biomass errors,
• but adapting just one parameter locally can substantially reduce these errors (forest structure is key!).

This is directly relevant for BIOMASS and GEDI: they provide precise forest height, but height ≠ biomass. Improving height-to-biomass allometries is essential for more accurate global carbon estimates – and FORMIND offers a powerful way to develop such adaptive approaches.

Read the paper