Stock di Carbonio Attuale - Biomassa Vivente (AGB+BGB)

Land Usev06.00 credits/per_km2

Responsible:Niccolò Calandri

Current Carbon Stock — Living Biomass (AGB+BGB)

Overview

The Current Carbon Stock — Living Biomass (AGB+BGB) layer represents the total carbon stored in all living plant tissue, combining above-ground biomass (trunks, branches, leaves, bark) and below-ground biomass (root systems), expressed in tonnes of carbon per hectare (tC/ha).

Living biomass carbon is the sum of the two biologically active carbon pools: AGB and BGB. This combined metric provides a complete picture of the carbon sequestered in living vegetation, excluding dead organic matter and soil organic carbon. It is the standard metric used in IPCC Tier 2 carbon accounting, forest inventory reporting, and biomass energy potential assessments.

The living biomass pool typically represents 40-60% of total ecosystem carbon in forests, but only 10-20% in grasslands where soil organic carbon dominates. Tracking living biomass separately from soil carbon is essential because the two pools respond to disturbances on very different timescales: living biomass can be lost rapidly through fire or logging, while soil carbon changes occur over decades to centuries.

Calculation Methodology

Random Forest downscaling pipeline for living biomass:

Baseline extraction — Both AGB and BGB carbon density rasters from Walker et al. 2022 are loaded from S3 and summed to produce the living biomass layer
Feature engineering — For each pixel:
- NDVI from Sentinel-2 — proxy for total vegetation biomass
- Land cover class from Dynamic World — determines vegetation type and typical root:shoot ratios
- Elevation from SRTM DEM — captures climatic and ecological gradients
Training — Random Forest regressor trained on combined AGB+BGB values
Prediction — Model predicts total living biomass at ~200 m resolution
Validation — Cross-validation metrics (R-squared, RMSE)

Output unit: tC/ha (AGB + BGB combined)

Data Sources

Code	Name	Provider	Type	Coverage	Resolution	Reference Year
Walker 2022	Global Carbon Density (AGB+BGB)	Walker et al. / S3	Raster (COG)	Global	~300 m	2016
`COPERNICUS/S2_SR_HARMONIZED`	Sentinel-2 L2A	ESA/Copernicus	Multispectral	Global	10 m	2017 — present
`GOOGLE/DYNAMICWORLD/V1`	Dynamic World	Google/WRI	Land cover	Global	10 m	2015 — present
`USGS/SRTMGL1_003`	SRTM DEM	NASA/USGS	Elevation	60N-56S	30 m	2000

Quality Range and Levels

Indicator	Unit	Range	Inverted
`carbon_stock_current_agb_bgb`	tC/ha	[0, 8, 25, 70, 130, 250]	No

Inverted = No: a higher value indicates greater living biomass carbon.

Level	Thresholds	Interpretation
E (Very Low)	< 8 tC/ha	Bare soil, urban, desert — negligible living biomass
D (Low)	8-25 tC/ha	Sparse shrublands, annual croplands
C (Moderate)	25-70 tC/ha	Grasslands, open woodlands, young planted forests
B (High)	70-130 tC/ha	Mature temperate forests, dense mixed woodlands
A (Very High)	> 130 tC/ha	Tropical forests, old-growth forests, mangroves

Technical Notes

Living biomass = AGB + BGB; dead organic matter (litter, deadwood) is excluded
The AGB:BGB ratio varies by ecosystem — forests ~3:1 to 5:1, grasslands ~1:1 to 1:3
This combined metric is directly comparable to IPCC living biomass carbon stock definitions
Seasonal variation in living biomass is captured through the NDVI temporal composite

References

Walker, W.S. et al. (2022). "The global potential for increased storage of carbon on land". PNAS, 119(23), e2111312119.
Spawn, S.A. et al. (2020). "Harmonized global maps of above and belowground biomass carbon density in the year 2010". Scientific Data, 7, Article 112.
Breiman, L. (2001). "Random Forests". Machine Learning, 45(1), pp. 5-32.

Data Sources & References

Sources

WRD_CARBN_22

Methodology

Il layer Carbon Stock Attuale - Biomassa Vivente (AGB+BGB) viene calcolato sommando le componenti di biomassa aerea e sotterranea dalla mappa globale di Walker et al. (2022). Questa metrica combinata rappresenta il carbonio totale nella vegetazione vivente, escludendo materia organica morta e carbonio del suolo. Entrambi i pool vengono estratti dal baseline e sommati, poi raffinati tramite Random Forest con NDVI (Sentinel-2), copertura del suolo (Dynamic World) ed elevazione (SRTM). La biomassa vivente e la metrica standard per la contabilita del carbonio IPCC Tier 2 e per il monitoraggio forestale. Output in tC/ha a ~200 m.