Calculator inputs
Choose a direct density workflow or estimate biomass from field inventory measurements.
Example data table
This worked example uses the direct biomass density method for a tropical wet mangrove stand.
| Item | Example value | Unit | Explanation |
|---|---|---|---|
| Study area | 12.5 | ha | Total mangrove block assessed. |
| Aboveground biomass density | 180 | t d.m./ha | Field or mapped aboveground dry biomass. |
| Root ratio | 0.492 | ratio | Tropical wet default root-to-shoot ratio. |
| Aboveground carbon fraction | 0.451 | fraction | Fraction of biomass represented as carbon. |
| Root carbon fraction | 0.39 | fraction | Lower carbon concentration for roots. |
| Dead wood carbon | 10.7 | t C/ha | Standing and downed woody debris carbon. |
| Litter carbon | 0.7 | t C/ha | Surface litter carbon pool. |
| Soil carbon | 320 | t C/ha | Measured or mapped soil organic carbon density. |
| Annual AGB growth | 9.9 | t d.m./ha/yr | Example annual biomass increment. |
| Total ecosystem carbon density | 447.12 | t C/ha | Combined living biomass, dead wood, litter, and soil. |
| Total ecosystem carbon stock | 5,588.98 | t C | Carbon density multiplied by study area. |
| Total CO2 equivalent | 20,492.93 | t CO2e | Carbon stock converted using 44/12. |
Formula used
This calculator combines biomass pools and carbon fractions to estimate living biomass carbon, total ecosystem carbon stock, and CO2 equivalent for a mangrove site.
| Purpose | Formula | Units |
|---|---|---|
| Direct belowground biomass | BGB density = AGB density × root ratio | t d.m./ha |
| Inventory aboveground biomass | AGB tree = 0.0509 × ρ × DBH² × Height, or 0.251 × ρ × DBH^2.46, or 0.168 × ρ × DBH^2.471 | kg/tree |
| Inventory biomass density | AGB density = sample biomass ÷ sampled area | t d.m./ha |
| Optional root equation | BGB tree = 0.199 × ρ^0.899 × DBH^2.22 | kg/tree |
| Living biomass carbon | (AGB density × aboveground carbon fraction) + (BGB density × root carbon fraction) | t C/ha |
| Total ecosystem carbon density | Living biomass carbon + dead wood carbon + litter carbon + soil carbon | t C/ha |
| Total carbon stock | Total ecosystem carbon density × study area | t C |
| CO2 equivalent | Total carbon stock × 44 ÷ 12 | t CO2e |
| Annual live carbon gain | (Annual AGB growth × aboveground carbon fraction) + (Annual AGB growth × effective root ratio × root carbon fraction), then × area | t C/year |
For highest accuracy, use site-specific plots, species equations, and measured soil carbon values where available.
How to use this calculator
- Select a calculation method. Use direct density when you already have per-hectare biomass estimates. Use field inventory when you have plot data.
- Enter the total study area in hectares. This converts per-hectare carbon density into total carbon stock and CO2 equivalent.
- Choose an ecological zone preset if you want default root ratio and growth values. You may overwrite them with local measurements.
- Fill in carbon fractions, dead wood carbon, litter carbon, and soil carbon. Soil values should come from cores, maps, or validated literature.
- For inventory mode, enter sampled area, number of measured trees, mean DBH, mean height, and wood density. Then choose your preferred biomass equation.
- Submit the form. The result panel appears below the header and above the form, including carbon density, total stock, and annual gain outputs.
- Use the export buttons to save the result summary as CSV or PDF for reporting, restoration planning, or project documentation.
FAQs
1. What does this calculator estimate?
It estimates aboveground biomass, belowground biomass, live biomass carbon, total ecosystem carbon density, total carbon stock, annual live carbon gain, and CO2 equivalent.
2. Why is soil carbon included?
Mangrove soils often contain a major share of ecosystem carbon. Excluding soil can severely understate total blue carbon storage and project climate value.
3. When should I use the direct method?
Use it when you already have aboveground biomass density from surveys, maps, or previous studies and only need carbon conversion and stock scaling.
4. When is inventory mode better?
Inventory mode is better when you collected DBH, height, tree counts, and plot area. It converts plot measurements into biomass density automatically.
5. Are the default ratios enough for reporting?
They are useful screening values, but formal reporting usually benefits from local field measurements, species-specific equations, and site-specific soil carbon data.
6. What is wood density used for?
Wood density links trunk size to biomass in allometric equations. Denser wood usually means higher biomass for the same tree diameter.
7. Why are there two root options?
The ratio method is faster and simpler. The root equation can better reflect measured stand structure when inventory data are available.
8. Can I use this for restoration monitoring?
Yes. Repeating the same method over time helps compare carbon recovery, stand growth, and ecosystem stock changes across restoration phases.