DendroGeo Methods
How tree biomass, carbon stock, geodesic area and 10 m land-cover analysis are computed, with sources, uncertainty and limitations.
Open the DendroGeo appBiomass and carbon
Above-ground biomass follows the pantropical allometric equation of Chave et al. (2014): AGB = 0.0673·(ρ·D²·H)^0.976, with D = DBH (cm), H = height (m) and ρ = wood density (g/cm³) by species or group default. Root biomass = AGB × 0.26; carbon = 0.47 × total biomass.
Location and area
Distances use the haversine formula on WGS84. Park areas use geodesic polygon mathematics; land-cover cells are intersected with the park polygon in the native UTM zone and only the true intersection area is counted (no pixel counting).
Land cover
The park polygon is intersected with 10 m categorical raster cells. Primary source: ESA WorldCover 2021 v200; independent cross-check: IO LULC 2020, reported as per-group agreement. OSM water and road vectors refine artificial pools and hard surfaces. OSM geometry does not change the numeric class result.
Uncertainty
Field sigmas (DBH ±0.5 cm, height ±0.25 m) and a conservative 22% CV for the allometric model are propagated by Monte Carlo (n=1000, fixed seed); totals treat model error as correlated across records. Totals are reported with 95% confidence intervals where enabled.
Geofence and approval
Measurements require an approved park identity; the device position must fall inside the park polygon (40 m edge margin) or the server rejects the row (trigger trg_geo_fence). Every record enters the public dataset only after moderator approval.
Limitations
- 10 m land-cover accuracy varies by class and site.
- Chave (2014) is pantropical; regional bias for Turkish species is possible.
- Group-level wood density is used when species density is unavailable.
- Satellite-derived boundaries estimate green cover, not administrative borders.