Tropical managed Forests Observatory
As the different study sites were independently set up, there is no standardized protocol of measurements. However, it appeared that the same standards were applied at most sites.
Basically, all trees above 10 or 20 cm diameter at breath height (DBH) were tagged and identified to the lowest taxonomical level. Girth measurement at 130 cm height were carried out before, directly and several time after logging.
Individual tree biomass was computed using the new pantropical allometric model equations proposed by Chave et al. (2014), where E is a composite climatic index retrieved at each site and WSG, the wood specific gravity retrieved from the Dryad Wood Density Database (Zanne et al. 2009).
AGB = exp(-1.803 - 0.976*E + 0.976*log(WSG) + 2.673*log(DBH) - 0.0299*log(DBH)2)
From the forest inventories, each site leader will extract the variables described below for each census:
Variable | Description |
site | site name |
plot | plot identifier |
plot size (ha) | size of the plot (ha) |
Logging treatment | the type of logging treatment (i.e. RIL, conventional,..) |
trees harvested (n/ha) | Number of trees harvested per hectare |
volume harvested (m3/ha) | Volume of trees harvested per hectare |
time since logging | Duration after logging |
Year | Average date of measurment |
DBH min | min Minimun DBH threshold at the site |
AGB10-20 | Biomass in the 10-20 cm DBH class |
AGB20-30 | Biomass in the 20-30 cm DBH class |
AGB30-40 | Biomass in the 30-40 cm DBH class |
AGB40-50 | Biomass in the 40-50 cm DBH class |
AGB50-60 | Biomass in the 50-60 cm DBH class |
AGB+60 | Biomass in >60 cm DBH class |
AGB total (DBH>10) | Total biomass DBH > 10 cm |
AGB total (DBH>20) | Total biomass DBH > 20 cm |
BA (DBH>20) | Basal area summed among trees DBH > 20 cm |
stem density (DBH>20) | Total number of stems DBH > 20 cm |
BA-weighted WD (DBH>20) | Average wood density weighted by basal area for trees DBH > 20 cm |
average WD (DBH>20) | Average wood density weighted for trees DBH > 20 cm |
Fire | Presence of fire at the site |
Rainfall | Annual rainfall (extracted from Worldclim data) |
Region | Type of region (for the choice of the appropriate allometric models) |
Soil type | Soil characteristics (extracted from the Harmonized World Soil Database) |
Soil fertility | Soil characteristics (extracted from the Harmonized World Soil Database) |
Copyright @TmFO.2014 contact@tmfo.org Updated: 22/10/2020