Data collection

Tropical managed Forests Observatory

Data collection

 

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.

 

Forest inventories and biomass computation

 

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)

 

 

Available metadata per site

 

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: 24/12/2014