Estimates the wood biomass of logs and truncated branches by computing their volume (using Smalian's formula) and converting it to fresh weight using wood fresh density.
Smalian's formula: V=\frac{Sb+Sd}{2}l where V is the log volume, Sb is the aerea of the basal (lower) section, Sd is the area of the higher section and l is the length of the log.
1  logBiomass(x, lowerD, higherD, logLength, density)

x 
the data frame holding the measures needed to perform the estimation 
lowerD 
The name of the data frame column holding diameter of the lower section in cm 
higherD 
The name of the data frame column holding the diameter of the higher section (usually smaller!) in cm 
logLength 
The name of the data frame column holding the length of the log or branch in m 
density 
The name of the data frame column holding the fresh density of the wood, defined as D=\frac{V_f}{W_f} where V_f is wood volume measured in the field (i.e. satured with water) in m^3 and W_f is wood fresh weight in kg. Fresh density is measured in \frac{kg}{m^3} 
Diameters used to compute section areas should be measured under the bark layer! When this is not the case (scarcely ever!) and diameters include bark thickness the log biomass is somewhat overestimated!
la Marca, O. Elementi di dendrometria 2004, Patron Editore (Bologna), p. 119
Other Biomass: allometryABDC
,
allometryAsca2011
,
allometryCutini2009
,
allometryPorte2002
,
powerEquation
,
pureQuadraticEquation
,
treeBiomass
, treeTotalBiomass
Questions? Problems? Suggestions? Tweet to @rdrrHQ or email at ian@mutexlabs.com.
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