Biomass to Carbon Conversion Factors.
Analysis
We reviewed the literature to find estimates of the carbon concentration
of dead wood in various states of decomposition. Given the paucity
of data, we averaged across all species within CWD decay classes to
derive a mean estimate. For FWD we averaged across all species for
undecayed and decayed wood. We used all available data to derive a
standard error of carbon concentration, weighting these estimates by
the sample sizes reported in the publications.
Results
There appears to be no consistent trend in carbon concentration as
wood decomposes (Table
1 and Table 2). The mean carbon concentration of
CWD across all decay classes is 49.8%, with the lowest mean concentration
for a decay class being 48.6% and the highest being 51.8%. For FWD
the mean carbon concentration was 50.8%, with a range of 49.1 to
51.6%. Although the range of values within decay and size classes
was up to 10% of the mean, the uncertainty in carbon concentrations
used to convert biomass to carbon is very low relative to densities.
As a first approximation using a mean concentration of 50% with an
uncertainty of 2% would be adequate.