The second generic model (Pearson,
Table 5) showed only small differences with Chave.H model, except in the Sumatran plot. The integration of regional height estimates into Chave.H model resulted in a slight overestimate of 5–10% in unmanaged forest, and almost no departure in secondary forest (−3–0%). The generic pantropical model developed by Chave et al. (2005) including tree height provided the best biomass estimates when applied to our destructive samples (Table 3). selleck screening library This result was expected as the Indonesian sites used in their study were both located in East Kalimantan, about 200 km from where trees used in this study where collected. Additionally, Chave et al. (2005) showed that H-models had smaller departure from observed values compared to DBH-models in most tropical forests, but with a notable exception in East Kalimantan. Our results are consistent with this finding, showing that generic models relying solely upon DBH and WSG (Chave.DBH or Pearson) were also very good at predicting biomass at our sites. MG-132 nmr However, these last models can result in an error of ±15% of the actual biomass stock in certain forests. Despite the fact that Dipterocarp forests represent the dominant vegetation in Borneo, it is most likely that accounting for other forest types with different structures (i.e. kerangas
forests, peat swamp forests, forests on limestone) would have given different Resveratrol results. For instance, in African forests where H:DBH relationship is very different and from which no data were used to calibrate those generic models, Chave.DBH model largely overestimated biomass while Chave.H gave very good fit (Henry et al., 2010, Vieilledent et al., 2011 and Fayolle et al., 2013). As tree height is generally not recorded in forest inventories, models relying solely upon DBH are likely to remain widely used by foresters. We showed here that the generic model developed by Brown (1997), updated by Pearson et al. (2005), showed similar performance to the model integrating WSG and DBH (Chave.DBH), but with slightly
smaller bias. Both models outperformed the regional models developed in East Kalimantan. In conclusion, generic models relying solely upon DBH and WSG remain appropriate, but should be used with caution as they generally overestimate biomass. With advances in laser instruments, it has become easier to accurately and rapidly assess tree height in the field. In a tropical forest, direct vertical measurements of the last branch was found to underestimate of actual tree height by 20% (Larjavaara and Muller-Landau, 2013). It is likely that the error remains proportional to tree height, affecting primarily emergent trees. Rapid advances in LiDAR-derived mean canopy height might help to overcome this caveat and seems to be a promising way of integrating average forest stand height into plot carbon stocks measurements (Asner et al., 2011).