Third, the plot network lacks the basic signatures of forests recovering from large disturbances.
Biomass in is not the only structural change recorded in Amazonian forest plots. Across 91 RAINFOR plots where we tracked popula tions back to 2002 there has been a small increase in the stand density between the first and last measurements of 0.84 t 0.77 stems per hectare per year, an annual increase of 0.15 0.13% (Phillips et al. 2004).
The same test using a longer-term subset of plots(50 plots from Lewis et al. 2004b) shows a slightly larger increase(0.18 t 0.12% per year).
These increases in stand density, while proportionally smaller than the biomass changes, run counter to expectation of declines if the plots were in an advanced state of secondary succession(e.g Coomes& Allen 2007), as do simultaneous increases in growth rates(see below) In Africa stand density changes have yet to be evaluated, but in both Africa and Amazonia there has been no shift in species composition towards more shade- tolerant taxa that would occur in a domain that was recovering from past disturbance events(eg. Lewis 2009a; Phillips et al. 2009).
In summary, analysis of other structural, dynamic and floristic change in the same plots is not consistent with a widespread disturbance recovery signature.
These results argue against the notion that the generalised biomass increase observed across Amazon and African plots can be explained as a result of a combination of disturbance recovery and small sample sizes.