Nature 462, 795–798 (2009)

In this Letter, the L/B terms in equations (3) and (4) should be inverted to B/L. The authors report that these equations are not integral to their hypotheses and were not part of the analysis. The sole function of these equations is to provide a heuristic to illustrate that the threshold element ratio (TER) is a distinct parameter from the actual elemental composition of available organic matter.