We assembled data from two sources. Over the years a substantial quantity of decayed wood density data has been generated by the Andrews LTER (Long-term Ecological Research) program. Some of this data has been published, but much of it has not, at least in terms of densities for decay classes. This program has also produced a large dataset on undecayed branch density as part of branch decomposition studies that have been conducted over the years. The other source was the published literature, which, although not as extensive as the first source, does provide information for many systems not sampled (Appendix 1).