Attributes of dead wood carbon stocks across forests of the U.S.

Background/Question/Methods

As signatories to the United Nation Framework Convention on Climate Change, the US has been estimating standing and down dead tree carbon (C) stocks using a model based on live tree attributes.  The USDA Forest Service began sampling forest detrital components nation-wide in 1999.  With comprehensive field data now available, the objective of this study was to compare field- and model-based estimates of forest dead wood C stocks across the US to refine national C stock estimates and improve the understanding of C dynamics. 

Results/Conclusions

Field inventory data indicated that most forests have relatively little standing dead tree C stocks (< 1 Mg/ha), whereas large C stocks (> 25 Mg/ha) are infrequent.  Models used for past NGHGIs to predict forest dead wood C stocks may not accurately reflect what was observed in inventory plots, resulting in an overestimation of dead wood C stocks at the national-scale.  A field-based approach is suggested for use in future C reporting efforts to reduce estimation bias.