Quantifying char in postfire woody detritus inventories

Abstract

Charred biomass generated by wildland fire has attracted increased interest as a functional component of terrestrial ecosystems. Black carbon (C) in the form of char is a widespread but unique material contributing to biogeochemical processes including long-term carbon storage and soil productivity. These functions have long been recognized by the biogeochemical and soil sciences, but have so far received little attention from wildland fire science. Fire scientists conducting postfire biomass (or fuel) inventories have an opportunity to quantify the formation of char on woody material, which is important to quantifying interactions between fire and global C dynamics. In addition, failure to account for mass loss due to charring can result in overestimation of down wood biomass and decomposition (12% to 233% for particles up to 20 cm diameter). In this paper, we present computational methods that can be incorporated into standard planar intercept transects for estimating black C production and reducing overestimation bias for charred down woody detritus. Methodologies for quantifying black C production in other ecosystem pools are also discussed.