The bark carbon storage of Austrian commercial forests

In Austria, the Austrian Federal Office and Research Centre for Forests (BFW) provides basic forest data such as volume stock or the national carbon inventory. The Austrian carbon inventory currently records the carbon stored in the bark as part of the forest's total tree carbon stock. However, tree bark plays a vital role in the life span of a tree and is also important for the decomposition process following tree death. There is a veritable need to quantify the proportion of bark accurately because it has an important impact on economic calculations. In this study we assess the amount of carbon stored in the stem bark of Austrian commercial forests (in German “Wirtschaftswald”) as it can be derived from (i) the taper curve, (ii) the bark percentage, (iii) the bark density, and (iv) the bark fissure index. We applied this “bark carbon model" to the latest data from the Austrian National Forest Inventory (NFI). The model predicts for each tree the corresponding bark carbon content, which can be easily aggregated to plot or regional level for further use. Our results suggest, that about 7% of the total carbon in Austrian commercial forest is stored in the bark of the tree stems. The findings provide bark carbon information that can also be used for other purposes like potential harvesting of bark, or determining the fire adaptation of tree species. Moreover, this study helps to provide information for the bark carbon share of the Austrian National carbon inventory.