Until now the data of growing stock were hardly comparable across country borders. The European National Forest Inventories have now succeeded to harmonise the computation of growing stocks within the scope of the Horizon 2020 project “DIABOLO”. A major support for the information needs at the European level.
National Forest Inventories are the major source of information about the status and development of forests. They provide statistically sound data bases for forest and environment related decision processes, ensure the fulfilment of reporting obligations in international treaties, and support research on forest ecosystems.
Forest inventory data from different countries usually lack international comparability due to several reasons, from the different historical development of forest inventories, to the adaptation of the sampling designs to country-specific conditions, and the different thematic focus on more ecological or economic topics. As forest inventories developed across Europe, inventory experts soon had recognised the difficulties in comparing inventory data across country borders. With the foundation of the European National Forest Inventory Network (ENFIN) numerous countries started an integrative harmonisation process. The primary objective was the development of a general harmonisation method for European National Forest Inventories.
From single trees to growing stock
Recently the harmonisation of single stem volumes was achieved for 21 countries and provided the input for the calculation of comparable growing stocks. According to a recent study by numerous forest inventory experts the discrepancies in growing stock were until now in the range of -10 % to +30% compared to a common reference volume. These inconsistencies were on the one hand due to different tree parts taken into account (for example stem top, large branches, or stump) and on the other hand caused by different diameter thresholds (some countries include trees from 0.1 cm diameter, others for instance from a diameter of 7 cm). Therefore, the harmonisation was essential for a consistent and international comparable computation of wood resources.
Now for the first time, comparable stem volume and growing stock data are available and will provide the basis for computations and future simulations of wood resources in Europe. “The harmonisation of single stem volumes provides a particularly important basis for the computation of comparable growing stocks and other important indicators like increment and harvest” says Thomas Gschwantner, Task leader in the Horizon 2020 Project DIABOLO (Distributed, Integrated and Harmonised Forest Information for Bioeconomy Outlooks).
The DIABOLO project received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 633464.