Unraveling the role of forests in the carbon cycle
According to the United Nations Framework Convention on Climate Change (UNFCCC), industrial and other emissions of carbon dioxide and other greenhouse gases (GHG) have an impact on climate. Kyoto's Protocol and its rulebook provided legal support towards limiting or reducing GHG emissions. An intergovernmental consortium was formed in an effort to collect sufficient information to estimate GHG emissions and take precautions for future climate changes. Forests play a key role in the implementation of the convention since they serve both as source and sink of carbon in the atmosphere. With the aim to perform carbon flux analyses and quantify carbon stocks in European forests, CARBO_INVENT network focused on integrating multi-source inventory methods. National Forest Inventories had laid the groundwork for this effort; however, internationally approved harmonization in a European assessment system was essential. CARBO_INVENT partners were successful in integrating forest inventory data with existing and newly developed biomass functions by employing two methods: a top-down and a bottom up approach. Both approaches assess biomass allocation and tree carbon stocks either utilizing the aggregated inventory data (top-down approach) or the inventory data at the plot level (bottom-up approach). Three regions in different countries (Austria, Finland and Germany) were examined. Detailed comparison of the approaches was carried out in the German region. The overall results obtained revealed that at regional level both approaches give equivalent estimates. However, carbon stock estimation is not accurate when the species or age classes vary even if the same biomass functions are employed. CARBO_INVENT set out the importance of a European Forest resource database comprising validated data emerging from close international cooperation and national policies in compliance with Kyoto's protocol. The more data get aggregated the better the estimation of carbon stocks and stock changes of forest ecosystems contributing to climate policy.
