Carbon stocks in forest ecosystems based on inventory data
Among the EU political priorities there is the need to implement the United Nations Framework Convention on Climate Change, and to meet the targets of the Kyoto Protocol for reducing greenhouse gas emissions. To this end, there is need for a uniform European system of greenhouse gas reporting which is scientifically based and follows principles like consistency and verifiability. CARBOINVENT project focused on the design of appropriate methods for carbon inventories of forests at a regional and national level that meet these requirements. Part of the project was directed to review the state of knowledge on changes in the carbon stocks in forests subject to major disturbances with special attention on inventory techniques suitable for their assessment. In the context of this work, disturbance was defined as any storm or fire event that changes the vitality status of trees from "living" to "dead" (ceasing autotrophic respiration). The reporting of carbon stock changes is often based on inventories that were mainly conceived to fulfil management information needs on timber volume, not necessarily the amount of carbon stored. Additional information on carbon sources following disturbances is needed since they change the ecosystem processes in a way that differs from the carbon dynamics following regular harvests. Forest management activities influence carbon stocks, either directly by transferring carbon from "live" to "dead" wood, or indirectly by altering the growth conditions of trees. They may affect the current or future stands, or be transients. To specify monitoring techniques for measuring and verifying carbon stock changes due to changes in the forest management practices, a fundamental condition is the definition of the latter. They can be regarded as laws, instructions and guidelines that shape external influences and frame decisions taken at the individual forest management unit. Alternatively, they can be considered as the selection of options within the frame of a standard practice which best meet the objectives set for the forests. These innovative approaches and subsequent improved methods for monitoring the effects of disturbances and forest management will enable extend National Forest Inventories to meet greenhouse gas inventory needs.
