Growing stocks of trees in Europe have increased in a magnitude that is significant in terms of carbon (C) sink strength. Estimates of the soil C sink strength that this increased stock of trees may ...have induced on a regional scale are scarce, uncertain and difficult to compare. This illustrates the need for a widely applicable calculation method. Here, we calculate a C budget of productive forest in southeast Norway based on forest inventory information, biomass expansion factors (BEF), biomass turnover rates and the dynamic soil model Yasso. We estimate a 29% increase (112–145
Tg) of C in biomass between 1971 and 2000, and estimate the associated increase of C in soils (including dead wood) to be 4.5% (181–189
Tg). The C sink strengths in biomass and soils (including dead wood) in 1990 are 0.38 and 0.08
Mg
ha
−1
yr
−1, respectively. Estimated soil C density is 58
Mg
C
ha
−1 or ca 40% of measured soil C density in Norwegian forest soils. A sensitivity analysis – using uncertainty estimates of model inputs and parameters based on empirical data – shows that the underestimation of the soil C stock can be due to overestimation of decomposition rates of recalcitrant organic matter in the soil model and to including only trees as a source of litter. However, uncertainty in these two factors is shown to have a minimal effect on soil sink estimates. The key uncertainty in the soil sink is the initial value of the soil C stock, i.e. the assumed steady state soil C stock at the start of the time series in 1970. However, this source of uncertainty is reduced in importance for when approaching the end of the data series. This indicates that a longer time series of forest inventory data will decrease the uncertainty in the soil sink estimate due to initialisation of the soil C stock. Other, less significant, sources of uncertainty in estimates of soil stock and sink are BEF for fine roots and turnover rates of fine roots and foliage. The used method for calculation of a forest C budget can be readily applied to other regions for which similar forest resource data are available.
Most European countries have signed the United Nations Framework Convention on climate change and its Kyoto Protocol. Because the European Union is a party to the convention just like the individual ...countries, there is a need for harmonizing emissions reporting. This specifically applies to the Land Use, Land-Use Change, and Forestry sector, for which harmonized reporting is complex and generally challenging. For example, parties use a variety of different methods for estimating emissions and removals, ranging from application of default factors to advanced methods adapted to national circumstances, such as ongoing field inventories. In this study, we demonstrate that without harmonization, national definitions and methods lead to inconsistent estimates. Based on case studies in Finland, Germany, Norway, Portugal, Slovenia, and Sweden, we conclude that common reference definitions and country-specific bridges are means to harmonize the estimates and make greenhouse gas reporting from forests comparable across countries.
National forest inventories (NFIs) are an important source of data for reporting greenhouse gas emissions and removals for the Land Use, Land-Use Change, and Forestry sector as required by the United ...Nations Framework Convention on Climate Change and its Kyoto Protocol. A major limitation is that NFI resources are generally not sufficient for producing reliable information on year-to-year variation. Interpolation, extrapolation, smoothing, and/or aggregation of data from several years are therefore needed to comply with the reporting requirements for a specific year. Various methods for accomplishing this task are illustrated and evaluated based on data and experiences from the NFIs of six countries, concentrating on the estimation of the stem volume of living trees as a surrogate for tree biomass. Six main conclusions were drawn: (1) NFI data from the target years only were not sufficient for reliable estimation of annual stock change; (2) changes between whole inventory cycles (typically 5 years) could be estimated with reasonable precision; (3) simple moving average estimators of stock are problematic in the estimation of changes; (4) interpenetrating panel designs with permanent sample plots are desirable from the point of view of inter/extrapolating and change estimation; (5) data on annual growth variation and harvests are important and can be used directly in the default method, which is based on differences between increment and drain; and (6) time gaps between NFI surveys may lead to significant errors in the estimation of stock changes.
Using a widely applicable method, a carbon budget of forest biomass and soils in southeast Norway was calculated. Estimated soil C density was 58 Mg C ha super(-1) or ca 40% of measured soil C ...density in Norwegian forest soils. The key uncertainty in the soil sink was the initial value of the soil C stock that is, assumed steady state soil C stock at the start of the time series in 1970. It indicated that a longer time series of forest inventory data could decrease the uncertainty in the soil sink estimate due to initialization of the soil C stock. The used method for calculation of a forest C budget could be readily applied to other regions for which similar forest resource data were available.
The Nordic Council of Ministers has set up the Nordic COP 15 Group to help achieve a successful outcome in the climate change negotiations at COP 15 in Copenhagen in December 2009. The Nordic COP 15 ...Group have identified key elements in the negotiations where efforts are needed to ensure a good outcome, i.e. adaptation to climate change, technolo-gy transfer, legal issues, sinks and deforestation. This report explore ways to adjust the current accounting rules on sinks into rules that would create better incen-tives for actively managing lands, in order to decrease the emission of greenhouse gases to the atmosphere and/ or to remove greenhouse gases from the atmosphere. Different proposals for the treatment of the LULUCF-sector (Land Use, Land Use Change and Forestry sector) are compared and analysed.
PDF
