Carbon account of forest ecosystems as a fuzzy system: a case study for Northern Eurasia

We consider practicality of a verified account of Net Ecosystem Carbon Budget for forest ecosystems (CA) that supposes reliable assessment of uncertainties, i.e. understanding uncertainty of The FCA is a fuzzy (underspecified) system, of which membership function is inherently stochastic. Thus, any individually used of FCA is not able to estimate structural and usually reported method are inevitably partial. Attempting an estimation of full uncertainties of the studied system we follow the requirements of applied systems analysis integrating the major methods of terrestrial ecosystems carbon account, assessing the method for intermediate and final indicators of CA with their following mutual constraints. Landscape-ecosystem approach (LEA) 1) serves for strict systems designing the account, 2)contains all relevant spatially distributed empirical and semi-empirical data and models, and 3) is presented in form of an Integrated Land Information System (ILIS). By-pixel parametrization of forest cover is provided by utilizing multi-sensor remote sensing data (1 RS products used) within GEO-wiki platform and other relevant information based on special optimization algorithms. Major carbn fluxes within the LEA (NPP, HR, disturbances etc.) are estimated based on fusion of empirical data with process-based elements by sets of regionally distributed models. Uncertainties within LEA are assessed for each module and at each step of the account. Withi method results and (including LEA, process-based models, eddy covariance, and inverse modelling) are harmoized based on the Bayesian approach. The above methodology have been applied to carbon account of Russian forests for 2000-2010;uncertainties of the FCA for individual years were estimated in limits of 25%. We discussed strengths and weaknesses of the paproach, system requirements to different methods of FCA, information and research needs, obtained and potential levels of uncertainties.