FORCE - FORecasting hydrological response, Carbon balance and Emissions from different types of mires in arctic-to-temperate zone transect in abrupt climatic change

Abstract

Mires remain the most significant terrestrial carbon stock of the world. The most up to date research results have informed that former estimates of the amounts of carbon stored in mires can be underestimated by even as high as 100%. Dominant direct drivers of mire status originate from hydrology, namely the type (i.e., rain- or groundwater feeding) and quantities of water supplied to a mire and removed from this system in result of natural drainage and evapotranspiration. Impaired peat accumulation processes can result in a positive feedback of the emission of CO2 as a response to supply of mineral-rich groundwater (resulting from permafrost thaw and increase of the fen catchment area in Arctic palsa mires) and water balance changes (resulting from shortages of water in temperate fens and sloping fens). FORCE project is focused at the verification of the hypothesis that ET-driven and catchment-change driven water balance and carbon balance changes on different mires in Arctit-to-temperate transect remains in a positive feedback with the abrupt climatic changes, resulting in expected decrease of carbon accumulation in peatlands and an increased emission of greenhouse gasses that will likely not to be stopped by any management measures. In order to verify this hypothesis we formulated set of research tasks based on general context analysis, groundwater flow modelling, Monte-Carlo parameter estimation and statistical techniques of risk assessment, isotope analyses of groundwater, surface water and vegetation and emission quantification to be integrated in a Bayesian belief approach. All of the research activities were based on the results of original data collected in a number of scheduled field research campaigns . Study sites represent the most significant examples of mires exposed to abrupt climat-change-related issues across the Arctic-to-temperate gradient: from Nordic permafrost (Suossjarvi) through the bog-lake system with expected significant role of aquatic ecosystems in total CO2 and CH4 balance (Midtfjellmosen), to fens in river valley dependent both on the draining role of the river and limited supply of water to the mire (Rospuda Valley, PL). In the framework of the project (i) we plan to reveal the amounts of CO2 transported by groundwater to the mires analysed and see how does the probable emission of CO2 from groundwater in mires contribute to total emission of CO2 from mires; (ii) we will establish groundwater flow models in order to reveal the origin of water supplying particular objects and its changes in modelled abrupt climatic change scenarios represented as changed parameters of ET, P in a Monte-Carlo procedure; (iii) we will assess the isotope composition of groundwater and surface water in order to confirm the origin of water feeding particular zones of the mire and calibrate groundwater flow models; and (iv) we will conduct laboratory estimation of greenghouse gasses and groundwater quality. It is likely that the messages resulting from the FORCE project implementation will influence international strategies oriented at promotion of mire research and conservation, placing new threads of peatland hydrology, emissions and carbon accumulation in a management context.