A possible response to climate extremes of fluxes and concentrations of CO2 and CH4 in northern fens
Marieke Oosterwoud (01/2006)
Support: Christian Blodau, Klaus-Holger Knorr
A long term sinks of atmospheric CO2 and persistent sources of CH4, peatlands are important biospheric feedback components of the global carbon cycle. Climate predictions show changes in the temporal pattern of precipitation, resulting in longer dry periods and more extreme precipitation events. Hence, water level fluctuations may show an increase at both seasonal and shorter term time scales. The speed of recovery of both methanogens and methanotrophs after periods of low water levels is an important factor in predicting the lag in the reactivation of methane production. Unfortunately, high resolution measurements of carbon mineralization rates under dynamic conditions and in undisturbed soil samples are sparse. The objective of this study is to determine the effect of drought followed by extreme precipitation events and the presence of vegetation on the sub-surface production and flux of CO2 and CH4 in undisturbed peat samples from a northern fen.