20160516

Author : 

O. Joos, F. Hagedorn, A. Heim, A. K. Gilgen, M.W. I. Schmidt1, R. T. W. Siegwolf, and N. Buchmann

Year : 2010

Title : 

Summer drought reduces total and litter-derived soil CO2 effluxes in

temperate grassland – clues from a 13C litter addition experiment

Journal : Biogeosciences

Comment : 

 Drought significantly decreased Rs in litter addition experiment by 59% and litter-derived CO2 efflux by 81% during the drought period itself (May to July, indicating that drought had a stronger effect on the CO2 release from litter than on the below ground-derived CO2 efflux (soil organic matter (SOM) and root respiration).

 Despite large bursts in respired CO2 induced by the rewetting after prolonged drought, drought also reduced Rs and litter-derived CO2 efflux during the entire 13C measurement period (April to October) by 26% and 37%, respectively. Overall, there result show that drought decreased Rs and altered its seasonality and its sources. 

 Thus, the C balance of temperate grassland soils respond sensitively to changes in precipitation, a factor that needs to be considered in regional models predicting the impact of climate change on ecosystems C balance.