Soil CO2 efflux in three wet meadow ecosystems with different C and N status

Data on soil respiration of three wet meadow ecosystems in the Czech Republic are presented. There were three study sites: two sites with peaty soil, one of them aneutrophic (nitrogen rich) and second of them oligotrophic. Third site was mesotrophic with mineral soil. Soil respiration was measured in situ as CO2 efflux using a Licor 6400 equipped with a soil chamber during the vegetation seasons, since June until October 2006. Soil respiration rates were significantly affected by soil temperature, although they differed among the sites, just as nutrient availability differed on each site. Despite of seasonal variation, the nutrient rich site on organic soil consistently yielded the highest respiration rates, and nutrient poor site yielded the lowest respiration rates. The highest CO2 emissions rates in situ were measured in June, when the soil temperature was 19°C. The rates reached up to 10.31 μmol CO2 m-2 s-1 at eutrophic site, at peaty oligotrophic site 7.03 μmol CO2 m-2 s-1 , and 8.38 μmol CO2 m-2 at mineral mesotrophic site, respectively. When we used a temperature dependency exponential model to avoid the effect of different soil temperature, the pattern observed in the field was even clearer. The peaty eutrophic soil was more sensitive to temperature then the mineral and peaty oligotrophic soil and C mineralization was more enhanced there