Median increases in respiration ranged from +83 % (early season tillage) to −50 % (rice paddy flooding and burning of rice residues) on the 28 days time scale, when only management types with a minimum of 7 replications are considered. Most management types showed a large variation among events and between sites, indicating that additional factors other than management alone are also important at a given site. Temperature is the climatic factor that showed best correlation with site-specific respiration fluxes. Therefore, the effect of temperature changes between the time periods before and after management were taken into account for a subset of 13 management types with adequate statistical coverage of at least 5 events during the years 2004–2007. In this comparison, late-season moldboard ploughing (30–45 cm) led to highest median increase in respiration on the 7 days timescale (+43 % ), which was still +15 % in the 28 days comparison. On average, however, management-induced increases in respiration losses from croplands were quite moderate (typically <20 % increase over 28 days).
An assessment of extreme values in daily respiration fluxes using the Gumbel distribution approach revealed that sites with larger average respiration fluxes also experience the larger extremes in respiration fluxes. This suggests that it is very unlikely that sites that generally have low respiration rates will have exceedingly high respiration rates as a result of certain specific management events.