TY - JOUR A1 - Werner, Christian A1 - Reiser, K. A1 - Dannenmann, Michael A1 - Hutley, Lindsay B. A1 - Jacobeit, Jucundus A1 - Butterbach-Bahl, Klaus T1 - N2O, NO, N2 and CO2 emissions from tropical savanna and grassland of northern Australia: an incubation experiment with intact soil cores T2 - Biogeosciences discussions N2 - Strong seasonal variability of hygric and thermal soil conditions are a defining environmental feature in Northern Australia. However, how such changes affect the soil–atmosphere exchange of nitrous oxide (N2O), nitric oxide (NO) and dinitrogen (N2) is still 5 not well explored. By incubating intact soil cores from four sites (3 savanna, 1 pasture) under controlled soil temperatures (ST) and soil moisture (SM) we investigated the release of the trace gas fluxes of N2O, NO and carbon dioxide (CO2). Furthermore, the release of N2 due to denitrification was measured using the helium gas flow soil core technique. Under dry pre-incubation conditions NO and N2O emission were very low (< 7.0± 5.0 μgNO-Nm−2 h−1; < 0.0± 1.4 μgN2O-Nm−2 h−1) or in case of N2O, even a net soil uptake was observed. Substantial NO (max: 306.5 μgNm−2 h−1) and relatively small N2O pulse emissions (max: 5.8±5.0 μgNm−2 h−1) were recorded following soil wetting, but these pulses were short-lived, lasting only up to 3 days. The total atmospheric loss of nitrogen was dominated by N2 emissions (82.4–99.3% of total N lost), although NO emissions contributed almost 43.2% at 50% SM and 30 °C ST. N2O emissions were systematically higher for 3 of 12 sample locations, which indicates substantial spatial variability at site level, but on average soils acted as weak N2O sources or even sinks. Emissions were controlled by SM and ST for N2O and CO2, ST and pH for NO, and SM and pH for N2. Y1 - 2016 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/42378 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-423783 SN - 1810-6285 N1 - © Author(s) 2014. CC Attribution 3.0 License. VL - 11 SP - 8399 EP - 8442 PB - Copernicus CY - Katlenburg-Lindau [u.a.] ER -