Similar temperature responses suggest future climate warming will not alter partitioning between denitrification and anammox in temperate marine sediments
Similar temperature responses suggest future climate warming will not alter partitioning between denitrification and anammox in temperate marine sediments
复制标题
DOI：
10.1111/gcb.13370
复制
发表时间：
2017-01
影响因子：
11.6
通讯作者：
Lindsay D. Brin;A. Giblin;J. J. Rich-J.
中科院分区：
文献类型：
--
作者：
Lindsay D. Brin;A. Giblin;J. J. Rich-J.
微生物介导的反硝化和厌氧氨氧化过程对生物可利用氮的去除影响生态系统氮的有效性。虽然很少有研究探讨反硝化和厌氧氨氧化的温度响应，以前的工作表明，反硝化可能会变得更重要，比厌氧氨氧化在应对气候变暖。为了验证这一假设，我们确定了反硝化和厌氧氨氧化反应的温度响应是否不同的陆架和河口沉积物从沿海罗得岛在一个季节性周期。在为期12周的实验室微观实验中进一步评估了温度和有机碳可用性的影响。温度响应，其特征在于热最佳值（Topt）和表观活化能（Ea），通过测量反硝化和厌氧氨氧化的潜在速率在31个离散的温度范围从3到59 °C。除少数例外，Topt和Ea的反硝化和厌氧氨氧化没有不同的罗得岛沉积物的季节性周期。在微宇宙沉积物中，Ea在所有处理中，厌氧氨氧化与反硝化相比略低。然而，Topt没有不同的过程，也没有Ea或Topt的变化与变暖或碳添加。因此，这两个过程表现出类似的温度响应，这些响应不受变暖。这使我们拒绝了在我们的研究系统中anammox比反硝化更冷适应的假设。总的来说，我们的研究表明，这两个过程的温度响应可以准确地模拟温带地区在未来使用一组参数，这是可能不会改变在未来世纪的预测气候变暖的结果。我们进一步得出结论，气候变暖不会直接改变通过厌氧氨氧化和反硝化氮流的分区。
Removal of biologically available nitrogen (N) by the microbially mediated processes denitrification and anaerobic ammonium oxidation (anammox) affects ecosystem N availability. Although few studies have examined temperature responses of denitrification and anammox, previous work suggests that denitrification could become more important than anammox in response to climate warming. To test this hypothesis, we determined whether temperature responses of denitrification and anammox differed in shelf and estuarine sediments from coastal Rhode Island over a seasonal cycle. The influence of temperature and organic C availability was further assessed in a 12‐week laboratory microcosm experiment. Temperature responses, as characterized by thermal optima (Topt) and apparent activation energy (Ea), were determined by measuring potential rates of denitrification and anammox at 31 discrete temperatures ranging from 3 to 59 °C. With a few exceptions, Topt and Ea of denitrification and anammox did not differ in Rhode Island sediments over the seasonal cycle. In microcosm sediments, Ea was somewhat lower for anammox compared to denitrification across all treatments. However, Topt did not differ between processes, and neither Ea nor Topt changed with warming or carbon addition. Thus, the two processes behaved similarly in terms of temperature responses, and these responses were not influenced by warming. This led us to reject the hypothesis that anammox is more cold‐adapted than denitrification in our study system. Overall, our study suggests that temperature responses of both processes can be accurately modeled for temperate regions in the future using a single set of parameters, which are likely not to change over the next century as a result of predicted climate warming. We further conclude that climate warming will not directly alter the partitioning of N flow through anammox and denitrification.