Management versus site effects on the abundance of nitrifiers and denitrifiers in European mountain grasslands.
Management versus site effects on the abundance of nitrifiers and denitrifiers in European mountain grasslands.
复制标题
DOI：
10.1016/j.scitotenv.2018.08.039
复制
发表时间：
2019-01
期刊：
影响因子：
--
通讯作者：
Ute Szukics;K. Grigulis;N. Legay;E. Kastl;Catherine Baxendale;R. Bardgett;J. Clément;S. Lavorel;M. Schloter;M. Bahn
中科院分区：
文献类型：
--
作者：
Ute Szukics;K. Grigulis;N. Legay;E. Kastl;Catherine Baxendale;R. Bardgett;J. Clément;S. Lavorel;M. Schloter;M. Bahn
研究表明，低地草原氮素转化微生物的丰度受土地利用强度的强烈影响。然而，它们对生产力较低和肥料较少的山地草原管理变化的反应在很大程度上是未知的。我们研究了奥地利、英国和法国沿管理强度梯度分布的8个山地草原，它们在历史管理轨迹上存在差异。利用特异标记基因测定氨氧化菌（AOB）、古菌（AOA）和亚硝酸盐还原菌的丰度。我们发现，管理影响了这些微生物群沿每个样带的丰度，尽管由于不同的管理历史和环境参数的变化，具体的响应在不同的地点有所不同。在奥地利，停止管理导致了nirkandnirsgene丰度的增加。在英国，加强草地管理导致AOA和AOB丰度增加了10倍，氮基因丰度增加了一倍。在法国，对以前割过的草地进行耕作导致AOA丰度增加了20倍。在亚硝酸盐还原剂中，氮丰度与土壤NO3−-N有效性相关性最强，微生物氮、渗滤液NH4+-N等氮参数相关性最强，而氮反硝化剂丰度受土壤全氮、有机质和含水量的影响。土壤环境条件的改变是土地管理措施影响各氨氧化剂和亚硝酸盐还原剂丰度的主要机制。
It is well established that the abundances of nitrogen (N) transforming microbes are strongly influenced by land-use intensity in lowland grasslands. However, their responses to management change in less productive and less fertilized mountain grasslands are largely unknown. We studied eight mountain grasslands, positioned along gradients of management intensity in Austria, the UK, and France, which differed in their historical management trajectories. We measured the abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA) as well as nitrite-reducing bacteria using specific marker genes. We found that management affected the abundance of these microbial groups along each transect, though the specific responses differed between sites, due to different management histories and resulting variations in environmental parameters. In Austria, cessation of management caused an increase innirKandnirSgene abundances. In the UK, intensification of grassland management led to 10-fold increases in the abundances of AOA and AOB and doubling ofnirKgene abundance. In France, ploughing of previously mown grassland caused a 20-fold increase in AOA abundance. Across sites the abundance of AOB was most strongly related to soil NO3−-N availability, and AOA were favored by higher soil pH. Among the nitrite reducers,nirSabundance correlated most strongly with N parameters, such as soil NO3−-N, microbial N, leachate NH4+-N, while the abundance ofnirK-denitrifiers was affected by soil total N, organic matter (SOM) and water content. We conclude that alteration of soil environmental conditions is the dominant mechanism by which land management practices influence the abundance of each group of ammonia oxidizers and nitrite reducers.