Nitrogen loading levels affect abundance and composition of soil ammonia oxidizing prokaryotes in semiarid temperate grassland
Nitrogen loading levels affect abundance and composition of soil ammonia oxidizing prokaryotes in semiarid temperate grassland
复制标题
氮负荷水平影响半干旱温带草原土壤氨氧化原核生物的丰度和组成
DOI：
10.1007/s11368-011-0375-y
复制
发表时间：
2011-10-01
影响因子：
3.6
通讯作者：
He, Ji-Zheng
中科院分区：
文献类型：
--
作者：
Shen, Xin-Yi;Zhang, Li-Mei;He, Ji-Zheng
目的全球氮沉降对包括半干旱温带草原在内的陆地生态系统产生了深远的影响，导致植被群落迁移和土壤酸化。关于氮(N)沉积对地下微生物群落的影响，人们知之甚少。本研究旨在研究半干旱温带草原氨氧化细菌和古细菌对添加氮素的响应。材料与方法在内蒙古半干旱温带草原为期6年的田间试验中，以氨氧化细菌和古细菌为研究对象，利用分子生物学技术研究了氨氧化细菌和氨氧化细菌在−2 a−1尿素施肥量梯度上的变化，即0、1、2、4、8、16、32和−2 a−1。结果和讨论AoB群落对尿素-N底物的响应明显，施N量2~4 g/N−2a−1诱导其丰度增加和组成转移。而−2Year−1a的最大N负荷甚至降低了AOA群落的丰度。此外，较高的氮素负荷率(大于16g·N/m−2年期−1)显著降低了土壤有机质的多样性，但其Shannon指数和均匀度指数的降低并不明显。结论在这一半干旱温带草原上，相对长期的氮素负荷(大于2~4g·N/m−2年期−1)导致了土壤有机质多样性的丧失。增加N负荷改变了AOB的丰度和组成，但AOA变化不显著。
PurposeGlobal nitrogen deposition has profound impact on the terrestrial ecosystem including the semiarid temperate grassland, causing vegetation community shifts and soil acidification. Little is known regarding the effect of nitrogen (N) deposition on the belowground microbial communities. This study aimed to examine the response of ammonia-oxidizing bacteria (AOB) and archaea (AOA) to added N in semiarid temperate grassland.Materials and methodsWe studied the changes of AOB and AOA by using molecular techniques targetingamoAgenes along a urea fertilization gradient, i.e., 0, 1, 2, 4, 8, 16, 32, 64 g N m−2year−1, in a 6-year field experiment of semiarid temperate grassland, Inner Mongolia of China.Results and discussionAOB community responded to urea–N substrate clearly, and N addition rates 2–4 g N m−2year−1induced an increase in its abundances and the shift of its composition. However, AOA community remained unchanged and the highest N loading at 64 g N m−2year−1even decreased its abundance. Moreover, higher N loading rates (more than 16 g N m−2year−1) significantly decreased the diversity of AOB but not AOA, as indicated by the decrease of its Shannon and Evenness indices.ConclusionsThe relative long-term nitrogen loading of more than 2–4 g N m−2year−1resulted in diversity loss of AOB in this semiarid temperate grassland. Increasing N loading altered AOB abundance and composition, but AOA showed nonsignificant changes.