Responsiveness of soil nitrogen fractions and bacterial communities to afforestation in the Loess Hilly Region (LHR) of China.
Responsiveness of soil nitrogen fractions and bacterial communities to afforestation in the Loess Hilly Region (LHR) of China.
复制标题
中国黄土丘陵区土壤氮组分和细菌群落对造林的响应
DOI：
10.1038/srep28469
复制
发表时间：
2016-06-23
影响因子：
4.6
通讯作者：
Yang G
中科院分区：
文献类型：
--
作者：
Ren C;Sun P;Kang D;Zhao F;Feng Y;Ren G;Han X;Yang G
本文研究了植树造林对土壤氮素组分和微生物群落的影响。采集了近40年来农田(FL)和刺槐(RP)、锦鸡儿(CK)和荒地(AL)3个绿地的24个土壤样品。利用16S rRNA基因的定量聚合酶链式反应和Illumina测序分析了土壤细菌的丰度、多样性和组成。此外，还估算了土壤氮(N)储量和形态。结果表明，造林后土壤N储量、N组分、细菌丰富度和多样性增加，土壤细菌组成以变形杆菌、酸性细菌和放线杆菌为主。总体来说，植树造林后土壤细菌组成总体上由以放线菌(酸性细菌)为主转变为以变形杆菌为主。土壤N组分，尤其是溶解有机氮(DON)与大多数细菌群和细菌多样性显著相关，而变形杆菌(根瘤目)和蓝杆菌之间存在潜在的竞争性相互作用。相反，硝态氮(NO3−-N)对土壤细菌组成的影响小于其他N组分。因此，本研究表明，细菌多样性和特定物种响应退耕还林，因此有可能影响黄土高原氮素的动态过程。
In the present paper, we investigated the effects of afforestation on nitrogen fractions and microbial communities. A total of 24 soil samples were collected from farmland (FL) and three afforested lands, namely Robinia pseudoacacia L (RP), Caragana korshinskii Kom (CK), and abandoned land (AL), which have been arable for the past 40 years. Quantitative PCR and Illumina sequencing of 16S rRNA genes were used to analyze soil bacterial abundance, diversity, and composition. Additionally, soil nitrogen (N) stocks and fractions were estimated. The results showed that soil N stock, N fractions, and bacterial abundance and diversity increased following afforestation.Proteobacteria,Acidobacteria, andActinobacteriawere the dominant phyla of soil bacterial compositions. Overall, soil bacterial compositions generally changed fromActinobacteria(Acidobacteria)-dominant toProteobacteria-dominant following afforestation. Soil N fractions, especially for dissolved organic nitrogen (DON), were significantly correlated with most bacterial groups and bacterial diversity, while potential competitive interactions betweenProteobacteria(orderRhizobiales) andCyanobacteriawere suggested. In contrast, nitrate nitrogen (NO3−-N) influenced soil bacterial compositions less than other N fractions. Therefore, the present study demonstrated that bacterial diversity and specific species respond to farmland-to-forest conversion and hence have the potential to affect N dynamic processes in the Loess Plateau.