文献类型：期刊文献

英文题名：The simulated N deposition accelerates net N mineralization and nitrification in a tropical forest soil

作者：Nie, Yanxia[1,2] Han, Xiaoge[1] Chen, Jie[3] Wang, Mengcen[4] Shen, Weijun[1]

第一作者：Nie, Yanxia

通信作者：Shen, WJ[1]

机构：[1]Chinese Acad Sci, South China Bot Garden, Key Lab Vegetat Restorat & Management Degraded Ec, Guangzhou 510650, Guangdong, Peoples R China;[2]Chinese Acad Sci, Core Bot Gardens, Ctr Plant Ecol, Guangzhou 510650, Guangdong, Peoples R China;[3]Chinese Acad Forestry, Res Inst Trop Forestry, Guangzhou 510520, Guangdong, Peoples R China;[4]Zhejiang Univ, Minist Agr, Key Lab Mol Biol Crop Pathogens & Insects, Hangzhou 310058, Zhejiang, Peoples R China

年份：2019

卷号：16

期号：21

起止页码：4277-4291

外文期刊名：BIOGEOSCIENCES

收录：;Scopus(收录号：2-s2.0-85074947174);WOS:【SCI-EXPANDED(收录号:WOS:000496726400002)】；

基金：This research has been supported by the National Natural Science Foundation of China (grant nos. 31600382, 31425005, 31290222 and 31600430).

语种：英文

摘要：Elevated nitrogen (N) deposition affects soil N transformations in the N-rich soil of tropical forests. However, the change in soil functional microorganisms responsible for soil N cycling remains largely unknown. Here, we investigated the variation in soil inorganic N content, net N mineralization (R-m), net nitrification (R-n), inorganic N leaching (R-l), N2O efflux and N-related functional gene abundance in a tropical forest soil over a 2-year period with four levels of N addition. The responses of soil net N transformations (in situ R-m and R-n) and R-l to N additions were negligible during the first year of N inputs. The R-m, R-n, and R-l increased with the medium nitrogen (MN) and high nitrogen (HN) treatments relative to the control treatments in the second year of N additions. Furthermore, the R-m, R-n, and R-l were higher in the wet season than in the dry season. The R-m and R-n were mainly associated with the N addition-induced lower C : N ratio in the dry season but with higher microbial biomass in the wet season. Throughout the study period, high N additions increased the annual N2O emissions by 78 %. Overall, N additions significantly facilitated R-m, R-n, R-l and N2O emission. In addition, the MN and HN treatments increased the ammonia-oxidizing archaea (AOA) abundance by 17.3% and 7.5 %, respectively. Meanwhile, the HN addition significantly increased the abundance of nirK denitrifiers but significantly decreased the abundance of ammonia-oxidizing bacteria (AOB) and nosZ-containing N2O reducers. To some extent, the variation in functional gene abundance was related to the corresponding N-transformation processes. Partial least squares path modelling (PLS-PM) indicated that inorganic N contents had significantly negative direct effects on the abundances of N-related functional genes in the wet season, implying that chronic N deposition would have a negative effect on the N-cycling-related microbes and the function of N transformation. Our results provide evidence that elevated N deposition may impose consistent stimulatory effects on soil N-transformation rates but differentiated impacts on related microbial functional genes. Long-term experimentation or observations are needed to decipher the interrelations between the rate of soil N-transformation processes and the abundance or expression of related functional genes.