Soil dissimilatory nitrate reduction processes in the Spartina alterniflora invasion chronosequences of a coastal wetland of southeastern China: Dynamics and environmental implications
Soil dissimilatory nitrate reduction processes in the Spartina alterniflora invasion chronosequences of a coastal wetland of southeastern China: Dynamics and environmental implications
复制标题
中国东南沿海湿地互花米草入侵时序中的土壤异化硝酸盐还原过程：动力学和环境影响
DOI：
10.1007/s11104-017-3464-x
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发表时间：
2017-12-01
期刊：
影响因子：
4.9
通讯作者：
Chen, Xing
中科院分区：
文献类型：
--
作者：
Gao, Dengzhou;Li, Xiaofei;Chen, Xing
互花米草的入侵对滨海湿地土壤生态地球化学循环有重要影响。然而，S.互花米草入侵时间序列在调节土壤异化NO3-还原过程（反硝化（DNF）、厌氧氨氧化（ANA）和异化硝酸盐还原成铵（DNRA））中的作用尚不清楚。因此，本研究的目的是揭示S。通过对互花米草入侵后植物生物量、土壤性质、NO3（-）还原过程和NO3（-）还原途径相关基因丰度的研究，探讨了互花米草入侵后土壤NO3（-）还原过程和相关基因丰度的变化规律。在中国东南沿海湿地，互花米草入侵的时间序列为6年、10年和14年。互花米草入侵增加了植物生物量、土壤含水量、有效基质、nirS、厌氧氨氧化细菌16 SrRNA和nrfA基因丰度，但降低了土壤容重。结果表明：在1998 ~ 2000年，杉木林分土壤中DNF、ANA和DNRA的含量均高于对照林分;互花米草的Ng（-1）h（-1）分别为1.52 ~ 17.58，0.31 ~ 1.27和0.14 ~ 2.01 nmol Ng（-1）h（-1），普遍高于林分的Ng（-1）h（-1）。马六甲。土壤NO3（-）还原速率随S.互花米草，而在DNF和ANA率的变化不太明显，比DNRA的变化。DNF是NO3（-）还原的主要途径（70.00-92.41%），ANA和DNRA对NO3（-）还原的贡献率分别为2.49-15.27%和5.10-20.75%。S处理后，DNF和ANA对总NO3（-）还原的贡献略有下降，而DNRA的贡献显著增加。互花米草入侵土壤NO3（-）还原过程受有效基质和微生物活动的影响。据估算，每年氮素损失量约为520.97 g N m（-2）。(-1)in C. malaccensis和794.46gNm（-2）yr. (-1)in S. alterniflora与DNF和ANA过程均相关。互花米草入侵通过增加土壤微生物活性和有效基质改变了土壤NO3（-）还原过程，从而可能进一步介导滨海湿地土壤N的有效性。
The invasion of Spartina alterniflora has a significant influence on soil biogeochemistry cycling in coastal wetlands. However, the roles of the S. alterniflora invasion chronosequence in regulating soil dissimilatory NO3 (-) reduction processes (denitrification (DNF), anaerobic ammonium oxidation (ANA) and dissimilatory nitrate reduction to ammonium (DNRA)) remains unclear. The objective of this study was therefore to reveal the effects of S. alterniflora invasion on the soil NO3 (-) reduction processes and associated gene abundance.We investigated plant biomass, soil properties, NO3 (-) reduction processes and associated gene abundance of NO3 (-) reduction pathways following S. alterniflora invasion chronosequences of 6, 10, and 14 years compared to Cyperus malaccensis in a coastal wetland of southeastern China.The S. alterniflora invasion generally increased plant biomass, soil water content, available substrates, nirS, anammox bacterial 16S rRNA and nrfA gene abundance, but it decreased soil bulk density. Soil DNF, ANA and DNRA rates in stands of S. alterniflora ranged from 1.52 to 17.58, 0.31 to 1.27 and 0.14 to 2.01 nmol N g(-1) h(-1), respectively, which were generally higher than the values in stands of C. malaccensis. The soil NO3 (-) reduction rates generally increased with the increasing chronosequence of invasion by S. alterniflora, while the changes in DNF and ANA rates were less pronounced than changes in DNRA. DNF was the dominant pathway (70.00-92.41%), and the ANA and DNRA contributed 2.49-15.27% and 5.10-20.75% to the total NO3 (-) reduction, respectively. The contributions of DNF and ANA to the total NO3 (-) reduction decreased slightly, while the contribution of DNRA increased remarkably after S. alterniflora invasion. Soil NO3 (-) reduction processes were influenced by available substrates and associated microbial activities. It is estimated that an N loss of approximately 520.97 g N m(-2) yr.(-1) in C. malaccensis and 794.46 g N m(-2) yr.(-1) in S. alterniflora were linked to both DNF and ANA processes.The S. alterniflora invasion altered soil NO3 (-) reduction processes by increasing soil microbial activities and available substrates and thus may further mediate the soil N availability in the coastal wetlands.