摘要
在重庆主城与涪陵选取了3个典型点位采集土壤样品,并对土壤的理化性质、原位反硝化速率、溶解性有机质(DOM)驱动的反硝化以及库区土壤的微生物进行了考察与分析.结果显示在海拔145~155m区间,淹水期镇安镇、涪陵区和鱼嘴镇最高氨氮(NH_(4)^(+)-N)平均浓度分别为31.32,28.63和19.23mg/kg,均高于落干期.在淹水期,与高海拔区域土壤中硝酸盐氮(NO_(3)^(-)-N)平均浓度相比,低海拔土壤中NO_(3)^(-)-N平均浓度分别增大了46.91%(镇安镇)、37.89%(涪陵区)和29.69%(鱼嘴镇).在淹水期,土壤有机质(SOM)平均浓度随着海拔高程的降低而降低,镇安镇、涪陵区和鱼嘴镇分别从109.16,80.93和82.61mg/kg降至65.63,64.53,53.41mg/kg.土壤中NH_(4)^(+)-N和NO_(3)^(-)-N的含量与现场反硝化速率呈显著正相关(P<0.05),在提供充足的碳(C)和氮(N)营养元素后,土壤潜在反硝化速率表现出较大的时间和空间差异性.在由DOM驱动的反硝化实验中,DOM降解符合一级动力学模型(R^(2)>0.93),N2O累积量符合Logistic模型(R^(2)>0.97).在三峡水库消落带土壤中,反硝化功能微生物主要是Bacillus和Comamonadaceae,其丰度变化与土壤潜在反硝化速率呈现显著的正相关性(P<0.05).
Soil samples were collected from three typical sites in the main city of Chongqing and Fuling,and the physical and chemical properties of soil,in-situ denitrification rate,DOM-driven denitrification process and soil micro-organisms community in the sampled sites were investigated and analyzed.The results showed that in the flooding period(145~155m),the average concentrations of the highest ammonia nitrogen(NH_(4)^(+)-N)in Zhen'an,Fuling and Yuzui were 31.32,28.63 and 19.23mg/kg,respectively,which were higher than those in the drying period.During the flooding period,compared with the average concentration of nitrate nitrogen(NO_(3)^(-)-N)in the soil at high altitude,the average concentration of NO_(3)^(-)-N in the soil at low altitude increased by 46.91%(Zhen'an),37.89%(Fuling)and 29.69%(Yuzui),respectively.During the flooding period,the average concentration of soil organic matter(SOM)decreased with the decrease of altitude,from 109.16,80.93 and 82.61mg/kg in Zhen'an,Fuling and Yuzui to 65.63,64.53 and 53.41mg/kg,respectively.The contents of NH_(4)^(+)-N and NO_(3)^(-)-N in the soil were significantly positively correlated with the in-situ denitrification rate(P<0.05).It was found that the potential denitrification rate of soil showed great temporal and spatial differences after given sufficient carbon(C)and nitrogen(N)nutrients.In the experiment of denitrification by using DOM as carbon source,the degradation of DOM conformed to the first-order kinetic model(R^(2)>0.93),and the accumulation of N2O conformed to the Logistic model(R^(2)>0.97).The denitrifying microorganisms in the soil of WLFZ are mainly Bacillus and Comamonadaceae,and their abundance changes have a significant positive correlation with the potential denitrification rate of the soil(P<0.05).
作者
朱砚涛
苏培兴
张代钧
袁淑培
张峻通
刘寅飞
ZHU Yan-tao;SU Pei-xing;ZHANG Dai-jun;YUAN Shu-pei;ZHANG Jun-tong;LIU Yin-fei(College of Environment and Ecology,Chongqing University,Chongqing 400045,China;State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2024年第6期3270-3279,共10页
China Environmental Science
基金
重庆市自然科学基金资助重点项目(cstc2017jcyjBX0042)。
关键词
三峡水库消落带
土壤反硝化
溶解性有机质
微生物群落
water-level-fluctuation-zone of the Three Gorges Reservoir
denitrification of soil
dissolved organic matter
microbial community
