【摘要】 为了解人工湿地处理中碳/氮水平的废水时植物种类及多样性对系统氧化亚氮释放及功能基因丰度的影响,本研究构建了实验尺度的垂直流人工湿地微宇宙实验系统。选取芦苇（Phragmites australis）、千屈菜（Lythrum salicaria）和海寿花（Pontederia cordata） 3种人工湿地常用、景观效果好的植物,在系统中配置了3个单种处理和1个三物种混种处理。结果表明:芦苇、千屈菜与海寿花混种系统的氧化亚氮释放强度(24597.0μg N₂O·m^-2·d^-1)高于三物种单种系统的平均值(11744.8μg N₂O·m^-2·d^-1)（P<0.001）,同氧化亚氮释放一样,混种系统的amoA基因绝对丰度(6.33×10⁷copies·g^-1soil)和nirS基因绝对丰度(1.92×10⁶copies·g^-1soil)也高于三物种单种系统的平均值(5.70×10⁷和1.58×10⁶copies·g^-1soil)。此外,混种系统的出水硝态氮浓度低于三物种单种系统的平均值（P<0.05）,但出水硝态氮浓度、微生物量和植物生物量在单混种系统间无显著差异（P>0.05）。3个单种系统间的氧化亚氮释放强度、amoA基因绝对丰度、nirS基因绝对丰度、出水铵态氮浓度、微生物量和植物生物量存在显著差异（P<0.01）,但出水硝态氮无显著差异（P>0.05）。通过植物种类和丰富度对各指标变异的解释度发现,植物种类和丰富度分别解释变异的比率存在一定差异,总体上,植物丰富度对氧化亚氮释放、amoA基因绝对丰度和nirS基因绝对丰度的影响大于植物种类,植物种类对出水硝态氮浓度的影响大于植物丰富度。更多还原

【Abstract】 To investigate the effects of plant species identity and diversity on nitrous oxide emission and functional gene abundance under moderate effluent C/N ratio,we constructed a vertical flow constructed wetlands in the laboratory. Three plant species,Phragmites australis,Lythrum salicaria,and Pontederia cordata,which are commonly used in constructed wetlands and with good landscape effects,were selected to establish the monocultures of each species and one threespecies mixture. Results showed that nitrous oxide emissions from the mixtures( 24597. 0 μg N₂O·m^-2·d^-1) were higher than the mean values of the three monocultures( 11744. 8 μg N2 O·m^-2·d^-1)（ P<0.001）. Similarly,the absolute abundances of amoA( 6.33×10⁷ copies·g^-1 soil) and nir S( 1.92×10⁶ copies·g^-1 soil) from the mixtures were also higher than the mean values of the monocultures( 5.70×107 and 1.58×106 copies·g^-1 soil). In addition,the effluent NO₃^--N concentrations in the mixtures were lower than that in the three monocultures（ P<0.01）,but there was no significant difference in the NH₄⁺-N concentration,microbial biomass and plant biomass between the mixtures and the mean values of monocultures（ P>0.05）. There were significant differences in the nitrous oxide emission,absolute abundance of amoA,absolute abundance of nirS,effluent NH4_<sup>+-N concentration,microbial biomass and plant biomass among the three monocultures,but with no significant difference in the effluent NO₃^--N concentration among the three monocultures. The effects of plant richness on nitrous oxide emission,amoA absolute abundance and nirS absolute abundance were greater than those of species identity,whereas the effects of plant species identity on effluent NO₃^--N concentration were greater than that of plant richness.更多还原