模拟人工湿地植物混种对氮去除及温室气体排放的影响

Effect of plant mixture on nitrogen removal and greenhouse gases emission in simulated constructed wetlands

为探究植物多样性对人工湿地生态系统功能的影响,在模拟人工湿地试验系统中配置的两种植物物种单种和混种处理方案。结果表明:单种系统的出水硝态氮(NO-3-N)和铵态氮(NH+4-N)及温室气体排放与混种系统无显著差异;单种系统基质无机氮积累量显著高于混种系统;单种系统生物量(地上、地下和总量)及氮积累量(地上和总量)显著低于混种系统;根据物质平衡法,单种系统植物吸收对系统氮去除的贡献显著低于混种系统,反硝化作用却显著高于混种系统,基质存留的总无机氮(TIN)也显著高于混种系统(P<0.05)。

To study the effects of plant diversity on ecosystem functions in constructed wetlands,simulated constructed wetlands with monoculture and mixture of two plant species were established.There was no significant difference in effluent ammonium (NH+4-N)and nitrate (NO-3-N)concentration and greenhouse gas emission rate between monoculture and mixture systems.Sub-strate total inorgnic N (TIN)accumulation in the monoculture system is significant higher than that in mixture system.Plant bio-mass (aboveground,belowground and total)and nitrogen accumulation (aboveground and total)in monoture system are signifi-cant lower than those in mixculture system.Based on the mass balance method,plant uptake has a less contribution rate to the TIN removal in monoculture system than that in mixture system,while denitrification and substrate sequestration has a greater contribution rate than that in mixculture system.This study provided a basis for species assembling in constructed wetlands to improve high nutrient removal efficiency and decrease greenhouse gases emission.