College of Civil Engineering, Sichuan Agricultural University, Dujiangyan, 611830, China.
Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, Dujiangyan, 611830, China.
Environ Sci Pollut Res Int. 2018 Sep;25(26):26433-26445. doi: 10.1007/s11356-018-2692-9. Epub 2018 Jul 9.
To investigate the effects of emergent plants on CH efflux and elucidate the key factors responsible for these effects, annual monitoring of CH emissions and methanogen community dynamics in a full-scale constructed wetland (CW) was conducted. Five emergent plants (Typha orientalis, Cyperus alternifolius, Arundo domax, Iris pseudacorus, and Thalia dealbata) commonly used in CWs were selected for investigation. The greatest CH flux (annual mean 19.4 mg m h) was observed from I. pseudacorus, while the lowest CH flux (7.1 mg m h) was observed from Thalia dealbata. The CH flux from five emergent plants showed marked seasonal variation. Total nitrogen (TN) and total phosphorous (TP) were weakly correlated with CH emissions, whereas total carbon (TC) and root biomass of plants were positively correlated with CH emissions. Quantitative real-time PCR (q-PCR) analysis indicated that the gene abundance of eubacterial 16S rRNA, particulate methane monooxygenase (pmoA) and methyl coenzyme M reductase (mcrA) significantly differed among plant species. Differences in TC, root biomass, and dissolved oxygen (DO) caused by plant species were potential factors responsible for differences in methanogens, methanotrophs, and CH emissions. Methanobacteriaceae, Methanoregulaceae, Methanomicrobiaceae, and Methanosarcinaceae were the dominant families of methanogens. The pathways of methanogenesis from the five emergent plants differed, with the main pathway being hydrogenotrophic, while both hydrogenotrophic and acetotrophic methanogens were involved in A. domax. Redundancy analysis (RDA) further indicated that emergent plant types had a profound influence on the methanogenic communities. Taken together, these results suggest emergent plant species can significantly influence CH fluxes in CW through microbial communities, biochemical pathways for methanogenesis, TC, and DO. Furthermore, plant species in CWs should be considered an important factor in evaluating greenhouse gases emission. Finally, it is necessary to effectively manage CWs vegetation to maximize their environmental benefits. Graphical abstract ᅟ.
为了研究挺水植物对 CH 排放的影响，并阐明导致这些影响的关键因素，对一个全尺寸人工湿地（CW）中的 CH 排放和产甲烷菌群落动态进行了年度监测。选择了五种常用于 CW 的挺水植物（东方香蒲、香蒲、芦竹、鸢尾和白菖蒲）进行研究。来自鸢尾的 CH 通量最大（年平均 19.4mg m h），而来自白菖蒲的 CH 通量最低（7.1mg m h）。五种挺水植物的 CH 通量表现出明显的季节性变化。总氮（TN）和总磷（TP）与 CH 排放呈弱相关，而总碳（TC）和植物根系生物量与 CH 排放呈正相关。定量实时 PCR（q-PCR）分析表明，细菌 16S rRNA、颗粒状甲烷单加氧酶（pmoA）和甲基辅酶 M 还原酶（mcrA）的基因丰度在植物物种之间存在显著差异。植物物种引起的 TC、根系生物量和溶解氧（DO）差异是导致产甲烷菌、甲烷营养菌和 CH 排放差异的潜在因素。甲烷杆菌科、甲烷杆菌科、甲烷微菌科和甲烷球菌科是产甲烷菌的主要科。五种挺水植物的产甲烷途径不同，主要途径是氢营养型，而芦竹则涉及氢营养型和乙酸营养型产甲烷菌。冗余分析（RDA）进一步表明，挺水植物类型对产甲烷菌群落有深远的影响。总之，这些结果表明，挺水植物物种可以通过微生物群落、产甲烷的生化途径、TC 和 DO 显著影响 CW 中的 CH 通量。此外，CW 中的植物物种应被视为评估温室气体排放的一个重要因素。最后，有必要有效管理 CW 的植被，以最大限度地发挥其环境效益。
