Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan, China.
University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom.
Chemosphere. 2021 May;270:128654. doi: 10.1016/j.chemosphere.2020.128654. Epub 2020 Oct 19.
Atmospheric CO levels have been increasing with increasing industrialization. Studies have shown the growth response of various plant species to climate change and increasing CO levels, but variations in phytoremediation caused by elevated CO levels, especially in intercropping systems, have rarely been reported. The current study therefore revealed variations in the phytoremediation effect of Festuca arundinacea intercropped with Echinochloa caudata, a pernicious annual weed, exposed to various CO levels (280, 400, and 550 ppm). The biomass yield and Cd uptake capacity of monocultured F. arundinacea were found to increase with increasing atmospheric CO level, highlighting the promoted phytoremediation efficiency of this species under elevated CO levels. Elevated CO levels also significantly increased the dry weight of monocultured E. caudata but did not change the Cd content in various parts of the plant. However, the intercropping system decreased the biomass yield of belowground and aerial parts of F. arundinacea under all treatments, since E. caudata competed with it for water and nutrients. The weight reduction of F. arundinacea in the intercropping system increased with increasing CO level, because elevated CO significantly increased the competitiveness of the weed. Therefore, the Cd phytoremediation efficiency of F. arundinacea intercropped with E. caudata exposed to 280, 400, and 550 ppm CO decreased by 46.1%, 81.5%, and 215.0%, respectively, as evidenced by the decreased dry weight of F. arundinacea. Therefore, elevated CO levels could decrease the phytoremediation effect of F. arundinacea in fields where weed growth is unavoidable.
大气中的二氧化碳水平随着工业化的发展而增加。研究表明，各种植物物种对气候变化和二氧化碳水平升高的生长反应，但由于二氧化碳水平升高而导致的植物修复的变化，特别是在间作系统中，很少有报道。因此，本研究揭示了在不同二氧化碳水平（280、400 和 550ppm）下，与恶性一年生杂草稗草间作的高羊茅的植物修复效果的变化。发现单独种植的高羊茅的生物量产量和镉吸收能力随着大气二氧化碳水平的升高而增加，这突出了该物种在高二氧化碳水平下促进的植物修复效率。高二氧化碳水平还显著增加了单独种植的稗草的干重，但没有改变植物各部分的镉含量。然而，间作系统降低了所有处理下高羊茅地下和地上部分的生物量产量，因为稗草与它竞争水和养分。在间作系统中，由于高二氧化碳显著增加了杂草的竞争力，高羊茅的体重减轻随着二氧化碳水平的升高而增加。因此，与稗草间作的高羊茅在暴露于 280、400 和 550ppmCO 下的镉植物修复效率分别降低了 46.1%、81.5%和 215.0%，这可以从高羊茅的干重减少中得到证明。因此，在杂草生长不可避免的田间，高二氧化碳水平可能会降低高羊茅的植物修复效果。
