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为了解红薯(Ipomoea batas)对农田杂草群落和生物多样性的影响,作者研究了云南省东南部红河州建水县5种不同覆盖度红薯田的杂草种类、密度、重要值及多样性。结果表明,5种红薯田共统计到25种杂草,隶属18科。其中4种入侵植物藿香蓟(Ageratum conyzoides)、鬼针草(Bidens pilosa)、牛膝菊(Galinsoga parviflora)、牛筋草(Eleusine indica)和2种本地植物马齿苋(Portulaca oleracea)、马唐(Digitaria sanguinalis)的密度较高,为红薯田杂草群落的优势物种。随红薯覆盖度增加,杂草优势物种的密度和重要值显著降低(P<0.05),然而2种本地物种打碗花(Calystegia hederacea)和早熟禾(Poa annua)密度却显著增加,2种本地物种铁苋菜(Acalypha australis)和稗(Echinochloa crusgalli)重要值与红薯覆盖度成正相关(P<0.05)。红薯覆盖度为1–25%和26–50%时,杂草群落的物种丰富度(23.5、24.5)、Simpson指数(0.89、0.85)、Shannon-Wiener指数(2.36、2.35)和Pielou均匀度指数(0.75、0.73)较高,说明中低水平的红薯覆盖度有利于提高群落的物种多样性。可以推断,红薯种植改变了农田杂草的群落结构,有利于限制优势杂草和入侵杂草的发生危害,中低水平的红薯覆盖度可作为一种有效的旱田替代化学除草剂的生态控草措施。
In order to understand the impact of sweet potato (Ipomoea batas) on the weed community and biodiversity of farmland, the authors studied the species, density, importance and diversity of weeds in five sweet potato fields with different coverage in Jianshui County, Honghe Prefecture, southeastern Yunnan Province . The results showed that 25 kinds of weeds were counted in 5 sweet potato fields, belonging to 18 families. Four invasive plants, Ageratum conyzoides, Bidens pilosa, Galinsoga parviflora, Eleusine indica and two native plants Portulaca oleracea, The higher density of Digitaria sanguinalis, which is the predominant species of sweetpotato weed community. With the increase of sweet potato coverage, the density and importance of weed dominant species decreased significantly (P <0.05), however, the density of two native species, Calystegia hederacea and Poa annua, increased significantly, while that of two native species Important values of species Acalypha australis and Echinochloa crusgalli were positively correlated with sweet potato coverage (P <0.05). The species richness (23.5,24.5), Simpson index (0.89,0.85), Shannon-Wiener index (2.36,2.35), and Pielou evenness index of weed community with sweet potato coverage of 1-25% and 26-50% (0.75, 0.73), indicating that the low and medium level of sweet potato coverage is conducive to increasing community species diversity. It can be inferred that sweet potato planting changed the community structure of farmland weeds, limiting the occurrence of dominant weeds and invasive weeds. Low-level sweet potato coverage could be used as an effective herbicide-controlled ecological herbicide Measures.