阔叶丰花草对荔枝园杂草群落特征及物种多样性的影响

【目的】明确阔叶丰花草在荔枝园定植对杂草群落特征及物种多样性的影响,为阔叶丰花草在果园应用提供参考依据。【方法】通过调查广东茂名高州荔枝国家现代农业产业园的荔枝园中90个有、无阔叶丰花草样方中杂草群落组成、群落高度以及物种多样性,探究阔叶丰花草定植对荔枝园杂草群落结构及物种多样性的影响。【结果】阔叶丰花草在荔枝园定植后,杂草种类减少,由对照样方的42种减少到试验样方的30种;杂草群落结构显著改变,牛筋草、白花鬼针草等恶性杂草重要值降低,薇甘菊、香附子、火炭母等杂草消失;阔叶丰花草的重要值与杂草群落高度和物种多样性指数为显著性负相关(P0.001),且均呈显著三项式回归关系。阔叶花草在荔枝园定植后可建立结构较为单一,且低矮的杂草群落。【结论】阔叶丰花草有望成为荔枝园生草的有益草种。

Effects of Spermacoce alata Aublet on the characteristics and species diversity of weed community in the litchi orchards

[Aim] The effects of Spermacoce alata on the characteristics and species diversity of weed community in the litchi orchards were studied for its potential application in orchards.[Method] A weed community experiment in litchi orchards of the Gaozhou Litchi National Modern Agricultural Industrial Park, Maoming, Guangdong Province, was conducted to assess the effect of S. alata on weed community by comparing weed diversity and height in 90 plots with or without this species.[Result] After the colonization of litchi orchards by S. alata, the number of weeds decreased from 42 in the control plots to 30 in the experimental plots. The weed community structure changed substantially. The importance value (IV) of malignant weeds such as Eleusine indica and Bidens alba decreased, and some weeds, such as Mikania micrantha, Cyperus rotundus, and Polygonum perfoliatum, disappeared. There was a significant negative correlation between weed community height, species diversity indices, and IV of S. alata (P<0.001), which both showed a significant trinomial regression relationship. After the colonization of S. alata in litchi orchards, a weed community with a relatively simple structure and low community height can be established.[Conclusion] S. alata is expected to become a useful Rubiaceae species that can be grown in litchi orchards.