江苏省宜兴市茶园秋季杂草种间生态关系及群落分类

Ecological Interspecific Relationship and Clustering of Autumn- Occurring Weed Communities in Tea Gardens of Yixing City,Jiangsu Province

2013年10月对江苏省宜兴市丘陵茶园秋季杂草发生种类、数量、高度等进行调查,将其转换成相对多度和重要值数据,在此基础上计测了宜兴丘陵茶园28种主要杂草的生态位宽度和生态位重叠值,用DCA排序法作出反映杂草生态学相似程度的DCA排序图,并对不同样地杂草类群进行聚类分析。结果表明:宜兴市丘陵茶园秋季杂草共发现80种,分属40科71属,其中,发生频率>20%的杂草有28种。28种主要杂草中,蓬蘽(Rubus hirsutus)、大巢菜(Vicia sativa)、酢浆草(Oxalis corniculata)、毛鸡矢藤(Paederia scandens var.tomentosa)、野老鹳草(Geranium carolinianum)等5种杂草实际生态位较宽,为宜兴茶园秋季最主要的杂草(恶性杂草);蓬蘽、毛鸡矢藤、苦苣(Sonchus oleraceus)、小飞蓬(Conyza canadensis)、马唐(Digitaria sanguinalis)、野茼蒿(Crassocephalum crepidioides)、一点红(Emilia sonchifolia)、乌敛莓(Cayratia japonica)、附地菜(Trigonotis peduncularis)、牛筋草(Eleusine indica)、爵床(Rostellularia procumbens)和狗尾草(Setaira viridis)之间生态位重叠值较大,对资源的竞争较为激烈,因此,其构成的杂草群落对茶树产生较大的危害;通过样地杂草相似性聚类分析,可将样地聚成5个明显类群:基质岩土不翻耕茶园,未翻耕除草、管理差茶园,翻耕除草、管理良好茶园,翻耕除草、管理精细茶园,不翻耕不化学除草、管理良好老茶园。茶园每个聚类群的秋季杂草优势种明显,群落结构不同。

A survey of weed species,density and height was conducted in Yixing tea gardens to estimate the weed relative abundance and importance values in October of 201 3.The niche breadth and niche overlap values of selected 28 main weeds with 20% frequency were calculated from the obtained data,and a two -dimensional scatter plot of DCA ordination was drawn based on relevant values.There were 80 weed species,belonging to 71 genera of 40 families.Among them,the occurrence frequency of 28 weed species was over 20%.Among these 28 species,Rubus hirsutus,Vicia sativa,Oxalis corniculata,Paederia scandens var.to-mentosa,and Geranium carolinianum had wider niche breadth than those of other species,being the important weeds in Yixing tea gardens.The highest niche overlap values were found between R.hirsutus,P.scandens var.tomentosa,Sonchus oleraceus,Conyza canadensis, <br> Digitaria sanguinalis,Crassocephalum crepidioides,Emilia sonchifolia,Cayratia japonica,Trigonotis peduncularis,Eleusine indica,Rostellularia procumbens and Setaira viridis that were highly competitive for available resources.Therefore they are the species posing the greatest harm to tea plants.All sampling sites were quantitatively clustered into five groups inclu-ding basalt soil tea garden,non plowed and general -managed tea garden,plowed and well -managed tea garden,plowed and fine -managed tea garden,non plowed non chemical weeding,and well -managed old tea garden based on the simi-larity coefficient.Dominant weeds were different among five groups and formed relatively different weed communities in the tea gardens.