不同棉花品种及种植区域对土壤无脊椎动物群落结构的影响

Effects of Cotton Varieties and Planting Areas on Soil Invertebrate Community Structures

采用干、湿漏斗分离法,在山东省陵县采集了试验田的Bt棉(新棉33B)和常规棉(中棉12)及大田条件下Bt棉的0～15cm土层中的土壤无脊椎动物,并对其群落结构进行了分析.结果表明,线虫和螨类是3种类型棉田的优势土壤动物类群,其频度分别为60%～85%和9%～27%.试验田的常规棉和Bt棉相比,33B棉田土壤动物的类群较多,线虫、鞘翅目、双翅目数量和土壤动物总数均较高,但各土层土壤动物的多样性指数H’和均匀度指数J值均较低.试验田和大田的33B相比,其土壤动物的类群数相近,但大田33B的轮虫和线蚓数量较高,线虫、蠋、鞘翅目数量和土壤动物总数均较低,各土层土壤动物的多样性和均匀度均较高.Rényi多样性指数曲线也表明,试验田33B棉田的土壤动物多样性高于中棉12,大田33B的土壤动物多样性高于33B试验田.6～11月期间,各土层土壤动物的数量动态在不同类型棉田趋势基本相同.7月是中棉12棉田土壤动物数量的高峰期,9月是试验田和大田33B的高峰期.试验田的中棉12和33B棉田,6～8月土壤动物的多样性指数和均匀度指数变化趋势较为一致;9～10月,33B棉田土壤动物的多样性和均匀度较高.6～11月,大田33B土壤动物的多样性和均匀度均显著高于试验田33B.可见,棉花品种和实验地点等因素均可显著影响土壤动物的群落结构.Bt棉33B棉田的土壤动物多样性高于常规棉中棉12;大田33B的土壤动物多样性高于33B试验田.

Soil invertebrates were collected by Tullgren and Baermann funnels from soil at 0～15 cm depth grown with Bt cotton （cv. NuCOTN 33B） and non-Bt cotton （cv. ZM12） in Lingxian, Shandong, China, and their community structures were analyzed. The structures in the experimental plots and fields planted with 33B were also compared. Nematodes and acarids were dominant groups and their frequencies were 60%～85% and 9%～27% in all treatments under survey. Soil invertebrate groups and individuals, as well as nematodes, Coleoptera and Diptera were found more in the plots with 33B than those with non-Bt cv. ZM12. But the Shannon’s diversity and Pielou’s evenness values were significantly lower in the plots with 33B. The numbers of soil invertebrate groups in 33B fields were similar to those in the plots with 33B. There were more Rotatoria and Enchytraelidae, but fewer nematodes, Pauropoda, Coleoptera, and also total invertebrate individuals in 33B fields. The Shannon’s diversity and Pielou’s evenness were significantly higher in 33B fields. From the scalable one-parametric Rényi- diversity profiles, it also showed higher diversity in the plots with 33B than in those with ZM12, and higher diversity in the fields than in the plots both with 33B. From June to November, the abundance of soil invertebrates fluctuated in similar trends in all the treatments. It peaked in July in the plots with ZM12, and in September in the experimental plots and fields with 33B. The diversity and evenness ofinvertebrates exhibited a similar trend from June to August in 33B and ZM12 plots, but they were higher in September and October in 33B than in ZM12 plots. The diversity and evenness in 33B fields were higher than in 33B plots in the period from June to November. These results indicated that cotton varieties and planting areas could change the soil invertebrate structures significantly. The soil invertebrate diversity was higher in 33B than in ZM12 plots, and higher in 33B fields than in 33B plots. Fig 2, Tab 4, Ref 29