多作对稻田蜘蛛功能团结构及多样性的影响

Effects of polycultural manipulation on the structure and diversity of spider guild in rice-based ecosystems

为探明蜘蛛功能团结构及多样性对多作农田生态系统的生态学响应,于2006年早稻期,在福建省武夷山试验基地,采用吸虫器法,系统调查了多作和单作稻田蜘蛛功能团的结构与组成;通过群落多样性指数分析了2类稻田蜘蛛功能团的结构特征及多样性动态;并运用多元统计方法[非度量多维标度(NMDS)、相似性分析检验(ANOSIM)和相似性百分比分析(SIMPER)]分析了2类稻田蜘蛛功能团的相似性及主要特征物种.结果表明:2类稻田蜘蛛功能团种类组成和优势种基本一致,球蛛科(Theridiidae)待定种和肖蛸科(Tetragnathidae)待定种是2类稻田的主要优势种类;个体丰盛度(N)、物种丰富度(S)、Shannon-Wiener指数(H′)、Simpson指数(D′)、均匀性指数(E)和绝对多度(澖)虽在个别季节差异显著,但是全年总体差异不显著;相似性分析进一步表明,2类稻田蜘蛛功能团结构差异不显著,主要特征种类为球蛛科待定种、肖蛸科待定种、锥腹肖蛸(Tetragnatha maxillosa)、食虫瘤胸蛛(Oedothoraxinsecticeps)、八斑鞘腹蛛(Coleosoma octomaculatum)、驼背额角蛛(Gnathonarimu giberum)和狼蛛若蛛(Lycosaspp.).因此,初步认为本研究所采用的多作模式未能有效地改善稻田蜘蛛功能团结构和提高其多样性.

To explore responses of spider guild to polycultural manipulation in rice-based ecosystems,experiments were carried out during the growing season of early rice in 2006.Spiders were sampled by suction sampler in the fields,and examined by microscope for identification and classification in the indoor labs at the Wuyishan Experimental Station of Agro-biodiversity and Ecologically-based Pest Management,Institute of Applied Ecology（IAE）,Fujian Agriculture and Forestry University（FAFU）.The polycultural manipulation was arranged in mosaic patterns of paddy plots intercropped with non-paddy plots（chili pepper,eggplant,maize and weed）.The plots were separated by planting soybeans on ridges.Monocultural paddy fields were set as controls.The results showed that the structure and composition of spider guild were almost similar between the two cropping systems,where the two unidentified species in Theridiidae and Tetragnathidae were the dominant species.Species richness（S）,species abundance（N）,Shannon-Wiener′s index（H′）,Simpson′s index（D′）,Pielou′s evenness index（E） and You′s absolute abundance（ń） were significantly different at some sampling dates,however,overall indices were not significantly different between the two cropping systems.ANOSIM also indicated that the guild structures were similar,and SIMPER revealed that the two unidentified species in Theridiidae and Tetragnathidae,Tetragnatha maxillosa,Oedothorax insecticeps,Coleosoma octomaculatum,Gnathonarimu giberum and Lycosa spp.were all characteristic species respectively contributing with more than 5% of overall average dissimilarity of spider guild between the two cropping systems.In summary,the polycultural manipulation didn′t effectively optimize the structure of spider guild and increase its diversity.