Bt水稻田不同斑块设计对田间节肢动物群落稳定性的影响

利用正交设计考察了B t水稻种植面积大小以及与非转基因水稻相间距离两个因素对稻田节肢动物群落稳定性的影响。结果表明:在转B t稻斑块与非转B t稻斑块共存格局下,尽管两因素对两个品种上节肢动物群落物种丰富度影响不大,但较大斑块面积对两个品种水稻而言均有利于其上节肢动物群落多样性的保持。同时还发现,两个因素对两个品种斑块上的节肢动物群落影响不尽相同,且起显著效应的时间分布也因品种而异。对转B t稻斑块上节肢动物群落显著影响集中在水稻生育期前期(7月份)和末期(9月份),以斑块面积因素相对而言对节肢动物群落稳定性影响更大,具体表现在其面积越大,多样性越高,优势集中度越大。而对于非转B t稻两个因素对其上节肢动物群落的影响几乎贯穿整个调查期,其中又以斑块相间距离因素的影响更大,距离越小,多样性越高,优势集中度越低。进一步品种间的比较发现,转B t稻对田间节肢动物群落影响显著,在靶标害虫危害盛期其上节肢动物群落明显比非转B t稻上的稳定,而在非靶标害虫危害为主的时期,转B t稻田上节肢动物群落均不如非转B t稻上的稳定,尤其在水稻移栽后初期表现显著。

The arthropod community stabilities and diversities in the Bt rice paddy field with different patch designs

In large patch,either Bt rice patch or Non-Bt rice patch,has positive influence on diversity of arthropod community,in spite of neither the two factors have no significant influence on richness of arthropod community.However,the effect of two factors on Bt rice patches is different from on non-Bt rice patches in orthogonality Bt rice patch design and with different distance between the transgenic Bt rice patch and the non-transgenic rice patch.Compared with the patch distance,the patch area is more important to the stability of the arthropod community on Bt rice patches during the early(July) and later(September) period of rice growing,which the larger patch is,the higher the diversity and concentration is.But compared with the patch area,the distance between patches is more important to the stability of the arthropod community on non-Bt rice patches during the whole period of rice growing,which the shorter the distance is ,the higher the stability is(higher diversity and lower concentration).Moreover,the parameters of arthropod community on Bt rice patch and Non-Bt rice patch are compared by analysis of variance(ANOVA),it shows that the arthropod community on Bt rice patches is more significantly steady than one on non-Bt rice patches during the middle period of rice growing when the target insects is dominant, but it is reverse during the remain period of rice growing when the non-target insects is dominant,specially during the early period.