应用多元逐步回归分析法评价稻田生态系统稳定性

为明确稻田生态系统稳定性量化评价指标,通过扫网法调查了2010年和2011年江西省万载县茭湖乡茭湖村有机稻田和化防稻田2种稻田节肢动物群落结构特征参数的动态变化,并利用SAS 9.0软件对2种稻田中节肢动物群落Shannon-Wiener多样性指数与个体数、物种数、优势集中性指数、物种丰富度指数、Pielou均匀度指数进行多元逐步回归分析。结果显示:连续2年有机稻田物种数(102、145)和个体数(5 228、5 811)均高于化防稻田物种数(78、102)和个体数(2 222、2 329);在2010年水稻生长期,除个别调查日期外,有机稻田优势集中性指数(0.25、0.27、0.15、0.10、0.11、0.09)整体低于化防稻田(0.30、0.40、0.18、0.17、0.24、0.14),多样性指数(1.69、2.44、2.83、2.93、2.85)整体高于化防稻田(1.39、2.24、2.35、2.29、2.49);在2011年水稻生长前、中期,有机稻田优势集中性指数(0.38、0.33、0.27、0.63、0.40)大于化防稻田(0.27、0.32、0.17、0.58、0.20);水稻抽穗扬花期,有机稻田优势集中性指数(0.06、0.04、0.05)低于化防稻田(0.12、0.05、0.12),多样性指数恰好相反。2011—2012连续2年2种类型稻田多元逐步回归方程中仅有Pielou均匀度指数与多样性指数呈显著正相关关系,有机稻田的Pielou均匀度指数回归系数(1.45、2.37)均小于化防稻田(3.37、3.16);有机稻田的常数(1.24、-0.37)均大于化防稻田(-0.64、-0.44)。表明以稻田节肢动物群落多样性指数为因变量的多元逐步回归方程中常数和Pielou均匀度指数回归系数可作为稻田生态系统稳定性测定指标。

Stability evaluation of rice field ecosystems using multiple regression analysis

In order to determine the quantitative evaluation index of rice field ecosystem stability, the dynamics of the structural characteristics of arthropod community in organic and chemical control paddy fields was investigated during 2010 to 2011 using sweeping method in Jiaohu Village, Jiaohu Town of Wanzai County, Jiangxi Province. Multiple regression analysis of the structural characteristic index of arthropod communities, Shannon-Wiener diversity and number of individuals, number of species, dominance index, dominant concentration, species richness, evenness index between organic and chemical control paddy fields were analyzed using SAS 9.0 software. The results indicated that species number (102, 145) and individual number (5 228, 5 811) in organic paddy fields were greater than species number (78, 102) and individual number (2 222, 2 329) in chemical control paddy fields. In 2010, the dominance index (0.25, 0.27, 0.15, 0.10, 0.11, 0.09) of arthropod community in organic paddy fields was generally lower than that (0.30, 0.40, 0.18, 0.17, 0.24, 0.14) of in chemical control paddy fields, but diversity index (1.69, 2.44, 2.83, 2.93, 2.85) of arthropod community was generally higher than that (1.39, 2.24, 2.35, 2.29, 2.49) in chemical control paddy fields. In 2011, before the metaphase of rice growth, the dominance index (0.38, 0.33, 0.27, 0.63, 0.40) of arthropod community in organic paddy fields was higher than that (0.27, 0.32, 0.17, 0.58, 0.20) in chemical control paddy fields, but after the metaphase of rice growth the dominance index (0.06, 0.04, 0.05) was lower than that (0.12, 0.05, 0.12) in chemical control paddy fields, and the transformation circumstance of diversity index of arthropod community was contrary to that of dominance index. Only evenness index was significantly positively correlated with arthropod diversity over two consecutive years in organic and chemical control paddy fields. The evenness index in organic rice fields (1.45, 2.37) was lower than that in chemical control paddy fields (3.37, 3.16), and the constant value in organic rice field (1.24, -0.37) was greater than that in chemical control paddy fields (-0.64, -0.44). The evenness index regression coefficient and the constant value of multiple regression equation could be used for the stability evaluation of the structural characteristics of arthropod communities in different rice ecosystems.