湖南省衡阳市紫色土丘陵坡地不同恢复阶段植物群落稳定性

Stability of plant communities in different re-vegetation stages on sloping-landwith purple soils in Hengyang City,Hunan Province

以典型的衡阳紫色土丘陵坡地不同恢复阶段为研究对象,采用空间序列代替时间序列的方法,选用立地条件基本相似的狗尾草群落(Comm.Setaria viridis)(Ⅰ)、紫薇+糯米条-狗尾草群落(Comm.Lagerstroemia indica+Abelia chinensis-Setaria viridis)(Ⅱ)和牡荆+紫薇群落(Comm.Vitex negundo var.cannabifolia+Lagerstroemia indica)(Ⅲ),通过模糊综合评价,研究不同恢复阶段植物群落的稳定性.结果表明:(1)3个植物群落的Margalef丰富度指数和Whittaker生境多样性指数的大小顺序为Ⅱ>Ⅲ>Ⅰ(P<0.05),Simpson优势度指数的大小顺序为Ⅲ>Ⅱ>Ⅰ(P<0.05),Pielou均匀度指数差异不大(P>0.05);(2)3个植物群落的Godron交点坐标分别为(35.51,64.51)、(36.23,63.79)和(35.59,64.43),均偏离稳定态坐标(20,80),处于不稳定状态;(3)3个植物群落的稳定性的隶属函数值的大小顺序为Ⅲ(0.777)>Ⅱ(0.760)>Ⅰ(0.715)(P<0.05).表3,参24.

By using the spatial series to replace time series,three typical plant communities,Comm.Setaria viridis,Comm. Lagerstroemia indica ＋ Abelia chinensis-Setaria viridis,and Comm. Vitex negundo var. cannabifolia ＋ Lagerstroemia indica were selected to explore the plant communities stability. The three plant communities were similar and typical,and denoted three successive re-vegetation stages. The results showed that：（ 1） The Margalef richness index and Whittakers were followed the order as Ⅱ〉 Ⅲ〉 Ⅰ（ P〈0. 05）; Simpson dominance index was followed the order as Ⅲ 〉Ⅱ〉 Ⅰ（ P〈0. 05）,and there was not significant difference of Pielou evenness index in three plant communities（ P〉0. 05）;（ 2） The Godron intersection point coordinate of three plant communities were（ 35. 51,64. 51）,（ 36. 23,63. 79） and（ 35. 59,64. 43）,respectively,and deviating stable state coordinate（ 20,80） and being instability;（ 3）The subordinative function value of comprehensive judgment on stability of three plant communities were followed the order as Ⅲ（ 0. 777）〉 Ⅱ（ 0. 760）〉 Ⅰ（ 0. 715）（ P〈0. 05）. 3tabs.,24 refs.