三峡水库支流浮游植物演替内外驱动力辨析

Discriminate on the internal and external driving force of phytoplankton succession in the Three Gorges Reservoir tributaries

为辨析三峡水库支流浮游植物演替的内外驱动力,以趋同性、趋异性理论为基础,在外界条件恒定和营养盐充足的情况下,通过光照和温度单一条件室内控制试验,分析其浮游植物的生物量和多样性变化。结果表明,光照组和温度组环境条件下的浮游植物群落演替更为明显,同一生境下浮游植物群落种类相似性指数达到中等以上,其多样性指数的总体变化趋势一致,无显著差异(P>0.05);不同生境间,浮游植物群落种类相似性为中等不相似,其多样性指数具有显著差异(P<0.05),符合趋同性理论。对照组的环境因子对浮游植物群落演替影响不明显,其优势种呈现出差异,符合趋异性理论。

In order to analyze the internal and external driving forces of phytoplankton succession in the tributary of the Three Gorges Reservoir,based on the theory of convergence and divergence,under the condition of constant external conditions and sufficient nutri⁃ent content,the biomass and diversity of phytoplankton were analyzed by indoor control experiment under light and temperature under single condition.The results showed that phytoplankton community succession was more obvious under the environmental conditions of light and temperature groups.The similarity index of the phytoplankton community species in the same habitat was above medium,and the overall variation trend of the species diversity index was consistent,without signiticant difference(P>0.05).The similarity of the phytoplankton community species among different habitats was moderate,and the diversity index had a significant difference(P<0.05),which accorded with the theory of convergence.The environmental factors of the control group had no obvious effect on the suc⁃cession of the phytoplankton community,and the dominant species showed the difference,which accorded with the theory of diver⁃gence.