阿哈水库浮游植物功能群时空分布特征及其影响因子分析

为了解贵州高原阿哈水库的浮游植物功能类群时空分布特征及其影响因素,于2012年至2013年枯水期(11月)、平水期(4月)、丰水期(7月)对浮游植物与水样进行分层采样分析.研究结果表明:浮游植物可分为23个功能群,优势功能群为B、D、J、LO、P、S1和X1,其时空分布特征表现为:枯水期、平水期与丰水期分别以B+D+P+LO、S1+LO以及S1为主,其丰度由枯水期至丰水期依次递增;优势功能群主要在15 m以下水体发生变化,营养物质分布差异及人工放闸泄水是产生该特征的主要原因;采样点大坝和库中的优势功能群季节变化大致相同,但却表现出大坝多于库中,而其丰度却低于库中的特征,水动力条件是导致这一变化的主要原因.经RDA分析得出,优势功能群丰度与水温呈正相关,与总氮、透明度、磷酸盐、硝氮呈负相关,其中水温、透明度为影响浮游植物功能群时空分布的主要因子.

Spatial and temporal distribution characteristics of phytoplankton functional groups in aha reservoir and their influencing factors

Aha Reservoir is a medium-sized reservoir designated as one of a drinking water source for Guiyang city, Guizhou Province. Besides, the reservoir has many other functions, such as, agricultural irrigation, flood control and tourism etc. In order to explore the spatial and temporal distribution characteristics of phytoplankton functional groups and their influencing factors in Aha Reservoir, phytoplankton and water samples were taken in dry period (November 2012), level period (April 2013) and wet period (July 2013). The results showed that there were 23 phytoplankton functional groups, and the dominant functional groups were B,D,J,L_O,P and S1. The spatial and temporal distribution characteristics were as follows: firstly, the dominant functional groups were mainly MP,X1,D and J during dry period, S1 and L_O during level period, and S1 during level period; the population abundance of dominant functional groups was the highest in wet period, followed by level period and dry period; the dominant functional groups changed easily below 15 meters of the sampling points in every period, which was attributed to the difference of nutrients distribution and the opening of discharge gate; seasonal distribution of the dominant functional groups were roughly the same in Daba and Kuzhong, and the population of the dominant functional groups in Daba was more than that in Kuzhong but the population abundance in Daba was less than that in Kuzhong, which was attributed to the difference of hydrodynamic condition. Results of multivariate analysis (RDA) indicated the population abundance of the dominant functional groups was positively correlated with water temperature (WT), and was negatively correlated with total nitrogen (TN), transparency, PO₄-P and NO₃-N. Among all the factors, WT and SD were the main factors affecting the spatial and temporal distribution of the dominant functional groups.