东江水系浮游植物功能群季节动态特征及影响因子

SEASONAL DYNAMICS CHARACTERISTICS AND AFFECTING PHYSICAL FACTORS OF PHYTOPLANKTON FUNCTIONAL GROUPS IN DONGJIANG RIVER

2009年12月至2010年9月对东江水系进行了枯水期、平水期、丰水期的三次浮游藻类采集,以分析浮游藻类功能群组成、季节变化特征及影响其季节变化的物理因子。结果表明,东江水系浮游藻类在样品中出现频率大于10%的物种归入14个功能群,分别是J、X2、P、W2、H1、MP、D、F、C、LO、W1、N、X1和M。其中优势功能群是J、X2、P、W2、H1、MP、D、F、C、LO和M。浮游藻类功能群组成明显随季节变化,枯水期时功能群MP、D、P、X2、F、J和W2占优势;丰水期时,功能群MP、J、H1、LO占优势。除功能群理论中提到的营养(碳氮硅)、光照强度和生物作用(滤食)外,水体物理因子溶氧、水温、pH、TDS也是影响浮游藻类功能群季节动态的重要环境因子。研究表明温带湖泊调查提出的浮游藻类功能群概念用于河流生态系统浮游植物的研究是合适的。

Dongjiang River lies in the subtropical monsoon climate region of the southern China. From December 2009 to September 2010, composition and seasonal succession of phytoplankton functional groups in the river were investigated during low, level and high water period, respectively. Altogether 14 functional groups （functional groups J, X2, P, W2, HI, MP, D, F, C, Lo, W1, N, X1 and M） were identified and the predominant groups in the succession were groups J, X2, P, W2, HI, MP, D, F, C, Lo and M. Functional groups composition in Dongjiang River demon- strated obviously seasonal dynamics. In low water period, the predominant functional groups were MP, D, P, X2, F, J and W2; however, the prevailing groups shifted to functional groups MP, J, Lo and H1 in high water period. The succession of phytoplankton functional groups was also significantly correlated with physical factors--water temperature （WT）, pH, dissolved oxygen （DO） and total dissolved solids content （TDS）. This study indicated that the functional groups concept was also useful and applicable in demonstrating phytoplankton composition of river ecosystem.