福建九龙江北溪浮游植物群落分布特征及其影响因子

Dynamic changes of phytoplankton ' s community structure in Beixi of Jiulongjiang River,Fujian Province of East China and related affecting factors

分别于2011年枯水期(2月)、丰水期(5月)和平水期(10月),系统调查研究了福建九龙江北溪浮游植物群落组成、丰度的分布特征及其与环境因子的关系.共鉴定浮游植物107种,隶属于7门64属.不同水文期浮游植物主要优势种类不同,枯水期为马索隐藻和梅尼小环藻,丰水期为四尾栅藻和四角十字藻,平水期则演替为微小平裂藻.不同水文期浮游植物丰度变化明显,其平均值依次为枯水期(154.77×104cells.L-1)>平水期(76.40×104cells.L-1)>丰水期(45.40×104cells.L-1).相关分析表明,枯水期和平水期浮游植物丰度与铵态氮(NH4+-N)呈显著正相关,丰水期浮游植物丰度与温度呈极显著正相关.典范对应分析(CCA)表明,水体温度是影响该水域浮游植物分布格局的重要因子,溶解态活性磷浓度也对浮游植物的分布有较大的影响.CCA排序图较好显示了浮游植物物种分布和环境因子之间的关系.

An investigation was conducted on the phytoplankton’s community composition,abundance,and their relations with environmental factors in Beixi of Jiulongjiang River,Fujian Province in February（dry season）,May（wet season）,and October（normal season）,2011.A total of 107 phytoplankton species were identified,belonging to 64 genera and 7 phyla.The dominant species changed with seasons.Campylomonas marssoni and Cyclotella meneghiniana dominated in dry season,Scenedesmus quadricauda and Crucigenia tetrapedia dominated in wet season,and Merismopedia tenuissima dominated in normal season.The phytoplankton’s abundance was the highest in dry season（averaged 154.77×104 cells·L-1）,followed by in normal season（76.40×104 cells·L-1）,and in wet season（45.40×104 cells·L-1）.The abundance in dry and normal seasons was significantly positively correlated with water ammonium nitrogen concentration（P〈0.05）,while that in wet season was significantly positively correlated with water temperature（P〈0.01）.Canonical correspondence analysis（CCA） showed that water temperature was the most important factor affecting the phytoplankton’s community structure,and dissolved phosphorous concentration also played important role for the community structure.The CCA ordination plots could well display the phytoplankton’s community structure and its relationships with environmental factors.