三峡小江回水区叶绿素a季节变化及其同主要藻类的相互关系

通过分析三峡小江回水区2007年5月～2008年4月115个样品叶绿素a的季节特点，提出了适用于表征小江回水区叶绿素a与不同藻类细胞密度和生物量的3种状态：Chla≤5 μg·L^-1、5 μg·L^-1-1和Chla>19 μg·L^-1，目的是探讨小江回水区不同水平下Chla与同期各主要藻类细胞密度和生物量的相互关系，为进一步了解三峡水库特定水域藻类季节演替特征提供参考. 全年数据下，小江回水区藻类总细胞密度、生物量和叶绿素a间均呈极显著的正相关关系（R>>0.70，Sig.≤0.01）. 研究期间小江回水区叶绿素a、绿藻、硅藻、蓝藻、甲藻生物量均值分别为(9.58±10.77)、(1605±647)、(707±124)、(511±266)和(4019±1345) μg·L^-1. Chla≤5 μg·L^-1的水平下，绿藻、硅藻与Chla浓度呈显著正相关；5 μg·L^-1-1水平下，仅有蓝藻与Chla含量呈显著正相关关系；Chla>19 μg·L^-1时，甲藻与Chla含量呈显著的正相关关系，但其它藻门与Chla含量无显著相关关系.

Seasonal Variation of Chlorophyll A and Its Potential Relationship with Various Algal Species in Xiaojiang River Backwater Area, Three Gorges Reservoir

The seasonal variation of Chlorophyll a (Chla) in Xiaojiang river backwater area from May 2007 to April 2008 with 115 water samples was studied. Three trophic states i.e. Chla < or = 5 microg x L(-1), 5 microg x L(-1) < Chla < or = 19 microg x L(-1) and Chla >19 microg x L(-1), were applied to represent the potential relationship of Chla, algal cell density (CellD) and biomass (BioM) in Xiaojiang river backwater area. The results showed that the algal cell density, biomass and Chla had significantly positive correlations (r > 0.70, Sig. < or = 0.01) and their seasonal variation processes are synchronous. The average values of Chla and biomass of chlorophyta, diatoms, cyanobacteria, dinoflagellate during the study period in Xiaojiang river backwater area were (9.58 +/- 10.77), (1605 +/- 647), (707 +/- 124), (511 +/- 266) and (4019 +/- 1345) microg x L(-1), respectively. When Chla < or = 5 microg x L(-1), chlorophyta, diatoms and Chla were significantly positively correlated; while under 5 microg x L(-1) < Chla < or = 19 microg x L(-1) level, only cyanophytes and Chla showed a significantly positive correlation; At Chla > 19 microg x L(-1) level, Chla was positively correlated to dinoflagellate, and there were no significant correlations among Chla and other algae.