增江底栖硅藻种类多样性及分布特征

Species Diversity and Spatial Distribution of Benthic Diatom in Zeng River, Guangdong Province, Southern China

摘要:

2010年1月和5月对东江水系重要支流增江进行底栖硅藻的采样调查，分析了增江流域底栖硅藻的多样性和时空分布特征，并探讨了硅藻优势种与环境因子的关系。结果表明，两次采样共检出底栖硅藻42属178种(包括亚种和变种)，与1月份相比，由于5月份降雨量较大，硅藻的数量有所下降，种类组成也有所改变。在两次采样中，藻类分布从下游到上游呈现了一定的规律。四级河流以菱形藻属(Nitzschia)占比例较大，三级河流以舟形藻属(Navicula)占比例较大，二级及一级河流以曲壳藻属(Achnanthes)占比例较大。相关性分析表明，菱形藻属的相对丰度与水体的总磷、电导率有很强的相关性。作为优势属，菱形藻属可进一步发展为对增江河段水质状况进行监测的指标。

Abstract:

To understand species diversity and spatial distribution of benthic diatom in Zeng River, a branch of Dongjiang River, Guangdong Province, southern China. The benthic diatoms were sampled in January and May, 2010, respectively. The diatom species were identified according to KLB classification system and photos provided by Patrick Environmental Research Center. The correlation between the dominant species and some influential factors were studied with multivariate analysis method based on the sample data and environmental parameters. Altogether 42 genera and 178 species were identified. Compared with those in January, the number of diatom decreased and the species composition changed in May. The species distribution exhibited regular pattern from downstream to upstream, in which Nitzschia occupied a significant proportion in the fourth class stream, Navicula in the third class stream, and Achnanthes in the first and second class streams. The abundance of Nitzschia was strongly correlated with total phosphorus and conductivity. It suggested that Nitzschia genus could be used to develop biological index for monitoring the water condition of Zeng River.