广西金鸡滩库区水深梯度下的硅藻生态特征研究

Ecological Characteristics of Diatoms under Water Depth Gradients in Jinjitan Reservoir Area

基于生物群落结构的生态水文特征,特别是水深梯度下的硅藻生物群落差异为研究历史水位变迁提供了重要依据,亦为水质生物监测的合理采样水深提供参考意见.通过采集金鸡滩库区不同水深下的附生硅藻,研究了喀斯特地区水深梯度下的硅藻分布特征,探讨了金鸡滩库区硅藻种属对水深变化的响应.研究结果表明曲壳藻属是该库区的绝对优势种,在2.2m深处达到峰值;在水深梯度上,桥弯藻属和脆杆藻属的丰度减小,异极藻属和直链藻属的丰度增加.硅藻的生态类群特征为:硅藻种群的耐污性和N-异氧类群增加,营养偏好和pH偏好呈波动变化,盐度偏好变化不明显.在不同水深下,各指数的相对离散程度很低,认为在合理水深内的生物采样对水质生物评价影响较小;在响应水深梯度上,SHE是所有生物指数中较理想的.该研究结果为重塑本地区的古水位、古洪水提供了重要的理论依据,对硅藻生物监测水质具有一定的指导意义.

Diatom communities at different water depths provide an important basis for studying the history of water level change. By the different depths of epiphytic diatoms, the diatom distribution characteristics and studied; Jinjitan reservoir diatom assemblages and the species of the response are discussed. The results show that, Jinjitan Reservoir diatom assemblages significantly affected by water depth; the achnanthes is the absolute dominant species in the reservoir area; and reached the peak at 2.2 m; in depth gradient, diatom by cymbella wed the gradient change obviously, stain resistance and N-ISO oxygen increased diatom, nutritional preferences and pH preference was fluctuating; but salinity preferences no obvious change. In indicator depth gradient, SHE is the most appropriate diatom index. The results of this study provide an important theoretical basis for the establishment of a diatom hydrological conditions in the area; the depth of the relational database to reshape the region and evaluation of water quality on diatoms has certain guiding significance.