大型水电站对河流底栖藻类群落的影响

Impacts of large hydropower station on benthic algal communities

2004年9月—2007年6月,对古夫河受大型水电站影响的GF04样点及高岚河的参照样点GL03进行逐月采样,研究了大型水电站对古夫河底栖藻类的影响.结果表明:研究期间,两样点主要理化指标差异均不显著(P>0.05);两样点水动力学差异显著(P<0.05),研究期间GL03样点基本处于缓流状态,其季节变化显著(P<0.05),而GF04样点由于受水库放水影响,采样期间60%以上时间处于急流状态,没有明显的季节节律,说明水动力学及生境的变化是影响研究区底栖藻类群落的重要因素;群落相似性以及非着生型硅藻、直立型硅藻、有柄型硅藻的相对丰度在两样点间的差异显著,可很好地反映大型水电站不定期放水对河流生态系统的影响.

To investigate the impacts of large hydropower station in Gufu River on benthic algae, monthly samplings were conducted from September 2004 to June 2007 at the site GF04 which was impacted by the hydropower station, with the site GL03 in Gaolan River as reference. During sampiing period, no significant differences were observed in the main physicochemical variables between GF04 and GL03, but the hydrodynamics differed significantly. GL03 was basically at a status of slow flow; while GF04, owing to the discharging from the reservoir, was at a riffle status during more than 60% of the sampling period. Such a difference in hydrodynamics induced significant differences in the community similarity of benthic algae and the relative abundance of unattached diatoms, erect diatoms, and stalked diatoms between GF04 and GL03, which could better reflect the impacts of irregular draw-off by large hydropower station on river eco-system.