光照度对水柱中斜生栅藻生长的影响

为探索在湖库中呈不均匀分布的光照度对藻类生长的影响,在水柱中研究了不同入射光照度和斜生栅藻生物量动态变化之间的关系。结果显示,在稀释率为10%的连续流条件下,当入射光照度低于10000lux,即可获得平均光照度低于2000lux时,斜生栅藻出现负增殖,而在摇瓶试验中,在入射光照度为500lux时,斜生栅藻就表现出正增殖。研究发现采用可获得平均光照度这一指标以更好地描述水柱中藻类可获得光资源量的实际状况,可获得平均光照度和斜生栅藻的稳态生物量之间呈极显著的正相关关系。此外,水体中pH值和磷酸盐浓度的变化也从侧面反映了光照度对藻类生物量的影响。

Influence of Light Intensity in Water Column on Growth of Scenedesmus obliquus

This paper is intended to investigate light-depended algal growth in lakes based on the fact that light intensity is often unequally distributed in the water column. Bench scale experiment using a water-column was conducted to simulate the natural circumstances with Scenedesmus obliquus used as the model algae species, and simultaneously a shaking flask test was done for comparison. The experimental results showed that the available average light intensity well represented the light resource acquired by algae, and remarkable positive correlation existed between the steady-state biomass of S. oblique and the available average light intensity. Furthermore, the observed changes of pH value and phosphorus concentration in water implied the dynamic relationship between light intensity and S. oblique.