不同环境因素影响下直链藻垂向分布特性研究

为了解不同环境因素对水库内直链藻(Melosira)垂向分布的影响程度, 作者利用自制沉降柱实验模拟不同光照、水动力以及降雨条件对水中直链藻垂向分布的影响。通过单因素方差分析实验数据表明光照和降雨条件的改变对上浮区内直链藻的垂向分布具有显著影响, 底部出流流量的改变对下沉区内直链藻的垂向分布具有显著影响。随着水深的增加, 光照和降雨对水中直链藻垂向分布的影响减弱而水动力则对其影响增强。同时还验证了直链藻具有较强的趋光性, 宜在低光强环境内生长, 模拟测得其最适光强在3 000 lx 左右; 降雨对水中直链藻的垂向分布起到抑制作用, 降雨强度越大水中直链藻就越偏离水体表面; 在底部出流流量影响范围内, 随着出流流量的增大水中直链藻就越向水动力改变处聚集且稳定时间越短。

Research on vertical distribution characteristics of Melosira with influence of different environmental factors

In order to understand the effects of environmental factors on the vertical distribution of Melosira in reservoir, the self-made settlement column experiment was used to simulate the influence of different light, water power and rainfall conditions on vertical distribution of Melosira in water. Data analysis using one-way ANOVA showed that light and rainfall conditions significantly changed the vertical distribution of Melosira in the floating zone, and the bottom flow significantly changed vertical distribution of Melosira in the sinking zone. With the increase in water depth, light and rainfall, the influence on the vertical distribution ofMelosira in water was weakened and hydrodynamic was enhanced. At the same time, Melosira was verified to have strong phototaxis and was suitable for growth in the low light environment with the optimal intensity of around 3 000 lx rainfall inhibited the vertical distribution of Melosira in water. Melosira was deviated from the water surface with the increase in rainfall intensity. In the bottom flow effect range, with the increase in water flow in water, the hydrodynamic change of Melosira was more and the stable time was shorter.