珠海地区小型抽水型与非抽水型水库的浮游植物群落结构变化

Variation of the Phytoplankton Community in the Pumped Storage Reservoirs and the Non-pumped Storage Reservoirs in Zhuhai

2006年4月、8月、12月对珠海3座抽水型水库和3座非抽水型水库的水质和浮游植物进行采样和测定。抽水型水库和非抽水型水库的浮游植物分别有67种和56种。蓝藻门的假鱼腥藻(Pseudanabaena sp.)、湖丝藻(Limnothrix redekei)和拟柱孢藻(Cylindrospermopsis rackiborskii)仅在抽水型水库中检到,而绿藻门的鼓藻(Cosmarium sp.)仅在非抽水型水库中检到。抽水型水库浮游植物种类的季节变化比非抽水型水库明显,且浮游植物的丰度和生物量均高于非抽水型水库。抽水型水库浮游植物丰度在1.25×105～4.38×106c ells L-1之间,以蓝藻和小型绿藻为主;非抽水型水库浮游植物丰度在7.1×104～4.61×106 cells L-1之间,以绿藻门的鼓藻为主。抽水型水库浮游植物的生物量在2.3～8.8mg L-1之间,非抽水型水库浮游植物的生物量在1.3～5.6mg L-1之间。抽水型水库浮游植物的生物量在冬春季高于夏季,而非抽水型水库浮游植物的生物量动态相反。抽水型水库浮游植物的优势种具有明显的季节变化。非抽水型水库浮游植物具有相对稳定的群落季节变化,其优势种的组成较为稳定。对于抽水型水库而言,咸潮前期集中调水入库,不仅改变了水库的营养盐负荷,也改变了水库水动力学的季节动态,这也是导致抽水型与非抽水型水库在浮游植物群落结构与动态上存在明显差别的关键因素。

Small reservoirs play an important role in both of city and country drinking water supply in the South China. To understand the phytoplankton community dynamics in these small reservoirs, three pumped storage reservoirs and three non-pumped storage reservoirs were investigated in April, August and December, 2006, respectively. 67 and 56 taxa in total were identified in the pumped and the non-pumped storage reservoirs, respectively. Pseudanabaena sp. ,Limnothrix redekei、Cylindrospermopsis raekiborskii only appeared in the pumped storage reservoirs, while Cosmcxium sp. only occurred in the non-pumped storage reservoirs. Cells abundance and biomass in the pumped storage reservoirs were higher than those in the non-pumped storage reservoirs. The abundance of phytoplankton ranged from 1.25 ×10^5cell L^-1 to 4.38×10^6 cells L^-1 in the pumped storage reservoirs, was mainly dominated by eyanobacteria and small cellular chlorococcacean, while the abundance of phytophnkton ranged from 7.1 × 10^4 cells L^-1 to 4.61 × 10^6 cells L^-1 in the non-pumped storage reservoirs, and dominated by Cosmarium sp.. The biomass of phytoplankton ranged from 2.3 mg L^-1 to 8.8 mg L^-1 in the pumped storage reservoirs, and from 1.3 mg L^-1 to 5.6 mg L^-1 in the non-pumped storage reservoirs. The dominant species were seasonally replaced in the pumped storage reservoirs, while those were seasonally constant in the non-pumped storage reservoirs. Water pumped into reservoir made the nutrient distribution and hydrologic processes change, which was a key factor for a significant difference in the structure and dynamics of phytophnkton community between the pumped storage reservoirs and non-pumped storage reservoirs.