| 富春江水库浮游植物功能群变化的成因 |
| 摘要点击 772 全文点击 216 投稿时间：2023-01-06 修订日期：2023-03-11 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 浮游植物 功能群 流态 气温 河流型水库 浮游动物 |
| 英文关键词 phytoplankton functional groups fluid regime air temperature river-channel reservoir zooplankton |
|
| 中文摘要 |
| 为探究富春江水库浮游植物群落结构的演替特征、水华风险机制及关键影响因素,分别于2020年8月和11月与2021年1月和4月在富春江库区及上下游11个断面采样分析浮游植物、浮游动物群落结构及相关理化指标,对浮游植物进行功能群（FG）分类,并应用非度量多维尺度分析（NMDS）和冗余分析（RDA）等统计方法探讨功能群变化的影响因素.结果发现,富春江水库浮游植物可分为18个功能类群,其中10个为优势类群；功能群的组成存在显著时空差异：空间上,库区上游江段主要以小环藻（Cyclotella）为代表的C类群和以沟链藻（Aulacoseira）为代表的P类群占优,与该江段中富营养混合水体的环境特征相符；富春江库区仍以P类群为主,但沿程优势度逐渐减小；库区下游江段MP类群逐渐占优,且在钱塘江口占据绝对优势,反映了感潮河流扰动频繁、浊度较高的环境特征；季节上,夏季功能群类型最为丰富,为P+L0+J+M+S1+H1+MP型,除了全年都占优的沟链藻为代表的P类群,还包括多个以蓝藻和绿藻为代表的类群,反映出生境多变、生产力旺盛的水环境特征；秋季演替以长孢藻（Dolichospermum）为代表的H1类群占优,总体为P+H1,反映了水量减少、流态趋于静止的水环境特征；冬季小环藻的突增,C类群占据优势,总体为P+C,反映出换水减弱、富营养化加剧的环境条件变化；而春季类群又逐渐丰富,为C+D+P+MP,也反映出降雨增多、气温升高引起的河流生境多变的环境背景特征.根据C-R-S生长策略分析,R策略类群是富春江水库浮游植物的主导类群,与富春江流域各江段高干扰、低胁迫的总体生境特征吻合.RDA分析表明,水温、浮游动物生物量、高锰酸盐指数、流量、总氮和总磷与浮游植物功能群组成显著相关（P<0.05）,温度和流态是影响富春江水库浮游植物功能群时空差异的主导因素,浮游动物是影响浮游植物功能群时空差异的关键因素.研究表明,水文气象过程对富春江流域浮游植物群落结构影响至关重要,夏季高温季节流态变化可能是诱发富春江库区蓝藻水华的关键因子；降低藻类水华的风险,应在河流氮磷负荷控制的基础上,充分考虑水利调度的协同控制. |
| 英文摘要 |
| To explore the distribution characteristics, blooming risk mechanism and driving factors of phytoplankton community structure in Fuchunjiang Reservoir. The variation characteristics of phytoplankton, zooplankton and physicochemical indicators in Fuchunjiang Reservoir and its upper and lower reaches were investigated in 2020 and 2021. Based on the phytoplankton functional groups, non-metric multidimensional scale analysis, redundancy analysis and other statistical methods, the seasonal succession characteristics and driving factors of phytoplankton functional groups were analyzed. A total of 18 phytoplankton functional groups were identified, in of which 10 were predominant. The composition of phytoplankton functional groups in the Fuchunjiang Reservoir was significant different. Spatially, the upstream were dominated by group C and P while the represent species were Cyclotella and Aulacoseira,reflecting the mixed meso-eutrophic environments. However, group P was the main group in Fuchunjiang reservoir, and the dominance decreased gradually along the stream direction. Meanwhile, in the downstream, MP has an absolute advantage at Qiantang River estuary. It reflected the environmental characteristics of frequent disturbance and high turbidity of tide-sensing rivers. In addition, the predominant functional groups demonstrated strong seasonal variations. The dominant functional groups were diverse in summer and consisted of P+L0+J+M+S1+H1+MP. In addition to group P (Aulacoseira), which was dominant throughout the year, it also included several groups represented by cyanobacteria and chlorophyta, reflecting the environmental characteristics of changeable habitats and vigorous productivity. In autumn, the succession was dominated by H1 group represented by Dolichospermum and the representative function groups were P and H1, reflecting the hydrological background of reduced flow and static flow. In winter, the increase of Cyclotella led to the predominance of group C, which was dominated by P+C, reflecting the changing conditions of weakened water exchange and intensified eutrophication problems. In spring, the dominant functional groups were gradually enriched and were composed of C, D, P, and MP, which also reflected the changing environmental habitat characteristics which caused by increasing rainfall and air temperature. According to the results of the C-R-S growth strategy, the Fuchunjiang Reservoir has been in the R strategy for a long time, which was consistent with the habitat characteristics of Fuchunjiang Reservoir and its upper and lower reaches with high disturbance and low stress. In addition, C strategy and S strategy appeared in some reaches, reflecting the variability of water quality and hydrology. RDA analysis showed that water temperature, discharge, zooplankton biomass, permanganate index, total nitrogen and total phosphorus were significantly correlated with the seasonal succession of phytoplankton functional groups (P < 0.05), and temperature and flow pattern were probably the most critical factors for the succession. Studies have shown that the impact of hydrometeorological processes on phytoplankton in the Fuchunjiang Reservoir is crucial:high temperature and changing discharge during the summer may lead to cyanobacterial blooms in the Fuchunjiang reservoir; To reduce the risk of algal blooms, it is still necessary to increase the control of nitrogen and phosphorus load in rivers, and fully consider the coordination of water conservancy dispatch methods. |
|
|
|
