摘要
在亚热带浅水湖泊中,由风浪引起沉积物再悬浮是其重要特征之一.沉积物再悬浮一方面直接影响浮游动物群落结构,另一方面通过影响食浮游动物鱼类对浮游动物的捕食而产生间接影响.以食浮游动物鱼类——餐条(Hemiculter leucisculus)为实验对象,通过模拟实验,比较不同再悬浮条件下餐条对浮游动物群落结构的影响.结果显示,在有餐条的处理组中,大型枝角类短钝溞(Daphnia obtusa)只在弱再悬浮条件下出现,并成为枝角类群落的优势种;在无餐条的处理组中,短钝溞生物量随再悬浮强度减弱而增加.强再悬浮(无餐条)和无再悬浮(有餐条)条件下,小型枝角类角突网纹溞(Ceriodaphnia cornuta)和盘肠溞(Chydorus sp.)为优势种.无论有、无餐条条件下,桡足类优势种均为中剑水蚤(Mesocyclops sp.),其生物量随再悬浮强度减弱而增加.所有处理组中,轮虫丰度均低于枝角类和桡足类丰度.研究表明,在亚热带浅水湖泊中,适当的悬浮质浓度既能干扰食浮游动物鱼类对大型浮游动物的捕食,又不影响大型浮游动物的生存,使得它们保持一定的丰度,通过对浮游植物的摄食,降低叶绿素a浓度.
Sediment resuspension resulted from wave actions is one of the major characters of subtropical shallow lakes. Resuspension can directly alter the zooplankton community structures,and indirectly influence the predation of planktivorous fishes. Our study aimed to reveal how planktivorous fish Hemiculter leucisculus affected the zooplankton community structures in different levels of sediment resuspension. The results showed that in the condition of H. leucisculus,large-sized cladoceran Daphnia obtusa was only found and became dominant in the treatment of weak resuspension. Biomass of D. obtusa decreased with the increase of resuspension intensity in treatments without H. leucisculus and Chydorus sp.. The Ceriodaphnia cornuta dominated the cladoceran communities in the treatments of strong resuspension without H. leucisculus or no resuspension with H. leucisculus. Regardless of fish and resuspension intensity,Mesocyclops sp. was dominant copepod and its biomass increased with the decrease of the resupension intensity. Rotifer abundances were lower than cladoceran and copepod in all treatments. This study indicates that in subtropical shallow lakes,a certain level of sediment resuspension can weaken both the predation of planktivorous fishes and resuspension effect on large-sized cladoceran,which can decrease the chlorophyll-a concentration through increasing the feeding of large-sized cladoceran on algae.
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2015年第5期911-916,共6页
Journal of Lake Sciences
基金
国家自然科学基金项目(41271523)
江苏省科技支撑项目(BE2011820)联合资助
关键词
沉积物再悬浮
浮游动物
餐条
群落结构
亚热带浅水湖泊
太湖
Sediment resuspension
zooplankton
Hemiculter leucisculus
community structures
subtropical shallow lakes
Lake Taihu
