Zn2+浓度和藻密度对多刺裸腹溞生命表统计学参数的影响

Effects of Zn2+ concentration and Scenedesmus obliquus density on life table demography of Moina macrocopa

应用生命表统计学方法,在0.5×106、1.0×106和2.0×106 cells/mL的斜生栅藻(Scenedesmus obliquus)密度下研究了Zn2+浓度(20.0、50.0、80.0、110.0和140.0μg/L)对多刺裸腹溞(Moina macrocopa)生命表统计学参数的影响。结果表明,Zn2+浓度对多刺裸腹溞的种群内禀增长率有显著影响(P<0.05),藻密度对多刺裸腹溞的世代时间、净生殖率和种群内禀增长率均有显著影响(P<0.05),藻密度和Zn2+浓度间的交相互作作用对多刺裸腹溞各主要生命表统计学参数都没有显著的影响(P>0.05)。三食物密度间,多刺裸腹溞的世代时间在1.0×106 cells/mL食物密度下显著短于0.5×106和2.0×106 cells/mL食物密度下;净生殖率和种群内禀增长率均在1.0×106 cells/mL食物密度下最高,2.0×106 cells/mL食物密度下最低。50.0和80.0μg/L的Zn2+使多刺裸腹溞的种群内禀增长率显著高于对照组和其它各Zn2+浓度组。Zn2+浓度与多刺裸腹溞的生命表统计学参数中的生命期望和平均寿命在0.5×106 cells/mL食物密度下存在着显著的剂量-效应关系,可分别描述为:e0=-0.004x2+0.063x+348.604(R2=0.434, P<0.05)和t=-0.025x2-0.507x+84.468(R2=0.434, P<0.05)。

The effects of Zn2+concentrations(20.0、50.0、80.0、110.0 and 140.0 μg/L) on the life table demographic parameters of Moina macrocopa under different Scenedesmus obliquus densities(0.5×106, 1.0×106 and2.0×106 cells/mL) were investigated. The results showed that Zn2+concentration had a significant effect on the intrinsic rate of increase(P<0.05), S.obliquus density had significant effects on the generation time, the net reproduction rate and the intrinsic rate of population increase(P<0.05), and the interaction between Zn2+concentration and S. obliquus density had no significant effects on all life table demographic parameters of M. macrocopa(P>0.05). At the three S. obliquus densities, the generation time of M. macrocopa was shorter at 1.0×106 cells/mL than those at both 0.5×106 and 2.0×106 cells/mL of S.obliquus. Both the net reproduction rate and the intrinsic rate of population increase of M. macrocopa were the highest at 1.0×106 cells/mL, and the lowest at 2.0×106 cells/m L of S.obliquus. Zn2+ at 50.0 and 80.0 μg/L made the intrinsic rate of population increase of M. macrocopa higher than that in the controls and in the other Zn2+treatments. At 0.5×106 cells/mL of S. obliquus, there were significant dose-effect relationships between Zn2+concentration and life expectancy at hatching and average lifespan of M. macrocopa, and could be described as e0=-0.004 x2+0.063 x +348.604(R2=0.434, P <0.05) and t =-0.025 x2-0.507 x+ 84.468(R2=0.434, P<0.05), respectively.