Abstract: By means of acute toxicity and life-table experiments, this paper studied the acute toxicity of molybdenum (Mo) to Moina macrocopa and the effects of Mo on the life-table demographic parameters of M. macrocopa. The 48 h LC50 of M. macrocopa for Mo was 134.46 mg·L-1, with the 95% confidence interval of 107.05-194.53 mg·L-1. At concentrations of 2.0-15.0 mg·L-1, Mo had no significant effects on the life expectancy at birth, generation time, average life span, and net reproduction rate, but affected the intrinsic rate of M. macrocopa population increase significantly. In the control, the intrinsic rate of M. macrocopa population increase was 0.0448±0.0033 h-1, which was higher than that when the M. macrocopa was exposed to 6.4, 8.4, 11.2, and 15.0 mg·L-1 of Mo (0.0334±0.0007, 0.0327±0.0010, 0.0335±00003, and 00346±00005 h-1, respectively). Compared with other test organisms, M. macrocopa was more sensitive to Mo, and among all the life-table demographic parameters, the intrinsic rate of population increase was the most sensitive.

Key words: climate, boundary constraint, area, vertical patterns, Baishuijiang Nature Reserve., species richness