Abstract: In this paper, the dynamics of microflora and microbial activity in soil added with 0, 100, 200 and 400 mg·kg^-1 of Cu²⁺ were studied under effects of inoculating earthworm and applying straw. Four treatments were installed, i. e. , CK, surface application of straw (M), inoculation of earthworm (E), and M plus E (ME). The results showed that Cu contamination had inhibitory effect on soil bacteria and actinomycetes, but no effect on soil fungi. Straw amendment increased soil fungi significantly, while earthworm inoculation could increase the numbers of soil bacteria and actinomycetes significantly but had little effect on soil fungi. When the Cu concentration was higher than 200 mg·kg^-1, soil microbial biomass carbon was depressed, but earthworm inoculation and straw amendment could enhance it, with most significant effect under the combination of these two treatments. Earthworm inoculation and straw amendment could enhance soil basal respiration markedly. When the Cu concentration was lower than 200 mg·kg^-1, treatment M had the highest soil basal respiration, being about 3.06-5.58 times higher than that of CK, while at Cu≥200 mg·kg^-1, soil qCO₂ followed the sequence of ME>E>M>CK. Treatments M and E had no effects on soil NH₄⁺-N. As for soil NO₃^--N, treatment E could increase it significantly, but treatment M was in adverse. Treatment ME induced the lowest soil NO₃^--N. In a definite degree, earthworm inoculation and straw amendment could mitigate the negative impact of Cu contamination on soil microflora and microbial activity.

Key words: Taxus chinensis var mairei, Clonal population, Population structure, Population dynamics