Sverdrup Line E, Linjordet Roar, Strømman Gjermund, Hagen Snorre B, van Gestel Cornelis A M, Frostegård Sa, Sørheim Roald
Bioforsk--Norwegian Centre for Soil and Environmental Research, NO-1432s, Norway.
Chemosphere. 2006 Dec;65(10):1747-54. doi: 10.1016/j.chemosphere.2006.04.075. Epub 2006 Jun 13.
The effect of zinc on soil nitrification and composition of the microbial community in soil was investigated using a full factorial experiment with five zinc concentrations and four levels of biological complexity (microbes only, microbes and earthworms (Eisenia fetida), microbes and Italian ryegrass (Lolium multiflorum var. Macho), and microbes, ryegrass and earthworms). After 6 weeks of exposure, the activity of soil nitrifying bacteria was measured and the microbial community structure was characterized by phospholipid fatty acid (PLFA) analysis. Soil nitrification and several PLFA markers were significantly influenced by either zinc addition and/or the presence of earthworms or ryegrass, and one of the most pronounced changes was the increase of fungi and decrease of bacteria with increasing concentrations of zinc. Of particular interest, however, was the potential interaction between the presence of plants and/or earthworms and the effect of zinc, which the factorial study design allowed us to explore. Such an effect was observed in two cases: Earthworms reduced the positive effect of zinc on the fungal biomass (ANOVA, p=0.03), and the effect of earthworms on the soil nitrification activity depended on zinc concentration (ANOVA, p<0.05). The effect of earthworm presence was not very large, but it does show that multispecies tests might give information about metal toxicity or bioavailability that cannot be predicted from single-species tests.
采用全因子试验，设置5个锌浓度水平和4个生物复杂程度水平（仅微生物、微生物和蚯蚓（赤子爱胜蚓）、微生物和多花黑麦草（马乔多花黑麦草变种）、微生物、黑麦草和蚯蚓），研究了锌对土壤硝化作用及土壤微生物群落组成的影响。暴露6周后，测定了土壤硝化细菌的活性，并通过磷脂脂肪酸（PLFA）分析对微生物群落结构进行了表征。土壤硝化作用和几种PLFA标记物受到锌添加和/或蚯蚓或黑麦草存在的显著影响，最显著的变化之一是随着锌浓度的增加，真菌增加而细菌减少。然而，特别值得关注的是植物和/或蚯蚓的存在与锌的影响之间的潜在相互作用，析因研究设计使我们能够探索这种相互作用。在两种情况下观察到了这种效应：蚯蚓降低了锌对真菌生物量的正向影响（方差分析，p = 0.03），蚯蚓对土壤硝化活性的影响取决于锌浓度（方差分析，p < 0.05）。蚯蚓存在的影响不是很大，但它确实表明多物种试验可能会提供有关金属毒性或生物有效性的信息，而这些信息是单物种试验无法预测的。
