Recent studies have revealed effects of various tree species on soil physical and chemical properties. However, effects of various tree species on composition and activity of soil microbiota and the relevant controls remain poorly understood. We evaluated the influence of tree species associated with two different mycorrhizal types, ectomycorrhiza (EcM) and arbuscular mycorrhiza (AM), on growth, biomass and metabolic activity of soil fungal and bacterial communities using common garden tree species experiments throughout Denmark. The soil microbial communities differed between six European tree species as well as between EcM (beech, lime, oak and spruce) and AM (ash and maple) tree species. The EcM tree species had higher fungal biomass, fungal growth and bacterial biomass, while AM species showed higher bacterial growth. The results indicated that microbial community composition and functioning differed between groups of tree species with distinct litter qualities that generate soil C/N ratio and soil pH differences. The mycorrhizal association only partly explained litter quality and soil microbial species differences since lime was more similar to AM tree species. In addition, our results indicated that tree species-mediated soil pH and C/N ratio were the most important variables shaping microbial communities with a positive effect on bacterial and a negative effect on fungal growth rates. The results suggest that tree species-mediated microbial community composition and activity may be important drivers of the different vertical soil C distribution previously observed in AM and EcM tree species.

最近的研究揭示了各种树木对土壤物理和化学性质的影响。然而，各种树种对土壤微生物群的组成和活性以及相关控制的影响仍然知之甚少。我们使用丹麦各地常见的园林树种实验，评估了与两种不同的菌根类型（外生菌根（EcM）和丛枝菌根（AM））相关的树种对土壤真菌和细菌群落的生长，生物量和代谢活性的影响。欧洲六种树种以及EcM（山毛榉，石灰，橡树和云杉）和AM（白蜡树和枫树）树种之间的土壤微生物群落都不同。EcM树种具有较高的真菌生物量，真菌生长和细菌生物量，而AM种具有较高的细菌生长。结果表明，具有不同凋落物质量的树木物种组之间的微生物群落组成和功能不同，从而产生土壤碳氮比和土壤pH值差异。菌根协会仅部分解释了凋落物质量和土壤微生物种类的差异，因为石灰与AM树种更相似。此外，我们的研究结果表明，树种介导的土壤pH和C / N比是影响微生物群落的最重要变量，对细菌产生积极影响，而对真菌生长速率产生负面影响。结果表明，树种介导的微生物群落组成和活性可能是先前在AM和EcM树种中观察到的不同垂直土壤C分布的重要驱动力。