Cotton T E Anne, Fitter Alastair H, Miller R Michael, Dumbrell Alex J, Helgason Thorunn
Department of Biology, University of York, York, YO10 5DD, UK.
School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
New Phytol. 2015 Mar;205(4):1598-1607. doi: 10.1111/nph.13224. Epub 2015 Jan 5.
Understanding the natural dynamics of arbuscular mycorrhizal (AM) fungi and their response to global environmental change is essential for the prediction of future plant growth and ecosystem functions. We investigated the long-term temporal dynamics and effect of elevated atmospheric carbon dioxide (CO2 ) and ozone (O3 ) concentrations on AM fungal communities. Molecular methods were used to characterize the AM fungal communities of soybean (Glycine max) grown under elevated and ambient atmospheric concentrations of both CO2 and O3 within a free air concentration enrichment experiment in three growing seasons over 5 yr. Elevated CO2 altered the community composition of AM fungi, increasing the ratio of Glomeraceae to Gigasporaceae. By contrast, no effect of elevated O3 on AM fungal communities was detected. However, the greatest compositional differences detected were between years, suggesting that, at least in the short term, large-scale interannual temporal dynamics are stronger mediators than atmospheric CO2 concentrations of AM fungal communities. We conclude that, although atmospheric change may significantly alter AM fungal communities, this effect may be masked by the influences of natural changes and successional patterns through time. We suggest that changes in carbon availability are important determinants of the community dynamics of AM fungi.
了解丛枝菌根（AM）真菌的自然动态及其对全球环境变化的响应对于预测未来植物生长和生态系统功能至关重要。我们研究了大气二氧化碳（CO₂）和臭氧（O₃）浓度升高对AM真菌群落的长期时间动态和影响。在一项为期5年的3个生长季节的自由空气浓度富集实验中，利用分子方法对在升高和环境大气浓度的CO₂和O₃条件下生长的大豆（Glycine max）的AM真菌群落进行了表征。CO₂浓度升高改变了AM真菌的群落组成，增加了球囊霉科与巨孢囊霉科的比例。相比之下，未检测到O₃浓度升高对AM真菌群落有影响。然而检测到的最大组成差异存在于年份之间，这表明，至少在短期内，大规模的年际时间动态比大气CO₂浓度对AM真菌群落的影响更强。我们得出结论，尽管大气变化可能会显著改变AM真菌群落，但这种影响可能会被自然变化和随时间的演替模式的影响所掩盖。我们认为碳有效性的变化是AM真菌群落动态的重要决定因素。
