Baudoin J M, Guérold F, Felten V, Chauvet E, Wagner P, Rousselle P
Laboratoire Interactions Ecotoxicité, Biodiversité, Ecosystèmes, UMR CNRS 7146, Université Paul Verlaine-Metz, Délestraint, 57070, Metz, France.
Microb Ecol. 2008 Aug;56(2):260-9. doi: 10.1007/s00248-007-9344-9. Epub 2008 Jan 17.
Aquatic hyphomycetes play an essential role in the decomposition of allochthonous organic matter which is a fundamental process driving the functioning of forested headwater streams. We studied the effect of anthropogenic acidification on aquatic hyphomycetes associated with decaying leaves of Fagus sylvatica in six forested headwater streams (pH range, 4.3-7.1). Non-metric multidimensional scaling revealed marked differences in aquatic hyphomycete assemblages between acidified and reference streams. We found strong relationships between aquatic hyphomycete richness and mean Al concentration (r = -0.998, p < 0.0001) and mean pH (r = 0.962, p < 0.002), meaning that fungal diversity was severely depleted in acidified streams. By contrast, mean fungal biomass was not related to acidity. Leaf breakdown rate was drastically reduced under acidic conditions raising the issue of whether the functioning of headwater ecosystems could be impaired by a loss of aquatic hyphomycete species.
水生真菌在异源有机物的分解过程中起着至关重要的作用，这是驱动森林源头溪流功能的一个基本过程。我们研究了人为酸化对六条森林源头溪流（pH范围为4.3 - 7.1）中与欧洲山毛榉落叶相关的水生真菌的影响。非度量多维标度分析显示，酸化溪流和对照溪流中的水生真菌群落存在显著差异。我们发现水生真菌丰富度与平均铝浓度（r = -0.998，p < 0.0001）和平均pH值（r = 0.962，p < 0.002）之间存在很强的相关性，这意味着酸化溪流中的真菌多样性严重减少。相比之下，平均真菌生物量与酸度无关。在酸性条件下，树叶分解速率急剧降低，这引发了一个问题，即水生真菌物种的丧失是否会损害源头生态系统的功能。
