Background and aims

Ecological restoration strategies are emerging globally to counteract biodiversity loss and ecosystem degradation. However, restored ecosystems may not reach undisturbed biodiversity and functionality. One reason of this limited success may be a focus on short-term recovery of diversity, composition, or isolated functions. These simplified metrics may underestimate the real time ecosystems need to recover. Thus, studies of more complex metrics, like biotic interactions, at larger timescales, are essential to understand ecosystem recovery.

Methods

Using molecular identification, we assessed the recovery of the interactions between ectomycorrhizal (EcM) fungi and European beech (Fagus sylvatica L.) in two opencast iron mines in use since the fourteenth century and abandoned over 107 and 148 years.

Results

Species richness, species diversity, Basidiomycota/Ascomycota abundance ratio and taxonomic distinctness of EcM fungi recovered to undisturbed values, whereas species composition was still different. Certain fungal functional traits (i.e. exploration and sporocarp types) also reached undisturbed values. Differences in soil pH and NH₄⁺ affected the composition of the EcM communities associated with beech, suggesting that mining caused a long-term impact in soil biogeochemistry, that directly impacted beech-EcM interactions.

Conclusion

Mycorrhizal interactions require more than 150 years to recover following mining. Contrary to the rapid recovery response provided by simple metrics like species richness, recovery metrics with more ecological information, like the identity of plant-EcM interactions, may be still capturing signals of incomplete recovery.

中文翻译：

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欧洲山毛榉林采矿后菌根相互作用长达一个世纪的恢复

背景和目标

全球正在兴起生态恢复战略，以应对生物多样性丧失和生态系统退化。然而，恢复的生态系统可能无法达到不受干扰的生物多样性和功能。这种有限成功的原因之一可能是对多样性、组成或孤立功能的短期恢复的关注。这些简化的指标可能会低估生态系统需要恢复的实时时间。因此，在更大的时间尺度上研究更复杂的指标（例如生物相互作用）对于了解生态系统的恢复至关重要。

方法

通过分子鉴定，我们评估了两个露天铁矿中外生菌根 (EcM) 真菌和欧洲山毛榉 ( Fagus sylvatica L.) 之间相互作用的恢复情况，这两个露天铁矿自 14 世纪以来一直在使用，并已废弃了 107 和 148 年。

结果

EcM真菌的物种丰富度、物种多样性、担子菌/子囊菌丰度比和分类学独特性恢复到未受干扰的值，但物种组成仍然不同。某些真菌功能性状（即探索和子实体类型）也达到了未受干扰的值。土壤pH 和NH ₄ ⁺的差异影响了与山毛榉相关的EcM 群落的组成，表明采矿对土壤生物地球化学产生了长期影响，从而直接影响了山毛榉-EcM 相互作用。

结论

采矿后菌根相互作用需要 150 多年才能恢复。与物种丰富度等简单指标提供的快速恢复响应相反，具有更多生态信息（如植物与 EcM 相互作用的身份）的恢复指标可能仍在捕获不完全恢复的信号。