Potential microbial bioindicators of phosphorus mining in a temperate deciduous forest

Aims The soil microbial community plays a critical role in increasing phosphorus (P) availability in low-P, weathered soils by mining recalcitrant organic P through the production of phosphatase enzymes. However, there is a lack of data on the fungal and bacterial taxa which are directly involved in P mining, which could also serve as potential microbial bioindicators of low P availability. Methods and Results Leveraging a 5-year P enrichment experiment on low-P forest soils, high-throughput sequencing was used to profile the microbial community to determine which taxa associate closely with P availability. We hypothesized that there would be a specialized group of soil micro-organisms that could access recalcitrant P and whose presence could serve as a bioindicator of P mining. Community profiling revealed several candidate bioindicators of P mining (Russulales, Acidobacteria Subgroup 2, Acidobacteriales, Obscuribacterales and Solibacterales), whose relative abundance declined with elevated P and had a significant, positive association with phosphatase production. In addition, we identified candidate bioindicators of high P availability (Mytilinidales, Sebacinales, Chitinophagales, Cytophagales, Saccharimonadales, Opitulales and Gemmatales). Conclusions This research provides evidence that mitigating P limitation in this ecosystem may be a specialized trait and is mediated by a few microbial taxa. Significance and Impact of the Study Here, we characterize Orders of soil microbes associated with manipulated phosphorus availability in forest soils to determine bioindicator candidates for phosphorus. Likewise, we provide evidence that the microbial trait to utilize recalcitrant organic forms of P (e.g. P mining) is likely a specialized trait and not common to all members of the soil microbial community. This work further elucidates the role that a complex microbial community plays in the cycling of P in low-P soils, and provides evidence for future studies on microbial linkages to human-induced ecosystem changes.

Automated summary

This study identified specific soil microbial taxa associated with manipulated phosphorus availability in forest soils, revealing candidates for phosphorus bioindicators. The research suggests that alleviating P limitation in this ecosystem may be a specialized trait mediated by a few microbial taxa. The findings provide evidence for future studies on microbial linkages to human-induced ecosystem changes.