Manganese (Mn) is an essential plant micronutrient that influences photosynthesis, ecosystem productivity, and soil carbon storage. Our objective was to quantify how Mn uptake by forest vegetation relates to Mn release into soil solution through mineral dissolution. A greenhouse pot experiment was conducted to quantify Mn uptake by red maple saplings as a function of mineral solubility to test whether Mn uptake was limited by the supply of Mn to soil solution. Differences in soil microbial community composition between treatments, particularly amongst Mn cycling bacteria and fungi, were also evaluated to assess potential microbial impacts on observed Mn fluxes. Plant Mn uptake was highest in systems supplied with dissolved Mn(II) because it was not kinetically limited by mineral weathering. Mn uptake was also higher in systems supplied with a fast-weathering substrate (shale containing Mn(II)-bearing pyrite) than a slow-weathering substrate (Mn(IV)-oxide). However, vegetation accumulated a decreasing proportion of available Mn with increasing solubility, indicating that uptake was tempered relative to solubility. The presence of bacterial phyla containing known Mn-oxidizing bacteria indicates the potential for Mn-oxidizing bacteria to influence Mn solubility within Mn-oxide and dissolved Mn treatments. A relatively low abundance of these bacteria points to their limited capacity to oxidize and retain Mn in the shale treatments, consistent with substantial Mn leaching. We conclude that Mn uptake was primarily controlled by dissolution rates of Mn-bearing minerals but modified by biological processes. The quantitative framework presented here can guide understanding of how biogeochemical processes control element cycling between plants and soils.

锰 (Mn) 是一种重要的植物微量营养素，影响光合作用、生态系统生产力和土壤碳储存。我们的目标是量化森林植被对锰的吸收与通过矿物质溶解释放到土壤溶液中的锰之间的关系。进行温室盆栽实验以量化红枫树苗对锰的吸收作为矿物质溶解度的函数，以测试锰的吸收是否受到土壤溶液中锰供应的限制。还评估了处理之间土壤微生物群落组成的差异，特别是锰循环细菌和真菌之间的差异，以评估微生物对观察到的锰通量的潜在影响。在提供溶解锰 (II) 的系统中，植物对锰的吸收最高，因为它不受矿物风化的动力学限制。在提供快速风化底物（含含锰（II）黄铁矿的页岩）的系统中，锰吸收量也高于慢风化底物（Mn（IV）-氧化物）。然而，随着溶解度的增加，植被积累的可用锰的比例下降，表明吸收相对于溶解度有所缓和。含有已知 Mn 氧化细菌的细菌门的存在表明 Mn 氧化细菌有可能影响 Mn 氧化物和溶解 Mn 处理中的 Mn 溶解度。这些细菌相对较低的丰度表明它们在页岩处理中氧化和保留锰的能力有限，这与大量的锰浸出一致。我们得出结论，锰的吸收主要受含锰矿物的溶解速率控制，但受生物过程的影响。