Manganese (Mn) has been identified as a regulatory bottleneck in carbon (C) turnover because of its role as an enzymatic co-factor in the oxidative decomposition of C by Mn-peroxidase (MnP). We tested this limit on decay using forest soils from coastal British Columbia with contrasting Mn concentrations. Moderately weathered soils (Brunisols) had an average 3.6-fold increase in MnP activity within the upper soil profile in comparison to highly weathered Podzols. Ordination of the Agaricomycete fungal community, which are responsible for MnP production, confirmed significant differences in assemblages between soil types for saprotrophic fungi, particularly species within Agaricales, Trechisporales and Auriculariales. Ectomycorrhizal fungi of Pseudotsuga menziesii were equally aligned with soil type and select taxa more abundant on Brunisols may have supplemented MnP activity. A laboratory incubation with an Mn amendment produced significant interactions in MnP activity by soil type. Surprisingly, MnP activity of both Brunisol substrates declined substantially with an amendment (− 56 and − 40% for forest floor and mineral soil, respectively), in contrast to Podzols (− 30 and + 26%, respectively). This inhibitory response was linked to considerable uptake of the added Mn in Brunisols, presumably by saprotrophic fungi, and underscores how Mn likely operates directly on fungi as a regulator of gene transcription for MnP production. Our study highlights a new perspective concerning the abiotic drivers underpinning the expansive soil C stocks across perhumid temperate rainforests of the Pacific Northwest.

锰 (Mn) 已被确定为碳 (C) 周转的调节瓶颈，因为其在 Mn 过氧化物酶 (MnP) 氧化分解 C 中作为酶促辅助因子的作用。我们使用来自不列颠哥伦比亚省沿海地区的森林土壤和对比 Mn 浓度测试了这种腐烂限制。与高度风化的灰化土相比，中度风化的土壤 (Brunisols) 在上层土壤剖面中的 MnP 活性平均增加了 3.6 倍。负责 MnP 生产的伞菌纲真菌群落的排序证实了腐生真菌的土壤类型之间的组合存在显着差异，特别是在伞菌目、Trechisporales 和 Auriculariales 中的物种。Pseudotsuga menziesii外生菌根真菌与土壤类型相同，并且选择在 Brunisol 上更丰富的分类群可能补充了 MnP 活性。使用 Mn 修正剂的实验室孵化在不同土壤类型的 MnP 活性中产生了显着的相互作用。令人惊讶的是，与 Podzols（分别为 - 30 和 + 26%）相比，两种 Brunisol 底物的 MnP 活性随着修正而大幅下降（森林地面和矿质土壤分别为 - 56 和 - 40%）。这种抑制反应与 Brunisol 中添加的 Mn 的大量吸收有关，大概是由腐生真菌引起的，并强调了 Mn 可能直接作用于真菌，作为 MnP 生产的基因转录调节剂。我们的研究强调了一个关于支撑太平洋西北部高湿温带雨林膨胀土壤碳库的非生物驱动因素的新视角。