The concentrations of microelements in forest mushrooms are influenced by soil pH and C/N ratio and less by stand characteristics

The fruitbodies or sporocarps formed by mushrooms can accumulate mineral elements, such as selenium, zinc or copper, making them an important source of micronutrients essential to humans. However, the literature about environmental factors affecting mineral composition in mushrooms is scarce and limited to the ambiguous impact of soil properties and region. In our study, we investigated the effects of tree stand characteristics (tree species and tree canopy cover), understory cover, and soil properties (pH and C/N ratio of the soil) on the concentration of minerals in six edible mushroom species: Laccaria laccata, L. proxima, L. amethystina, Lepista nuda, Lycoperdon perlatum, and Calvatia excipuliformis, collected on 20 plots covered by stands of different tree species composition and varying in the understory cover. We estimated the concentration of eight elements (Zn, Se, Mg, Mn, Cu, Co, Cr, Mo) using the ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) technique and compared their concentration between the plots, using ordination and linear regression methods. Our research revealed that mushroom species identity, including its ecological role and phylogenetic affinity, had the greatest effect on the mineral composition of mushrooms. The effect of environmental factors depended also on the micronutrient identity. Some elements were not affected at all (Co, Cr), some only by soil reaction or C/N ratio (Mn, Mg, Cu), while others were influenced by both tree stand characteristics and soil properties (Se, Zn, Mo). This knowledge enables us to maximize the content of minerals in harvested mushrooms by collecting them in specific areas. For example, mushrooms, which are sources of Se and Zn, can be gathered in coniferous forests characterized by acid soils, low canopy cover, and minimal understory cover. This targeted collection approach can effectively increase the mineral content in harvested mushrooms, thereby enhancing their health benefits.