Effects of common European tree species on soil microbial resource limitation, microbial communities and soil carbon. (September 2022)

• Record Type: Journal Article
• Authors: Zheng, Haifeng; Heděnec, Petr; Rousk, Johannes; Schmidt, Inger Kappel; Peng, Yan; Vesterdal, Lars
• Is Part Of: Soil biology and biochemistry. Volume 172(2022)
• Publication Date: 2022-09
• Subjects: Soil enzyme activity -- Ecoenzymatic stoichiometry -- Vector analysis -- Mycorrhizal association -- Common garden experiment; Soil biochemistry -- Periodicals; Soil biology -- Periodicals; Sols -- Biochimie -- Périodiques; Sols -- Biologie -- Périodiques; Sols -- Microbiologie -- Périodiques; Bodembiologie; Biochemie; 631.46
• DOI: 10.1016/j.soilbio.2022.108754
• Languages: English
• ISSNs: 0038-0717

Abstract

Abstract: Studies of tree species effects on soils have revealed a significant impact on soil organic carbon (SOC) stocks and the carbon (C) distribution between forest floor and mineral soil, but the underlying mechanisms including the roles of litter traits, soil properties, and microbiome remain unclear. To address this challenge, we tested the effect of six common European tree species on the quality and nutrient availability of soil organic matter (SOM) as perceived by the naturally assembled microbial communities and explored the possible links between soil enzyme activities (EAs), microbial resource limitation, and microbial community with SOC stocks. The six studied tree species ( Acer pseudoplatanus L., Fraxinus excelsior L, Fagus sylvatica L., Quercus robur L., Tilia cordata L., and Picea abies L.) were planted in common garden monocultures more than 40 years ago at six sites across Denmark. In forest floor, microbial biomass C, fungal and total microbial biomass and fungi to bacteria (F/B) ratios decreased with decreasing litter quality. Ecoenzymatic stoichiometry and relative EAs indicated that microbes in spruce forest floor were more limited by phosphorus (P) than in maple, lime, and beech, while microbes in mineral soils were less P limited in spruce than in other monocultures. Mineral soil under the tree species associated with arbuscular mycorrhizal (AM) fungi had higher microbial C and P limitation, bacterial biomass and total microbial biomass than under tree species associated with ectomycorrhizal (EcM) fungi. Our results indicated that tree species with high-quality litter (i.e. AM-associated trees) had (i) higher microbial biomass and less nutrient limitation that were conducive to higher decomposition rates and lower C stocks in the forest floor, and (ii) such tree species could lead to both greater stabilization of mineral soil C by mineral-associated OM formation and greater microbial mineralization of SOM with higher microbial resource demand. The results suggest that tree species-mediated EA, microbial resource limitation and microbial community composition are important drivers of stocks and vertical distribution of SOC among tree species and between the two types of associated mycorrhiza. Highlights: We investigated the effects of tree species on soil biochemical properties. Tree species affected microbial resource limitation and community composition. AM soils had higher microbial C and P limitation than EcM soils. Microbial resource limitation and biomass are important drivers of SOC stocks. The potential mechanisms of SOC stabilization were different in forest floor and mineral soil.