Relationships between microbiological features and arbuscular mycorrhizal fungi in Andosols with contrasting degradation stages

Modifications in physical and chemical soil properties caused by land use affects Arbuscular mycorrhizal fungi (AMF). However, responses of AMF to land use can also be explained by the parallel effects of land use on other soil microbiological aspects. This study examined 90 soil samples of andosols collected from natural forests, agricultural areas, and mining sites in the southeastern region of Antioquia (Colombia), to evaluate the relationships between soil microbiological features, AMF responses, and soil abiotic properties into a soil degradation gradient. Through a reliable ANOVA approach, we determined that populations of culturable mesophilic bacteria and fungi, catalase activity, microbial basal respiration, diversity of AMF spores, abundance of AMF spores, and contents of total glomalin-related soil proteins (TGRSP) declines significatively depending on the soil degradation stage. Linear mixed models were tested using a dropping column algorithm (DCA) revealing that 70% of the variance in TGRSP was explained by populations of culturable fungi, bulk density, and concentrations of Ca and S. Additionally, a non-metrical dimension scaling analysis (NMDS) revealed significant correlations between variations in diversity of AMF spores and urease activity, populations of culturable fungi and mesophilic bacteria, as well as abiotic factors including soil temperature, soil organic carbon, and Ca concentrations. The findings suggest that soil microbiological features may play significant roles in the variations of AMF. Thus, this study offers new considerations for future studies about the use of microbiological agents to improve the implementation of AMF in soil conservation strategies.