Linking Soil Chemical Parameters and Arbuscular Mycorrhizal Fungal Communities in Qatar

Much of Qatar’s habitats are characterized by a hyper-arid climate, low rainfall and scarce soil nutrients; all of which combine to create a stress-induced environment for fungal development. Agricultural productivity and soil fertility in turn, are highly dependent on the diversity of soil microbiota. The soil environment is a heterogeneous habitat shaped by various components including soil chemical properties and habitat types i.e. wetlands, barren land and grasslands. Arbuscular mycorrhizal fungi (AMF) are one of the key components vital for ecological processes in stress-induced systems as the complex hyphae systems of AMF assemblages permit sufficient nutrient exchange in mycorrhiza symbionts. However, much of the diversity and community composition of AMF in Qatar are poorly studied. In this study, Illumina sequencing by MiSeq platform was used to identify and explore the diversity and composition of AMF communities. Our results revealed 127 virtual taxa (VTs) from eight AMF families, 87 of which were identified as species from Glomeraceae family; while indicator analysis showed that Glomeraceae species served as the indicator species in 15 sites with an indicator index value of 13.33 (indicator value > 0.25)

Temperature and pH define the realised niche space of arbuscular mycorrhizal fungi

The arbuscular mycorrhizal (AM) fungi are a globally distributed group of soil organisms that play critical roles in ecosystem function. However, the ecological niches of individual AM fungal taxa are poorly understood. We collected > 300 soil samples from natural ecosystems worldwide and modelled the realised niches of AM fungal virtual taxa (VT; approximately species-level phylogroups). We found that environmental and spatial variables jointly explained VT distribution worldwide, with temperature and pH being the most important abiotic drivers, and spatial effects generally occurring at local to regional scales. While dispersal limitation could explain some variation in VT distribution, VT relative abundance was almost exclusively driven by environmental variables. Several environmental and spatial effects on VT distribution and relative abundance were correlated with phylogeny, indicating that closely related VT exhibit similar niche optima and widths. Major clades within the Glomeraceae exhibited distinct niche optima, Acaulosporaceae generally had niche optima in low pH and low temperature conditions, and Gigasporaceae generally had niche optima in high precipitation conditions. Identification of the realised niche space occupied by individual and phylogenetic groups of soil microbial taxa provides a basis for building detailed hypotheses about how soil communities respond to gradients and manipulation in ecosystems worldwide