Decoding soil microbiotaâ€“plant associations in Mediterranean ecosystems of eastern Spain
While interactions between plants and soil microbiota play a key role in driving biodiversity and ecosystem functioning, it is still unclear how much plant composition changes modulates the microbiota and vice versa. This study investigates intricate ecosystem associations among plant, fungal, and bacterial diversity across 59 permanent plots in diverse undisturbed natural parks of eastern Spain (Valencian Community). Diversity indices of both soil microbiome and vegetation, as well as the contributions of factors such as micro and macroclimatic variables, plot heterogeneity parameters, soil characteristics and plant functional traits, have been determined. Results indicate some weak relations between the local (alpha) diversity of bacteria and fungi and between fungi and plants with a variable response to environmental drivers. On the other hand, changes in composition (beta diversity) in bacteria and fungi were strongly related and were associated to functional traits of the vegetation. This suggests coordinated changes across habitats in the association between vegetation and the microbiota. These findings also highlight the need to consider biotic and abiotic factors when assessing plant-microbial changes along gradients and designing conservation strategies promoting microbial diversity. Maintaining a variety of habitats along different environmental and spatial gradients is key to maximizing the pool of microorganisms present in the region.