Response of soil general and specific functions following loss of microbial diversity: A review

Although an alarming rate of global biodiversity loss is occurring, the effects of belowground microbial diversity on soil functioning still remain uncertain and debated across numbers of experiments data. In this context, we synthesize and evaluate the impacts of microbial diversity loss on soil ecosystem functioning from published literatures, and elaborate the probable mechanisms of the different response in terms of soil general and specific functions. The results showed that the loss of microbial diversity decreases both specific (e.g. pollutant degradation, methane metabolism, pathogen control) and general functions (e.g. C and N mineralization, soil respiration, biomass production), indicating that functional redundancy may be overestimated, even for general functions. The processes that drive the link between microbial diversity and ecosystem processes are influenced by environmental factors in the soil (e.g. nutrient condition, pollution stress, moisture content). However, high functional diversity and stability are crucial in explaining the maintenance of soil ecosystem function under the scenario of global biodiversity declining, which involves the process of genotypic/phenotypic functional traits and diversity effects. In summary, our review has implications for an improved understanding regarding the relationship between diversity and general/specific functions, with suggestions for the future research provided.