Root Economic Spectrum Regulates Soil Fungal Community Assembly: Interaction Between Root Traits and Fungal Functional Groups

Soil fungi play a pivotal role in maintaining ecosystem functions and regulating plant health. Although it is well-established that plant root traits can significantly impact the abundance and diversity of different fungal groups, the mechanism by which plant root strategies drive the assembly of soil fungal guilds remains limited. Utilizing Root Economics Space theory, this study investigates how four cover crops with contrasting root functional strategies regulate the composition and functional structure of soil fungal communities. Specifically the community characteristics of three functional guilds, as well as relationships between these communities and plant root traits, were evaluated using a combination of Illumina high-throughput sequencing, functional annotation, and multivariate statistical analysis. Overall, different root strategies were found to regulate fungal community structure by influencing carbon input intensity. The slow and the DIY strategies were found to inhibit r selected pathogens and promote K selected saprophytes by increasing soil pH and stabilizing carbon inputs. In contrast, the fast and outsourcing strategies released a large amount of available carbon, favoring pathogen expansion and enhancing the diversity and functional adaptability of AMF, which may increase the risk of pathogen invasion. Optimizing the root traits of cover crops can enhance soil functionality, ecosystem resilience, and agricultural productivity.