soil fungi in arable ecosystems in a 2200km distance

Fungi regulate nutrient cycling, decomposition, symbiosis and pathogenicity in arable soils. However, the relative importance of generalist and specialist taxa in regulating fungal ecological networks remains largely unresolved. We hypothesized that common generalist taxa, which are expected to dominate across contrasting environmental conditions and to resist disturbance, could potentially provide foundation for fungal networks in cropping systems. In this study, we identified the generalist and habitat specialist fungi taxa (through the niche breath definition) across a 2,200 km environmental gradient including three bioclimatic regions (subtropical, warm temperate and temperate) from eastern China. A few fungi in our database were classified as generalist taxa (~1%), which however, accounted for >35% of the relative abundance of all fungal populations. Compared to specialist taxa (5-17% of all phylotypes in three regions), generalist had a higher degree of connectivity (p < 0.05) and were often identified as hub taxa within the network. Structural equation modelling provided further evidence that within-network, fungal community composition was largely driven by generalist fungi. Taken together, our study provides evidence that generalist taxa are the central components for fungal ecological network, and suggests that an improved ecological understanding of generalist taxa has important implication for managing croplands at the large spatial scale.