Responses of Soil Fungi to Long‐Term Nitrogen‐Water Interactions Depend on Fungal Guilds in a Mixed Pinus koraiensis Forest

Abstract

AbstractDifferent fungal guilds within the soil fungal community regulate forest ecosystem processes. Soil fungi are dictated by edaphic factors such as soil water and nutrient availabilities. However, how the total number of fungi and the composition of different fungal guilds in the soil vary under covarying pattern of nitrogen deposition and precipitation regime in temperate forests has not been well documented. In this study, we explored the effects of long‐term nitrogen‐water interactions on the diversity and composition of soil overall fungi and different fungal guilds, and their relationships with fine‐root and soil fungal mycelial traits in a temperate forest. The diversity of the totality of soil fungi or any fungal guilds did not change, but the community composition of saprotrophic and symbiotrophic fungi was significantly changed by nitrogen addition (N), showing increased abundance of soil symbiotrophic fungi but decreased abundance of soil saprotrophic fungi. Precipitation reduction (W) significantly altered soil overall and pathotrophic fungal community. Precipitation reduction combined with nitrogen addition (WN) significantly changed soil overall, pathotrophic and symbiotrophic fungal community composition. Soil pathotrophic, saprotrophic and symbiotrophic fungal community composition was variously related to fine‐root diameter, root tissue density, nitrogen and/or phosphorus concentration. Long‐term nitrogen‐water interactions decreased the complexity of soil fungal networks, reflected by the lower edges and average degree, but the higher average path distance and modularity. These findings of soil fungal guild‐specific responses to nitrogen‐water interactions will deepen our understanding of soil carbon sequestration potential and nutrient cycling in temperate forest ecosystems under future climate changes.