Effect of long-term destocking on soil fungal functional groups and interactions with plants

Aims While the effects of destocking on soil nutrient and plant productivity are known, the effect on functional groups of fungi has received less attention. The objective of this study was to evaluate the effect of long-term destocking on fungal functional guilds and their association with plants and soil. Methods We characterized the changes in five fungal functional guilds, including plant pathogens, animal pathogens, wood saprotrophs, dung saprotrophs, and arbuscular mycorrhizal fungi (AMF), along a 35-year chronosequence following destocking at 0-60 cm soil depths on the Chinese Loess Plateau. Fungal community composition was assigned by comparing with the FUNGuild database. Results After 35 years of destocking, diversities of plant pathogens, wood saprotrophs, and AMF increased, while that of animal pathogens and dung saprotrophs decreased. Destocking had a greater effect in the near-surface layers (0-10 and 10-20 cm) owing to the greater influence of plant biomass and soil nutrients. Among the above- and belowground drivers, plant pathogen diversity was largely associated with plant diversity, while animal pathogens, dung saprotrophs, and wood saprotrophs were associated with aboveground biomass, AMF were responsive to soil conditions (e.g., organic C, NO3--N, C:N ratio, and moisture). Conclusions Long-term destocking can be considered to be an important predictor of fungal functional guilds, and changes in these microorganisms were associated with cessation-induced shifts in plants and soil by grazing. Our findings provide insights into the duration of destocking necessary to benefit fungal communities, and how this varies according to soil depth.