Data for: Fire season and time since fire determine AM fungal trait responses to fire management

Rationale: AM fungi are common mutualists in grassland and savanna systems that are adapted to recurrent fire disturbance.  This long-term adaptation to fire means that AM fungi display disturbance associated traits which are useful for understanding environmental and temporal effects on AM fungal community assembly. 

Methods: In this work, we evaluated how fire driven ecological selection on AM fungal spore traits varies with fire season (Fall vs. Spring) and time since fire.  We tested this by analyzing AM fungal spore traits (e.g., colorimetric, sporulation, and size) from a fire regime experiment. 

 Key results: Immediately following Fall and Spring fires, spore pigmentation darkened; however, this did not mediate the observed differences between Fall burned and no burn communities.  Six months after Fall fires, spores in burned plots were lower in volume, produced less color rich pigment, and had higher sporulation rates, and these differences in spore traits were associated with shifts in AM fungal spore communities.

Main conclusion: This shows that AM fungal responses to fire vary based on season (stronger effects in the Fall) and with time since fire.  Variation in AM fungal responses to fire time may reflect greater exposure to fire in Fall, when sporulation is highest.