Plant community legacy effects on nutrient cycling, fungal decomposer communities and decomposition in a temperate grassland

Soil legacies mediated by plant species-specific microbial communities are
major drivers of plant community dynamics. Most soil legacy studies focus
on the role of pathogens and mutualists in driving these processes, while
much less is known about plant litter-mediated changes to the soil
microbial community. Here, we used an existing plant-soil feedback field
experiment in which plant communities with different growth strategies
(i.e., fast versus slow) and different proportions of functional groups
(grasses versus forbs) were allowed to condition the soil over contrasting
temporal scales (i.e., one versus two years) in a natural grassland. In
the feedback phase, we removed the existent plant community, and replaced
it with a standardized response plant community. We then tested the legacy
effects of these different soil conditioning treatments on decomposition
processes, nutrient cycling and soil decomposer community composition.
Soil legacy effects on decomposition and the soil decomposer community
composition were most evident right after the start of the feedback phase,
but disappeared soon after the new community established. The soil
conditioning time and years since disturbance affected most of the soil
functions consistently, while no strong effects of plant functional group
and plant growth strategy were found. We conclude that after disturbance,
it is recovery time, not soil legacy effects, that is the most important
factor driving soil functions.