Data from: Plant community evenness responds to spatial plant-soil feedback heterogeneity primarily through the diversity of soil conditioning

1.Plant-soil feedback (PSF) has been identified as a key driver of local
plant diversity and evenness in competitive communities. However, while it
has been shown that spatial PSF heterogeneity can alter plant performance
and competitive interactions, there is no proof of principle that spatial
PSF heterogeneity enhances community diversity. 2.Using a grassland model
system we separated two aspects of spatial heterogeneity: the number of
species conditioning the soil and spatial distribution of the PSFs. 3.Our
data show that PSFs promoted a higher plant evenness when the soil was
conditioned by multiple species (mixed-conditioned), then when the soil
was conditioned by a single species (mono-conditioned). On
mono-conditioned soils, heterospecifics typically outperformed the focal
species. In addition, there was a trend for increasing community evenness
from uniform, via fine-grained to coarse-grained mixed-conditioned soils,
but this was not significant. 4.On mixed-conditioned soils, performance of
all competing species was intermediate to the best and the worst
mono-conditioned soils, leading to higher community evenness. 5.Our data
demonstrate that PSFs play a role in promoting plant evenness. Across
mono-conditioned soils, PSF led to altered competitive hierarchies.
However, on soils conditioned by multiple species, competitive ability
among species was more similar and this led to higher plant evenness. The
spatial distribution of the heterogeneity, on the other hand, did not
significantly affect plant evenness. Our data therefore show that
community evenness was more strongly related to the number of plant
species that conditioned the soil than the spatial distribution of the PSF
heterogeneity. Future studies need to investigate the importance of PSFs
in the field across plant life-stages and multiple generations.