Data from: Escape from harmful soil biota at high elevations: Plant-soil feedbacks along stress gradients

Plant-soil feedbacks (PSFs) have strong effects on plant community
diversity and composition, but we know less about how the abiotic
environment alters PSFs.  In the context of the Stress Gradient
Hypothesis (SGH) we predicted less negative PSFs in alpine vs. prairie
systems and tested this with three alpine and four prairie species and
soil from three elevational gradients in western Montana, USA.
 All species were smaller when grown in prairie soil than in
alpine soil, and sterilization of soil increased the growth only of alpine
species in prairie soil.  Training prairie soil with conspecifics
decreased the biomass of both alpine and prairie species, but training
alpine soil had no effect.  PSFs were three times more negative
when plants were grown in low-elevation prairie soils than in alpine
soils.  Consistent with the original ideas for the SGH, the
frequency of positive PSFs were higher in alpine soil than in prairie soil
and the frequency of negative PSFs was higher in prairie soil than in
alpine soil.  Our results suggested that alpine species may
escape more intense negative PSFs at lower elevations and that PSFs will
not limit the upward movement of plant species as temperatures warm.