Plant-Soil Feedback: Alpine Grassland Plants in Home and Away soil

Abstract

For the grassland, plant soil feedback (PSF) has been the focus of much recent research to understand plant species dynamics. Experimental methods are very important in the plant soil feedback (PSF) analysis, and it has been observed that various PSF experimental approaches yield in different feedback values. More field type experiments are required to understand the role of PSFs in plant communities in natural sites. Here, I describe an experiment designed to test PSFs for grassland in field type conditions. In my research field-soil from six different sites (subsites/replicates) along the latitudinal gradient in alps and tundra region of Europe are considered to determine the impact of away and home soils in the growth of forbs and grass in the alpine grassland. These collected soils were directly used (without any conditioning or sterilization) for the response phase experiment to understand the PSF direction and strength. Plant–soil feedback effects have been statistically (directly by Anova) analysed using the plant total biomass data subjected to two treatments (‘Home’ vs. ‘Away’ soil and ‘Home’ vs. ‘Away’ climate). We found that although effects varied between soil sites, PSF were more often positive for plants growing in their home soil than for plants growing in away soil. In our study, we also examined plant-soil feedback responses to two important climate factors together, photoperiod (15hrs and 24hrs) and temperature (+12 ºC and +15 ºC), representing climate of the Alps and/ or Tundra region respectively. We found that experimental home climate resulted in positive PSF, where plants showed greater growth in plant traits, such as biomass, root length, canopy height and root mass fraction. It was also observed that the direction of growth was also affected with the choice of soil origin (home vs. away) in conjunction with the home climate. These results in plant-soil feedbacks were not consistent across a simulated community of grass and forb (simulated by planting one grass and one forb species together in single pot). We also observed that plant origin is another factor along with soil origin and climate origin which may contribute to strength and direction of the PSF in grassland. These data should aid theory and predictions for conservation and restoration applications in alpine grassland by showing the relative importance of ‘home’ soil and ‘home’ climate for grass and forb.