Plant-soil feedback is shut down when nutrients come to town

Abstract

Background and aims The concept of plant-soil feedback is increasingly used to explain plant community assembly processes. Soil nutrient availability can be expected to play a critical role on these processes. However, little is known about the effects of nutrient availability on feedback direction and strength. Methods A plant-soil feedback experiment was performed with the grasses Anthoxanthum odoratum and Festuca rubra, and the forbs Leontodon hispidus and Plantago lanceolata, on soil with either low or high nutrient availability. Additionally, we tested if plantsoil feedback of the two forbs under these conditions changed by inoculation of the soil with spores of an arbuscular mycorrhizal fungus. Results Increased nutrient availability neutralised plantsoil feedback based on shoot biomass independent of its negative or positive direction, whereas the effects on root biomass were either not altered or turned negative. Mycorrhizal fungi spore addition decreased negative feedback and increased positive feedback. Conclusions Our results suggest that negative plant-soil feedback on low nutrient soil can be overcome with nutrient addition, and that positive soil biota associations on low nutrient soil may become superfluous with nutrient increase. We hypothesize that species-specific, microbial mediated plant community assembly processes occur in low rather than high nutrient environments.

Site Soil-Fertility and Light Availability Influence Plant-Soil Feedback

“…Our findings are the first showing the importance of soil fertility on PSF in a tree species and are mostly consistent with the conceptual framework for PSF context dependence proposed by Smith-Ramesh and Reynolds (2017), and experimental work with herbaceous grassland species that shows stronger negative PSF in low fertility conditions (Petermann et al, 2008;in 't Zandt et al, 2019; but see Harrison and Bardgett, 2010 which found no effect of soil fertility on PSF). However, instead of the PSF becoming less negative (Petermann et al, 2008), absent (in 't Zandt et al, 2019, or weakly positive (Smith-Ramesh and Reynolds, 2017) we found PSF in higher fertility conditions to be equally strong, but in the opposite direction (i.e., seedling survival switching from worse to better in conspecific relative to heterospecific cultured soil).…”

“…These soil biotic responses suggest increased negative PSF as soil fertility increases (as postulated by Revillini et al, 2016;Lekberg et al, 2018). However, in greenhouse experiments, fertilization reduced negative PSF (Petermann et al, 2008) or neutralized either positive or negative PSF (in 't Zandt et al, 2019). As outlined by Smith-Ramesh and Reynolds (2017), negative PSF may be expected to weaken due to a decline in nutrient stress and strengthened physical or chemical defenses (especially those that are N-based) against soil pathogens, and/or ability to re-grow lost tissue from non-structural carbohydrates.…”

Species abundance fluctuations over 31 years are associated with plant–soil feedback in a species‐rich mountain meadow

“…We show that this relation was highly time-dependent, suggesting that species abundance fluctuations may underlie the contrasting results in literature. Our results add to an increasing number of theoretical (Broekman et al, 2019;Kandlikar et al, 2019) and empirical studies (in 't Zandt, Hoekstra, et al, 2020;in 't Zandt et al, 2019;Kulmatiski et al, 2017;Lekberg et al, 2018;Teste et al, 2017) emphasising that plant traits, competitive ability and soil nutrient availability must be taken into account in interpreting community effects of plant-soil feedback. Indeed, our cyclic patterns can only be understood if negative feedback is particularly prominent in more abundant species that profit more from readily available soil nutrients than less abundant species with positive feedback.…”

“…Here, we investigated (a) if species relative abundance fluctuations over time resulted in fluctuations in the relation between abundance and single time point plant-soil feedback, (b) whether coupled species' increases and decreases in abundance in time were related to plant-soil feedback and (c) whether these abundance changes were moderated by manuring events. Apart from its direct effects on species relative abundances, nutrient enrichment has also been shown to modify or even overrule plant-soil feedback and its effect on plant species community composition (Castle et al, 2016;in 't Zandt, Hoekstra, et al, 2020;in 't Zandt et al, 2019;Manning et al, 2008). Based on our results, we discuss the long-term role of plant-soil feedback in shaping plant communities and the potential underlying mechanisms driving these processes.…”

“…Years with manuring were a common force that affected all species at the same points in time and often resulted in an increase in relative abundance of negative feedback species followed by a decrease in relative abundance of these species the years after ( Figure 4b). Manuring may increase the plant species' ability to cope with negative feedback effects (in 't Zandt et al, 2019;Klinerová & Dostál, 2020), by changing microbial soil communities (Fierer et al, 2009;Leff et al, 2015;Ramirez et al, 2012) (Bonanomi, Giannino, et al, 2005;Fry et al, 2018;in 't Zandt et al, 2019;Vincenot et al, 2017). Similarly, feedback effects are expected to be density-dependent with negative effects being most strong in high intraspecific competition.…”