The abundance of plants in natural plant communities may be affected by many factors, including plant-soil feedbacks (PSF). Several studies reported a positive correlation between plant abundance and PSF, suggesting negative PSF effects are a putative driver of plant rarity. Others have reported no or a negative correlation, raising uncertainty about the general relationship between abundance and PSF. In a meta-analysis of 21 PSF experiments distributed worldwide ranging from tropical forest to semiarid grasslands, we examined the generality of the positive correlation between plant field abundance and PSF.
Results/Conclusions
Across 245 PSF measures, negative PSF were predominant. We also found 1) an overall small positive correlation between field abundance and PSF across plant functional types and 2) important variation by functional type. We provide quantitative support that PSF is a general albeit weak putative driver of variation in plant abundance across species. Experiments of herbaceous species, which are most common in the literature, had no appreciable correlation thereby indicating a need to resolve the factors affecting relationships between plant abundance and PSF. More research is needed to truly test whether PSF affect plant communities and build understanding of the factors regulating variation in PSF among species.