Search for: All records

Abstract While the positive relationship between plant diversity and ecosystem functioning is frequently observed and often attributed to direct plant–plant interactions, it remains unclear whether and how the effects of plant diversity endure through soil legacy effects, particularly at the level of genotypic diversity. We manipulated the genotypic diversity ofScirpus mariqueterand tested its soil legacy effects on a conspecific phytometer under low‐ and high‐water availability conditions. We found that genotypic diversity enhanced phytometer productivity through soil legacies, with stronger effects under low‐water availability conditions, improving its resistance to water stress. Moreover, this effect was attributed to the association between asexual and sexual reproductive strategies by increasing ramet number to ensure plant survival under low‐water availability and promoting sexual reproduction to escape stress. The observed diversity effects were primarily associated with increased levels of microbial biomass in soils trained by populations with diverse genotypes. Our findings highlight the importance of plant genotypic diversity in modulating ecosystem functioning through soil legacies and call for management measures that promote genetic diversity to make ecosystems sustainable in the face of climate change. 

Abstract Plant–soil feedback (PSF) is an important mechanism determining plant community dynamics and structure. Understanding the geographic patterns and drivers of PSF is essential for understanding the mechanisms underlying geographic plant diversity patterns. We compiled a large dataset containing 5969 observations of PSF from 202 studies to demonstrate the global patterns and drivers of PSF for woody and non‐woody species. Overall, PSF was negative on average and was influenced by plant attributes and environmental settings. Woody species PSFs did not vary with latitude, but non‐woody PSFs were more negative at higher latitudes. PSF was consistently more positive with increasing aridity for both woody and non‐woody species, likely due to increased mutualistic microbes relative to soil‐borne pathogens. These findings were consistent between field and greenhouse experiments, suggesting that PSF variation can be driven by soil legacies from climates. Our findings call for caution to use PSF as an explanation of the latitudinal diversity gradient and highlight that aridity can influence plant community dynamics and structure across broad scales through mediating plant–soil microbe interactions. 

Abstract Feedbacks between plants and soil microbial communities can play an important role in structuring plant communities. However, little is known about how soil legacies caused by environmental disturbances such as drought and extreme precipitation events may affect plant–soil feedback or whether plant–soil feedback operates within species as it does between species. If soil legacies alter plant–soil feedback among genotypes within a plant species, then soil legacies may alter the diversity within plant populations. We conducted a fully factorial pairwise plant–soil feedback experiment to test how precipitation legacies influenced intraspecific plant–soil feedbacks among three genotypes of a dominant grass species,Panicum virgatum.Panicum virgatumexperienced negative intraspecific plant–soil feedback, i.e., genotypes generally performed worse on soil from the same genotype than different genotypes. Soil precipitation legacies reversed the rank order of the strength of negative feedback among the genotypes. Feedback is often positively correlated with plant relative abundance. Therefore, our results suggest that soil precipitation legacies may alter the genotypic composition ofP. virgatumpopulations, favoring genotypes that develop less negative feedback. Changes in intraspecific diversity will likely further affect community structure and ecosystem functioning, and may constrain the ability of populations to respond to future changes in climate. 

Abstract Plant‐soil feedback (PSF) theory provides a powerful framework for understanding plant dynamics by integrating growth assays into predictions of whether soil communities stabilise plant–plant interactions. However, we lack a comprehensive view of the likelihood of feedback‐driven coexistence, partly because of a failure to analyse pairwise PSF, the metric directly linked to plant species coexistence. Here, we determine the relative importance of plant evolutionary history, traits, and environmental factors for coexistence through PSF using a meta‐analysis of 1038 pairwise PSF measures. Consistent with eco‐evolutionary predictions, feedback is more likely to mediate coexistence for pairs of plant species (1) associating with similar guilds of mycorrhizal fungi, (2) of increasing phylogenetic distance, and (3) interacting with native microbes. We also found evidence for a primary role of pathogens in feedback‐mediated coexistence. By combining results over several independent studies, our results confirm that PSF may play a key role in plant species coexistence, species invasion, and the phylogenetic diversification of plant communities.