Understanding what species characteristics allow some alien plants to become invasive while others fail is critical to our understanding of community assembly processes. While many characteristics ...have been shown to predict plant invasiveness, the importance of plant–soil feedback (PSF) in invasions has been difficult to assess since individual studies include only a few species and use disparate methodology. We studied PSF of 68 invasive and non‐invasive alien species in a single two‐phase common garden experiment, and compared the relative importance of PSF, residence time, phylogenetic novelty and plant traits for plant invasiveness. Additionally, we explored relationships between PSF, residence time and phylogenetic novelty. PSF for seedling establishment, but not for biomass, was a significant predictor of invasive status, with invasive species having more positive PSF than non‐invasive species. Its explanatory power was, however, much lower than that of specific leaf area, height and residence time. Phylogenetically novel species experienced less negative PSF than species with native congeners, suggesting they benefit more from enemy release. PSF of non‐invasive species, contrary to that of invasive species, was becoming more negative with increasing residence time. We demonstrated that PSF for seedling establishment plays a role in predicting plant invasiveness and is a better predictor than more commonly studied PSF for plant biomass. Other species traits, such as specific leaf area, however, predict plant invasiveness much better than the PSF.
Plant–soil feedback (PSF) is recognized as an important mechanism shaping plant communities and determining plant abundance and coexistence. Under natural conditions, plants affect the outcome of ...plant–soil interactions simultaneously by conditioning the soil by living roots and by litter inputs into the soil. However, most experimental studies only focus on one of the pathways, which limits our understanding of PSF in the field.
Here, we simultaneously explored the effect of soil conditioning by living roots and of root and shoot litter addition on the performance of seven Impatiens species grown in a two‐phase garden experiment.
Soil conditioning negatively affected plant performance, which was at least partly explained by nutrient depletion. Root litter addition affected plant performance negatively and the results suggest that biotic effects such as pathogen transmission via the root litter played a role. The effects of root litter addition were more pronounced in control soil which, contrary to the conditioned soil, supposedly did not accumulate pathogens during the conditioning phase. Shoot litter addition increased soil nutrient levels, but had no impact on plant performance. However, presence of shoot litter aggravated the negative effects of root litter, probably due to increased amounts of nutrients available for soil biota and thus their faster growth and intensified effect on the plants.
Overall, our study suggests that root and shoot litter have contrasting roles in plant–soil interactions and understanding their separate and interactive effects together with effects of soil conditioning is crucial for assessing the complexity of PSF.
•Intraspecific plant-soil feedback (PSF) of invasive and native dominants was compared.•Native species showed more negative PSF for root biomass than invasive species.•PSF for germination and shoot ...biomass differed under some cultivating conditions.•Cultivating conditions had different effect on PSF of invasive and native species.•Higher investment into belowground biomass led to more negative PSF.
Intraspecific plant-soil feedback (PSF), a process in which a plant species affects the soil and the modified soil affects further growth of the same plant species, has been proposed to be one of the mechanisms controlling plant dominance in the field, as well as plant invasiveness. However, very few studies compared the PSF of invasive species with native species of a similar level of dominance. In this study, we compared PSF of three pairs of invasive and native congeners with the same level of dominance in the field and with similar ecological requirements. Additionally, we assessed the role of conditions of plant cultivation for the PSF by growing the plants under four treatments (two moisture × two shading regimes).
Both invasive and native dominants showed neutral to positive PSF for seedling establishment and negative PSF for biomass. Native species had more negative PSF for belowground biomass than invasive species. PSF for seedling establishment and aboveground biomass showed no overall difference between invasive and native dominants, although differences existed under some cultivating conditions. PSF for seedling establishment was affected by moisture with the response of individual genera reflecting their ecological requirements. PSF for aboveground biomass was affected by the interaction of moisture and shading and was most negative under the dry light treatment. PSF for aboveground biomass was negatively correlated to root biomass, indicating that higher allocation into roots under dry conditions might lead to intensified interactions with soil biota and thus more negative plant-soil feedback. Our study showed that cultivating conditions can significantly affect results of PSF experiments and pointed to the importance of including multiple measures of PSF in future experiments.
Plant invasions represent a major ecological and socio-economical issue and understanding the drivers as well as consequences of plant invasions is thus one of the main goals of plant ecology. It is ...equally important to reveal general patterns underlying plant invasions and to understand the details of biology of individual invaders. In this thesis I explored plant-soil feedback (PSF) as a possible general mechanism underlying plant invasiveness, and also focused in detail on drivers and consequences of Impatiens parviflora invasion. The aims of this thesis were to i) assess the differences in intraspecific PSF between invasive and alien non-invasive species using a large set of species; ii) explore the relationship between PSF, residence time and phylogenetic novelty of the alien species; iii) compare the importance of PSF and other plant characteristics for plant invasiveness; iv) compare PSF between invasive and native congeners of similar level of dominance in the field; v) evaluate the effect of cultivating conditions on results of PSF experiments; vi) describe invasion dynamics and determine factors affecting spread of invasive I. parviflora using a method of monitoring its natural spread in several types of habitats, and vii) assess the impact of I. parviflora on native vegetation of oak-...