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The increasing threat of biological invasion poses significant challenges to global ecosystems, necessitating urgent management measures. This study investigated the potential of biochar derived from invasive plant Chromolaena odorata, produced through anaerobic digestion, as a tool for mitigating the soil legacy effects of this species and restoring the plant community. Soil samples were collected from artificially constructed plots of invasive plant communities and were subjected to treatments with different levels of fungicide and biochar addition. Potted plant communities replicating the original species composition were established, and biomass were used to evaluate the effectiveness of soil restoration. Our results demonstrated that soil sterilization enhanced plant biomass, with invasive plants showing a more pronounced increase compared to native species, indicating different responses to the soil biota. The addition of biochar influenced plant biomass, with an optimal biochar concentration of 2% of the soil mass, promoting the growth of native plants. The application of biochar in conjunction with soil sterilization facilitated the restoration of native communities in areas with low invasion intensity. Overall, these findings provide valuable insights into the potential of biochar-based strategies for managing invasive plants and restoring ecosystems, underscoring the necessity for further research to optimize field applications and evaluate ecological impacts. [ABSTRACT FROM AUTHOR]

The effect of crop rotation on soil-borne diseases is a representative case of plant–soil feedback in the sense that plant disease resistance is influenced by soils with different cultivation histories. This study examined the microbial mechanisms inducing the differences in the clubroot (caused by Plasmodiophora brassicae pathogen) damage of Chinese cabbage (Brassica rapa subsp. pekinensis) after the cultivation of different preceding crops. It addresses two key questions in crop rotation: changes in the soil bacterial community induced by the cultivation of different plants and the microbial mechanisms responsible for the disease-suppressive capacity of Chinese cabbage. Twenty preceding crops from different plant families showed significant differences in the disease damage, pathogen density, and bacterial community composition of the host plant. Structural equation modelling revealed that the relative abundance of four key bacterial orders in Chinese cabbage roots can explain 85% and 70% of the total variation in pathogen density and disease damage, respectively. Notably, the relative dominance of Bacillales and Rhizobiales, which have a trade-off relationship, exhibited predominant effects on pathogen density and disease damage. The disease-suppressive soil legacy effects of preceding crops are reflected in compositional changes in key bacterial orders, which are intensified by the bacterial community network. [ABSTRACT FROM AUTHOR]

The increasing threat of biological invasion poses significant challenges to global ecosystems, necessitating urgent management measures. This study investigated the potential of biochar derived from invasive plant Chromolaena odorata, produced through anaerobic digestion, as a tool for mitigating the soil legacy effects of this species and restoring the plant community. Soil samples were collected from artificially constructed plots of invasive plant communities and were subjected to treatments with different levels of fungicide and biochar addition. Potted plant communities replicating the original species composition were established, and biomass were used to evaluate the effectiveness of soil restoration. Our results demonstrated that soil sterilization enhanced plant biomass, with invasive plants showing a more pronounced increase compared to native species, indicating different responses to the soil biota. The addition of biochar influenced plant biomass, with an optimal biochar concentration of 2% of the soil mass, promoting the growth of native plants. The application of biochar in conjunction with soil sterilization facilitated the restoration of native communities in areas with low invasion intensity. Overall, these findings provide valuable insights into the potential of biochar-based strategies for managing invasive plants and restoring ecosystems, underscoring the necessity for further research to optimize field applications and evaluate ecological impacts.

Soil legacy effects and biodiversity play important roles in driving plant community dynamics and functioning. However, experimental evidence of the effects of soil legacy on ecosystem multifunctionality (maintaining multiple functions simultaneously) is lacking. We first conducted a mesocosm experiment in which three common species (grass, legume, and forb) were planted in monocultures and mixed cultures to produce soil legacies. Subsequently, soils were sampled to test the soil legacy effects on ecosystem multifunctionality in a greenhouse experiment. Our findings showed that plant‐mediated soil legacy effects were species‐specific and strongly influenced the productivity of subsequent plants or combinations. Specifically, plant‐specific soil legacies had considerable impacts on the magnitude and direction of diversity‐dependent overyielding effects. Such effects can compensate for non‐legume soil legacy effects and maintain overall productivity. Functional diversity and ecosystem multifunctionality were largely affected by soil legacy effects and were significantly positively correlated with functional group richness. Based on our results, plant‐specific soil legacy is an important factor limiting the development of plant community and ecosystem multifunctionality in the early stage of community construction. The rational use of the synergistic effects of plant‐specific soil legacy and functional group richness may be a key to ensure the successful establishment of vegetation and grassland management. [ABSTRACT FROM AUTHOR]

Soils contain biotic and abiotic legacies of previous conditions that may influence plant community biomass and associated aboveground biodiversity. However, little is known about the relative strengths and interactions of the various belowground legacies on aboveground plant–insect interactions. We used an outdoor mesocosm experiment to investigate the belowground legacy effects of range‐expanding versus native plants, extreme drought and their interactions on plants, aphids and pollinators. We show that plant biomass was influenced more strongly by the previous plant community than by the previous summer drought. Plant communities consisted of four congeneric pairs of natives and range expanders, and their responses were not unanimous. Legacy effects affected the abundance of aphids more strongly than pollinators. We conclude that legacies can be contained as soil 'memories' that influence aboveground plant community interactions in the next growing season. These soil‐borne 'memories' can be altered by climate warming‐induced plant range shifts and extreme drought. [ABSTRACT FROM AUTHOR]

Genetic diversity can have important ecological consequences on population dynamics and ecosystem functions and processes. While the direct effect of genetic diversity on population performance has been widely documented, its soil legacy effect has received little attention. To assess both the direct and soil legacy effects of genetic diversity on population performance, we conducted a plant-soil feedback experiment with 12 genotypes of a clonal plant Hydrocotyle vulgaris. We first conditioned soils (conditioning phase) by growing populations of H. vulgaris consisting of 1, 2, 4 and 8 genotypes in the soils and then tested the soils (test phase) by growing populations consisting of all 12 genotypes in sterilized bulk soils inoculated with each of the conditioned soils at a volume ratio of 10%. At the end of the conditioning phase, both biomass and the number of ramets of the populations of H. vulgaris first decreased and then increased with increasing genotypic diversity, indicating a direct effect of genetic diversity on population performance. At the end of the test phase, both biomass and number of ramets were significantly higher when the populations were grown in the soils conditioned by the populations consisting of 1 and 2 genotypes than when they were grown in the soils conditioned by the populations consisting of 4 and 8 genotypes, suggesting a soil legacy effect. Therefore, genetic diversity can have both a direct and a soil legacy effect on population productivity and size of H. vulgaris. These results highlight the importance of intraspecific differences on population performance and suggest that soil legacy effects should also be considered to fully understand the role of genetic diversity.

Parasitic plants can mediate soil conditioning by invasive and native host plant species, but how this may affect the competitive ability of these plants when they later grow in the conditioned soil has never been tested. This study tested whether soil conditioned by three invasive and three native plant species, either parasitized by a holoparasitic plant Cuscuta gronovii or non-parasitized, would differentially affect the competitive ability of those species. In the first phase, field soil was conditioned using individuals of the six host plant species, either parasitized or non-parasitized. The second phase tested the competitive ability of individuals of those invasive and native plants by growing them alone or in competition with Trifolium repens in either live or sterilized conditioned soil. In the soil conditioning phase, parasitism significantly increased soil NH 4 +-N concentration by 17 %, decreased soil organic carbon by 18 %, and marginally decreased microbial biomass carbon concentration by 21 %. In the soil feedback phase, native plant species generally had higher competitive ability in soil that was conditioned by parasitized plants than in soil that was conditioned by non-parasitized plants. In contrast, soil conditioned by parasitized plants had only a marginal effect on the competitve ability of invasive plants, compared to growth in soil conditioned by non-parasitized plants. Native plants had greater competitive ability in soil with lower soil organic carbon, while invasive plants had greater competitive ability in soil with higher microbial biomass carbon and lower NH 4 +-N. These findings demonstrate that parasitism by C. gronovii mediated different soil legacy effects of invasive and native plant species through changes in soil organic carbon, soil NH 4 +-N, and microbial biomass carbon levels. Broadly, these results suggest that parasitic plants may limit invasions by alien plant species and promote the co-existence of the invaders with native plant species through soil-mediated legacy effects. • Parasitism increased soil NH 4 +-N, decreased SOC, and marginally decreased MBC concentrations. • Parasitism increased competitive ability of native plant through soil legacy effect. • Parasitism marginally decreased competitive ability of invaders through soil legacy effect. [ABSTRACT FROM AUTHOR]

Understanding the causes of variation in foliar plant metabolomes is essential for our understanding of ecological interactions between plants and other organisms. It is well‐accepted that foliar herbivory alters metabolites in leaves. However, soil (micro)organisms can also induce such changes.We generated plant‐specific soil legacies by growing 12 plant species individually in a common starting soil. Then we planted all plant species in all soils and exposed a subset to foliar herbivory. We then used 1H nuclear magnetic resonance to analyse the shoot metabolomes of all responding plants.Above‐ground herbivory and soil legacies altered shoot metabolomes. In most plant species, soil legacy more strongly affected shoot metabolomes than foliar herbivory.Synthesis. Our results show that plant‐induced changes in soil alter metabolomes of plants that grow later in those soils. Such below‐ground legacy effects can have far‐stretching consequences for above‐ground multitrophic interactions as these often depend on the plant chemical composition. Recently, plant–soil feedbacks have received considerable attention in ecological studies, and our study now highlights that these feedbacks can be an important determinant of the often unexplained intraspecific variation in chemical composition among plants. [ABSTRACT FROM AUTHOR]

Many studies have examined how human-induced atmospheric changes will influence ecosystems. The long-term consequences of human induced climate changes on terrestrial ecosystems may be determined to a large extend by how the belowground compartment will respond to these changes. In a free-air ozone enrichment experiment running for 5 years, we reciprocally transplanted soil cores from ambient and elevated ozone rings to test whether exposure to elevated ozone results in persistent changes in the soil biota when the plant and soil are no longer exposed to elevated ozone, and how these legacy effects of elevated ozone influenced plant growth as compared to current effects of elevated ozone. After one growing season, the current ozone treatment enhanced plant growth, but in soil with a historical legacy of elevated ozone the plant biomass in that soil was reduced compared to the cores originated from ambient rings. Current exposure to ozone increased the phospholipid fatty acids of actinomycetes and protozoa, however, it decreased dissolved organic carbon, bacterivorous and fungivorous nematodes. Interestingly, numbers of bacterivorous and fungivorous nematodes were enhanced when soils with a legacy of elevated ozone were placed under elevated ozone conditions. We conclude that exposure to elevated [O 3 ] results in a legacy effect in soil. This legacy effect most likely influenced plant growth and soil characteristics via responses of bacteria and fungi, and nematodes that feed upon these microbes. These soil legacies induced by changes in soil biotic community after long-term exposure of elevated ozone can alter the responses of ecosystems to current climatic changes. [ABSTRACT FROM AUTHOR]

Increasing plant species richness generally enhances plant biomass production, which may enhance accumulation of carbon (C) in soil. However, the net change in soil C also depends on the effect of plant diversity on C loss through decomposition of organic matter. Plant diversity can affect organic matter decomposition via changes in litter species diversity and composition, and via alteration of abiotic and/or biotic attributes of the soil (soil legacy effect). Previous studies examined the two effects on decomposition rates separately, and do therefore not elucidate the relative importance of the two effects, and their potential interaction. Here we separated the effects of litter mixing and litter identity from the soil legacy effect by conducting a factorial laboratory experiment where two fresh single root litters and their mixture were mixed with soils previously cultivated with single plant species or mixtures of two or four species. We found no evidence for litter-mixing effects. In contrast, root litter-induced CO2 production was greater in soils from high diversity plots than in soils from monocultures, regardless of the type of root litter added. Soil microbial PLFA biomass and composition at the onset of the experiment was unaffected by plant species richness, whereas soil potential nitrogen (N) mineralization rate increased with plant species richness. Our results indicate that the soil legacy effect may be explained by changes in soil N availability. There was no effect of plant species richness on decomposition of a recalcitrant substrate (compost). This suggests that the soil legacy effect predominantly acted on the decomposition of labile organic matter. We thus demonstrated that plant species richness enhances root litter-induced soil respiration via a soil legacy effect but not via a litter-mixing effect. This implies that the positive impacts of species richness on soil C sequestration may be weakened by accelerated organic matter decomposition. [ABSTRACT FROM AUTHOR]

• Chromolaena odorata invasion effect on the soil was greater in savanna than in forest. • Specifically, soil microbial C declined in C. odorata , mostly in invaded forest sites. • Invaded forest and savanna sites got closer in terms of microbial activity without mixing. • Native soils had a legacy effect on the changes in most of the microbial attributes. Plant invasion may have significant ecological and socio-economic impacts across agroecologies. Chromolaena odorata (Asteraceae) is one of the world's most invasive plants albeit it is considered a suitable fallow plant in West Africa. However, its impacts on soil biological processes are poorly understood. This study was conducted in intermingled forest and savanna sites invaded by C. odorata in Central Côte d'Ivoire (West Africa) to bridge this knowledge gap. Invaded forest sites (CO FOR) were compared to adjacent natural forest fragments (FOR) while invaded savanna sites (CO SAV) were compared to adjacent natural savanna fragments (SAV). Soil (0–10 cm depth) physico-chemical variables, including soil organic C (SOC), total soil N and available N and P concentrations were measured. Additionally, soil microbial biomass (MBC), carbon mineralization (C min), acid phosphatase, β-glucosidase, and fluorescein diacetate were measured. Further, the MBC/SOC ratio and the metabolic quotient (q CO 2) were calculated. An index of invasion effect (IE) computed as the cumulative percent change in the microbial and enzyme activities was determined for each ecosystem context. Results showed that soil MBC and MBC/SOC ratio declined in CO FOR relative to FOR. In general, C min , enzymatic activities, q CO 2 and available N and P significantly increased in the C. odorata sites relative to the respective reference ecosystems, particularly savanna, potentially due to a larger gap in the litters' quality. As a result, the invasion effect was twice as high in savanna (IE = 292.8%) as in forest (IE = 147.5%). However, a Principal Component Analysis showed that the CO SAV were close to CO FOR stands without mixing, probably due to contrasting initial soil organic matter and clay contents. These results improved our knowledge on the changes in soil microbial attributes and the mechanisms of soil fertility restoration or improvement in response to C. odorata invasion in natural forests and savannas of West Africa. [ABSTRACT FROM AUTHOR]