Soil Legacy Effects of Chromolaena odorata and Biochar Remediation Depend on Invasion Intensity

Abstract

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.