Alien plants invasion have become a hot issue in the field of ecology. The invasion of alien plants is usually accompanied by changes in the physical and chemical properties of the soil, the ensuing negative feedback creates a favorable environment for its own growth and expansion. Invasive plans have a strong ability to sequester carbon, which can greatly affect the original local ecological environment. In this study, we selected Rhus typhina, an invasive plant widely used for greening, as the experimental subject and natural growing grassland as the control. The aims were to investigate the effects of different degrees of invasion of R. typhina on soil physicochemical properties and carbon emissions, and to explore the influential factors on carbon emission. The results showed that R. typhina invasion significantly increased soil pH, total nitrogen content, easy extraction of glomalin-related soil protein (EEG) and cumulative CO₂ emissions (CEM). It is worth noting that the CEM increased significantly during the severe invasion by R. typhina. The significant increase in soil NH₄⁺-N content and the decrease in soil NO₃⁻-N content indicate that the soil after the invasion of R. typhina has better uptake of NH₄⁺-N. Temperature and soil moisture content had significant direct effects on CEM, while NH₄⁺-N, NO₃⁻-N, EEG and temperature sensitivity of soil organic carbon mineralization Q₁₀ (30 °C/20 °C) had a direct but non-significant effect on CEM. The above findings suggest that R. typhina can generate positive feedback by influencing the physicochemical properties and CEM of the soil, opening the way for its own expansion, which can be targeted to prevent the destruction of local ecosystems during the introduction of cultivation and subsequent management.

A Cypripedium plant was discovered in Wangqing County, Changbai Mountain, Jilin Province. This newly discovered plant of Cypripedium not only inhabits the same natural habitat as Cypripedium calceolus L. and Cypripedium × ventricosum Sw. but also has a morphology intermediate between that of C. calceolus and C. × ventricosum. Its dorsal sepals, petals, and synsepal are similar to those of C. calceolus, while the color of its lip is intermediate between that of C. calceolus and C. × ventricosum. For the purpose of distinguishing the newly discovered plant of Cypripedium from other Cypripedium plants, we provisionally named it W1. To further verify the taxonomic status of W1, we introduced three identified forms of C. × ventricosum and conducted molecular biology analyses with W1, C. calceolus, and C. × ventricosum. The analyses further confirmed the relationship between W1 and C. × ventricosum, and the phylogenetic analysis of the nuclear region demonstrated a close relationship between W1 and C. calceolus. Collectively, the morphological and molecular evidence indicates that W1 is a product of the backcross between C. × ventricosum and C. calceolus. Although it shows morphological differences from typical C. × ventricosum, it can still be considered a form of C. × ventricosum. We further investigated the chloroplast genome of this form of C. × ventricosum and determined that its total genome length was 196,850 bp. The genome contains 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. By analyzing the phylogenetic position and chloroplast genome of the form of C. × ventricosum, this study clarified the relationships among Cypripedium taxa with similar morphological characteristics, laying a foundation for research on orchid evolution and species conservation.