This study investigated the impact of Bacillus subtilis on plant growth and the rhizosphere microbial community in rose cultivation under saline–alkaline stress. Saline–alkaline stress was simulated with varying salt and alkali levels. Bacillus subtilis was introduced, and 16S rRNA high-throughput sequencing was conducted to analyze the root microbial community. Introduction of Bacillus subtilis significantly promoted rose growth and mitigated saline–alkaline stress effects. Gene sequencing revealed increased abundance of microbial genera, such as Tessaracoccus, Intrasporangium, Glutamicibacter, Agrobacterium, Saccharibacteria, Falsochrobactrum, Mesorhizobium, Bacillus, Ensifer, and Ornithinicoccus, under normal and saline–alkaline conditions, while functional changes in colony abundance were observed under different environments through PICRUST2 analysis. Bacillus subtilis demonstrated potential in enhancing rose growth and stress resistance under saline–alkaline conditions, affecting the regulation of the root microbial community. This study provides insights for improving soil conditions and enhancing plant adaptability in saline–alkaline regions.

Differences in topography and environment greatly affect the genetic structure and genetic differentiation of species, and endemic or endangered species with limited geographic ranges seem to be more sensitive to changes in climate and other environmental factors. The complex topography of eastern China is likely to affect genetic differentiation of plants there. Carpinus tientaiensis Cheng is a native and endangered plants from China, and exploring its genetic diversity has profound significance for protection and the collection of germplasm resources. Based on AFLP markers, this study found that C. tientaiensis has low genetic diversity, which mainly came from within populations, while Shangshantou and Tiantai Mountain populations have relatively high genetic diversity. The Nei genetic distance was closely related to geographical distance, and temperature and precipitation notablely affected the genetic variation and genetic differentiation of C. tientaiensis. Based on cpDNA, this study indicated that C. tientaiensis exhibits a moderate level of genetic diversity, and which mainly came from among populations, while Tiantai Mountain population have the highest genetic diversity. It demonstrated that there was genetic differentiation between populations, which can be divided into two independent geographical groups, but there was no significant phylogeographic structure between them. The MaxEnt model showed that climate change significantly affects its distribution, and the suitable distribution areas in Zhejiang were primarily divided into two regions, eastern Zhejiang and southern Zhejiang, and there was niche differentiation in its suitable distribution areas. Therefore, this study speculated that the climate and the terrain of mountains and hills in East China jointly shape the genetic structure of C. tientaiensis, which gived rise to an obvious north-south differentiation trend of these species, and the populations located in the hilly areas of eastern Zhejiang and the mountainous areas of southern Zhejiang formed two genetic branches respectively.

This study utilized the platform for ensemble forecasting of species distributions, biomod2, to predict and quantitatively analyze the distribution changes of Zelkova schneideriana Hand.-Mazz. under different climate scenarios (SSP1-2.6 and SSP5-8.5) based on climate and land-use data. This study evaluated the geographic range changes in future distribution areas and the results indicated that, under both SSP1-2.6 and SSP5-8.5 scenarios, the distribution area of Zelkova schneideriana would be reduced, showing a trend towards migration to higher latitudes and elevations. Particularly, in the more extreme SSP5-8.5 scenario, the contraction of the distribution area was more pronounced, accompanied by more significant migration characteristics. Furthermore, the ecological structure within the distribution area of Zelkova schneideriana also experienced significant changes, with an increasing degree of fragmentation. The variables of Bio6 (minimum temperature of the coldest month), Bio2 (mean diurnal temperature range), Bio15 (precipitation seasonality), and elevation exhibited important influences on the distribution of Zelkova schneideriana, with temperature being particularly significant. Changes in land use, especially the conversion of cropland, had a significant impact on the species’ habitat. These research findings highlight the distributional pressures faced by Zelkova schneideriana in the future, emphasizing the crucial need for targeted conservation measures to protect this species and similar organisms.

Leaf functional traits are an important part of plant adaptive strategies and respond differently to different environments, but our understanding of how plants adapt to highly complex urban environments through coordinated changes in leaf functional traits is limited. In order to deeply explore the effects of different urban environments on the leaf functional traits of landscape plants, this study focused on ten common landscape plants in Nanjing, specifically, Euonymus japonicus, Pittosporum tobira, Loropetalum chinense, Photinia × fraseri, Acer palmatum, Euonymus japonicus ‘Aurea-marginatus’, Platanus acerifolia, Camphora officinarum, Ginkgo biloba, and Lagerstroemia indica. The study employed one-way analysis of variance (ANOVA), two-way ANOVA, principal component analysis (PCA), and membership function comprehensive evaluation to explore the responses of green space plants to the environments of urban park green spaces (PAR), urban community green spaces (NL), and urban road green spaces (CR) and to analyze the impact of the trade-off strategies of plants in different green space environments based on leaf functional traits. The results showed that plant leaf functional traits and their adaptive strategies varied in different urban environments in Nanjing. The contents of LDMC, MDA, POD, and CAT in the ten plant species followed the order CR > NL > PAR, and SLA, SOD, SS, and total chlorophyll showed trends of PAR > NL > CR. The microstructures of the leaves of the ten plant species, such as SA, TUE, and TS, were evident in the expression of adaptive adjustments to the different green space environments. The principal component analysis and the comprehensive evaluation of the affiliation function of the indicators of the ten plant species revealed that the adaptability of the ten green space plants to the complex urban environment was as follows: Euonymus japonicus ‘Aurea-marginatus’ > Lagerstroemia indica > Acer palmatum > Photinia × fraseri > Platanus acerifolia> Camphora officinarum > Loropetalum chinense > Ginkgo biloba > Euonymus japonicus > Pittosporum tobira. The results of the study will help to further understand the layout, application, and maintenance of landscape plants in the context of urbanization and provide support for related theories.

Carpinus betulus is an important ornamental landscape tree species with colorful foliage. It is widely used in landscaping due to its upright tree shape, significant seasonal changes, and good tolerance to pruning. Propagation methods for C. betulus include grafting, cutting, and seeding. However, the germination rate of seeding is low, and the rooting of cuttings is difficult; moreover, plant tissue culture techniques are complex, and the key technologies have not been disclosed. Grafting has therefore become the primary means of propagation. However, enabling the rapid reproduction of C. betulus through appropriate grafting methods and in appropriate environments remains an urgent issue to be addressed. In this study, Carpinus turczaninowii was used as a rootstock to graft C. betulus, and the effects of the grafting periods, technique, and environmental conditions on the survival rate of grafted C. betulus were discussed. The results showed that branch grafting (cleft graft and whip-and-tongue graft) performed in March to April and August to November resulted in the highest survival rates, whereas budding grafts (chip budding and patch budding) were more suitable in May and June. Increasing ambient humidity was a key measure for improving graft survival rates and germination rates. In terms of grafting survival rate, germination rate, and leaf growth, humidification and treatment with 60–70% light transmission had better results than treatment with natural humidity or 20–30% light transmission and full light treatment under humidification conditions. Under low-light conditions, increasing air humidity had a particularly pronounced effect on promoting the growth of grafted seedling branches. In the future, further research should be conducted on the molecular mechanism mediated by soil environment and temperature changes for the successful grafting of C. betulus, providing a theoretical basis for the propagation and cultivation of C. betulus.