Introduction: Drought stress usually inhibits plant growth, which may increase the difficulty of greening slopes.Methods: In this study, we systematically investigated the effects of arbuscular mycorrhizal (AM) fungi on the growth and drought tolerance of two plant species, Festuca elata and Cassia glauca, in a vegetation concrete environment by exogenously inoculating AM fungi and setting three drought levels: well water, moderate drought and severe drought. The results showed that plant growth was significantly inhibited under drought stress; however, AM fungi inoculation significantly promoted plant height, root length, and above- and belowground biomass in these two plant species.Results: Compared with, those in the CK treatment, the greatest increases in the net photosynthesis rate, stomatal conductance and transpiration rate in the AM treatment group were 36.72%, 210.08%, and 66.41%, respectively. Moreover, inoculation with AM fungi increased plant superoxide dismutase and catalase activities by 4.70–150.73% and 9.10–95.70%, respectively, and reduced leaf malondialdehyde content by 2.79–55.01%, which alleviated the damage caused by oxidative stress. These effects alleviated the damage caused by oxidative stress and increased the content of soluble sugars and soluble proteins in plant leaves by 1.52–65.44% and 4.67–97.54%, respectively, which further increased the drought adaptability of plants. However, inoculation with AM fungi had different effects on different plants.Conclusion: In summary, this study demonstrated that the inoculation of AM fungi in vegetation concrete environments can significantly increase plant growth and drought tolerance. The plants that formed a symbiotic structure with AM fungi had a larger root uptake area, greater water uptake capacity, and greater photosynthesis and gas exchange efficiency. In addition, AM fungi inoculation further increased the drought adaptability of the plants by increasing their antioxidant enzyme activity and regulating their metabolite content. These findings are highly important for promoting plant growth and increasing drought tolerance under drought conditions, especially for potential practical applications in areas such as slope protection, and provide useful references for future ecological engineering and sustainable development.

In order to investigate the effects of brassinolide (BR) on the ecological stoichiometric characteristics and internal stability of plants in slope ecological protection under different drought conditions, the biomass, proline content, nutrient content, and internal stability of tall fescue (Festuca arundinacea) in three stress periods were analyzed by weighing water control method, with three drought degrees (75% ± 5%), mild drought (55% ± 5%) and severe drought (35% ± 5%) and four BR concentrations (0 mg/L, 0.05 mg/L, 0.2 mg/L and 0.5 mg/L). The results showed that drought stress resulted in a decrease in plant biomass and nutrient content, and there were differences in carbon, nitrogen and phosphorus contents and their stoichiometric ratios in different organs. Spraying suitable concentration of BR could alleviate plant nutrient loss and promote nutrient accumulation of the tall fescue. Under normal water spraying conditions 0.2 mg/L, under mild and severe drought conditions with spraying of 0.5 mg/L BR, it is most suitable for the nutrient accumulation in tall fescue. The tall fescue showed high sensitivity to exogenous BR input, and the internal stability of the underground part of the tall fescue increased clearly. BR is propitious to the synthesis of proline and enhances the drought resistance of plants. According to stoichiometric characteristics, BR can improve the nitrogen and phosphorus utilization efficiency of tall fescue to a certain extent, and the results of the nitrogen and phosphorus ratio show that nitrogen is the main factor limiting plant growth in a vegetation concrete ecological restoration system, which can supplement nitrogen to accelerate the process of vegetation restoration. The application of BR can improve the biomass and stress resistance of tall fescue, adjust the nutrient distribution strategy and stoichiometric stability, and alleviate the adverse effects of drought on plants. This study provides new ideas and methods for ecological restoration and vegetation reconstruction in arid areas.

Based on vegetation-soil nutrient monitoring data under different precipitation conditions, this study investigated the impact of precipitation changes on the ecological restoration process of disturbed slopes. Precipitation change, to a certain extent, changed the carbon (C), nitrogen (N) and phosphorus (P) content and the stoichiometric ratio of the soil–plant system. With the increase of the weekly precipitation from 10 to 20 mm, the C content of Cynodon and Indigofera Amblyantha Craib on each slope gradually increased, increased by 8.69% and 4.28%, respectively, compared with the initial recovery period, and the N/P of Cynodon increased from 3.81 to 4.94, and the N limit gradually decreased, while the limit of P increased continuously. The efficiency of the coordinated utilization of N and P of the Indigofera Amblyantha Craib increased, which had a certain adaptability to changes in precipitation. The C/N and C/P in the soil first increased and then decreased, and reached the peak at the slope of 15 mm precipitation, while the N/P fluctuated around 0.35 overall. N was an important element restricting the growth of grass, while P was an important influencing element limiting the growth of shrubs. This also showed that soil C, N and P had a good promoting effect on plant growth, and the self-regulating nutrient utilization strategies of different growth forms of plants under different precipitation conditions differed. There was a coupling effect in the contents of C, N, P and their stoichiometric ratio in the soil–plant system, and stoichiometry and elastic ecological interactions jointly controlled the supply and demand of elements in the plants, but there was no consistent temporal pattern of nutrient ecological stoichiometric ratio in the plant–soil system during the recovery process, thus requiring further research and evaluation.

Introduction: The objective of this study was to investigate whether dark septate endophytes (DSEs) can increase plant drought tolerance in the context of vegetation concrete, which is a complex environment.Methods: This study employed a controlled simulation experiment to investigate the influence of inoculation with diverse DSEs, namely, Paraphoma chrysanthemicola (PC), Alternaria alternata (AA), and Cladosporium cladosporioides (CC), on the growth, photosynthetic characteristics, osmoregulatory substance content, and antioxidant enzyme activities of Cynodon dactylon in vegetation concrete subjected to drought stress.Results: These findings demonstrated that DSEs were capable of effectively mitigating the adverse impacts of drought on plant growth. Under moderate drought (MD 55%±5% of the maximum moisture capacity in the field), DSEs increased the dry weight (DB), net photosynthetic rate (Pn), soluble sugar (SS) and peroxidase (POD) of C. dactylon by up to 14.21%, 32.63%, 40.73% and 31.43%, respectively, and reduced the malondialdehyde (MDA) content by 8.02-13.77%. Furthermore, under severe drought (SD, 35%±5% of the maximum moisture capacity in the field), DSE inoculation enhanced the photosynthetic capacity of C. dactylon, stimulated the accumulation of osmoregulatory compounds such as proline (Pro) and soluble protein (SP), and mitigated the water loss associated with drought.Conclusion: The results demonstrate that DSE inoculation enhances the drought resistance of plants used in vegetation concrete by increasing the photosynthetic rate, and contents of antioxidant enzymes and osmoregulatory substances. This study provides reference for the use of DSEs in ecological restoration with vegetation concrete.