Rainfall events coupled with shallow and gravelly sloping farmland have led to serious soil erosion and associated problems in the Three Gorges reservoir. Previous studies have shown that the use of vegetation is an effective way to control soil erosion. Therefore, an artificial, simulated rainfall experiment study is conducted to determine the effect of rainfall intensity and vegetation cover on runoff volume, sediment load, and runoff hydraulics characteristics. The experiment consists of seven vegetation treatments subjected to three rainfall intensities on a soil that contains rock fragments on a slope of 30°. The results indicate that the runoff volume and sediment load of the bare plot were greater than those of vegetation‐covered plots under three different rainfall intensities. When Cynodon dactylon and Indigofera amblyantha were applied together, the plot displayed the best performance for soil loss control, with a reduction of 87.88%–99.11%. According to a redundancy analysis, the change in rainfall intensity had the least impact on the Reynolds number and the runoff volume of the herb‐shrub mixed plot in this study. These findings suggest that the effect of combining Cynodon dactylon and Indigofera amblyantha and increasing the vegetation coverage is an effective solution for soil and water loss conservation. The application of this method can alleviate environmental stress on the Three Gorges reservoir.

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.

To investigate the effects of different dominant species on the microbial functional diversity of vegetation concrete substrates, the rhizosphere and non-rhizosphere soils of three dominant species (Pennisetum alopecuroides (PA), Arthraxon hispidus (AH) and Pueraria lobata (PL)) of vegetation concrete were studied using the Biolog-Eco method at Xiangjiaba Hydropower Station. The results showed that the microbial activity and microbial functional diversity indices in the rhizosphere soil of the three dominant plants were significantly higher than those in the non-rhizosphere soil and that the microbial activity and functional diversity indices in the rhizosphere and non-rhizosphere soil of AH, as well as in the rhizosphere soil of PL, were at a high level. The carbon sources predominantly used by rhizosphere soil microbes were carbohydrates, amino acids and polymers, while the carbon sources predominantly used by non-rhizosphere soil microbes were carboxylic acids, amino acids and polymers. The governing elements of the carbon source metabolic features of the microbial community were the soil moisture content (WC), organic matter (OM), total nitrogen (TN), potential of hydrogen (pH), microbial carbon (MBC), microbial nitrogen (MBN) and microbial phosphorus (MBP). Based on a thorough examination of these aspects, it was concluded that vegetation had altered the microbial community structure and functional diversity of the vegetation concrete substrate, perhaps improving the overall metabolic activity. A. hispidus with high adaptability should be prioritized in the regeneration of vegetation on concrete slopes.

The goal of this research is to investigate strategies to increase the erosion resistance of the slope surface during the early stages of vegetation concrete construction, as well as to offer a scientific foundation for improving vegetation concrete formulation. Simulated rainfall experiments were carried out at 2 different slope gradients (50° and 60°), 2 different rainfall intensities (60 and 120 mm·h⁻¹), and 4 treatments (CK-no additive, 0.4% P-polyacrylamide, 4% C-biochar, and 0.4% F-palm fiber). PAM, palm fiber, and biochar significantly reduced the initial runoff time of the vegetation concrete slope by an average of 47.03%, 46.41%, and 22.67%, respectively (p < 0.05). The runoff rate of each slope under different conditions increased with the expansion of rainfall duration and then fluctuated and stabilized, whereas the erosion rate decreased and then fluctuated and stabilized. PAM and palm fiber both increased runoff rates while decreasing erosion rates, but biochar increased both runoff rates and erosion rates. The runoff reduction benefits of PAM, palm fiber, and biochar were −69.84~−1.97%, −68.82~−14.28% and −63.70~−6.80%, respectively, while the sediment reduction benefits were 69.21~94.07%, −96.81~−50.35%, and 36.20~60.47%, respectively. PAM and palm fiber both have obvious sediment reduction benefits and can be used in the ecological restoration of high and steep slopes in areas with heavy rainfall.