Background Ecological revetment is one of the protection technologies widely used in the stability of river banks, lakeshore, reservoir banks and water-level-fluctuating zones. The harsh land-water ecotone environment makes it challenging to choose appropriate plants for the purpose of ecological slope protection. The soil reinforcement capacity of plants is a key factor of ecological revetment technology. Quantitative assessment and comparison of the soil reinforcement capacity of wetland plants can provide a theoretical basis for ecological slope protection in land-water ecotone.

Methods In this study, Arundo donax, Phragmites australis and Cyperus alternifolius, which are drought and waterlogging resistance and have well-developed root system, were selected as the material in this research. Soil anti-shearing strength and anti-scourability were determined by in-situ shear test and anti-scour tests, enabling us to compare and analyze the soil reinforcement capacity of the plants and the influencing factors.

Results 1) The results showed that A. donax, P. communis, and C. alternifolius significantly improved theanti-shearing strengthandanti-scourability, the anti-shearing strength of the three plants increased by 111.80%, 77.43% and 99.17% respectively, and the anti-scourability increased by 299.40%, 140.21% and 183.79% respectively. 2) The proportion of stem cross-sectional area, root biomass, root density and root number per unit branch number of A. donax were significantly higher than those of P. communis and C. alternifolius. 3) The analysis showed that the average diameter, total volume and total number of plant roots were positively correlated with the anti-shearing strength of soil. And the root biomass, root density, number of roots per unit branch and proportion of stem cross-sectional area in the quadrat were positively correlated with the anti-scourability of soil.

Conclusions This study demonstrates that suitable plants can significantly improve the erosion resistance of soil in land-water ecotone regions. A. donax shows the strongest effects on soil reinforcement and has strong drought and waterlogging resistance, making it an ideal candidate for ecological revetment in land-water ecotone regions.