## 4 Discussion
### Application to the Southwest Reservoir Riparian Zone  
Due to the prolonged inundation of the riparian zone resulting from the anti-seasonal water level regulation in the Southwest Reservoir Area, the original vegetation ecosystem has sustained significant damage, leading to the near-complete disappearance of native vegetation. To restore the ecosystem of the floodplain and control soil erosion, scholars have proposed a program to artificially restore the vegetation of the floodplain in the southwest reservoir area. _Cymodon dactylon_ is one of the primary vegetation types that naturally reestablished in the riparian zone of the Three Gorges Reservoir following its formation and prolonged environmental selection. Studies have shown that the synergistic effect of plant roots, aboveground stems, and leaves can effectively reduce soil erosion. _Cymodon dactylon_, in particular, has a significant impact on reducing erosion [30]. However, this thesis concluded that the enhancement of soil shear strength by _Cymodon dactylon_ is relatively small. This is primarily due to the fact that the soil and water conservation effect of plants relies on the combined action of their above-ground parts and below-ground plant roots. Although the root system of _Cymodon dactylon_ mentioned in this paper has a lower soil-fixing effect compared to other plants, field investigations have revealed that its stolon growth is vigorous and its above-ground portion is well developed. This results in the formation of a denser vegetation layer on the soil surface, providing effective protection and significantly reducing the soil damage caused by external forces. In the southwest reservoir area of the riparian zone during the summer dew period, which is the most concentrated period of rainfall throughout the year, precipitation and the generation of slope runoff lead to significant splashing and scouring of the soil in the riparian zone, resulting in severe soil erosion issues. Therefore, _Cymodon dactylon_ is of great value in vegetation restoration and soil erosion control in floodplains.  
During the summer, the peak growth period of herbaceous plants enhances their overall water and soil conservation effect on both the aboveground and underground root systems. This effectively reduces soil erosion caused by rainfall runoff and prevents the loss of soil and nutrients in the riparian zone. During the winter flooding period, although most aboveground parts of plants may die, their underground root systems remain active, continuing to play a significant role in soil stabilization. This helps protect the surface soil of the riparian zone from erosion caused by reservoir water waves or reduces the extent of their impact. It is worth mentioning that the roots of _Cymodon dactylon_ remain active in winter, thus performing their soil conservation function throughout the entire growth period. The water level in the southwest reservoir area is gradually regulated in a fluctuating manner, rather than rising instantly. During the rising water process, vegetation that is not submerged or re-emerges after short-term submersion continues to play a role in water and soil conservation. Furthermore, the vegetation in the water-land transition zone also plays a crucial role in attenuating waves, thereby reducing wave erosion on reservoir banks. In conclusion, this article discusses the strong root system stabilization ability of _Cymodon dactylon_. Combined with its good flood tolerance and ability to reduce concentrated flow erosion, this plant can be utilized in vegetation restoration and soil conservation projects in the riparian zone of the southwest reservoir area. Additionally, the excellent characteristics of _Cymodon dactylon_ make it potentially suitable for promotion and application in other reservoirs or lake riparian zones.