Abstract: Ditch slope is one of the corridors for species spread and plays an important role in species spread and succession process. The dominant plant communities and the environmental factors affecting them on ditch slope in the Ningxia Plain were studied using the principal component analysis and PCA sequence analysis, and the relationship between plant community and environment was quantitatively analyzed. The results show that the main factors affecting the plant communities on ditch slope in the Ningxia Plain were the soil moisture content and soil organic matter content, and the soil salinity was related to the plant community dominance and biodiversity in a function of Y2=0.516-0.005X1+0.506X2, on which the relationships between the soil salinity and the diversity of plant communities and ecological dominance could be mathematically explained. The results also show that the soil moisture gradient and soil nutrient content were the main factors affecting the distribution of plant communities on ditch slope. As the important irrigation facilities in arid and semiarid regions, ditches could be used to effectively regulate water and fertilizer regime through plant communities. In addition, ditches could also be used to improve the ecological performance by improving hydrologic cycle efficiency in ditch wetlands.

Key words: font-family: 宋体, mso-bidi-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, plain')">mso-bidi-language: AR-SA">plain, ditch slope wetland, plant community, diversity, PCA sequence, environmental factor, Ningxia