宁夏平原沟渠边坡植物群落多样性的影响因子分析

沟渠边坡是物种传播的廊道之一，在物种传播与演替进程中起重要的作用。采用主分量分析和PCA排序的方法，对宁夏平原沟渠边坡的优势植物群落与其环境影响因子进行了定量分析。结果表明：宁夏平原沟渠边坡植物群落的主要影响因子是土壤水分和土壤有机质，且土壤盐分与植物群落的优势度和生物多样性之间有Y2=0.516-0.005X1+0.506X2的关系，可以根据此模型对宁夏平原沟渠湿地的土壤盐分和植物种群多样性及生态优势度做出具体的数学解释。同时表明，沟渠边坡水分梯度和土壤养分是决定其植物分布的主要影响因素。沟渠作为干旱半干旱区绿洲的重要水利设施，从获取最大用水效率、减少水分损失角度，可以高效地通过植物群落控水控肥；而从沟渠强化水文生态效益的角度，则可以提高沟渠湿地的水文循环效率。

Factors Affecting the Diversity of Plant Communities on Ditch Slope in the Ningxia Plain

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.