Effects of vegetation type and topography on vegetation restoration after pipeline construction in the Northern Shaanxi Loess Plateau, China

Vegetation disturbance during infrastructure construction can cause serious ecological problems, especially in fragile environments. The Northern Shaanxi Loess Plateau is an oil industry base in China with a fragile ecosystem. Vegetation restoration on the disturbance area can effectively control soil erosion and ensure the safety of oil pipelines. In the linear disturbance area, surrounding vegetation traits and topography may play an important role in vegetation restoration by influencing propagules and recruitment microsites. This study aimed to reveal the influence of vegetation type and topography on vegetation restoration in the disturbance area along the oil pipeline. The results showed that 89 species were recorded, and they belonged to 30 families and 74 genera. These species were mainly native herbaceous plants, especially perennial herbs. The species number and species diversity index in the disturbance area had a positive relationship with the undisturbed area. The lateral undisturbed vegetation type and species reproductive strategies influenced the vegetation restoration in the disturbance area. The species that produce a large number of seeds or regenerate by rhizome recolonized quickly in the disturbance area. However, the shrubs and arbor species that need seeds for recruitment will take a long time for restoration. The topographic factor had an obvious influence on the vegetation restoration and species diversity in the disturbance areas. On the sunny and steep slopes, vegetation restoration was difficult and slow, and artificial measures were needed to control soil erosion and maintain soil moisture to help seedling recruitment and survival.