Objectives Studying the changes in plant community structure and stability during vegetation reconstruction can help analyze succession patterns of plant communities in the ecological restoration process. Investigating the early community assembly characteristics and stability of damaged slopes under different vegetation reconstruction modes in the northwestern Sichuan Plateau is of great scientific significance for supporting highway construction in ecologically fragile, high-altitude alpine regions and guiding initial ecological restoration measures for linear engineering projects such as plateau highways.

Methods Relying on the early-stage vegetation reconstruction project of damaged slopes along National Highway G248 in Zoige, this study employed a space-for-time substitution approach and selected three vegetation reconstruction modes for experimental research. Based on field surveys of vegetation communities, the early community assembly characteristics and stability of damaged slopes in the Northwest Sichuan Plateau under different vegetation reconstruction modes were investigated.

Results (1) A total of 57 species of trees, shrubs, and herbs belonging to 51 genera and 22 families were recorded in the survey quadrats (including control plots). Among them, there was 1 species of tree ( 1 family, 1 genus), 4 species of shrubs (4 families, 4 genera), and 52 species of herbs(20 families, 46 genera,). The families Poaceae, Asteraceae, Fabaceae, Ranunculaceae, Rosaceae, and Scrophulariaceae were the main species components, accounting for 61.40% of the total species. (2) Herbaceous communities dominated the life-form structure (91.23% of species), with perennial plants accounting for over 50%. (3) After 4 years of vegetation reconstruction modes on typical alpine damaged slopes, all indicators of the vegetation communities in the experimental quadrats were significantly better than those in the natural restoration control areas. The aboveground biomass and average coverage of the herb layer showed the following order: Shrub-herb (Ⅱ) > Tree-shrub-herb (I) > Hydroseeding grass (Ⅲ) > Natural restoration control group (Ⅳ). The biomass of the shrub-herb (Ⅱ) was 2.68 times that of the hydroseeding grass (Ⅲ) mode. The overall performance of the herb layer community diversity (Margalef richness index R, Simpson diversity index D, Shannon-Wiener index H, and Pielou evenness index J) was: Ⅱ > Ⅲ > I. However, in terms of the Pielou evenness index J, the hydroseeding grass (Ⅲ) mode outperformed the other two modes.

Conclusions Artificial vegetation reconstruction is an effective method to advance the vegetation recovery and succession on damaged slopes. Among the three different artificial vegetation reconstruction modes, the shrub-herb mode (Ⅱ) demonstrated remarkable effects in accelerating vegetation reconstruction on damaged slopes. It holds high promotional value for vegetation reconstruction on alpine and high-altitude damaged slopes characterized by fragile ecological environments and extremely poor self-recovery capacities.