Attention to habitat dynamics in subtropical mid-mountain forest plant communities containing endangered vegetation is critical for understanding the responses of ecosystems to global climate change and for their effective conservation. This study examines the species composition, structure, and interspecies competition within endemic and endangered Abies ziyuanensis (Abies ziyuanensis L.K.Fu and S.L.Mo) communities in China, comparing undisturbed and anthropogenically disturbed conditions. The survey recorded a total of 71 plant species across 39 families and 60 genera. PERMANOVA analysis highlighted significant disparities in species composition between the two forest community conditions. Communities impacted by anthropogenic disturbances showed a higher diversity of shrub and herbaceous species compared to those that were undisturbed, coupled with a significant increase in the number of Abies ziyuanensis seedlings, suggesting a greater potential for self-renewal. Nonetheless, the distribution of diameter class structures in these two community conditions indicates a declining trend in population numbers. In undisturbed Abies ziyuanensis communities, the Weighted Hegyi Competition Index (WCI) for Abies ziyuanensis was 6.04, below the average WCI of 12.24 for all trees within these communities. In contrast, within communities affected by anthropogenic disturbances, the WCI for Abies ziyuanensis reached 7.76, higher than the average WCI of 7.43 for all trees, indicating that Abies ziyuanensis in disturbed communities face heightened competitive pressure compared to undisturbed settings. These findings underscore that previous anthropogenic disturbances have altered the community composition, competition dynamics, growth environment, and succession trends of Abies ziyuanensis communities. While these disturbances promote the regeneration of Abies ziyuanensis, they also reduce its current dominance as a target species.

Understanding the interplay between plant leaf functional traits and plant and soil factors under different soil thicknesses is significant for quantifying the interaction between plant growth and the environment. However, in the context of ecological restoration of vegetation in mining areas, there has been a lot of research on trees, shrubs, and grasses, but the characteristics and correlations of leaf functional traits of vines have not been fully studied to a large extent. Here, we report the differences in leaf functional traits of six vine plants (Parthenocissus quinquefolia, Pueraria lobata, Hedera nepalensis, Campsis grandiflora, Mucuna sempervirens, and Parthenocissus tricuspidata) with distinct growth forms in different soil cover thicknesses (20 cm, 40 cm, and 60 cm). In addition, soil factor indicators under different soil cover thicknesses were measured to elucidate the linkages between leaf functional traits of vine plants and soil factors. We found that P. lobata showed a resource acquisition strategy, while H. nepalensis demonstrated a resource conservation strategy. C. grandiflora and P. tricuspidata shifted toward more conservative resource allocation strategies as the soil cover thickness increased, whereas M. sempervirens showed the opposite trend. In the plant trait–trait relationships, there were synergistic associations between specific leaf area (SLA) and leaf nitrogen content (LNC); leaf moisture content (LMC) and leaf nitrogen-to-phosphorus ratio (LN/P); and leaf specific dry weight (LSW), leaf succulence degree (LSD), and leaf dry matter content (LDMC). Trade-offs were observed between SLA and LSW, LSD, and LDMC; between leaf phosphorus content (LPC) and LN/P; and between LMC, LSW, and LDMC. In the plant trait–environment relationships, soil nutrients (pH, soil total phosphorus content (STP), and soil ammonium nitrogen content (SAN)) and soil enzyme activities (cellulase (CB), leucine aminopeptidase (LAP), enzyme C/N activity ratio, and enzyme N/P activity ratio) were identified as the primary drivers of variation in leaf functional traits. Interestingly, nitrogen deficiency constrained the growth of vine plants in the mining area. Our study revealed that the responses of leaf functional traits of different vines under different soil thicknesses have significant species specificity, and each vine shows different resource acquisition and conservation strategies. Furthermore, soil cover thickness primarily influences plant functional traits by directly affecting soil enzyme activities and nutrients. However, the pathways through which soil thickness impacts these traits differ among various functional traits. Our findings provide a theoretical basis and practical reference for selecting vine plants and optimizing soil cover techniques for ecological restoration in mining areas.