Background  Alpine meadows which is a vital component of the alpine ecosystem in Hengduan Mountains, is highly sensitive to climate change and human activities due to harsh regional environment, short growing seasons, simple ecological structures, weak self-renewal capacity and other characteristic. The land surface disturbance caused by tower foundation construction of power transmission line project significantly poses a negative effects on native vegetation composition and diversity of the alpine meadows. Therefore, conducting research on how construction disturbance impacts plant diversity in the Hengduan Mountains' alpine meadows and analyzing the limiting factors for their restoration holds substantial practical significance for facilitating the vegetation restoration of alpine meadows.

Methods  The research area was selected from alpine meadows above 4000 m in the western of Sichuan and the southeastern of Xizang within the Hengduan Mountains. The geographic location and altitude information of the quadrat centers at tower foundation construction sites were obtained using the omap. Based on the geographic location, environmental condition indexes of the sample plots were acquired from the WorldClim and SolarGIS datasets. In each surveyed sample plot, the vegetation species, coverage, and the Gleason index, Simpson index, Shannon-Wiener index, and Pielou evenness index of the were calculated. Additionally, we analyzed the key drivers of plant diversity changes induced by construction disturbance.

Results 1) Compared with the control plots, the plant species composition in all disturbed plots changed after construction disturbance. The number of plant species in the control plots ranged from 18 to 37, while after construction disturbance, it ranged from 19 to 38, with 81.25% of the disturbed plots showing an increase in species number. Specifically, the number of native species decreased by 4–20 in disturbed plots, whereas the number of newly colonizing species ranged from 5 to 23. Additionally, the dominant species changed in 75% of the sample plots. 2) Construction disturbance had a significant impact on vegetation coverage (P < 0.05), with the coverage in disturbed plots decreasing by 42.87% compared to the control plots. The Simpson’s index, Shannon-Wiener index, and Pielou evenness index in disturbed plots were all lower than those in the control plots, with respective decreases of 0.11, 0.43, and 0.12. 3) Construction disturbance altered the soil physical properties, the average soil organic matter decreased from 9.99% to 3.11%, with a reduction of 6.88%. Simultaneously, the mass fraction of soil gravel content increased from 41.21% to 65.61%, with an increase of 24.40%. After construction disturbance, plant diversity indices showed significant correlations with mean annual temperature, elevation, and soil organic matter content. Therefore, mean annual temperature, elevation, and soil organic matter content were identified as limiting factors for vegetation recovery.

Conclusions Tower foundation construction of power transmission line project has a significantly effects on species composition and plant diversity of alpine meadows. It is recommended to restore the topsoil and apply temporary cover after construction to improve plant growth conditions. Additionally, using native plant species for vegetation restoration can enhance plant diversity in disturbed areas and promoting regional vegetation recovery and sustainable ecosystem development.