Impact of road corridors on soil properties and plant communities in high-elevation fragile ecosystems

Abstract

Road construction constitutes a significant disruption to natural ecosystems. Globally, high-elevation regions are among the most fragile and sensitive ecosystems, while systematic information regarding the impact of road construction on soil properties and plant communities in these regions remains scarce. To fill this gap, this study employed a paired plot design, establishing the natural and disturbed plots along the National Highway 214 (48 years) and 219 (12 years) from Yunnan Province to Tibet Autonomous Region in Southwest China, with elevation ranging from 2,400 m to 4,900 m. A total of 68 sampling plots (34 locations) were selected to compare the pattern of soil properties and plant communities between the two categories along elevation gradient. Results revealed the restoration of soil properties post-disturbance had been multifaceted and long-lasting. Specifically, disturbed plots exhibited a significant increase in soil pH, while soil moisture, TC, TN, TP, NH₄-N, and AK suffered substantial loss. Moreover, the strong recovery ability of shrub and herbaceous species was observed in our study, while tree communities were difficult to revert to their original state. Furthermore, the influence of elevation on vegetation restoration also varied depending on plant life forms. In light of these findings, appropriate strategies including restorative planting, soil amelioration, customized restoration plan for specific ecosystems, monitoring and adaptive management, were proposed to mitigate the negative impacts and promote the ecosystem recovery after road construction in these ecologically fragile regions.