In a study published in Journal of Environmental Management, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences have uncovered how large-scale railway construction can fundamentally alter soil properties and underground fungal networks, creating conditions that favor invasive alien plants over native species.
The researchers surveyed 84 plots integrating vegetation, soil and fungi across 14 railway stations and adjacent undisturbed habitats along the newly opened China-Laos Railway in Yunnan Province, China. Their findings show that railway construction not only changed soil chemistry and moisture content but also reshaped the composition of belowground fungal communities.
In station habitats, the researchers observed lower levels of soil organic carbon, total nitrogen, and moisture, alongside higher pH values and modified nutrient stoichiometry. These abiotic shifts were accompanied by a marked reorganization of soil fungal assemblages,characterized by reduced beta diversity and increased richness of both plant pathogenic and arbuscular mycorrhizal fungal guilds.
Such belowground changes carry significant ecological implications. Arbuscular mycorrhizal fungi form mutualistic associations with plants, enhancing water and nutrient uptake, a critical advantage in the disturbed, resource poor soils typical of railway corridors.
Compared with adjacent undisturbed control sites, the disturbed vegetation near railway stations supported substantially greater alien plant richness, cover, and biomass. The researchers suggest that construction activities create open niches and introduce propagules, favoring alien species that often possess physiological adaptations or symbiotic capabilities enabling them to colonize these ruderal environments.
“Our analysis shows that railway construction promotes higher alien plant richness through multiple interlinked pathways,” said LI Weitao of XTBG. “These include shifts in soil nutrient stoichiometry, a decline in native plant richness, and an increased abundance of potential plant pathogenic fungi.” Among all factors examined, the loss of native plant richness showed the strongest correlation with increased alien richness, underscoring that reduced biotic resistance is a key driver of invasion patterns along railway corridors.
The study also found that the mean phylogenetic distance between alien and native species decreased with increasing latitude, indicating a shift in the mechanisms governing invasion success. In species rich tropical regions, successful invaders tend to be evolutionarily more distinct from native flora. In contrast, in temperate regions, alien species closely related to natives are more likely to establish, a pattern consistent with environmental filtering and pre adaptation. However, this natural latitudinal gradient was weakened in railway station habitats, where disturbance appeared to override the typical filtering patterns.
The researchers emphasize that railway corridors are not merely passive conduits for alien plant dispersal, but active agents of ecological change. “Our findings suggest that railways may influence plant invasions not only by facilitating species movement, but also by altering local environmental conditions and community structure,” added ZHNEG Yulong of XTBG.
Available online: 2 July 2026
