Roadside plant diversity and invasion potential: A quantitative assessment of native and non‐native species of Khadukhel Valley, northern Pakistan

Abstract Roadsides are increasingly recognised as ecological corridors that support a diverse range of plant species, including those with invasive potential. However, their role in shaping vegetation structure and biodiversity, particularly in mountainous regions, remains understudied. The present study focused on analysing the diversity, distribution patterns, and structural composition of both indigenous and alien plant species inhabiting roadside habitats of the study area. The quadrant method was used for field data collection. The structure of the vegetation was analysed in terms of density, frequency, abundance, importance value index (IVI), Shannon–Wiener index ( H ′), evenness ( E ), and Simpson's concentration index (Cd). Following Raunkiær's classification, the collected plants were classified. All the recorded species were grouped into two main classes of native and non‐native species. A total of 258 species of plants belonging to 83 families were collected. Among them, 148 species were native and 108 species were non‐native. The non‐native plants were further classified into casual (22 species), invasive (30 species), and neutralised (56 species). Asteraceae was the dominant family with 26 representative species. Therophytes were the most common life form with 69 species, while microphyllous, with 111 species, was the most common leaf size type. Among the collected plants, 95 species were near threatened, 80 species were vulnerable, 59 species were endangered, and 24 species were least concern. The Shannon–Wiener diversity value for all the sites was 5.38; the species evenness value for all sites was 0.96, and the effective number of species (ENS) for all sites was 217.212. The highest average abundance of all plant species was recorded at Site‐6 (46.76). Furthermore, the highest average frequency was recorded at Site‐7 (7.03). The highest Shannon–Wiener diversity index ( H ′ = 5.36) and species evenness value ( E = 0.96) were both recorded at Site‐6. Based on the IVI value, the dominant species was Parthenium hysterophorus L. (1.37). The findings highlight the urgent need for monitoring and managing roadside vegetation to prevent the proliferation of invasive species and conserve native plant diversity in ecologically sensitive mountain landscapes.