Roads act as corridors for the spread of alien plant species in the mountainous regions: A case study of Kashmir Valley, India

The distribution and abundance of alien plant species can be strongly influenced by corridors that facilitate their dispersal. Although roads have been implicated as an important contributory factor in biological invasions, their precise role as conduits in the spatial spread of alien species remains poorly understood. In order to investigate the role of roads in alien plant invasions, we explored diversity and abundance of native and non-native plant species along two road transects (50 and 56 km in length, respectively) and surveyed 5 sites (100 x 100 m) at each of these transects. The sites namely Zakoora, Gulabbagh, Daren Nagbal, Ganderbal; Kangan (along transect I) and Galendar, Lethpoora, Awantipoora, Sangam, Qazigund (along transect II) are located in four districts (Srinagar, Ganderbal, Pulwama and Anantnag) of Kashmir valley in India. Floristic surveys during the growing season in the study sites revealed occurrence of 197 vascular plant species. Out of these 136 species were non-native and only 61 were native. 57 non-native species were invasive, 71 naturalized and 08 were casual. Compared to alien plant species, richness and abundance of native species increased with increase in distance perpendicular to the road. The high percentage (69 %) of alien plant species in the roadside flora and also the greater number of alien plant species close to the roads clearly indicate that roadsides act as anthropogenic corridors for the spread of alien plant species.