Attitudinal distribution of native and alien plant species along roadsides in Kashmir Himalaya, India

Presently alien species are invading least invaded areas largely because of anthropogenic activities. The distribution of alien plant species is determined by many factors and in mountainous areas altitude is one of the most important factors determining the distribution of plant species. In order to understand the role of roads in distribution of alien plant species along elevational gradient, two road transects were selected. These two road transects were divided into equally spaced altitudinal zones and at each site 3 plots were selected. A total of 200 species were recorded out of which 133 were native and 67 were alien. Total species richness decreased with altitude while as native species richness increased. Level of invasion expressed as proportion of alien plant species decreased with altitude in all the three plots. In addition, floristic similarity between plots decreased with increasing altitudinal difference. From the present study it is clear that alien plant species have not invaded the alpine areas to a large extent but anthropogenic activities like unplanned road development and promotion of tourism in the area is likely to threaten the uninvaded high altitude areas of the region.