Distribution pattern and management of invasive alien plant species in Sikkim Himalaya, India

Abstract

An assessment of the distribution pattern of Invasive Alien Plant species in the Sikkim Himalayas was conducted at different elevation gradients and accordingly, management strategies were recommended to combat the ever-increasing condition of invasive plant species threatening the sensitive ecoregions. Among the most relevant factors supporting the present study were changes in the importance value index (IVI), variety, and evenness. There is a greater percentage of domination of invasion at lower elevations than at higher elevations. Species diversity, dominance, and evenness values decreased significantly at higher elevations; interestingly, the fraction of invaded regions is lower at higher elevations. Several factors may contribute to the large cover of invasive plants at lower elevations, including the enabling climate and anthropogenic activities. As a result of invasive alien plant species, such as Ageratum conyzoides, Ageratina adenophora, Bidens pilosa, Chromolaena odorata, Lantana camara, Mikania micrantha and Parthenium hysterophorus, native vegetation, and fauna may suffer adverse consequences, as well as socioeconomic conditions and health issues. This study determined that the invasion of these invasive alien plants in different elevations in the Sikkim Himalaya impacts ecosystem services and depletes several species of commercial importance. The current study recommends quick action to control harmful invasive alien plant species in the Sikkim Himalaya