Distribution and implication of alien invasive plant species of Assam: a review

Abstract

The vegetational landscape of Assam is a collage of grassland, agriculture field, wetland, wasteland, and forest ecosystems. Like many other parts of the country, this region is also infested with alien intruders which not only interfere with the growth and production of food crops but also exercise adverse effects on the biodiversity of native species. The present study attempts to catalogue the invasive alien species of the Assam state especially with reference to their habit, taxonomic position, and nativity. A total of 25 invasive alien species under 25 genera, belonging to 14 families have been recorded. Among these, majority of them belongs to dicotyledons families and very few to monocotyledons families. The analysis of invasive species reveals that 5 species have been introduced intentionally, while the remaining species established unintentionally through trade. In terms of nativity, amongst 13 geographic regions, the majority of invasive plants reported from tropical American continent (73%) and have been found to be invasive aliens as evident from their center of origin, past history, nature of aggregation, and invasion observed under field conditions. While in life form analysis, the herbs (18 species) are dominant, followed by trees (3 species), shrub & under shrub (2 species each), Grass (1 species). Most of the invasive species are perennial habit (68%). Therefore, it is very important to make an effective implication management of invasive species, knowledge about their diversity, life form, habitat, uses, is essential.