Invasion Status of Three Non-Native Species from Family Asteraceae in Mizoram

In the present paper history of invasion/introduction, brief descriptions, and quantitative assessment of three alien species of Asteraceae namely Ageratina riparia (Regel) R.M.King & H.Rob., Ageratina adenophora (Spreng.) R.M.King & H.Rob., Chromolaena odorata (L.) R.M.King & H.Rob have been provided. These species, native to Mexico and tropical South America, have invaded natural vegetations in Mizoram very aggressively and form pure stands. Random ecological sampling along different altitudinal gradient in six natural vegetation sites revealed high importance value index (IVI: 34.47 - 72.51) of these three species. Ageratina riparia widely invaded Lengteng wildlife sanctuary & Sangau at 1400–1800 m altitudinal range, Ageratina adenophora invaded in Sangau, Phawngpui national park, and Dampa tiger reserve at 500–2238 m altitudinal range; and Chromolaena odorata widely invades Aizawl, Dampa tiger reserve and Murlen national park at 500–1800 m altitudinal range. A total of 70 species were found associated with these three invasive species which shows a negative impact in their natural vegetation. Occurrence of A. riparia is also reported for the irst time from Mizoram. The paper also appraises ecology and extends of spread, local dependency and menace of each of the species in Mizoram.