The Convention on Biological Diversity (CBD), 1992 underlines invasion of invasive alien plant species
(IAPS) as the second worst threat to biological diversity, even if management of IAPS remains less priority.
This study attempts to assess the impact of IAPS on the Panchase area in Nepal. Methods used were
literature reviews, household interviews, group discussions, key informant interviews, transect walks, and
soil test. An Importance Value Index analysis on 13 randomly selected sample plots recorded 9 major
IAPS were prevalent, where Ageratum conyzoides and Ageratina adenophora were the most abundant
and problematic species. The trend analysis over the last 25 years and climatic data analysis of 30 years
revealed a rapid expansion of both species. A. adenophora has been distributed homogeneously whereas,
A. conyzoides highly invaded in low altitudes. Among two species A. adenophora found to be more harmful.
Nevertheless, the economic potential of these species cannot be ignored.