DISTRIBUTION, SPREAD AND PRESENT STATUS OF Mimosa pigra L. (MIMOSACEAE) IN PENINSULA MALAYSIA: 1980-2004

Mimosa pigra L. (Mimosaceae), a noxious semi-aquatic woody plant and once considered to be an important invasive species in the early 1980s has now spread through out Peninsula Malaysia. This happened despite an effort to control the spread through the introduction of two biological control agents, Carmenta mimosa and Acanthoscelides puniceus between 1992 and 1994. To assess the present status of Mimosa spread, a survey was conducted in 2004, which covered six habitat types namely a construction site, roadside, riverbank, reservoir, plantation and forest reserve. A total of 53 from 80 sites visited have been recorded with Mimosa populations. Five habitat types were more prone to be invaded by Mimosa whilst forest reserves were found to be non-susceptible to Mimosa invasion. Three conclusions can be drawn from this survey; (1) Soil contaminated with Mimosa seeds used in construction industries is likely to be the main dispersal agent, (2) Mimosa infestation has never been dealt successfully at its earliest establishment phase, and (3) the invasion is no longer restricted to wetland habitat but has spread into various types of landscapes and terrestrial ecosystems.