Mikania micrantha (vine, climber)

Ecology Distribution Management Info Impact Info References and Links Contacts

General Impact Once established, Mikania micrantha spreads at an alarming rate, readily climbing and twining on any vertical support, including crops, bushes, trees, walls and fences. Its shoots have been reported to grow up to 27mm a day. Vegetative reproduction is also efficient and vigorous. Although intolerant of heavy shade it readily colonises gaps. M. micrantha damages or kills other plants by cutting out the light and smothering them. In this respect it is especially damaging in young plantations and nurseries. It also competes for water and nutrients, but perhaps even more importantly, it is believed that the plant releases substances that inhibit the growth of other plants. M. micrantha is one of the three worst weeds of tea in India and Indonesia and of rubber in Sri Lanka and Malaysia. In Samoa, incursions of M. micrantha have caused the abandonment of coconut plantations, and the weed has been reported to kill large breadfruit trees. It also causes serious problems in oil palm, banana, cacao and forestry crops, and in pastures. While it does not grow well in rice paddies, it can encroach from the edges to smother the crop. (Northern Territory Department of Business, Industry and Resource Development)          Location Specific Impacts: India   Economic/Livelihoods: In the tea plantations of north-west India farmers lose 30% of their profits controlling Mikania, dubbed the "mile-a-minute" weed, with chemicals and armies of machete-wielding workers. But this isn't always successful, because chemicals can only be used early in the season, to avoid contaminating the crop's leaves. In the worst cases, growers lose their entire crop (New Scientist, 2003). Habitat alteration: The Greater One-horned Rhino (Rhinoceros unicornis) is listed as 'Vulnerable (VU) in the IUCN Red List of Threatened Species. The range of the Greater One-horned Rhino extended across the entire northern part of India from Pakistan to the Burmese border including parts of Nepal, Bangladesh and Bhutan. Currently, it exists in a few small subpopulations in the Nepal and India (West Bengal, Uttar Pradesh, Assam) and is considered Regionally extinct in Bangladesh and Bhutan. The major threat to this species includes habitat alteration (grasslands to woodlands due to invasion of woody species like black catechu (Senegalia catechu) and Dalbergia sissoo); habitat loss and degradation due to invasion of alien invasive species. These include the vine (Mikania micrantha which overgrows and smothers vegetation; Eupatorium ; Lantana camara; M. cordata, M. scandens, and Leea spp. (Talukdar et al 2008) Kerala (India)   Agricultural: Plantain, pineapple, cassava and ginger are the worst-affected crops. Economic/Livelihoods: 75% of teak plantations surveyed in Kerala are affected by Mikania infestations, young teak suffer most from the effects of the weed. Physical disturbance: Infestations of Mikania make harvesting of non-wood products such as bamboos an onerous task.