KOZHIKODE: Alien plant species have spread unbridled in the wild in Wayanad district posing a threat to environment, farming and wildlife, according to forest department officials. These alien species are preventing the growth of local plant varieties which are endearing fodder for wildlife and also affect the ecology of the region. As per a recent report submitted to the forest department by the Wayanad Wildlife Sanctuary authorities, as many as four varieties of alien species are spreading in jungle regions. None of these plant species are fodder to animals.
They are Senna spectabilis, a tree species belonging to the family Fabaceae (subfamily Caesalpiniaceae), Lantana (Lantana camera), Eupatorium (Chromolena odorata) and Mikenia (Mikania micrantha) In ideal conditions, Senna Spectabilis can grow up to a height of more than 20 metres. Propagation is mainly through seeds. The tree is capable of invading natural habitats, grow into thickets and displace indigenous flora. At present 2 per cent of Wayanad Wildlife Sanctuary is infested with this alien invasive species, says the report. Introduced as avenue trees in Wayanad decades ago now the forest department is exploring ways to eliminate these species.
Mikania micrantha is a perennial creeping climber known for its vigorous and rampant growth. A single stalk of mikania can produce 20,000-40,000 mature seeds in one season. Growth of young plants is extremely fast (8-9 cm in 24 hours) and, using trees as support, the weed rapidly forms a dense cover over entangled leafy stems. Another variety Eupatorium prevent establishment of other species. Wherever it has been introduced, it has become an aggressive and invasive weed. It forms dense thickets, choking out all other vegetation.
Chemicals in the leaves and stems suppress the growth of other plants, and hence there is loss of productivity. It affects the overall productivity of forest ecosystem. The eupatorium weeds have invaded 80 per cent of the total sanctuary area. Wayanad Wildlife Warden P. Dhanesh Kumar told this newspaper that though weed cutters and proclains were used to destroy the alien plants, they are still spreading. “More concerted efforts are needed to eliminate these weeds from the eco-system,” he said, adding that nature lovers, scientists and forest staff should join together against the spread of these weeds.
Senna spectabilis : Introduced as avenue trees. Invaded 2 percent area of WWS. Grow up to 20 meters height.
Mikania micrantha: Single stalk can produce 20,000 - 40,000 mature seeds. Creeper grow up to 9 centimeters in 24 hours
Eupatorium. Chemicals in the leaves and stems suppress the growth of other plants. Invaded 80 percent of sanctuary area
