Valparai, also known as the seventh heaven, is a biodiversity hotspot in the Western Ghats. One gets to witness the beautiful shades of green everywhere while driving past the 40 hairpin bends. The trees are covered by green climbers, which are a treat to the common man’s eyes. But the sad truth is that these climbers, Mikania micrantha, are a bane to the forest.

Mikania micrantha is a fast growing perennial vine and one of the world’s worst invasive weeds. It is a major threat to the ecosystem, plantation, and forests, particularly in and around Valparai, under the Anamalai Tiger Reserve. The vine originated from Central South America and is said to have reached India during the World War II when the Allied forces were at war with Japan. It was introduced in Northeast India as a cover crop for artilleries or as an air force runway camouflage, and has now become a serious problem in Southeast Asia.

Notorious for its fast growth, the vine also is known as “a mile a minute plant.” Once established, the weed damages or kills other plants by cutting out sunlight, and twinning and smothering the host. It competes for water and soil nutrient and releases substances that inhibit the growth of other plants.

Invasion of non-native and exotic plants is a major threat to native biodiversity. Steps therefore have to be taken to destroy and remove Mikania micrantha in the Valparai forest cover to prevent the loss of its natural flora.

(The author is Frank Benjamin , environmentalist)