6 days ago
Unabated Lantana camara invasion in Himachal needs swifter, more rigorous response
Lantana camara, an invasive alien species introduced decades ago as an ornamental plant, now infests approximately 3,25,282 hectares of forests in Himachal Pradesh, posing a threat to the State's native biodiversity. Even though the Forest Department has achieved significant progress by clearing 51,114.35 hectares of Lantana camara since 2009-10, ecologists are calling for faster, more rigorous action to curb the spread of the noxious weed.
Lantana, a pantropical weed species, is native to the tropical and sub-tropical regions of Central and South America. In India, it was first introduced in the early 18th century, and since then, it has invaded almost all the tropical areas across the country, including Himachal Pradesh. According to the State Forest Department, a survey was carried out in 2010-11 and 2015-16 to asses the extent and level of invasion, which showed forest areas of around 2,35,491.93 hectares as being significantly infested with lantana, and varying intensity of infestation in seven territorial circles, namely, Dharamshala, Nahan, Hamirpur, Chamba, Bilaspur, Mandi, and Shimla.
However, according to the India State of Forest Report 2023, the extent of Lantana camara infestation inside the recorded forest area in Himachal Pradesh is estimated to be around 3,252.82 sq. km. or 3,25,282 hectares.
Kuldip Dogra, a noted taxonomist, acknowledged the progress made by the Forest Department in clearing lantana, which 'offers hope' in tackling the menace, but emphasised the need for an integrated, transdisciplinary, time-bound approach by involving stakeholders and members of civil society to create livelihood opportunities in the process of eradicating Lantana camara.
'There's no doubt that the area under alien invasive plant species, such as lantana, is on the rise, which is threatening the rich, native species diversity. To control the spread of lantana, it's important that stakeholders are involved — be it locals, industrialists, civil society organisations, etc. — and a mechanism evolved to enhance their livelihood options,' Mr. Dogra, Scientist at the Botanical Survey of India, High Altitude Western Himalayan Regional Centre in Solan district, told The Hindu.
'Lantana's management can be achieved by using its biomass for socioeconomic purposes — its timber for making furniture and also as fuelwood, etc. Its biomass can be used to produce organic compost and vermicompost, which will be better for organic farming and an alternative to inorganic manures available in the market,' he added.
'However, the cultivation of alien invasive plant species in home gardens, for landscaping, or for other economic purposes, and around the National and State Highways should be strictly avoided to prevent their further spread and establishment. Pharmaceutical companies should be encouraged to collect these species from the wild to extract potent alkaloids to be used for different industry purposes. Its management should be focused strongly on prevention, early detection and eradication strategies. Most importantly, the eradication programme should be carried out within stricter timelines by involving all the stakeholders, and increasing momentum to achieve optimal outcomes,' he added.
The State Forest Department's policy document for managing Lantana camara points out that this noxious, exotic weed aggressively proliferates and forms a dense mesh of bushes. This happens excessively at the edges of forests having sparse canopies. Lantana camara is known to produce allelochemicals that restrict the growth of other species under its canopy. Hence, it replaces native flora, resulting in homogeneous vegetation, significantly contributing to decline in biodiversity.
'We have eradicated lantana in 51,114.35 hectares so far since 2009-10. The removal of lantana is being done through the 'cut root stock' method, and to ensure that lantana doesn't invade again, we are planting native species as well. We are making headway. On average, every year, we are expecting to eradicate lantana on 1,000 hectares of forest,' Girish Hosur, Additional Principal Chief Conservator of Forests, Himachal Pradesh, said.
'The immediate focus should be to contain the speed of spread of lantana. It has been observed that it has been infesting from lower areas towards higher regions, which is worrying. The 'cut root stock' method is good, but the eradication should be tackled at the higher elevation first, so that the infestation could be restricted to the lower areas only, and then gradually rehabilitate all the areas with native species,' G.S. Goraya, researcher on floral diversity and former Principal Chief Conservator of Forest, Himachal Pradesh, said.
