Climate change will come as a boon to the alien invasive species of Lantana Camara, a weed that is great in adapting as it can tolerate high temperatures and moisture. The species which came as an ornamental plant in India in the early 1800s now threatens about 300,000 sq. km of Indian forests.
With calculations for present (2020) and future (2050), the study — with area pertaining to Jharkhand — was aimed to understand the potential risk zones prone to the invasion of the perennial ornamental plant, the Lantana Camara, known as Raimunia in Hindi.
"Results showed the presence of Camara invasion in more than 13 percent of the geographical area of Jharkhand, Chotanagpur plateau, which may expand up to 20-26 percent by 2050 depending upon emission scenarios as characterized by the four different temperature rise scenarios in future," the study 'Modelling the potential risk zone of Lantana Camara invasion and response to climate change in eastern India' said. The study is published recently in the journal Ecological Processes.
The observation should ring alarm bell among the policymakers as yet another study “Expanding niche and degrading forests: Key to the successful global invasion of Lantana camara (sensu lato)” published in Global Ecology and Conservation reported that lantana occupies 154,000 sq.km forests (more than 40 percent by area) in India’s tiger range. Among forests, Shivalik Hills in the North, fragmented deciduous forests of Central India, and Southern western Ghats are worst hit by its invasion.
The present study in Jharkhand region has been conducted by a team of Sharad Tiwari, S N Mishra, Basant Kumar, S N Vaidya, Brojo Gopal Ghosh, SK Mujibar Rahaman, Masjuda Khatun and Sanjoy Garai from Institute of Forest Productivity, Lalgutwa, Ranchi; Dharmendra Kumar from Department of IT, Jharkhand Government and Amit Kumar from the Department of Geoinformatics, Central University of Jharkhand.
Lantana Camara of the Verbenaceae family has more than 600 varieties and is a native terrestrial weed of South and Central American origin, which is considered among the top 10 worst invasive species by the IUCN.
The study noted that the weed distribution has adversely impacted the population stratification, regeneration, and anticipated future composition of tree communities in tropical dry deciduous forests of India. “The species, due to its wide eco-tolerance has dominated varied landscapes including disturbed areas, along streams, open and disturbed forests, and riparian vegetation,” it said.
"Importantly, the temperature seasonality was observed as the most contributing factor for the distribution of L. Camara for current and future scenarios across all possible climate scenarios depending on temperature rise. Suitable habitat for L. Camara mostly occurred under natural vegetation (66.05 -percent of critical risk zones (CRZ) and 60.71 per cent of high-risk zones (HRZ)) and agriculture landscape (29.51 per cent of CRZ and 34.48 percent of HRZ).
It also found the inability of L. Camara to penetrate through the intact native virgin forests, in contrast to its abundant distribution along with agricultural land and in open and disturbed forest areas including wide distribution in Betla National Park.
The researchers have now recommended prioritisation of sensitive natural sites at the verge of greater invasion threat and adoption of native tree and grass-based intervention models to address invasion issues; support richer biodiversity and environmental amelioration and outreach programs to educate people with the harmful effects of L. camara and other similar invasive species.