DEHRADUN: A recent study by the Wildlife Institute of India, Dehradun revealed that one of the most dangerous invasive species 'Lantana camara' has invaded 154,000 square kilometres area, nearly the size of Odisha, which makes 40% of Indian's tiger range posing a further threat with Shivalik Hills, Central Indian and the Western Ghats.
The three regions are considered rich in biodiversity with a plethora of species of diverse flora and fauna.
"It was widely distributed across landscapes with maximum invasion in fragmented dry deciduous forests of Central India, Shivalik hills and the Southern Western Ghats," the study by Ninad Avinash Mungi, Qamar Qureshi and YV Jhala from the WII, Dehradun.
In an unprecedented effort, the experts involved in the study surveyed 207,100 km of Indian forests by sampling 13715 grids of 25 square km, each with 1-31 plots of 10-meter diameter, to record the abundance of the invasive species.
The study also stated that with this large invaded range, Lantana is "probably the most widely distributed invasive plant in India, as compared to other invasive plants" in India.
Across the globe, the grass is said to have invaded over 11 million square kilometres of area.
The grass which is said to have arrived in Indian in early 19th century from Central America aids forest fires, hinder native species for local fauna causing health hazard in turn proving harmful for the entire ecosystem, the study pointed out.
According to the study, 303,697 square kilometres of forest area which is nearly the size of Maharashtra in India. The area stands around 44% of the total forest area of the country is likely invaded by the invasive species of 'High Concern' already. India has a total of 712, 249 square kilometres of forest area across the country.
The recently published study conducted in 18 tiger states of India which was part of National Tiger Estimation Project also revealed that anthropological pressure and related activities such as mining, dams, roads and other related activity encourages the spread of the invasive species.
The study elaborating on this said, "Our results highlight the role of forest degradation and climate change in elevating the global risk of biological invasions and the importance of large-scale ecological monitoring for a better understanding of invasions that can potentially guide management actions."
Interestingly, to free one square kilometre of the area of the invasive grass disrupting the local ecosystem and whole in the larger scheme of things takes Rs 14 lakh along with other resources such as time and manpower making it virtually impossible to eradicate at once.
The experts involved in the study also recorded that the grass has dilated quickly in India and has been displaying 'adaptability' in terms of thermal tolerance and resource preference within a short span of time with increased tolerance to higher temperatures, lower fertility and denser canopy cover as compared to its native land.
However, a silver lining was also pointed out in the study stating that Northeastern tropical forests, Northern Western Ghats, semi-arid and arid landscapes of Western India are relatively less or not invaded by the vicious grass.