India is facing an escalating ecological threat as invasive alien plants spread through forests, grasslands, wetlands and agricultural land at unprecedented speed, according to new research. A peer-reviewed study published in Nature Sustainability this year has provided the most detailed national assessment so far, showing that invasive species are advancing across nearly 15,500 square kilometres of natural areas every year. This rapid spread is displacing native flora, degrading wildlife habitats and endangering the livelihoods of pastoral communities, with researchers warning of long-term ecological disruption.
The danger is part of a wider global trend. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has identified invasive species as one of the top five drivers of biodiversity loss worldwide, costing more than $423 billion annually in economic damage and management efforts. For India, home to some of the world’s richest biodiversity and large rural populations reliant on natural systems, the implications are severe.
The Nature Sustainability study, which analysed 16 years of data across 2,77,000 square kilometres, revealed that by 2022, more than 2,66,000 square kilometres of natural landscapes in India had been overtaken by invasive plants. Researchers estimate that 144 million people, 2.79 million livestock and about 200,000 square kilometres of smallholder farmland are already exposed to invasive spread. Alarmingly, over 1,05,000 square kilometres of tiger habitat has been affected. Lead author Ninad Mungi warned that at current rates of spread, entire ecosystems could shift from native to invasive dominance within a generation.
Prominent invasive species include Chromolaena odorata, Prosopis juliflora, Lantana camara and Senna spectabilis. Chromolaena is spreading at almost 2,000 square kilometres a year, while Prosopis is transforming arid regions across western and southern India. These invasions reduce fodder availability, alter fire cycles and undermine the ecosystems that support both herbivores and top predators, posing risks to biodiversity and rural livelihoods.
Researchers say the rapid spread reflects deeper systemic issues, including fragmented landscapes, land-use change, agricultural expansion and climate stress. Despite the scale of the threat, national management remains fragmented and underfunded. The IPBES report noted that 83 percent of countries lack basic invasive species laws. India has no national legislation dedicated to invasive species, limited biosecurity protocols and no unified monitoring system.
One exception is Tamil Nadu, which has introduced India’s first dedicated State Policy for Invasive Plant Eradication and Restoration (PIPER). The state has already identified more than 1,77,000 hectares of forest land infested with major invasive plants and cleared nearly 35,000 hectares so far. Tamil Nadu’s approach combines scientific mapping, long-term maintenance and partnerships with industry.
The state has worked with paper manufacturers such as Tamil Nadu Newsprint and Papers Limited (TNPL) and Seshasayee Paper and Boards (SPB) to convert invasive biomass into pulpwood, creating a circular-economy model that supports restoration.
Senior officials say the urgency is clear. Supriya Sahu, additional chief secretary for Environment, Forest and Climate Change, said Tamil Nadu recognised the risk early and moved from policy to action, systematically clearing invasive species across tiger reserves and dryland ecosystems. Experts, however, caution that clearing invasive plants is only the first step and must be followed by two to three years of regular maintenance to prevent regrowth.
Global research highlights the importance of such coordinated strategies. Over 37,000 alien species have been introduced worldwide, more than 3,500 of them are invasive, and invasive species have contributed to 60 percent of recorded extinctions. Economic losses have risen sharply, quadrupling every decade since 1970. Scientists argue that India needs a National Invasive Species Mission to develop unified monitoring systems, build a national database, strengthen legal frameworks and support long-term restoration.
Researchers warn that without immediate and coordinated national action, many of India’s natural ecosystems could reach irreversible tipping points. Co-author Y.V. Jhala said the nation risks “losing biodiversity, livelihoods and the fragile balance of coexistence” if invasions continue unchecked.