India is confronting a rapidly escalating ecological crisis as invasive alien plants surge across forests, grasslands, wetlands and farmlands — reshaping ecosystems at a pace and scale not previously understood. A recent peer-reviewed study published in Nature Sustainability this year presents the clearest national picture yet. Invasive plants are spreading across nearly 15,500 sq km of natural areas every year, displacing native vegetation, degrading wildlife habitats, threatening pastoral livelihoods and creating cascading socio-ecological risks across the country.
At the same time, the world’s top biodiversity science body, IPBES, warns that invasive species are now among the top five direct drivers of global biodiversity loss, costing economies more than $423 billion annually in damages and management costs. For India, which is home to extraordinary biodiversity and hundreds of millions whose lives are directly tied to natural systems, the implications are profound. Amid this national emergency, Tamil Nadu has emerged as a rare example of proactive, policy-driven management, attempting what few states have even articulated, which is controlling invasives at scale, restoring ecosystems.
The Nature Sustainability study, based on 16 years of field monitoring across 2,77,000 sq km, paints an alarming picture. By 2022, nearly 144 million people, 2.79 million livestock and about 2,00,000 sq km of smallholder agriculture had already been exposed to new invasions. Over 2,66,954 sq km of India’s natural landscapes are now invaded, including more than 1,05,000 sq km of tiger habitat. Many invasions are expanding fastest in ecosystems weakened by climate change, rising temperatures, altered fire regimes, fragmentation and habitat degradation.
“At current rates, entire ecosystems could shift from native to invasive dominance within a generation,” said lead author Ninad Mungi in a statement, adding, “These plants are moving faster than we can manage or even monitor them.”
Species such as Chromolaena odorata are spreading at nearly 1,988 sq km a year, outpacing any existing management efforts. Lantana camara, Prosopis juliflora and Chromolaena dominate large swathes of forest and dryland habitats, with Prosopis transforming entire arid and semi-arid regions of western and peninsular India. Researchers warn that without decisive interventions, several natural ecosystems could shift entirely from native to invasive dominance within a generation. These shifts have direct ecological consequences, invasions affect tens of thousands of square kilometres of herbivore habitat annually and erode the ecosystems upon which large carnivores and pastoral livelihoods depend.
The study’s authors argue that invasions reflect deeper systemic disruptions. Fragmented landscapes, rapid land-use change, intensifying agriculture and climate extremes have created ideal conditions for invasives to spread. Meanwhile, the IPBES assessment highlighted how poorly equipped countries are to respond. Most nations—including India—lack national-level legislation for invasive species, dedicated regulatory frameworks or long-term financing mechanisms. Eighty-three percent of countries worldwide lack even basic invasive species laws. In India, management remains fragmented, reactive and heavily underfunded.
Few states demonstrate both the scale of the challenge and the possibility of coordinated response as clearly as Tamil Nadu. According to official government data, 1,77,363 hectare of forest land in the state are infested with major invasive plants. As of October 2025, the state had cleared 34,710 hectare, including 26,735 hectare of Lantana, 4,685 hectare of Prosopis, 1,963 hectare of Senna spectabilis and 1,327 hectare of wattle. The remaining 142,653 hectare still require removal and restoration. Some of the worst invasions occur in Mudumalai Tiger Reserve, Sathyamangalam Tiger Reserve, the Nilgiris and the dry eastern ghats — landscapes that the Nature Sustainability study also mapped as national invasion hotspots. Tamil Nadu’s approach, however, sets it apart. It has pioneered a circular-economy model by partnering with pulp and paper industries to repurpose invasive biomass. Tamil Nadu Newsprint and Papers Limited (TNPL) has removed over 31,000 tonne of Senna spectabilis from 854 hectare and used it as pulpwood. Combined with Seshasayee Paper and Boards (SPB), the state has cleared Senna across Mudumalai, Sathyamangalam, Pollachi, Erode, Ooty and Masinagudi. Instead of burning or dumping biomass, Tamil Nadu has created a new economic loop—removal, utilisation and reinvestment in restoration.
Equally significant is the introduction of India’s first dedicated State Policy for Invasive Plant Eradication and Restoration (PIPER), launched by Chief Minister MK Stalin himself. The policy’s framework mirrors IPBES recommendations calling for coordinated governance, early detection, long-term monitoring, community participation and science-based restoration. Senior officials say the urgency is clear. Supriya Sahu, additional chief secretary (Environment, Forest and Climate Change), told TNIE, “Tamil Nadu recognised this challenge early and moved from policy to practice. From pioneering India’s first invasive plant eradication policy to systematically clearing Senna, Prosopis and Lantana across thousands of hectares, we are showing that scientific restoration and circular economy can go hand in hand. Time is running out—the global evidence is clear, and urgent action is the only way to bring back lost biodiversity.”
On the ground, forest managers emphasise the long-term nature of the work. Removal alone is not enough; maintenance is essential. As R. Kiruba Shankar, field director of Mudumalai Tiger Reserve, notes, “We need to maintain cleared landscapes for at least two to three years for permanent change. Fresh Senna shoots are emerging despite all our efforts—maintenance is the key.”
The global numbers illustrate why Tamil Nadu’s efforts are nationally significant. More than 37,000 alien species have been introduced worldwide, over 3,500 are already invasive, and invasions have contributed to 60 per cent of recorded global extinctions—acting as the sole cause in 16 per cent of cases. Economic costs are rising exponentially, with damages quadrupling every decade since 1970. These patterns increasingly resemble India’s unfolding reality that is shrinking grasslands, altered fire regimes, soil degradation, reduced fodder availability, respiratory irritants, and the widespread displacement of native biodiversity. The Nature Sustainability paper calls for a National Invasive Species Mission, arguing that India lacks a unified national strategy, standardised monitoring, coordinated biosecurity, and a central repository of management outcomes. Tamil Nadu’s approach—combining policy, industrial partnerships, science-led mapping, tiger reserve integration and restoration of native grasslands—offers a replicable blueprint for the country.
Scientists caution that without coordinated national action, many ecosystems may cross irreversible thresholds. Co-author YV Jhala warns that failing to manage invasives risks “losing biodiversity, livelihoods and the fragile balance of coexistence.”