Invasive Alien Species

Invasive Alien Species (IAS) are plants, animals, or microorganisms introduced outside their natural range — intentionally or accidentally — that establish, spread, and cause significant harm to native ecosystems, biodiversity, agriculture, or human health. The CBD (Convention on Biological Diversity) identifies IAS as one of the top five drivers of global biodiversity loss.

• 1 CBD identifies IAS as 2nd biggest driver of biodiversity loss (after habitat destruction)
• 2 Major IAS in India — Prosopis juliflora (vilayati babool), Lantana camara, water hyacinth (Eichhornia crassipes), African catfish (Clarias gariepinus), Parthenium hysterophorus (Congress grass)
• 3 Prosopis juliflora — introduced in 1870s for afforestation, now covers 5+ million hectares, displaces native species in Rajasthan, Gujarat, Tamil Nadu
• 4 Water hyacinth — clogs water bodies, reduces dissolved oxygen, harms fisheries
• 5 Biological Diversity Act, 2002 — Section 36(4) addresses invasive species regulation
• 6 IPBES Global Assessment (2019) — IAS cause $423 billion annual economic damage globally
• 7 Kunming-Montreal Global Biodiversity Framework (GBF) Target 6 — reduce introduction rates of IAS by 50%
• 8 IUCN maintains the Global Invasive Species Database (GISD)

Prosopis juliflora, introduced for afforestation in the 1870s, has become India's most destructive invasive species — covering over 5 million hectares and replacing native vegetation in arid regions.