Invasive Plant Species


    In News

    • Recently, Kaziranga National Park & Tiger Reserve (KNP&TR) are facing a new threat from invasive plant species.
      • These several invasive plant species in KNP&TR are threatening to destroy the habitats of one horned rhinos and other animals in the wild.

    Invasive Alien Species (IAS)

    • Definition: 
      • An alien species is a species introduced outside its natural past or present distribution; if this species becomes problematic, it is termed an invasive alien species (IAS). 
      • The Convention on Biological Diversity (CBD) defines IAS as “an alien species whose introduction and spread threaten ecosystems, habitats, or species with socio-cultural, economic and environmental harm and harm to human health”.
    • Examples:
      • Unintentionally introduced fungal pathogens continue to cause widespread declines in taxa ranging from bats and amphibians to corals and native forests.
      • Intentionally introduced feedstock and biofuel crops that go on to invade carry high financial and environmental risk, as realized in Africa and Asia. 
      • Invasive pines (Pinus species) transform habitats and fire regimes in the biodiverse South African fynbos and Brazilian cerrado. 
    • IAS are such a problem that Aichi Biodiversity Target 9 and one clause of UN Sustainable Development Goal 15 – Life on Land specifically address the issue.
    • Common features of invasive exotics include
      • The ability to reproduce both asexually and sexually
      • Fast growth
      • Rapid reproduction
      • High dispersal ability
      • Tolerance of a wide range of environmental conditions
      • Ability to live off of a wide range of food types


    • Human & Animal Health: Direct impact on human health. They have potential threats to livestock health. 
    • Food Security: Biological invasions are a major threat to global food security and livelihoods, with developing countries being the most susceptible. 
    • Environmental Consequences: 
      • The biological invasion could lead to changes to fire regimes, disease transmission to native species, forest loss, reduction in water flows, and habitat transformation, among others.
      • IAS are the most common threat to amphibians, reptiles and mammals on The IUCN Red List; 
      • IAS reduces the resilience of natural habitats, making them more vulnerable to the impacts of climate change. 
    • Financial Costs: On average, 32% of the farmers’ budget goes into the control of weeds, which includes the regular spraying of insecticide and labour costs. 
    • Man Animal Conflict: The widespread prevalence of IAS like Lantana Camara has reduced the proportion of natural grasses for herbivorous animals. 
      • This has resulted in the movement of animals like the Indian gaur and the chinkara (Indian gazelle) from their natural habitats to human settlements, thus endangering them.


    • Some of the species are not weeds but are highly economic species.
    • Though they are a weed, they are of high medicinal value, being a potent source of Vitamin D-3.
    • Such weed could be turned into a potential crop for the people living in the vicinity of the park to uplift their livelihood.
    • Conservation and propagation of the members of the Poaceae family in a very holistic manner will  help in countering the shrinking grasslands.

    Way Ahead

    • A comprehensive plan of action for dealing with the menace of expansion of the species as well as regeneration of the invasive species at an alarming rate is needed.
    • The permission should be granted under the Section 17B of the Indian Wildlife (Protection) Act, 1972 for experimental cutting, slashing, uprooting, and girdling of the invasive plants in approximately two-hectare plots in Kaziranga Tiger Reserve on a pilot basis.

    Kaziranga National Park 

    • About: 
      • It lies partly in Golaghat District and partly in Nagaon District of Assam. 
      • It is the oldest park in Assam covering an area of 430 sq km along the river Brahmaputra on the North and the Karbi Anglong hills on the South. 
      • National Highway 37 passes through the park area.
      • It is a world heritage site that is famous for the Great Indian one-horned rhinoceros.
      • It was declared a National Park in 1974.
      • It is recognized as an Important Bird Area by BirdLife International for the conservation of avifaunal species. 
    • Biodiversity:
      • The landscape of Kaziranga is of sheer forest, tall elephant grass, rugged reeds, marshes & shallow pools. 
      • It is inhabited by the world’s largest population of one-horned rhinoceroses, as well as many mammals, including tigers, elephants, panthers and bears, and thousands of birds.


    Image Courtesy: TH 

    Source: ET