Invasive alien species attack on western ghats

Invasive alien species attack on western ghats

Subject : Environment

Section: Ecosystem

Context:

• The Western Ghats are feeling the impact of a new invasion: by plants that are not native to the region and which threaten to alter natural habitats and native biodiversity.

Invasive Alien Species (IAS):

• When animals, plants, or other organisms are introduced in areas outside their natural range, they might eventually turn into invasive alien species, degrading natural habitats and affecting native biodiversity.
• According to the International Partnership for Biodiversity and Ecosystem Services, biotic invaders threaten around one-fifth of the earth’s surface.
• A 2020 study showed that Lantana camara, a tropical American shrub, has invaded more than 40 per cent of India’s tiger habitats, threatening them through a causal chain that ultimately depletes the tiger’s prey base.
• The shrub’s presence was most prominent in the Shivalik hills, central India, and the southern Western Ghats.
• It is among the world’s 10 worst invasive species and one of high concern in India.
• They have certain common features like the ability to reproduce quickly, the lack of natural predators, the capacity to outcompete local species for food, water, and habitat -which ensure that they flourish wherever they go.
• Though the impact of invasive species is well known across the world, efforts to manage them are usually minimal in undeveloped and developing countries.
• In India, so far nearly 1,600 invasive plant species have been introduced, and the number is likely to rise further.
• Another alien species is Senna Spectabilis, called Manja Konna or Golden Wonder, in the Western Ghats.
  • It is an exotic tree and it was introduced as an ornamental species and for use as firewood from South and Central America.
  • It has become highly invasive in the Sigur plateau in both the core and buffer zones of the Mudumalai Tiger Reserve.
  • Over the last few years, its bright yellow flowers have become more visible across the Tiger Reserve, with conservationists stating that the invasive weed has a negative effect on local biodiversity, crowding out native species and limiting food availability for wildlife.
• Impact on biodiversity:
  • Native food sources below these invasive trees’ canopy get destroyed, impacting the survival of herbivores and dependent carnivores.
  • The resulting reduction of foraging grounds pushes wildlife beyond the boundaries of protected areas, leading to negative interactions with humans.
  • Eucalyptus plantation along the riverbanks and swamps has affected the wild ginger, turmeric, tubers and all medicinal plants which were common in the forest.
• Removal of these invasive species:
  • Proper girding, or ring-barking (removal of bark from around the circumference of a tree to disrupt the movement of water and nutrients between the roots and the top), of adult trees during peak summer is one of the best methods to kill the trees.

Initiative taken:

• PARDESI programme:
  • Scientists from Ashoka Trust for Research in Ecology and the Environment (ATREE), in collaboration with the Keystone Foundation and World Wildlife Fund (WWF), have started an initiative to study the distribution patterns of invasive species in the Nilgiris Biosphere Reserve (NBR).
  • This regional endeavour, titled the Participatory Assessment of the Regional Distribution of Exotic Species in India (PARDESI) programme, aims to engage citizens, who can utilise the Open Data Kit Collect application on their smartphones, to identify and map invasive species.

A comprehensive list of 89 invasive plant species from the Moyar-Bhavani Landscape of the NBR has already been compiled.