Invasive plant species, “Senna spectabilis”threatens wildlife habitats of Western Ghats

A recent study revealed that the invasive species has now spread through the most iconic wildlife habitats of the Western Ghats, destroying habitats of elephants, deer, gaur and tigers by pushing out native flora.

About Invasive plant species:

• The rampant growth of invasive plants, especially Senna spectabilis, in the forest areas of the Nilgiri Biosphere Reserve (NBR), including theWayanad Wildlife Sanctuary, is a matter of serious concern to the conservation of wildlife habitats of the Western Ghats.
• The allelopathic traits of the species prevent other plants from growing under it.
• It is a form of chemical warfare where the shed leaves decompose and change the chemical composition of the soil, rendering it unsuitable for the growth of other plant species.
• This drastically affects primary productivity at the ground level.
  • The forest floor is almost bare under the invasive species.
  • Grasses and herbs get completely wiped out and herbivores are deprived of their forage.
  • The carrying capacity of forests to feed wildlife is drastically declining under the invasion, which accelerates man-animal conflict further.
• Introduction of species: The invasive species found its way to Wayanad in the 1980s, when the seedlings of the plant were first raised in the nurseries of the social forestry wing, and planted as avenue trees.
  • It was noticed regenerating profusely about 25 years after its introduction in Wayanad.
  • Over the period, it got established in the Bandipur and Nagarhole Tiger Reserves of Karnataka, and the Mudumalai and Sathyamangalam Tiger Reserves in Tamil Nadu as well.

Key Findings of the study:

• The study found around 23% of the area of Wayanad Wildlife Sanctuary is infested by Senna spectabilis.
• The study says 1,305 trees were found in one hectare in the most affected areas of the sanctuary.
• The tree species was found in nearly 10 sq km area of the 344.44 sq km sanctuary around five years ago.Now, it had invaded to more than 50 sq km of the sanctuary.