How T.N. Forest Dept. is tackling Senna tora plants, an emerging threat to Mudumalai’s native ecology

The Tamil Nadu Forest Department is experimenting with the removal of a potential new species of invasive plant that has begun emerging in parts of the Mudumalai Tiger Reserve (MTR).

The Tamil Nadu Forest Department is experimenting with the removal of a potential new species of invasive plant that has begun emerging in parts of the Mudumalai Tiger Reserve (MTR).

Senna tora, a plant native to Central America, has been emerging over the last few years in Sigur and Moyar in the buffer zone of MTR, with concerns that it could be spreading. Forest Department officials fear that this new threat to MTR’s ecology could pose a risk to the open grasslands in the area, which elephants, deer, and Indian gaur depend on as food sources.

Speaking to The Hindu, officials from MTR said that discussions with local communities have revealed that the plant’s emergence in the region could date much farther back than previously estimated. “During discussions, some local elders said that they had been seeing the plant for many years, and that it appears and disappears every few years, pointing to its emergence being cyclical,” said a top official from MTR.

However, as the plant prefers drier areas and grasslands, officials fear that if its spread is left unchecked, it could threaten the region’s fragile ecology, which is already home to a number of other invasive flora, including the deciduous tree Senna spectabilis, as well as Lantana camara.

P. Arunkumar, Deputy Director of MTR (Buffer Zone), when contacted, said that while Senna spectabilis populates parts of the reserve with higher rainfall, Senna tora is emerging in drier areas. Mr. Arunkumar also said that the plant germinates after the southwest monsoon and gradually withers by the end of the year. “However, it does have the potential to become an invasive species,” said Mr. Arunkumar, adding that the threat to local ecology at the moment from the species is limited.

“We do not know the exact area of distribution of the species within the reserve. Efforts to estimate this must be undertaken,” he said.

Acting pre-emptively to eliminate the species from competing with native ecology, the Forest Department has already begun experimenting with removing the plants from a 15-hectare area. Mr. Arunkumar said that while manually removing the plants using human labour was difficult, they have had success removing the plants using mechanised equipment.