The Forest and Wildlife Department is planning to adopt steps to arrest the rampant growth of invasive plants, especially Senna spectabilis, in the forest areas of the Nilgiri Biosphere Reserve (NBR), including the Wayanad Wildlife Sanctuary.
“The spread of invasive plants, especially Senna spectabilis, is posing a major threat to the forest areas of the reserve, owing to its quick growth and coppicing character,” said B.N. Anjan Kumar, Chief Conservator of Forest, Wildlife, Palakkad.
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,” he said.
A recent study of the Ferns Nature Conservation Society recorded the presence of the plant in 78.91 sq km area of the sanctuary.
The plant has started to invade the adjacent Bandipur and Nagarhole tiger reserves in Karnataka and the Mudumalai tiger reserve in Tamil Nadu, P.A. Vinayan, president of the society, said.
Earlier, the plant species was planted as avenue trees in Wayanad.
Mass flowering
Due to mass flowering and drying of bamboo species in Wayanad, lots of open spaces were created which had been occupied by Senna spectabilis.
“An adult tree grows up to 15 to 20 metres in a short period of time and every year distributes thousands of seeds after gregarious flowering. The thick foliage arrests the growth of other indigenous tree and grass species and causes food shortage for the wildlife population, especially herbivores. Moreover, wildlife will not feed on the leaf of the treeas it is not palatable for them,” Mr.Anjan Kumar said.
Chemical measures
“The vayal ecosystem (marshy land) of the forest area now has this plant in large numbers.
The allelochemicals produced by this plant adversely affect the germination and growth of the native species,” T.K. Hrideek, scientist, Kerala Forest Research Institute (KFRI), who conducted a study on invasive plants, said.
“The KFRI has developed some physical and chemical measures to tackle the threat of the plant. Though we have been following the physical method to tackle the issue for the past five years, it is yet to have any desired effect.
Hence, we are planning to adopt an integrated method combining physical as well as chemical measures to address the issue,” Mr. Anjan Kumar said.
Tiger reserves
With the adjacent tiger reserves also under threat, managers of these reserves had agreed to follow similar steps to address the issue. The issue would be discussed at interstate meetings, he said.
