BENGALURU: While concerns are being expressed over depleting forest cover, the forest department is now faced with a situation where 40-50% of the state’s forests are affected by invasive weeds.
Forest officials are at a loss over how to manage the situation as these weeds are now not just multiplying rapidly, but are also growing resistance to weedicides.
Most areas in Nagarahole and Bandipur tiger reserves are weed infested, but the question facing the foresters is how to get rid of them. The identified weeds include Lantana camara, Eupatorium perfoliatum, Senna occidentalis, Parthenium hysterophorus and Mikania micrantha. There are also aquatic weeds, water hyacinth and Salvinia molesta, which are an equal concern.
Additional Principal Chief Conservator of Forests (Wildlife) Subhash B Malkhade, while admitting to weeds infesting 40-50% of the forests, said there is an urgent need for an ecological study to find appropriate solutions to the problem.
The forest officials are finding it difficult to dispose of the weeds as not all the species can be utilised. For example, in Lantana camara and Senna occidentalis, only the hardy and sturdy ones can be used in making furniture, artifacts, handicrafts, or in the paper industry.
The forest officials and researchers are now looking for out-of-the-box solutions to uproot the weeds and utilise them profitably. “The definition of weeds now needs to be changed. Earlier it was an invasive, non-native species of no use. But now, it is an invasive species with limited known use,” a senior forest official said. “It has been observed that the area occupied by weeds is increasing not just by seeds, but even through leftover stems and leaves.” Also, weeds earlier were lesser due to less moisture content, but with stringent laws and afforestation measures, moisture content has increased...and with this, new species have started growing, said senior forest officials.
Worse, the officials pointed out that the recently found weed, Mikania micrantha, which is not just limited to Bhadra Tiger Reserve but also other forests, has developed resistance to weedicides, which had to be stopped because of their high toxic levels.
Dr Siddappa Setty, senior fellow and centre convener at Ashoka Trust for Research in Ecology and the Environment (ATREE), said discussions on generating electricity using lantana are on. In this case, the type of lantana — whether sturdy or not — will not play an important role. Hence, there is a lot of opportunity, but procurement is a challenge. Foresters and contractors cannot go deep into forests, where the problem is more acute.
Rajesh S Kalleje, director, Institute of Wood Science and Technology (IWST), said talks are on with Bhopal’s Indian Institute of Forest Management to address the issue of funding for developing economical business models to use weeds in making briquettes as well as in other applications like energy generation.