Weed wars – invasive plants battle it out

I recently traveled in the forests of North Kerala. I visited the upper catchments of River Chaliyar in Malappuram district and of River Kabini in Wayanad district.

The forests in Malappuram were nice with the pachyderms roaming without fear or worries. In fact they could be seen in the wild, thankfully from a safe distance of about 500 metres, as they walked to the river for their daily bath or to quench their thirst. the  drink. 

The largely teak forest is abundant.  Of course, there are is both floral and faunal diversity, though some parts appeared to be “managed forests” with their 40–50-year cycle. 

Nilambur is very well known for the its teak. It and also has a teak museum there. High rainfall keeps the vegetation that way. Those people who had have lands in or along the forest periphery had have adjusted their cropping pattern and now grow crops such as rubber which do not attract the elephants much. 

In the Wayanad Wildlife Sanctuary, the matter wasthings were different. The forests near Mananthavady, which is also a part of the Nilgiri Biosphere Reserve, which borders on reserved forests and sanctuaries of Nagarahole, Bandipur and Mudumalai. Three States have borders with each other in what can be called a distance of an evening walk for an elephant or a tiger. This too was a deciduous forest once dominated by teak. However, there appeared to be awas a somewhat larger human interference here.. here with fair number In fact, in this part cattle could be to be seen grazing fearlessly. etc. 

What really set the Wayanad Sanctuary area apart is the profusion of tall trees which have narrow and longish leaves crowding out virtually all other flora. On enquiry I was told it was senna (Golden Shower or Senna Spectabillis). Our friend and philosopher there told us that this was a very invasive species. While the timber trees of course were very sturdy and sort of looked at senna with a contemptuous glance, other floral species and grasses were reportedly suppressed by the very aggressive senna.

 A few score kilometers north in the Western Ghat ecosystem I had noticed huge profusion of lantana, also an invasive species. Here in Mananthavady, lantana seemed to be largely absent or if present, was not obvious to a casual visitor. Some published papers report that this species now has invaded over 20000 Hectares of forest land, banishing lantana so to say.

Both the species are aggressive and spread really fastfast. As a matter of fact, the entire and hugelarge jungle stretches in Jharkhand and MP, possibly totaling up to over a million hectares, of forest land have been invaded and captured by lantana. 

There are some more commonalties. Lantana produces coloured flower and small black, sweet fruit. Birds are fond of them and through their droppings spread the seeds over wider areas. All uncultivated areas are prone to lantana infestations. Neither the leaves, nor flowers or seeds have any proven economic value. 

After huge several efforts, a method for using branches of old lantana shrubs to make furniture have born limited fruit. The effort to uproot lantana is stupendous.

 Senna too has no economic value. Senna seed pods are rich in number of seeds. Wild animals such as elephants and chital forage on them and scatter the seeds through their waste. Huge efforts including use of JCB machines are needed to uproot Senna trees. 

Both these trees suppress growth of grasses, herbs, small shrubs and other plants – thus negatively impacting floral biodiversity. Reduction in grasses available is also an issue for cattle herders. 

If these trees aren’t enough a cause of huge headache for foresters, degraded forests, shrub forests and wastelands particularly in relatively dry ecosystems get taken over by three more weeds: parthenium, prosopis juliflora and Bodha grass. 

While young shoots of grass are fodder for goat, even goats does not forage on stiffened grasses. Seed pods of prosopis are used to feed goat, further and otherwise, in many regions there is a vibrant charcoal industry based on prosopis. Parthenium (Congress grass) is completely useless except as an input in making organic pesticide. 

All these very extremely invasive species cause negative consequences on biodiversity, reduce availability of fodder for herbivores and in fact also invade farm lands. Efforts to eliminate them by employing manual labour under MNREGA have been made in different parts of the country, but these are sort of few and far in between. Villagesquare had documented one such effort by FES in Mandla.

It perhaps is a repetition of the basic strand of logic of many actors in the field., but Inin my view the solution does not lie in using public resources for physically eliminating these very aggressive and invasive weeds. It may be far more prudent to invest in large scale research aimed at finding economic value of the components of the plants, including value arising out of their  chemicaltheir chemical and phytochemical properties. 

If through this kind of applied research, processes are discovered to make economically useful products from these productsusing these plants, that it will create a huge incentive to for  neighbouring residents to cut them or regulate them. Considering the scale of the problem affecting our already endangered forest resources and common lands, the investment is well worth making even if there is a high ab initio uncertainty about results.

Sridhar Ananth is an independent consultant.

Sanjiv Phansalkar is the director of VikasAnvesh Foundation. He was earlier a faculty member at the Institute of Rural Management Anand (IRMA). Phansalkar is a fellow of the Indian Institute of Management (IIM) Ahmedabad.