Wild weed threatens Nepal's ecosystem

The problem first came to light when Chanda Rana, environmentalist and president of the Save the Environment Foundation in Nepal released a documentary film in 2010 - the first to highlight the devastating impact of Mikania Micrantha, locally known as banmara, in Chitwan National Park.

"It’s a disaster. When I went last year I noticed it at once. I didn’t find animals, rhinos, which I used to see in the resort areas. Instead I saw all the trees being surrounded by this wild weed," Rana told Deutsche Welle. "If you go there right now, you’ll get scared."

During a recent elephant polo game at the Chiwan national park, Rana said she felt very bad seeing the difference between what she saw six months ago and now. "It’s thickly carpeted the park," she said.

The origin of the weed

Villagers say it has been over a decade since the weed has infested Chitwan and other national parks.

The wild weed - originally from South America - found its root in Nepal soil as early as 1951 through flooding. It competes with trees and other crop plants for soil nutrients, water and sunlight, causing significant reductions in growth and crop productivity.

Rana's documentary "Mile-a-Minute: A serious threat to Chitwan National Park" brought the issue to the attention of Nepal's ministry of forests and soil conservation and an awareness campaign was organized.

But Rana says not much is being done. Secretary of Forests and Soil Conservation Yubraj Bhusal agrees that they have not come very far.

"The government of Nepal has just attempted to create awareness among the people about how dangerous it is," he said.

"Across half of Nepal, from east to midwest, from the Koshi River to West Rapti River, it has invaded the area. And it has the tendency to move forward to Bardiya National Park and even Shuklaphanta and other parts," he added.

Rhino habitat being lost

The rate at which the invasion is taking place is a great threat to Nepal's wildlife and national parks. "As our ecologist mentions, it grows very quickly, as fast as 80mm in 24 hours for a young plant," Bhusal pointed out, concerned with the rapid infestation.

In Koshi Tappu, eastern Nepal, it has covered almost "one third of the prey base of the wild buffalo and other wild animals" and in Chitwan National Park it has covered "almost 95 per cent of the prey base," particularly of rhinos, deers and other wildlife.

This has led to wildlife moving toward farmlands, often causing human-wildlife conflict.

Out of the 24 rhino deaths in 2010, almost 11 were poached because "they come out of the prey base as it is invaded by these invasive species or banmara," said Bhusal.

World heritage site threatened

Bhusal said some in-depth research is badly needed to find a way out. In the long term, the weed poses a severe threat not just to the wildlife and ecosystem but also to tourism and the livelihood of the people.

While efforts are on to study the possibility of using the banmara to make bio briquettes, Rana said the only effective control measure is to uproot them. She is planning a three-year pilot project to see how effective it is. "A plant has 40,000 seeds, so we need to take out the plant before it starts flowering."

But she said it is going to be a difficult task. "We need lots of manpower and first of all we need to do surveys about the infestation in the parks," not just in Chitwan but other parks as well.

According to Rana's findings, if prompt action is not taken, within five years 50 per cent of the flora and fauna of the Chitwan National Park, a world heritage site, will be lost.

Author: Sherpem Sherpa
Editor: Thomas Baerthlein