KATHMANDU, JUNE 6

Chiranjavi Paudel of Haldipalika Rural Municipality-4 in Jhapa district does not recall exactly when the alien invasive plant species 'Ulta Kada,' scientifically known as Mimosa diplotricha, was first discovered in the district.

However, upon hearing reports of dead goats and cattle after consuming the weed, we visited the affected area, which was previously occupied by Bhutanese refugees.

Locals suggested that the refugees might have brought the seeds with their food grains and left them in the nearby jungle and river areas around the Charali and Beldangi refugee camps.

As we were not well-educated, we did not realize the danger until researchers Dr Bharat Babu Shrestha and his team from Tribhuvan University visited the area. It was only then that we learned about the significant harm this invasive species posed to both humans and biodiversity.

Paudel recounted an incident where a local tried to remove the invasive species from his corridor, resulting in a severe allergic and toxic reaction. Home remedies worsened his condition, leaving permanent scars on his hands, Paudel shared.

How does climate change fuel expansion of invasive species

According to Professor Dr Ram Prasad Chaudhary at TU, invasive alien species establish themselves by rapidly replacing native species following habitat destruction and global warming.

Once these species invade a habitat, they are exceedingly difficult to eradicate due to their aggressive occupation of both terrestrial and wetland areas. "They are particularly prevalent in the lowland Chure-Terai Madhesh landscape."

Dr Jagadish Parajuli, a climate public finance specialist at Asian Disaster Preparedness Centre, said, climate change influences precipitation patterns by alterning atmospheric moisture content, weather system, storm characteristics and seasonal cycles, leading to diverse and region-specific changes in precipitation.

"These species will thrive once they encounter favorable temperatures," said Dr. Bharat Babu Shrestha, noting that these alien invasive species have even been discovered in higher altitudes.

In their research paper, researchers Dr. Lila Nath Sharma and Dr. Shrestha have acknowledged the discovery of 26 problematic invasive species, among which 'Ulta Kada' poses the most significant threat.

Dr. Sharma explained that the species contains 'mimosin,' a poisonous chemical fatal to cattle when ingested. He also noted in his research paper that more than 250 cattle and 500 goats had died in Morang district. The presence of this species makes harvesting difficult and encroachment challenging for both humans and animals. Additionally, contact with the plant causes allergic and toxic reactions in the body.

Chiranjavi Paudel remarked that, thanks to the initiatives led by Dr. Sharma and Dr. Shrestha, we villagers have become aware of the ongoing proliferation of these species, which are expanding steadily with each passing day. "These invasive species have already spread to Morang and Sundari districts."

Turning challenges into opportunities

Dr. Bharat Babu Shrestha remarked that while it poses a challenge, there is an opportunity to prevent its spread beyond the areas where it has been identified.

Several species, such as Pistia Stratiotes, have been observed in Nuwakot. Similarly, Spergula arvensis has been discovered in Parbat, Myagdi, Baglung, and Kaski districts. Additionally, Mesosphaerum sunaveolens, Ageratum houstonianum, and Parthenium hysterophorus have been identified in and around protected areas, posing a threat to biodiversity, Dr Shrestha shared.

In his research paper, Dr. Sharma discusses Mimosa diplotricha, native to South America, spanning from Mexico to Argentina, including the Caribbean. This species has been introduced to South and Southeast Asia, Africa, Australia, and the Pacific islands, where it has become invasive.

In Nepal, two varieties of this species have been identified: Mimosa diplotricha and Mimosa pudica. Dr. Sharma emphasized that these species must be managed before they become unmanageable.

Chiranjavi Paudel also emphasized the importance of controlling these species at their source to mitigate the potential damage to biodiversity and agriculture. "The unchecked spread of these invasive species would lead to significant agricultural productivity losses and a severe decline in biodiversity," Paudel warned.

Dr Sharma noted that the weed, previously confined to limited areas along riverbanks for decades, is now spreading rapidly due to the transport of sand and gravel from these invaded riverbanks to newly graveled and paved roads and construction sites. "According to his research findings, the weed has already adversely affected livestock, human health, and the environment."

Government intervention

Talking to THT, Sunita Ulak said, "The government has been conducting studies on invasive species and its impact on forests. And a strategy and action plan are ready."

When asked about Ulta Kada in Jhapa, Ulak, the government-appointed focal person at the Asia-Pacific Forest Invasive Species Network (APFISN), responded, "We have not conducted any investigations on this species."

She added that, in coordination with local communities, Forest Action has carried out investigations and distributed leaflets to raise awareness.

Badri Raj Dhungana, spokesperson for the Ministry of Forests and Environment, announced that the initial draft of the invasive control strategy has been completed. Currently, we are soliciting feedback from various departments, divisions, and relevant authorities.

"The strategy formulation on invasive species is in its final stages and is being spearheaded by the Forest Research and Training Centre," Spokesperson Dhungana said to THT.

Chiranjavi Paudel expressed disappointment at the lack of government support in controlling the escalating invasive species in the region.

He emphasized that with government assistance, they could have taken more effective measures to prevent its spread to neighboring districts. "Despite the presence of three tiers of government, there has been no support from authorities in terms of logistics, expertise, or technical resources on this matter," Paudel criticized the government.

Dr. Shrestha also emphasized that the government should consider hiring experts in the field to effectively control and mitigate the challenges posed by the increasing presence of invasive species nationwide.

Despite our efforts to raise awareness about invasive species among the locals, Dr. Lila Nath Sharma urged the government to intervene promptly to mitigate the potential damage it may cause in the future.

Meanwhile, Dr. Niraj Parajuli, a senior consultant dermatologist at Bir Hospital in Kathmandu and the General Secretary of the Society of Dermatologists, Venereologists, and Leprologists of Nepal (SODVELON), urged locals to seek medical attention from qualified practitioners rather than attempting self-treatment, as this may exacerbate their conditions.