Kathmandu: Indigenous species of plants are increasingly under threat of extinction due to the spread of invasive plant species inside Jalthal forest area in the south-eastern part of Jhapa district. With a rich biodiversity, Jalthal forest is spread over approximately 6,000 hectares from Kachankabal, the place at the country’s lowest altitude, to Haldibari and Bahradashi, covering three rural municipalities and the Bhadrapur Municipality.
According to National News Agency Nepal, Dr. Lila Nath Sharma, an expert at Forest Action Nepal, describes the forest as a model natural forest not only of Nepal but also of South Asia because of a variety of rare plants, shrubs, and herbs that grow here. More than 450 species of plants thrive in the forest, which also serves as a habitat for over 200 species of birds and more than 140 species of trees.
Dr. Sharma highlights the forest’s unique biodiversity, noting its range of terrestrial and aquatic life, including elephants and more than 40 species of fish found in the local wetlands. The geographical uniqueness of the Jalthal forest, an “island” in a densely populated region, makes it distinct from other forests in Nepal. It is a significant habitat for Burmese Python and various faunal groups like birds, reptiles, amphibians, mollusks, and butterflies.
Research by Dr. Sharma has documented six species of trees not previously recorded in Nepal within Jalthal forest. Notably, plants typically found in the hills and Chure region have been identified here, a surprising discovery. Iconic trees such as the Latahar and Cycas, along with a rare species of palm, are found in the forest. The Himalayan Pinanga, a species of betel nut plant, is also present, though many rare plants lack adequate conservation.
Human encroachment and the spread of exotic species are contributing to the decline in biodiversity. Poaching threatens animals like deer, antelopes, and wild boars, while the mousedeer, unique to the area, has not been seen for years.
As many as 17 species of invasive plants have been observed in Jalthal forest, with Mikania, locally known as Pyangri Lahara, posing the biggest threat. These invasive species are more prevalent in open areas and forest fringes, with lower density under continuous and close crown cover. Another invasive shrub known as ‘ultokanda’ is also causing significant problems, threatening rare plants like ‘sarpagandha’, ‘kurilo’, ‘madhu’, and ‘deule chyau’.
Dr. Sharma emphasizes the need for local community forest user groups and municipalities to implement programs to control these invasive species, protecting the indigenous species of trees and plants in Jalthal forest.