Nepal has the longest elevation gradient in the world i.e. 8000 meters vertical ascend within horizontal distance of 200km. The Himalayan country is known for majestic mountain peaks of which eight peaks cross 8000 meter above sea level (masl) but it also has land as below as 60 masl. Jalthal forest is the forest located in the lowest elevation in Nepal in the south eastern corner of the country in Jhapa district. Jalthal is a relict and remnant forest island in the densely populated region of eastern lowland of Nepal in Jhapa district. The forest gets its name from a nearby area called Jalthal. ‘Jalthal’ refers to waterlogged or marshy area. It is the largest forest island in lowland of Nepal. I had opportunity to learn about the wealth of flora of the forest from different people who have been there earlier. Two year back, I along with colleagues organized a quick visit of the forest and interacted with local people on various issues around the status and management of forest, which further helped me understand the uniqueness, importance and challenges of the forest. After the visit and the interaction, I realized the need for conservation and comprehensive assessment of forest so that we can get better idea about forest status and biodiversity for its evidence based management. With new project supported by Darwin Initiative UK, our plan to work for conservation of Jalthal forest became possible. After completing preparation, I decided to undertake fieldwork to sample the vegetation of the forest in the beginning of 2020.
I was excited and worried simultaneously for the fieldwork! Compared to mountain, no doubt Tarai topography is certainly a comfort to work with. Wildlife is a threat not to underestimate in some of the Terai forest. I had worked in the core area of Chitwan National Park. I was much worried to sample Jalthal than Chitwan National park. Jalthal forest has become a habitat of a heard wild elephants. Jhapa district is the worst affected by elephant attack. During the last one decade, so far over forty people were already killed in elephant attack of which over half dozen were from Jalthal area. Local reported that elephant roam throughout the forest.
Bigger team for fieldwork
After initial planning I called a community forest leader to discuss about the field work. I requested him to find some local helper for us and informed him that we go deep inside the jungle to work . When I said we are four and want two local helpers. He asked me ‘ is not this group small to go and work inside the core of the forest? I understood the level of threat and fear. After discussion with locals we decided to work in relatively larger group. Being in larger group would increase our confidence and feeling of safety. It would also allow us to invigilate on the way and around while working. Making too large group of course had resource limitation. As part of the sampling, we also had plan to engage locals in our team so that there will be mutual learning and sharing.
We decided to work in a group of 7-10 people depending on the location. In the team we four were researchers and other four to five people from local community. For the ease of sampling, we have two local youths who would work with us for the entire sampling while other three were from respective community forest. Two locals in our team would work with us during entire period of sampling. Purpose of bringing local people was to share learning and experiences of local people and technicians. In the team three were Master students namely Yogendra, Ramu and Shankar from Tribhuvan University. They are expected to develop their master thesis out of the plot data.
While browsing Google earth, if we look closely in the lowland of Nepal, we can see a green patch in the south eastern corner of the country. The isolated patch is a 6000 hectare Jalthal forest in Jhapa district. If we look further, it is an island in the densely populated region. It is also true that forest island of this size does not exist in the Terai region of Nepal. This shows geographical uniqueness of Jalthal forest, a Charkose forest. The forest is considered as unique and biodiversity rich. In short visits made earlier in 2018, I had also similar impression. I was curious to visit the forest again to have a closer look into its biodiversity and importance to local people. From the mid-2019, I had some opportunities to walk through the forest along with local people. Such walks are often labeled as ‘ forest transect walk’ by researchers and are used to understand the various dimensions of people-nature interactions. During ‘walk through the forest’ we talked about species, ecosystems, threats and management of Jalthal forest.
Biological Invasion: a major burden
It was a day in the Month of June last year; we entered the forest from the Pathibhara temple. After walking few minutes, Chiran Paudel, chairman of Pathibhara Kalika community forest stopped us and pointed towards a giant tree which had a dark green and spreading crown. The tree had more than 15 meter long clear trunk. A member from my team asked him ‘which tree is this?’ Mr Paudel replied ‘It is called Lathar, Its fruits are edible, leaves are good fodder and trunk is used for timber’. I had heard and read about this tree but this was the first time I have seen it. According to updated record of plant distribution in Nepal published by Department of Plant Resources (DPR), the species has only been reported from the Jalthal forest. The tree was new for foresters and other visitors from western and central Nepal who have been there for the first time. The tree is well distributed mainly in the south East Asia, all the way from Northeastern India through Malaysia, and the eastern Nepal could be its last resort of distribution. This tree signifies the importance of Jalthal forest for botanists and nature lovers.
The tree was just 50 meter away from the trail where we were standing. I tried to approach the tree for a closer photograph of fruits, a local people requested me not to try. He pointed towards the green mat covering the forest floor and said ‘it takes you twenty minutes to reach to the tree; you will drown in the bush of Tyangri lahara and will be lost’. Tyangri or Pyangri lahara is local name for the invasive species that has been reigning the open areas of the forest for about last two decades. The invasive species called mile a minute due to its fast growing and rapidly spreading nature. The weed native to South America was first reported in eastern Nepal in early 60’ies. Locals report that in April 1996, there was a horrible storm which felled about 50% of trees in the forest; the northern parts of the forest was particularly hard hit by the storm. Some people claim that the weed proliferated in Jalthal after the incidence. Which may be valid given that disturbance events are key in spread of invasive weeds. In our preliminary estimation, the weed is already a major problem in more than half of the forest. The weed is moving fast in Nepal. In the west, it has been spotted in Dang valley and in Pokhara in the north. Including Mikania the forest has now 15 invasive plant species out of 27 invasive species reported from Nepal. Invasive species cover was not equal in the forest, they were plentiful in open areas and forest fringes while their density was lower under the continuous and close crown cover.