Understanding Mountain Grassland Resilience in Kinnaur

Guest blog by Áine Nicholson, PhD Candidate in Ecological Sciences, Charles

Darwin University, Australia.

In May, I travelled to Kinnaur after learning about Preeti's conservation efforts in the mountains surrounding Rali, in the Baspa Valley. I study how mountain grasslands are changing across the world, with a particular interest in how invasive plant species are expanding into higher elevations. The Himalayas hold some of the world's most culturally and ecologically important grasslands. As climate change, tourism, and other human pressures intensify, these ecosystems face growing uncertainty, making it crucial to understand how they are adapting and changing.

Grasslands of Harang, Mebar village. Photo by Tanisha Negi

Why invasive species matter

Non-native plants are an issue when they become invasive. The term "non native" is somewhat arbitrary (how long does a plant need to be present to be considered native—1000 years? 100?, and introduced species can sometimes provide benefits, like faster-growing fodder crops for livestock. Problems arise when non-natives spread widely beyond our control and destabilise local ecosystems Gioria et al. 2023. 

In another Indian mountain range, the tropical Western Ghats, large portions of the native mountain grasslands have been overtaken by non-native woody species such as Acacia, Eucalyptus and Pine. These trees were originally introduced by colonial-era foresters and have since spread uncontrollably 

Arusmani et al. 2023. What were once open, old-growth grasslands have become low-diversity stands of trees, with a cascade of consequences:, grazers lose habitat, fire behaviour changes, biodiversity declines, recreational values are lost and drainage patterns alter. The ecosystem fundamentally transforms to one of reduced ecological, functional and aesthetic value Pejchar & Mooney 2009. 

Grasslands are particularly vulnerable to invasion because of their open structure and because they're often already in use by locals and their livestock. For decades, mountain grasslands remained surprisingly resistant due to harsh conditions (snow and frost, high winds, erosion) limiting human use of the areas and making it difficult for new species, usually originating from milder lowland environments to establish. However, recent studies show invasives making their way into higher elevations Barros et al. 2022. I came to Kinnaur to investigate: as tourism expands and climate change takes hold, how resistant, or how vulnerable, are these grasslands to invasion?

Climbing a glacier during fieldwork. Photo by Tanisha Negi

The Fieldwork

My work followed that of the Mountain Invasion Research Network MIREN, a global collaboration studying plant invasions along mountain trails across six continents. MIREN focuses on how roads and trails facilitate the spread of non-native species. 

The fieldwork was a team effort. With support from Preeti and her family, particularly her father, Parmeshwar Singh Negi, her friend Tanisha Negi (known to everyone as Nicky), local guide Manish and other residents of the neighbouring Sangla Valley, as well as Johnny Negi, Ishan and their contacts, and my friend Jamie, we surveyed five trails spanning elevations from 3,000 to 4,500 metres. Together, we established 153 plots, documenting plant species, vegetation structure, and signs of disturbance such as fire and grazing. These plots extended MIREN's elevational range by 500–600 metres, contributing valuable data on how some of the world's highest grasslands are responding to tourism pressure.

What the Data Tells us?

For now, Kinnaur's grasslands appear free of non-native plants. Even on the most heavily trafficked tourist trail, we found only one non-native individual— and its identity was questionable. This contrasts with many of the lower elevation mountain sites in the MIREN data, including in neighbouring Kashmir, where road invasion is substantial. High altitudes in the region so far remain a refuge for uninvaded ecosystems Barros et al. 2025. 

This isn't for lack of disturbance. Human use is evident everywhere, including in Kinnaur and particularly in the easier-access valleys. Trash is visible along trails, foot traffic is exacerbating erosion on steep slopes, and native plant diversity suffers. Tourism and trails still matter—the MIREN global data show that trails and roads consistently predict higher invasion—but at Kinnaur's elevations harsh conditions may create a filter that currently overrides the effects of trail users Iseli et al. 2023. 

As temperatures warm and weather patterns shift, the harsh environmental conditions that have shielded these ecosystems from rapid land use change and the establishment of non-natives may weaken Gioria et al. 2023. If tourism numbers increase and the construction of roads and other infrastructure into higher elevations continue then Kinnaur's mountains may follow the pattern of other alpine regions, where warming is beginning to translate human activities into widespread invasion. 

This matters for management. Non-native plant invasion is something we can address if we intervene early enough Gioria et al. 2023. We can use this data to identify vulnerable ecosystems now and in the future, and take action before invasion takes root. Right now, Kinnaur's mountain grasslands seem to be protected by their high elevations and comparative lack of roads. The question is, how long will it last?

Áine and Preeti. Photo by Tanisha Negi

What Next?

This work wouldn't have been possible without the support of the Saryan Foundation and local communities who shared knowledge and facilitated access

to these landscapes. I'm just at the start of data analysis, and as I dig deeper, I'll continue to share my results with Preeti so she can share them with those interested in the future of Kinnaur's mountain ecosystems.

References:

Arusmani, N., Parida, M., Arjun, C. P., Parasharya, B. M. & Quayle, L. 2023. Invasive species threaten the global commons: a case study from the Nilgiris Biosphere Reserve, Western Ghats, India. Front. Ecol. Evol. 11, 1198085. 

Barros, A., Chytrý, M., Pauchard, A., Schulze, K. A., McDougall, K. L. & Alexander, J. M. 2022. Plant invasions in mountain ecosystems. In Mountain Biodiversity, 4156 CABI, 2022. 

Barros, A., Chytrý, M., Pauchard, A., Alexander, J. M., Daehler, C. C., Elsen, P. R. et al. 2025. Mountain ecosystems as a global refugium from plant invasions. Glob. Ecol. Biogeogr. 34, e70060. 

Gioria, M., Hulme, P. E., Richardson, D. M. & Pyšek, P. 2023. Why are invasive plants successful? Annu. Rev. Plant Biol. 74, 635670. 

Iseli, E., Chisholm, C., Lenoir, J. et al. 2023. Rapid upwards spread of non native plants in mountains across continents. Nat. Ecol. Evol. 7, 405413. 

Pejchar, L. & Mooney, H. A. 2009. Invasive species, ecosystem services and human well-being. Trends Ecol. Evol. 24, 497504.