PhenoCams on the roof of the world: community-maintained timelapse trail cameras for monitoring vegetation dynamics at high altitude (proof-of-concept)

PhenoCam networks are useful for unattended monitoring of ecological dynamics at daily time-steps. Despite extensive networks of PhenoCams in many regions of the world, especially in North America and Europe, there are none in High Mountain Asia (HMA). Standard PhenoCams also require power and internet infrastructures that are not readily available in remote mountain areas such as HMA. Here, we assessed for the first time, the use and effectiveness of low-cost trailcams for high altitude phenological and temperature logging within the Himalayan alpine zone (>4000 m.a.s.l.). The ethos of this approach was to work with local community members in Himalayan villages above the treeline to maintain the PhenoCam systems for year-round operation. Results from this study show variations in phenology between two dominant plant communities - Juniperus spp. and Rhododendron spp. – in two high-altitude villages Dole (4038 m.a.s.l.) and Machermo (4392 m.a.s.l.) in the Khumbu region of Nepal. Juniperus spp. was found to have a longer growing season at higher altitudes (Machermo) compared to Dole. Seasonal temperature variations were demonstrated through temperature data extracted from the trailcam images. This study fills the current gap in our understanding of seasonal variations in phenophase of dwarf plants in the Himalayan alpine zone, but more importantly provides a proof-of-concept for a low-cost, low-carbon and community-maintained methodology to obtain long-term in-situ observations in the remote mountainous regions. While some missions encountered challenges due to user errors, this study underscores the potential for implementing citizen science initiatives in high-altitude Himalayan ecosystems, and demonstrates pathways for doing so.