Fragile Peaks, Fading Orchids: Multiscale Patterns of Diversity, Climate Risk and Conservation in Western Himalaya

The Himalayan canopy orchids constitute an ecologically significant yet understudied group of epiphytic plants that thrive in the fragile montane ecosystems of the North Western Himalaya. This study examines the patterns of diversity, distribution, and climate sensitivity of canopy orchids along altitudinal gradients, integrating multiscale field data, GIS-based habitat mapping, and species distribution modelling. Results revealed a distinct mid-elevation diversity peak (1,800–2,200 m) driven by microclimatic stability and host-tree diversity, with projected models showing a 23–41% contraction of suitable habitats and potential loss of unique evolutionary lineages under high-emission scenarios.

By combining landscape-level environmental data with fine-scale ecological observations, this research highlights temperature seasonality and canopy humidity as dominant predictors of orchid occurrence and demonstrates how microhabitat heterogeneity buffers orchids from macroclimatic changes. Projected models indicated a significant upward contraction of suitable habitats by 23–41% under high-emission scenarios, particularly threatening narrowly distributed taxa such as Dendrobium sp. and Bulbophyllum sp.. The findings underscore the vulnerability of canopy-dependent orchids to both anthropogenic pressures and climate-induced habitat fragmentation. Conservation efforts should prioritize the protection of mid-elevation forest canopies and the creation of climate-resilient corridors to facilitate species persistence. Overall, this work provides a baseline for long-term monitoring and adaptive management strategies essential for safeguarding Himalayan orchid diversity under future climate change scenarios.