Climate-Driven Early Flowering in Rhododendron: Field Observations across Altitudes in Bageshwar, Western Himalaya

Abstract

Climate change deeply impacts plant phenology, mostly in vulnerable high-altitude ecosystems like the Himalaya. This study investigates climate-driven shifts in the flowering phenology of Rhododendron a keystone species and significant bio-indicator to climate warming across a multi-altitudinal gradient (1500-3000 m) in Bageshwar district, Uttarakhand. Combining decadal climate records, attentive field observations (December 2023- October 2024), and invaluable local ecological knowledge from interviews with 150 respondents and a synthesis of recent literature. Analysis revealed a significant mean winter temperature increase of 1.3oC over last few decades in the study area. Results indicate significant advancement in flowering time, especially at lower and mid-altitudes, lower elevations experienced blooming 6-8 weeks earlier. While mid to high elevations showed 3–4-week advancement compared to historical norms. Essentially observation of community independently verified these shifts, with local inhabitants also reporting a perceived decline Rhododendron populations at lower altitudes. These findings underscore the high climate sensitivity of Rhododendron arboreum and highlight profound ecological implications, including potentially phenological mismatches with pollinators and a risk of range contraction. The study emphasizes the urgent need for elevation specific monitoring and targeted conservation strategies of long-term phenological monitoring to protect Himalayan Mountain Biodiversity.