Abstract: This study investigates phenological changes in plants of the Indian Himalayan region in response to global warming. Phenology, the study of recurring biological events in relation to climate, has emerged as one of the most sensitive bioindicators of climate change. Using four decades of data (1980–2020) derived from field monitoring, herbarium records, citizen science datasets, and remote sensing, we analyzed shifts in flowering, fruiting, and leaf senescence across six altitudinal zones. Results show that flowering and fruiting have advanced by 2–4 days per decade, while autumn senescence has been delayed, effectively extending the growing season. Regression analyses revealed strong correlations between temperature anomalies and earlier flowering, with each 1 °C increase advancing phenophases by 3–4 days. Early-blooming species were more responsive than late-flowering perennials, reflecting interspecific variability in climatic sensitivity. These findings align with global trends and highlight risks of ecological mismatches with pollinators, altered plant competition, and agricultural vulnerabilities such as frost damage and pest emergence. The study underscores the urgency of long-term monitoring and adaptive strategies to safeguard biodiversity, agricultural productivity, and ecosystem resilience in a warming climate.

Keywords: Phenology; Climate Change; Global Warming; Indian Himalayas; Flowering Shifts; Fruiting; Leaf Senescence; Bioindicators; Agriculture; Ecosystem Resilience

Downloads: | DOI: 10.17148/IARJSET.2025.12828