Climate Driven Vegetation Shifts Across High-Altitude Zones for Sustainable EcosystemResilience of the Garhwal Himalayas over last 50 years using Multi - Temporal Remote Sensing and AI/ML techniques

Abstract. High-altitude vegetation change dynamics are essential for unraveling the complex interrelationship between climatic variability and energy exchange processes that occur in these sensitive ecosystems. They are also important for understanding the function of vegetation cover as an essential element of global and regional climate systems. Vegetation cover change is time-specific and represents fundamental indicators of Earth system dynamics. This research is an attempt to detect and analyze vegetation cover change patterns in various altitudinal zones (3000 m and above) of the Garhwal Himalayas during the past half century from 1972– 73 to 2022–23 and analyze their ecological implications for changes in every decade in between, employing multi-temporal Landsat satellite data, remote sensing, GIS, and AI/ML-based spatial analysis. Decadal and slope-wise (altitudinal) zonal analysis indicates a steep rise in vegetated cover, especially in the 3000–3500 m and 3500–4000 m zones. For example, in the 3000–3500 m zone, vegetated cover rose from 56.42% in 1972–73 to 66.87% in 2022–23 of the areas, whereas in the 3500–4000 m zone, it went up from 43.78% to 59.03%, covering the areas that were previously under snow and barren land. This suggests a clear upward change in vegetation distribution, which is presumably caused by warming climate. The zones above 4000 m remains covered with snow and barren land, but also exhibits moderate vegetation intrusions, indicating a slow alpine ecosystem transformation. Predictive analysis of all the six maps from 1972-73 until 2022-23 to give forecast for 2033 shows significant changes with pine forests, moist alpine pastures, dry alpine scrubs, and barren land are predicted to increase by 65%, 13%, 9%, and 14%, respectively. Conversely, snow cover is anticipated to decline by 33% and Oak forests by 3%, indicating significant environmental shifts in the Himalayas. These results are crucial for formulating specific strategies for sustainable ecosystem resilience in the high-altitude zones of the Garhwal Himalayas.