Format: ORAL

Chu-Chia Kuo1, Yu Su2, Ho-Yih Liu3, Cheng-Tao Lin2,*

1 Department of Biological Resources, National Chiayi University, Taiwan 2 School of Forestry and Resource Conservation, National Taiwan University, Taiwan 3 Department of Biological Sciences, National Sun Yat-sen University * oral speaker/corresponding author

Climate change is notably affecting natural vegetation, especially in mountainous regions. Alpine plants, adapted to harsh conditions such as cold, low nutrients, and high radiation, are particularly vulnerable to climatic shifts. Changes including uneven precipitation, increased droughts, and fewer rainy days significantly impact these plants. To assess the long-term effects on Taiwans alpine vegetation, we established dynamic plots on 15 high mountain summits, aiming to study these impacts and develop conservation strategies. Our study used three methodological scales. On a landscape level, we employed the Standardized Precipitation Evapotranspiration Index (SPEI), Temperature Anomaly Index (TA), and Enhanced Vegetation Index (EVI) to link moisture balance with vegetation changes. Community-scale analysis involved examining alpine plant communities using moist-philic and thermophilic indices, diversity indices, and principal component analysis. At the species level, we assessed changes through climatic ecological niches to understand species richness variations. Our third survey revealed negative SPEI and extreme TA values, suggesting drought and high-temperature impacts. These conditions led to reduced plant growth, a decrease in EVI, fewer species, reduced diversity, and shifts towards species suited to warmer, drier environments. This suggests significant effects on Taiwans alpine vegetation, decreasing its resilience to environmental disturbances. Considering ongoing climate change and its expected reduction in Taiwans precipitation, our findings underscore the urgent threat of drought to alpine ecosystems, even in typically moist areas like Taiwan. Given the high sensitivity of alpine vegetation to these changes, proactive and robust conservation measures are critical to protect these vital ecosystems.