以植物功能性狀評估氣候變遷對高山植群造成之影響 — 以大水窟山及雪山山域為例

Abstract

氣候變遷導致高山地區升溫及極端乾旱事件增加，對高山生態系統造成植群生產力下降及特有物種減少等負面影響。高山植物因應逆境演化出如葉片增厚、具毛葉表及發達地下根莖等功能性狀。本研究假設，隨乾旱逆境加劇，具降低水分散失及地下存活策略的物種在高山植群中將增加。 本研究分析2008至2024年間臺灣大水窟與雪山區域的監測樣區之植群資料，探討氣候變遷對高山植群組成結構的改變的影響。此外透過文獻建構臺灣高山植物功能性狀資料庫結合植物分布、氣候區位和4次調查的物種豐度數據，使用典型對應分析並建立植物抗性評分系統以評估氣候變遷對於高山植群功能群之影響。結果顯示兩個區域均經歷顯著升溫 (每年0.042－0.066°C)及2019年後的持續水分不足。草本植物可分為4個功能群，木本植物分為2群，對乾旱的反應各異。葉緣反捲、葉質和葉表毛狀體等功能性狀與年均溫、年降水量、季節降水標準差等特定氣候因子存在相關性。研究證實具有耐旱及耐熱功能性狀的物種在面對乾旱時豐度波動較小，而生長在低溫區位的木本物種，如玉山杜鵑 (Rhododendron pseudochrysanthum)則大量枯死。本研究顯示植物功能性狀是預測高山植群對氣候變遷反應的有效指標，強調以功能群為單位反映植群結構動態的重要性，可為高山生態系保育提供科學依據。

Climate change has led to rising temperatures and increased extreme drought events in alpine regions, resulting in negative impacts such as reduced plant productivity and a decline in endemic species. Alpine plants have evolved functional traits to cope with harsh conditions, such as thicker leaves, hairy leaf surfaces, and well-developed underground rhizomes. This study hypothesizes that as drought stress intensifies, species with traits that reduce water loss and enhance underground survival will become more prevalent in alpine plant communities. This research analyzes vegetation data from monitoring plots in the Dashueiku and Hsuehshan regions of Taiwan, collected between 2008 and 2024, to investigate the effects of climate change on the composition and structure of alpine plant communities. In addition, a database of functional traits of Taiwan’s alpine plants was constructed through literature review, and combined with data on plant distributions, climatic niches, and species abundance from four surveys. Canonical correspondence analysis and a plant resistance scoring system were used to assess the impact of climate change on functional groups within alpine plant communities. The results indicate that both regions have experienced significant warming (0.042—0.066°C per year) and persistent water deficits since 2019. Herbaceous plants were classified into four functional groups and woody plants into two, each responding differently to drought. Traits such as leaf margin curling, leaf texture, and leaf pubescence were found to correlate with specific climatic factors, including mean annual temperature, annual precipitation, and the standard deviation of seasonal precipitation. The study confirms that species with drought- and heat-resistant traits exhibited less fluctuation in abundance during drought events, while woody species occupying colder niches (e.g., Rhododendron pseudochrysanthum) experienced significant dieback. This research demonstrates that plant functional traits are effective indicators for predicting alpine plant community responses to climate change, and highlights the importance of using functional groups to reflect vegetation dynamics. The findings provide a scientific basis for the conservation of alpine ecosystems.