評估氣候變遷對臺灣外來入侵植物侵略性的影響

Assessment of the Effects of Climate Change on the Invasiveness of Invasive Alien Plant in Taiwan

有效掌握氣候變遷對外來入侵植物侵略性的影響，將有助於入侵防治措施的擬定及防治 優先性的規劃。本研究將氣候變遷資料納入最大熵模式（MaxEnt），建立49種入侵植物空間侵 略性評估指標，評估當前與未來氣候變遷情境下（RCP8.5, 2060~2080）下，入侵植物族群建立 與擴散潛勢。此外，藉由入侵植物侵略性的量化與分級，確認當前與未來需要加強防範的關 鍵物種。研究結果顯示，溫度是改變入侵植物生態棲位的主要驅動因子，未來氣候可能導致多數物種之棲地適宜性、適宜棲地面積及最適棲地面積將所有提升，同時縮減已知族群與最適棲地間的距離，但仍有部份物種因無法適應氣候改變，致使侵略性下降。侵略性分級結果顯示，當前有10種入侵植物屬非高侵略性，但未來可能轉為高侵略性，有必要著手進行該些物種對生態環境或農業生產力的影響評估。總結而言，本研究的架構下可瞭解氣候變遷對臺灣入侵植物侵略性的影響，過程所建立之侵略性指標，亦可提供未來入侵防治策略制定之參考。

An effective understanding of the influence of climate change on the invasiveness of invasive alien plant species will contribute to the formulation and priority planning of control measures. In this study, climate change conditions were incorporated into a maximum entropy model to build a spatial invasiveness evaluation index for 49 invasive plant species. This index was used to assess the potential for population establishment and diffusion of invasive plant species under present day and future climate change conditions (RCP 8.5, 2060-2080). Furthermore, key invasive plants species that require reinforced precaution today and in the future were verified through quantifying and classifying their invasiveness. The results of this study indicated that temperature is a major driving factor in ecological niche for invasive plant species. Future climates may lead to habitat suitability for most species and increase the area size of suitable habitats and optimal habitats, while simultaneously reducing the distance between known populations and their optimal habitats. However, some species may be unable to adapt to climate change, thereby reducing their invasiveness. This study's classification of invasiveness indicated that 10 species of invasive plants, although not highly invasive at present, may become highly invasive in the future, and thus their effects on ecological habitats or agriculture production must be assessed. In summary, the influence of climate change on the invasiveness of invasive plants in Taiwan can be understood under the framework of this study, and the invasiveness index can serve as a reference when drafting future preventive strategies against invasive species.