植物的潛在分布與實際分布之比較— 以東亞及東南亞植物為例

Abstract

島嶼─海洋是東亞島弧及東南亞群島的主要地貌。此區過去的生物地理研究主要透過歷史來源解釋物種分布範圍，或透過物種名錄的比對劃分生物地理區域。本研究透過GBIF的出現紀錄和Worldclim的生物氣候圖層，以物種分布模型─Maxent模擬在此區域有不同分布情形植物科或屬的潛在分布與實際分布，釐清植物的分布的限制除了海洋外是否包含了氣候。結果發現多數東南亞的熱帶植物，包含: 橄欖科的六個屬、龍腦香科(Dipterocarpaceae)、金蓮木科(Ochnaeae)、豬籠草科(Nepenthaceae)和小盤木科(Pandaceae)，在緯度較高的東亞沒有潛在分布，然而馬來西亞區內分布於特定亞區的植物:橄欖科的馬蹄果屬(Protium)、Scutinanthe、Haplolobus、Triomma皆在區內的其它亞區有潛在分布。以上結果符合兩個假說:1.分布於東南亞的熱帶植物，分布受到氣候所限制，適合的棲地不包含緯度較高的東亞；代表在大空間尺度下，氣候是植物分布的重要限制因子。2.僅分布於單一或部分生物地理亞區的植物，在其它區域依然存在潛在棲地，但因為海洋的阻隔無法擴散過去；代表在小空間尺度下，物理屏障對於植物分布的影響大於氣候。本研究透過物種分布模型模擬適合棲地，探討生物地理的區域間及區域內兩種空間尺度中植物的分布是受到氣候或是海洋限制，為東亞及東南亞不同地區之間的植物群差異提供一個新的解釋。

Island-ocean is the main landform of the East Asian island arc and the Southeast Asian archipelago. Past biogeographic studies in this area mainly explained species distribution ranges through historical sources, or divided biogeographic regions through comparisons of species lists. This study uses the occurrence records of GBIF and the bioclimatic layer of Worldclim to simulate the potential and actual distribution of plant families or genera with different distribution situations in this area, and using the species distribution model, Maxent to clarify the distribution limits of plants. It was found that most of the tropical plants in Southeast Asia, including: six genera of the family Buseraceae, Dipterocarpaceae, Ochnaeae, Nepenthaceae and Pandaceae, is no potential habitat in higher latitude regions in East Asia. However, plants distributed in specific subregions in Malaysia: Protium, Scutinanthe, Haplolobus, and Triomma of the Burseraceae family all have potential distribution in other subregions. The above results are consistent with two hypotheses:1. The distribution of tropical plants distributed in Southeast Asia is restricted by climate, and their suitable habitats do not include East Asia with higher latitudes；This means that climate is an important limiting factor for plant distribution at large spatial scales.2. Plants that are only distributed in a single or part of a biogeographic subregion still have potential habitats in other areas, but cannot spread because of the barriers of the ocean； This means that at small spatial scales, physical barriers have a greater impact on plant distribution than climate. This study uses a species distribution model to simulate suitable habitats and explores whether the distribution of plants at the inter-regional and intra-regional biogeographic spatial scales is restricted by climate or ocean, providing insights into the differences in flora between different regions in East Asia and Southeast Asia a new explanation.