全球山區氣候變異度及其對生物分布範圍影響

Climatic Variability in Global Mountain Areas and Its Impacts on Species Range Size

謝婷竹(Ting-Chu Hsieh)

指導教授 ： 沈聖峰

共同指導教授 ： 羅敏輝(Min-Hui Lo)

國立臺灣大學/理學院/氣候變遷與永續發展國際學位學程/碩士(2018年)

https://doi.org/10.6342/NTU201802437

摘要

近年關於氣候變遷的相關討論由大氣領域，逐漸擴展至公共衛生、農業與生態等相關學門，其中，氣候變遷對生物分布範圍（species range size）變化之潛在影響，是生態領域的新興議題之一。氣候變異假說（climatic variability hypothesis）即描述環境因子如何影響物種分布：氣候變異度大的區域，較適合溫度容忍範圍（thermal tolerance）與生物分布範圍廣的物種生存。Stevens以此假說解釋生物分布範圍隨緯度或海拔增加而變廣之現象，即Rapoport’s rule，但過去以來，關於Rapoport’s rule的相關研究結果仍有爭議，可能與缺乏實際分析日溫差與年溫差等氣候變異度沿海拔變化相關。因此本文希望透過了解全球網格資料的山區日溫差與年溫差變化，以及各別山系的日溫差與年溫差對生物分布範圍之影響，以氣候變異度假說解釋山區生物分布範圍變化。全球日溫差、年溫差與降水等網格資料來自Climatic Research Unit (CRU) TS3.10.01資料庫的1901-2000年間資料，海拔網格資料取自Digital Elevation Model (DEM)，距海遠近資料取自National Aeronautics and Space Administration (NASA)，並使用「影響面積」考量地表向上長波輻射對地表溫度之影響。所有資料按Natural Earth所定義的山系範圍，選取全球共182座山系，生物分布範圍資料取自相關發表文獻，透過R以單因子與多因子簡單線性模式，以及混和效果模式（mixed- effect model）分析。全球網格資料結果顯示，海拔對部分山區的日溫差或年溫差沒有顯著影響，但有顯著影響的山系，多座落於中高緯度與較內陸地區，各別山系結果僅部份支持氣候變異度假說，但辨別海拔對山區日溫差與年溫差影響顯著與否，以及區分不同海拔段分析仍有助於討論日溫差與年溫差對生物分布範圍影響，此外，本文最後也提出鑑別海拔是否影響山區日溫差與年溫差之參考標準。上述結果除作為探討氣候變異度對山區生物分布範圍影響之背景知識外，也能用於評估未來全球暖化將對山區生物產生哪些衝擊，以及應用於人體健康與農業等其他領域。

關鍵字

日溫差 ； 年溫差 ； 氣候變異度假說 ； 生物分布範圍

並列摘要

Climatic variability hypothesis, which predicts the correlation between range sizes of species and the variation of climatic parameters experienced by these species, is used to explain Rapoport’s rule, an increase of elevational range size with higher elevations. However, the generality of the rule has been challenged and evidence towards explanatory mechanisms has been equivocal. The aims of our study are to analyze the pattern of diurnal and seasonal temperature range (DTR and STR) in global mountains and investigate its’ relationship to species range sizes. The meteorological data for mountain DTR were extracted from the Climatic Research Unit (CRU) TS3.10.01 dataset, and the geographical data for elevation and distance to coast were obtained from Digital Elevation Model (DEM) and National Aeronautics and Space Administration (NASA), respectively. All the information of mountain ranges is from the website, Natural Earth. Simple linear regression and mixed-effect model in R program was used to examine on mountain climatic variability and its related factors. Besides, we also tested for relationships between mountain climatic variability and species range sizes across 31 mountains worldwide. Our results indicated that the trends of DTR and STR in some global mountains were weakly influenced by elevation, yet the other mountains, which mostly located at inland or higher latitudes, were significantly affected by elevation. Although only a few results suggested a positive relationship between mountain climatic variability and species range sizes, we found that sorting species range sizes by elevation and investigating the trend of local climatic variability can enhance our ability to understand the distribution of biodiversity.

並列關鍵字

diurnal temperature range ； seasonal temperature range ； climatic variability hypothesis ； species range size

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