台灣地區氣溫差異與主要林植物分布之探討－ 以檜木、烏心石、九芎為例

Abstract

溫度對林木的影響是連續的，透過溫量指數的分析可幫助了解氣溫與森林分佈的關係，本文旨在探討緯度與海拔因素造成台灣氣溫的變異，經由研究結果求得許多植群與氣溫變化相互支持的證據。為避免大範圍的推估而忽略區域性的特色，本研究以淡水河流域、濁水溪流域及高屏溪流域為基礎將台灣區分為北中南三區。月均溫分析結果顯示，緯度因子在中海拔地區對於氣溫變化的影響最大，海拔因子則在台灣中部與南部最具影響力；溫度垂直遞減率在中部最緩（海拔每上升100公尺，溫量指數下降5.7度），在北部與南部的陡降率最高（約6.7度），使得相同樹種（檜木、烏心石、九芎）於北中南分布卻有不同海拔範圍，尤其在北部地區的變異程度高於中南部，推測東北季風的影響不容忽視；根據大山塊加熱效應，陸塊面積大小（山地面積）亦造成區域的溫度變化。所以建議未來在台灣溫量指數模式或其他生態分區的建立上，自變數除了海拔高與緯度以外，尚可將山地面積與東北季風的效應納入考量，以期更符合台灣植群帶分布的現況。

This study was to analyse the relationship between temperature (warmth index) and flora distribution in Taiwan. Based on basins of Tamsui Rirver, Jhoushuei River, and Gaoping River, we divided Taiwan into Northern, Center, and Southern areas, in order to distinguish regional featurs. Through the analysis of monthly average temperature, the results suggested that the region of middle elevation was effected most by the latitude factor. Center and Southern areas were influenced under the altitude factor. The variability in Northern area was the greast, and this might attribute to northeastern monsoon. According to the ‘messenerhebung’, the superficial measurements made fluctuations of temperature. To sum up, there were four independent variables as forcasting warmth indexes in Taiwan: latitude, altitude, northeastern monsoon, and mountain areas.