本研究係以台灣海岸防風林樹種，木麻黃、瓊崖海棠、欖仁、水黃皮及黃槿等5種為研究材料，於現場進行實地根系挖掘，調查樹高、胸徑及其根系生長垂直深度與水平長度，並進行統計分析。結果顯示，5種樹種根系平均垂直深度為1.96±0.19 m，且分析發現瓊崖海棠根系垂直深度為2.3±0.2 m與其他樹種比較，具有顯著差異。5樹種根系平均水平長度為5.7±1.5 m，其中以欖仁7.81±2.23 m分布最廣；統計分析發現欖仁根系水平分布長度與其他樹種比較，具有顯著差異，五樹種根系深度與水平分布之迴歸分析結果，以欖仁Y=2.618+0.243X，R2=0.817 較具可信度。本研究結果可供給經營管理者做為往後海岸防風林經營參考之依據。
In this study, 5 tree species of coastal protective forests in Taiwan were selected as research material. They are Casuarina equisetifolia, Calophyllium inophyllum, Terminalia catappa, Pongamia pinnata, and Hibiscus tiliaceus. We dig root by using excavator, and investigate root's horizontal and vertical length of roots, The results are that the average root vertical depth is 1.96±0.19 m, and the species of Calophyllium inophyllum is the most depth distribution, which is 2.3±0.2 m, and significant differences with the other 4 species. The average root horizontal distribution is 5.7±1.5 m, and the species of Terminalia catappa is the most length in level distribution, which is 7.81±2.23 m, and significant differences with the other 4 tree species, Regression analysis of root depth and horizontal length showed that Y=2.618+0.243X(R2=0.817). This study could provide the root system information about the Coastal Protective forest in Taiwan, and assessed the condition of tree growth from the root information.
