綠島地景動態之研究

Landscape Dynamics of the Lutao Island of Taiwan

綠島因地理環境特殊使其具豐富的自然資源，惟經數十年的開墾與砍伐，原始林已遭到嚴重的破壞。本研究以綠島為研究區，整合航空照片材料、地理資訊系統與馬可夫模式，進行該區地景動態之探討。研究結果顯示，1979-1989年間，天然闊葉樹林的面積有明顯的增加，反觀木麻黃造林地面積有明顯的減少現象，由兩時期的轉移機率矩陣表可知，因森林生態系產生自然演替之現象，綠島原生植群有自然回復的趨勢。利用Markov模式預測未來地景動態之結果顯示，綠島之植群生態隨著長期間的演替，終將形成以天然闊葉樹林為主之植物社會，從地景穩定性指標分析結果顯示，於30-60年後，地景系統的演變情況應可形成穩定的現象。 The Lutao Island situated offshore from the southeast coast of Taiwan has unique naturalenvironments with abundance in natural resources, but its native forests was nearly devastated fewdecades ago. We used aerial photographs, geographic information systems (GIS), and Markov modelingtechnique to study the landscape dynamics of the island. The results indicated that during the periodbetween 1979 and 1989, the hardwood forests increased rapidly, while the Causuarina qutiferra forestsdecreased. The transition probability indices of these two types of the forests suggested that the forest ecosystem of the island has been in the process of a temporal succession toward the native hardwoodforests, and will be stabilized in 30 to 60 years later.