墾丁國家公園銀合歡植群之光譜反射特徵研究

Spectrum Reflectance of an Exotic Plant Leucaena leucocephala (Lam.) De Wit in the Kenting National Park

銀合歡（Leucaena leucocephala（Lam.）de Wit）自引進台灣後，由於生長優勢，逐漸影響本土植群，危害本土生態環境。本研究主要以墾丁國家公園內銀合歡植群為研究對象，於2005年3月至12月間，以GER 1500手持光譜儀，進行銀合歡植群與其伴生樹種問之光譜反射特徵的量測，並進行差異性比較；另以雙光譜分析法，進行銀合歡植群光譜反射特徵之季節性變化研究。研究結果得知，銀合歡與其伴生樹種間（相思樹、血桐、木麻黃、構樹）之反射光譜有顯著性差異；在銀合歡雙光譜分析結果得知，季節變化對於光譜反射特徵曲線形態影響不大，但是不同生長季節的光譜反射特徵有顯著性差異，秋季及冬季是區分銀合歡與其他伴生樹種最佳之季節，研究結果可供銀合歡入侵之衛星影像監測研究參考。 Leucaena leucocephala (Lam.) de Wit is an exotic plant that has caused devastating damages on native plants in Taiwan. Using the GER 1500 spectroradiometer, we measured the spectrum reflectance of the species and its adsorbing plants, Broussonetia papyrifera (L.) L'Heritex Vent., Macaranga tanarius (L.) Müll. Arg., Acacia confusa Merr. and Casuarina equisetifolia Forst. in the Kenting National Park, March to December, 2005. The spectrum reflectance was examined with the bi-spectral analysis. The results showed that there were significant seasonal differences in the spectrum reflectance but not in the spectrum patterns between L. leucocephala and its adsorbing plants. The fall and winter, the growth seasons of L. leucocephala, were the best time of the year for the distinction. Accordingly, the spectrum reflectance is suggested as a guideline for monitoring the invasion of L. leucocephala in the satellite remote sensing program.