Impact of Land-use Change on Distribution of Invasive Leucaena leucocephala in Kenting National Park, Taiwan

Land-use plays an important role in causing landscape and ecosystem changes. This impact alters abiotic conditions and species composition which increases the opportunities for species invasion and threatens biodiversity. I studied the land-use and land-cover change over the past 30 years to test the hypothesis that previous land-use has strongly influence on the invasion of Leucaena leucocephala in Kenting National Park, southern Taiwan. Using remote sensing and GIS datasets, I generated distribution maps of Leucaena in 1976, 1986, 1996, and 2007, sisal plantation in 1976, road-effect factors, land management types, and topographic factors. Data were analyzed by discriminant function analysis (DFA). The distribution maps from 1976 to 2007 suggested that Leucaena widespreaded in the western part of Kenting National Park and the invaded area increased exponentially. Previous sisal plantation and disturbance due to road development were strongly correlated with current Leucaena occurrence. The whole-region DFA model had 72.2% classification accuracy (Wilks’s λ=0.52, df=9, p<0.001). The eastern-region DFA model performed better than the western-region or the whole-region ones. Previous sisal plantation, proximity to roads, land management types, and elevation were the major factors in determining the distribution of Leucaena. This study supports the hypothesis that previous land-use has strong influence on the distribution of invasive species.