The inventory of vascular plant of Green Island

Project Duration	2005-12-31 ~ 2006-12-30
Research Title	The inventory of vascular plant of Green Island
Contracted Organization	Taiwan Society for Biodiversity Conservation
Principal Investigators	Chen Tzu-Ying, Lu Ting-Hui
Project Personnel	Chiu Tsung-Yi, Lee Shu-Ming, Chen Chien-Chung, Hung Tsung-Tai, Wu Hsin-Ling, Sung Wu-Kuei, Cheng Tsung-Te
Keywords	Existing vegetation map, Detrended Correspondence Analysis (DCA), Canonical Correspondence Analysis (CCA), Two-way Indicator Species Analysis (TWINSPAN), vegetation type, secondary vegetation
Abstract	Green Island is located southeast of Taiwan. This study conducted a systematic vegetation survey, established geo-referenced sample plots, compiled species inventories, classified vegetation types, and produced a current vegetation map. A total of 155 sample plots were analyzed along with three environmental variables. Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) were applied to examine species distribution gradients, and vegetation communities were classified using results from Two-way Indicator Species Analysis (TWINSPAN). TWINSPAN classified Green Island vegetation into 15 types: A. Zoysia–Pemphis type B. Euphorbia–Ipomoea type C. Lysimachia–Ipomoea type D. Pandanus type E. Crinum–Scaevola type F. Hibiscus tiliaceus type G. Arundo–Clerodendrum type H. Fimbristylis–Zoysia type I. Coastal Pandanus type J. Litsea–Ardisia type K. Barringtonia–Schefflera type L. Dendrocnide–Pterospermum type M. Ficus type N. Casuarina type O. Emilia–Youngia type Survey results recorded 339 species of vascular plants on Green Island, including 31 rare or endemic species. Statistical tests indicated significant differences among vegetation types in relation to environmental variables such as elevation, distance from the sea, and slope aspect. Ordination results showed that the first gradient axis was dominant, with elevation, distance from the sea, and slope being key environmental factors influencing plant distribution patterns. Vegetation mapping divided Green Island into 13 land-use/land-cover categories, including seven natural vegetation types, one plantation forest type, and five other land-use types. Casuarina forests covered the largest area (449.15 ha). Primary and secondary forests together accounted for only 170.02 ha, representing 10.66% of the island’s total area. The study also examined rare plant species, landscaping vegetation, and vegetation succession patterns. These findings provide essential baseline data for vegetation management and ecological conservation planning on Green Island.