Studies on the distribution og stream-edge plants in the middle amd downstream area of Tachiashi

• Main Authors: Liao, Pei-Chih, 廖培智
• Other Authors: Jinn-Lai Tsai
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/09511645030344206757

碩士 === 國立中興大學 === 植物學系 === 86 === Tachiashi is one of the principal rivers in center Taiwan. It originates in Hsueshan and Nanhutashan of Central Mountains of Taiwan, and it flows into Taiwan Strait passing over 124 km. The plants of riparian vegetation are growing on the sides of both riversides and riverbed. Their growth are influenced by the periodic flood. Those sites are eroded by river water in the rainy season and are arid in the droughty season.Therefore, the diversity of those plants are dependent upon their environmental conditions. The riparian plants are tolerant toward wateriness and drought. The composition of riparian vegetation and the distribution of riversideplants in the middle and downstream areas of Tachiashi were investigated by employing the line- transect sampling method at the fifteen plotted sites. The vegetation distribution may be divided into two types : (1) downstream- area vegetation and (2) middle-area vegetation. The former is characterized by its higher richness in plant diversity and having some dominant species : Saccharum spontaneum , Pennisetum purpureum , Rhynchelytrum repens , Bidens pliosa and Brachiaria mutica ; the latter lower richness and having various vegetation composition in the different plots. According to the growing locations , riparian vegetation can be categorized into three types of distribution patterns. (1) Watercourse-tolerant distribution pattern , e.g. Saccharum spontaneum which is a perennial herbaceous plant growing near the river and propagating by its subterranean stems. (2) Widespread distribution pattern, e.g. Bidens pilosa ,propagating by its seeds and widely distributing in riparian area by means of the highly germinating rate of seeds dispersed by animals or wind . (3) Specialized distribution pattern , e.g. Arundo donax var. coleotricha and Miscanthus floridulus , appearing in the special sites where probably have a proper disseminating environment.