碩士 / 國立中興大學 / 生命科學系 / 93 / There were abundant greenbelts in the coastal zones of Miaoli County. Following long-term human and natural disturbances, the original coastal vegetations have been disappeared or gradually changed. We study the plant composition in Tonsiao and Houlong coastal areas by field inventory, and also use aerial photogrammetry technology to study the greenbelt changes during the past 30 years.
Totally 253 species of vascular plants belonging to 207 genera and 90 families were found in the coastal zones of Miaoli County. The rare species that need to be preserved include Dregea volubili, Ipomoea imperati, Vitex trifolia, Phoenix hanceana, Styrax matsumuraei, Eleochairs dulcis, Taraxacum formosanum, and Eulophia graminea. According to the matrix cluster analysis (MCA) of the results of plot investigations in the coastal area of Miaoli County, understory vegetation could be grouped into six types, including: Ⅰ. Miscanthus floridulus type；Ⅱ. Imperata cylindrica－Saccharum spontaneum type；Ⅲ. Panicum maximum type；Ⅳ. Panicum repens－Polygonum lapathifolium type；Ⅴ. Ipomoea cairica－Tetrastigma formosanum type；Ⅵ. Cyrtococcum patens type. The Ⅰ, Ⅱ and Ⅲ types are in burned areas.
Interpreting and comparing the aerial photos of 1977, 1993 and 2000 years, we found that fire and human disturbances have greatly changed coastal greenbelts during the past 30 years, especially Acacia forests. Twenty fires were recorded in the Coastal zones of Miaoli during September 2002 to April 2005. Fires were most frequent in the unusual drought year of 2003. Total burned area was about 747 hectares, mostly in grasslands and forest edge. Post-fire sprounting rate of Casuarina equisetifolia was the lowest, and that of Eucalyptus robusta was the highest. For the natural seeding following fire, Acacia confusa was the best. No natural seedings of Casuarina equisetifolia and Eucalyptus robusta have been found. Fire disturbances promoted some grass species such as Panicum maximum and Miscanthus floridulus that could naturally invade and colonize rapidly after burning. These grasslands are quite flammable to the next fires.
There is a marsh in Wanwa coast. It was naturally formed from abandoned farms. This wetland has become suitable habitat for diverse plant and animal species. In the drought January of 2004, the marsh was burned too, and the secondary succession was initiated. If there are no more disturbances for a long time, the succession tendency of this wetland would toward coastal forest. In order to preverve the precious diverse natural resources, it is suggested to set up Wanwa Coastal Preserve which includes wetland, sand dune, farm, coastal forest, Ruditapes variegatus Preserve Area, and Paishatuen Shell Fossil Reserve.
| Identifer | oai:union.ndltd.org:TW/093NCHU0105034 |
| Date | January 2005 |
| Creators | Yung-Wei Wang, 王勇為 |
| Contributors | Ming-Yih Chen, 陳明義 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 70 |
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