臺灣博碩士論文加值系統

本研究以營養鹽循環的觀點，研究竹圍紅樹林內之矮小水筆仔生長受限制的原因。研究項目除了利用野外施肥試驗，以了解N和P營養鹽與水筆仔生長之關係外，並分析植物組織，水文環境和土壤中營養鹽含量之季節性變化。施加N肥後，矮小水筆仔之植株高度，樹冠直徑，與新生枝條之數目與長度，與其他處理區比較下，均有顯著的增加。此外，葉片組織中之N與P含量亦顯著增加。此顯示，水筆仔的生長與N肥的供應有密切的關係。水文環境中之營養鹽含量分析結果顯示，上游河水中，由潮汐帶入紅樹林生育地的N與有機質，可能是水筆仔生長所需之N營養鹽之主要來源。而潮水淹蓋的頻率與時間長短不僅造成營養鹽供應的差異，亦間接影響土壤質地組成和其物理化學特性的不同。竹圍紅樹林區之矮小林生長地勢高度在平均高潮位之上，有別於潮溪林之位於平均高潮位之下。因此，潮水淹蓋頻率的差異可能是造成N營養鹽供應量不同之主要原因。此外，颱風過境造成植株的傷害，翻攪土壤之螃蟹種類的分布與活動程度的差異，亦可能是限制矮小水筆仔生長與N營養鹽供應不足的重要影響因子。

The effect of nutrients on the growth of dwarf Kandelia candel in the Chuwei mangrove swamp was studied. In addition to the field fertilization experiment, seasonal changes of nutrient content in leaf tissues, soil and water in the swamp were also examined in this study. Growth parameters, i.e., tree height, canopy diameter, number and length of young shoots, and the N and P content in leaf tissues were significantly increased in fertilization treatments containing nitrogen. No difference was found between phosphorus and control treatments. This indicates that nitrogen is the nutrient limiting factor for the growth of dwarf K. candel in the Chuwei mangrove swamp. According to the analyses of nutrients in the hydrological environment, inorganic nitrogen and organic matters in the inundation tide could be the main nitrogen sources for the swamp. Therefore, frequency and duration of tidal inundation not only affect the nitrogen supplement to the swamp, indirectly, also affect the texture composition and chemical properties in the soil. The elevation of the area where the dwarf forest grows in the Chuwei mangrove swamp is higher than the average height of high tide. This differs from the tidal creek forest whose height of growing area is lower than the average height of high tide. Therefore, the frequency discrepancy of tidal inundation is probably the reason of nutrient distribution causing difference in growth response between the dwarf and tidal creek forest. The damage caused by typhoon on plant, and the difference in burrowing activity of crabs between the dwarf and tidal creek areas could also be some important effects to limit the growth of K. candel and the deficiency of N in the dwarf forest area in the Chuwei mangrove swamp.