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99年度紅樹林清除面積5公頃，鏟除胸徑(DBH)3公分以上水筆仔植株約3,123棵，海茄冬植株15,656棵，合計18,779棵。小型水筆仔植株5,039棵，小型海茄冬22,327棵。總計水筆仔8,162棵，海茄冬37,983棵。96年至98年清除後續維護剷除水筆仔小苗3,535棵、海茄苳10,145棵總計13680棵。 各年度清除區當下的環境因素均與紅樹林覆蓋對照樣區之間有顯著的差異，紅樹林對照樣區底質有較高的底藻生產力及有機碳含量。各區之底質表面的粒徑受空間因素影響明顯，99年清除區期末紅樹林清除之後的區域，泥灘的表面結構出現較粗顆粒的沙，底質中的有機碳含量已經緩慢下降。 紅樹林對照樣區的底棲生物群聚多樣性顯著低於其它樣區。相對於紅樹林覆蓋區，94年至98年的清除區已經足以說明紅樹林清除後能顯著增加底棲生物群聚多樣性。蟹類調查結果顯示紅樹林清除後蟹類群聚從弧邊招潮及台灣厚蟹的幼蟹為優勢的聚集轉變為清白招蟹、弧邊招潮蟹及萬歲大眼蟹為優勢的聚集，96年清除區已經成就一塊新的台灣著潮蟹棲地，97年及98年清除區的台灣招潮蟹復育區目前成效有限，台灣招潮蟹的密度增加緩慢，99年清除區內現存一塊約0.5公頃的台灣招潮蟹密集區，清除之後預期潮水淹蓋的狀態及高程的改變將逐漸增加其棲地面積。 5 hectars of mangrove forest was cutted away in 2010, we eliminated 3,123 individuals of Kandelia obovata Sheue, Liu & Yong, and 15,656 individuals of Avicenia marina (Forsk.) Vierh, all the individuals with DBH (diameter at breast height) over 3 cm. Furthermore, 5,039 and 22,327 young shoot of K. obovata and A. marina were also eliminated, total of 8,162 individuals of K. obovata and 37,983 individuals of A. marina . The other deforestation area in 2007, 2008 and 2009; 3,535 and 10,145 young shoot of K. obovata and A. marina were also eliminated. I n this study, between each deforestation area and the study site still cover by dense mangrove forest, their enviromental factors differed significantly. The forest cover site had higher primary production and more organic carbon content. The particle size distribution in different area with strong spital effects. After forest cutted away in the early of 2010, mud flat of this area had more larger particles in the end of season, and with less organic carbon in the substrate. Forest cover site, the biodiversity of benthic community was significent lower than other site. Relative to forest cover site, deforestation can increase the benthic community diversity is undoubtedly in this study. Under mangrove forest the dominate crab species were Uca arcuata and young Helice formosensis, after forest was cutted away, the dominate species became Uca arcuata, Uca lactea and Macrophthalmus banzai. We found a new habitat of Uca formosensis in this year, which was locatd near the deforestation area in 2007. In the restoration sites near the deforestation area in 2008 and 2009, the population of U. formosensis still very low and increased slowly. Near the 2010 deforestation area, about 0.5 hectar of habita with high density of U. formosensis, which area will become more widely after now, follow by the changing of tidal movement and the elevation of mud flat. |
