台灣粗榧分布之調查研究

Distribution of the Taiwan Plumyew (Cephalotaxus wilsoniana Hayata)

本研究調查台灣粗榧（Cephalotaxus wilsoniana Hayata）在台灣分布現況、族群數量、分布特性及其目前面臨之生存壓力。從蒐集之文獻資料整理得知，台灣粗榧分布紀錄之地點包括大元山等47處。檢視標本採集紀錄地點有太平山等62處。經參酌上述地點及另行實地調查，得知目前台灣粗榧在本省之實際分布地點至少有包括礁溪等57處，其中28處為新分布紀錄。台灣粗榧分布於本島宜蘭等12縣行政轄區的森林中，海拔分布範圍從650至2,800m，主要生育地則集中在海拔1,800至2,300m之間。除14處呈較大族群外，大多為低於20棵的少數散生分布。野外調查得雄雌性植株比例為1：1.35極為接近，應不致構成繁殖障礙。惟「能繁殖之成熟個體數」僅佔13.5％，應予重視。另台灣粗榧除因生育地環境迭遭破壞影響其生存外，亦正面臨被濫採盜伐、園藝栽培、林相變更及其他破壞或開發威脅生存的危機。目前保育評估其保護等級則列屬「瀕臨絕滅」，應積極保護其生育地以維繫其生機。 Taiwan plumyew (Cephalotaxan wilsoniana Hayata) is an endemic and threatened species,belonging to the family Cephalotaxaceae. It is the only species of the family represented inTaiwan. It is widely distributed but locally scarce. In this study, a total of 57 populations but only1,035 individuals were recorded throughout its range in Ilan, Taoyuan, Hsinchu, Miaoli,Taichung, Nantou, Chiayi, Kaohsiung, Pingtung and Hualien prefectures at the elevations of 650~2,400m. The Taiwan plumyew is a shade tolerant tree, and usually found beneath the canopyof large trees in both broad-leaved and coniferous forests. According to the criteria of the 1994IUCN Red List Categories and the present status of wide distribution but extremely smallpopulation sizes, the Taiwan plumyew should be accommodated within the endangered (EN)category for protection.