台灣中西部氣候區楠櫧林帶植群分類系統之研究

Vegetation Classification System of the Machilus- Castanopsis Zone in the Central-West Climatic Region of Taiwan

本研究針對台灣中西部氣候區海拔500-1,500m之楠櫧林帶，蒐集有關植群分析之文獻及新調查的樣區，將有定量紀錄之樣區資料進行整合，共314種木本植物進入分析，利用雙向指標種分析法，再參考群團分析之相似性水準，依據歐陸學派列表比較法之原則，將樣區與物種進行排序上的調整，製成植群分化表。本研究仿照美國自然植群分類系統，採用形相來區分高階單位－－群系，並根據歐陸學派之植相社會學研究法，以植相區分低階單位－－群團及群叢，共區分出大冇榕、台灣雅楠、油葉石櫟、火燒柯、奧氏虎皮楠、鬼石櫟、台灣杜鵑、山黃麻、櫸、野核桃、阿里山千金榆、栓皮櫟、台灣赤楊及台灣二葉松等14個群團，以下計分出31群叢。 Sample stands from the Machilus-Castanopsis forest zone in the central-west climatic region ofTaiwan were collected for the synthesis of a regional vegetation classification system. The upper level of the classification hierarchy is delimited by the physiognomy of forests, following the treatment of theUS National Vegetation Classification (USNVC) System. The lower two levels of the hierarchy, allianceand association, were based on floristic composition according to the concept of diagnostic species andfloristic-sociological classification of the Braun-Blanquet approach. The original data were subjected tocluster analysis and two-way indicator species analysis (TWINSPAN) for grouping the stands intocomposite samples and summarization of species abundance. The matrix of the composite samples wasre-arranged by the tabular comparison method for developing a hierarchy of the forest vegetation system.The resultant system consisted of 3 formations and 14 alliances, characterized respectively by Ficusseptica, Phoebe formosana, Pasania konishii, Castanopsis fargesii, Daphniphyllum glaucescens subsp.oldhamii, Lithocarpus lepidocarpus, Rhododendron formosanum, Trema orientalis, Zelkova serrata,Juglans cathayensis, Carpinus kawakamii, Quercus variabilis, Alnus formosana, and Pinus taiwanensis.A total of 31 associations were proposed under the alliances.