合歡溪流域植群分類與製圖

Vegetation Classification and Mapping of Hehuanshi Watershed

合歡溪發源於合歡主峰（3417m），流域面積8396ha，存有大面積的天然植群，然而有濫墾壓力，且外來植物入侵日益嚴重。本研究於合歡溪流域設置72個400平方公尺樣區，記錄樣區內出現物種、上木胸高直徑、非上木覆蓋度及環境因子。流域內共記錄維管束植物850種，含括37種稀有種，以及56種外來入侵種。植群分類採用階層式群集分析（hierarchical cluster analysis）及降趨對應分析（detrended correspondence analysis, DCA），共分類植群型為11個群團（alliance），命名為：I.臺灣二葉松群團、II.小葉鐵仔－臺灣黃杉群團、III.化香樹－栓皮櫟群團、IV.二齒香科科－霧社木薑子群團、V.細枝柃木－狹葉櫟群團、VI.臺灣鐵杉群團、VII.臺灣雲杉群團、VIII.臺灣冷杉群團、IX.蕨－芒群團、X.玉山石松－玉山箭竹群團、香青群團。將DCA各軸與環境因子進行相關性檢定，得知海拔高度為影響植群分布最主要的環境因子。依樣區及調繪點資訊繪製植群圖，原生闊葉樹林主要分布於合歡溪東岸，為保育生物多樣性，應嚴禁濫墾、盜採及放火。 The Hehuanshi watershed originates in Mt. Hehuan (3417 m). The total area of watershed is 8396 ha. The steep mountains preserve large natural vegetation, but some has been illegally reclaimed. In this study, 72 plots, 400 m^2 each, were sampled. The number of plant species, the diameter at breast height (DBH), the coverage of understory, and environment factors of each plot were measured and recorded. Totally 850 taxa of vascular plants were recorded, including 37 rare species, and 56 invasive alien species. Vegetation data were adopted with hierarchical cluster analysis and detrended correspondence analysis (DCA) to classify the vegetation type. The vegetation types were classified into 11 alliances: I. Pinus taiwanensis ALL., II. Myrsine Africana-Pseudotsuga wilsoniana ALL., III. Platycarya strobilacea-Quercus variabilis ALL., IV. Teucrium bidentatum-Litsea elongata var. mushaensis ALL., V. Eurya loquaiana-Cyclobalanopsis stenophylloides ALL., VI. Tsuga chinensis var. formosana ALL., VII. Picea morrisonicola ALL., VIII. Abies kawakamii ALL., IX. Pteridium aquilinum subsp. latiusculum-Miscanthus sinensis ALL., X. Lycopodium veitchii-Yushania niitakayamensis ALL., and . Juniperus squamata ALL. The correlation between axes of DCA and environment factors were determined. The most important environment factor affecting vegetation distribution is altitude. The vegetation map was established based on vegetation types. Natural broad-leaved forests distribute mainly on the east side of the Hehuanshi Stream. All illegal cutting, farming, and fire setting should be strictly prohibited for biodiversity conservation

The Hehuanshi watershed originates in Mt. Hehuan (3417 m). The total area of watershed is 8396 ha. The steep mountains preserve large natural vegetation, but some has been illegally reclaimed. In this study, 72 plots, 400 m^2 each, were sampled. The number of plant species, the diameter at breast height (DBH), the coverage of understory, and environment factors of each plot were measured and recorded. Totally 850 taxa of vascular plants were recorded, including 37 rare species, and 56 invasive alien species. Vegetation data were adopted with hierarchical cluster analysis and detrended correspondence analysis (DCA) to classify the vegetation type. The vegetation types were classified into 11 alliances: I. Pinus taiwanensis ALL., II. Myrsine Africana-Pseudotsuga wilsoniana ALL., III. Platycarya strobilacea-Quercus variabilis ALL., IV. Teucrium bidentatum-Litsea elongata var. mushaensis ALL., V. Eurya loquaiana-Cyclobalanopsis stenophylloides ALL., VI. Tsuga chinensis var. formosana ALL., VII. Picea morrisonicola ALL., VIII. Abies kawakamii ALL., IX. Pteridium aquilinum subsp. latiusculum-Miscanthus sinensis ALL., X. Lycopodium veitchii-Yushania niitakayamensis ALL., and . Juniperus squamata ALL. The correlation between axes of DCA and environment factors were determined. The most important environment factor affecting vegetation distribution is altitude. The vegetation map was established based on vegetation types. Natural broad-leaved forests distribute mainly on the east side of the Hehuanshi Stream. All illegal cutting, farming, and fire setting should be strictly prohibited for biodiversity conservation