雪山翠池玉山圓柏林植物社會之研究

Study on Plant Community of Juniperus Morrisonicola Forest at Cuei-Chih Area in Mt. Shye

雪山翠池地區之玉山圓柏林為臺灣地區面積最大且最具代表性的玉山圓柏群落，本研究針對本區之玉山圓柏林進行植群生態調查，透過多樣區法之集落樣區設置法，調查該林分之群落組成物種及數量，並建立其族群結構。本研究區域內之維管束植物組成計有36科69屬85種（含種以下分類群）植物，蕨類商數為4.11；植物生活型方面以半地中植物最優勢計有48種（56.47%），依次為地中植物有20種（23.53%）、地表植物有11種（12.94%）及地上植物有6種（7.06%），無一年生種子植物。森林植群分析結果顯示：依上層林木之組成，可區分成玉山圓柏林型及臺灣冷杉林型2種優勢林型，林木徑級分布方面，玉山圓柏屬於波動型直徑分布，而臺灣冷杉屬呈反J型直徑分布。下層地被之矩陣群團分析與降趨對應分析結果相符，分別為玉山圓柏－玉山杜鵑型、曲芒髮草—臺灣冷杉型及玉山小蘗—高山珠蕨型等3個類型；典型對應分析之結果顯示，下層地被與海拔高之相關性較高，其次為坡度及水分梯度。 The most representative Juniperus morrisonicola community was at Cuei-Chih Area in Mt. Shye of Taiwan, where the vegetation can be distinguished into 2 categories by physiognomy as following arbor forest and krummholz. In this paper, the vegetation was surveyed via contagious quadrat method. A total of 85 species of vascular plants belonging to 36 families and 69 genera were recorded in our studied plots. Pteriodophyte-Quotient was 3.24. According to Raunkiarer`s life-form system, all the species were determined into five major life-forms that exhibited dominance of hemicryptophytes (56.47%) in this community, followed by cryptophtes (23.53%), chamaephytes (12.94%), and phanerophytes (7.06%). Therophyte species were not distributed in this studied site. Vegetation was classified by the matrix cluster analysis (MCA) where the results were similar to detrended correspondence analysis (DCA). The forest sampled plots were classified into 2 forest types: (1) Juniperus morrisonicola forest type and (2) Abies kawakamii forest type. The DBH class distribution of J. morrisonicola and A. kawakamii belonged to the rotated S-shape and reversed J-shape respectively. The understory vegetation can be divided into (1) Juniperus morrisonicola-Rhododendron pseudochrysanthum type, (2) Deschampsia flexuosa-Abies kawakamii type and (3) Berberis morrisonensis-Cryptogramma brunoniana type. There were significant correlations between axis of canonical correspondence analysis (CCA) and environmental factors. The most important environmental factor affecting understory vegetation distribution was altitude followed by slope and moisture gradient.

The most representative Juniperus morrisonicola community was at Cuei-Chih Area in Mt. Shye of Taiwan, where the vegetation can be distinguished into 2 categories by physiognomy as following arbor forest and krummholz. In this paper, the vegetation was surveyed via contagious quadrat method. A total of 85 species of vascular plants belonging to 36 families and 69 genera were recorded in our studied plots. Pteriodophyte-Quotient was 3.24. According to Raunkiarer`s life-form system, all the species were determined into five major life-forms that exhibited dominance of hemicryptophytes (56.47%) in this community, followed by cryptophtes (23.53%), chamaephytes (12.94%), and phanerophytes (7.06%). Therophyte species were not distributed in this studied site. Vegetation was classified by the matrix cluster analysis (MCA) where the results were similar to detrended correspondence analysis (DCA). The forest sampled plots were classified into 2 forest types: (1) Juniperus morrisonicola forest type and (2) Abies kawakamii forest type. The DBH class distribution of J. morrisonicola and A. kawakamii belonged to the rotated S-shape and reversed J-shape respectively. The understory vegetation can be divided into (1) Juniperus morrisonicola-Rhododendron pseudochrysanthum type, (2) Deschampsia flexuosa-Abies kawakamii type and (3) Berberis morrisonensis-Cryptogramma brunoniana type. There were significant correlations between axis of canonical correspondence analysis (CCA) and environmental factors. The most important environmental factor affecting understory vegetation distribution was altitude followed by slope and moisture gradient.