Vegetation Structure of Subalpine Ecosystem in Taiwan: A Case Study of Xue Mountain

• Main Authors: Min-Chun Liao, 廖敏君
• Other Authors: King-Cherng Lu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/31759761240448401654

博士 === 國立中興大學 === 森林學系所 === 104 === Subalpine ecosystems vegetation composition and structure are the accumilation of complex dynamic. The composition, structure and spatial pattern becoming one of the most important evidence of global climate change. This study investigated the subalpine ecosystems vegetation structure at Xue Mountain in Taiwan. i.e. Abies kawakamii forest type, A. kawakamii-Juniperus squamata treeline ecotone, J. squamata-Rhododendron pseudochrysanthum krummholz vegetation type, and alpine vegetation. Totally investigated 800 stems of A. kawakamii, tree density was 571 stem/ha. The associated trees species are Tsuga kawakamii, Juniperus squamata, Sorbus randiensis, and Rhododendron pseudochrysanthum. The diameter at breast height (DBH) classes of A. kawakamii at 7 sampling plots in different stands, can divided population structure distribution into 3 types: bell shaped curve, two-peak shaped curve and reverse-J-shaped curve. Synthesis all numbers of stem, the DBH class distribution belong to the reverse-J-shaped curve in the A. kawakamii forest type, and reflected the structure characteristic of mature forest at the post succession. Then according the results of the static life table, A. kawakamii seedlings have high ratio death rate. This survivor curve of A. kawakamii population is Deevey-III type at Xue Mountain. This can reflect A. kawakamii at the sapling and adult period had self-thinning caused by competition, then old age wood physiologically grow to death. Furthermore, based on the understory vegetation type, at the moss dominance type the seedlings numbers of A. kawakamii are highly than the Yushania niitakayamensis dominance type. It means the Bamboo dominates would impede A. kawakamii regeneration. Most of the trees at treeline ecotone at the subalpine region in Taiwan have different form. The study focused on the vegetation structure, spatial patterns and associations of the A. kawakamii-Juniperus squamata treeline ecotone. As result, along the altitude gradient increasing the numbers of erect trees had a decreasing trend and the numbers of krummholz are increasing. The spatial structures were also different from forest to krummholz ecotone. J. squamata-Rhododendron pseudochrysanthum krummholz vegetation type has high density per ha. DB class of J. squamata and R. pseudochrysanthum are the bell-shaped distribution. Furthermore these two kinds of species intraspecific competition and interspecific competition index are different. Most of the alpine vegetation plant life form at Xue Mountain Glacial Cirques are hemicryptophytes (65%) it means plant’s grow sprouts in soil, may be affected by winter snows, litter and soil protection.