蓮華池研究中心臺灣杉人工林土壤種子庫組成與空間分布

本研究調查林業試驗所蓮華池研究中心32年生臺灣杉人工林土壤種子庫，分析物種組成與種子儲量、歸化物種、種子空間分布及其與地上植群相似性等。樣區為20 m×20 m，區分成16個次樣區，進行地被調查和臺灣杉林木相對位置量測，以及在次樣區交界點（25個）進行土壤種子庫採集。土壤種子庫發芽試驗結果，共44種種子植物，記錄1,691株幼苗，其中232株鑑定至屬，39株未鑑定即死亡；種子密度為3,006粒/m^2，以莎草科、菊科與禾本科的種數最多，種子儲量最豐富的物種為野牡丹、竹葉草與揚波。種子庫儲量組成以草本和灌木植物為主；歸化植物種子儲量佔比例不高，顯示歸化植物入侵尚不嚴重。野牡丹等8種種子儲量豐富的主要組成物種出現樣點頻度皆超過50%，其中野牡丹、揚波、昭和草的種子儲量空間樣點呈顯著均勻分布，弓果黍呈顯著聚集分布，其餘4種呈逢機分布；種子儲量空間分布特性可能受到種子散播方式影響，即以鳥類、風媒為主的植物多呈均勻分布，重力傳播為主者呈現聚集分布。種子庫與地上植群的相似性偏低，可能與森林經營（刈草、疏伐等）、植群歷史等因素綜合影響所致。透過調查蓮華池人工林種子庫，了解潛在植群組成和歸化植物的影響，期望可提供當地人工林演替及更新的參考。

關鍵字

臺灣杉；人工林；土壤種子庫；演替；歸化植物；空間分布

並列摘要

This research studied the soil seed bank in a 32-year-old Taiwania cryptomerioides (Taiwania) plantation in the Lianhuachi Research Center. The species composition, seed abundance, effect of naturalized species, seed spatial distribution and the similarity of the aboveground vegetation were analyzed. The sampling plot was 20 m × 20 m and was divided into 16 subplots. The relative position of each Taiwania tree was measured, and soil seed bank was collected at the borders of the subplots. In total, 1,691 seedlings were germinated, of which 232 were identified at the genus level, 39 were not identified due to death, and a total of 44 species were identified for the remaining seedlings. The Taiwania plantation had a seed density of 3,006/m^2. Cyperaceae, Compositae, and Gramineae were the most dominant families. The species with the largest seed abundance were Melastoma candidum, Oplismenus composites, and Buddleja asiatica. The life-form composition of the soil seed bank was dominated by herbs and shrubs, and the proportion of naturalized plants was not high, indicating that alien plant invasion was not severe. The highest eight species which occupied seed abundance dominate appeared in more than 50% of subplots. The seed distributions of M. candidum, Crassocephalum crepidioides, and B. asiatica were significantly uniform; Cyrtococcum patens exhibited a significantly clumped distribution, whereas the other four species showed random distribution patterns. The seed spatial distribution patterns was affected by seed dispersal methods; seeds dispersed mainly by birds and wind had a uniform distribution, whereas those dispersed by gravity exhibited a clumped distribution. The low-similarity composition between soil seed bank and aboveground vegetation was attributed to complex effects such as forest management (e.g., mowing and thinning) and vegetation history. The findings in this research further our understanding of the potential vegetation composition and the effects of naturalized plants, and provide information on local forest succession and regeneration.

並列關鍵字

naturalized plants ； plantation ； soil seed bank ； spatial distribution succession ； Taiwania cryptomerioides

國際替代計量

蓮華池研究中心臺灣杉人工林土壤種子庫組成與空間分布

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