2007-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/675447摘要：臺灣全島人工林造林地面積達四十二萬公頃，以往基於經濟林經營的觀點，人工林採取密植的方式，且林相單純化，故人工林生態系的生物多樣性遠甚於天然林。甚至人工林冠層鬱閉度高、地被植物覆蓋度不佳，對林地的微環境造成不利的影響。現今林業永續經營政策已由早期的木材生產，轉變為國土保安、生態保育、以及維護生物多樣性，因此，如何有效經營人工林，改善林地微環境，復育生態系等，乃當前的重要課題之一。 人工林疏伐作業，為促進林分生長、改善林地微環境、維護生物多樣性等森林撫育作業的方式。以往，人工林疏伐作業大都是以考慮促進林分生長為主，國內並進行相當多的疏伐影響林分生長、地被植物的相關研究。然而，疏伐作業對樹冠層產生疏開作用，增加林內穿落雨量，以及對林地產生不同程度的干擾等，對林地的土壤水、逕流、土壤沖蝕等微環境條件，產生不同程度影響的研究極為缺乏。 本研究為探討不同疏伐強度對森林微環境的影響，選擇林務局南投林區管理處巒大事業區74、75、76林班柳杉人工林試驗地，依照0%、25%、50%之三種不同疏伐強度處理，配置四個重複，共建立12個1公頃疏伐試驗區，每一個疏伐試驗區分別設置一組自記式觀測儀器，蒐集溫、濕度、可見光輻射量、不同深度的土溫以及土壤水分變化的資料。並且，依照坡度、坡向、樹冠層鬱閉度等條件，對於三種不同疏伐強度試驗區，分別於選擇的一個試驗區域內，設置長10 m、寬5 m的小試區，供蒐集不同疏伐強度試區之土壤水、逕流、土壤沖蝕等觀測資料，分析降雨時不同疏伐強度對土壤水、逕流、土壤沖蝕的影響程度。研究成果作為將來在實施人工林疏伐作業的決策依據。 <br> Abstract: There are about 420 thousand hectares of tree plantations in Taiwan. Because of economical management concept in the past, tree plantations was almost high density stand constituted by single species, so the biodiversity of tree plantations is worse than natural forest. Also, the ground vegetation coverage is worse that is of no advantage to forest microenvironment. In now, forest policy about forest sustainable management change from wood supply in the past to environmental protection, ecological conservation, and biodiversity maintenance. How to effectively manage tree plantations ecosystem is important issue. Thinning is tree plantations intermediate operation method that could promote forest stand growth, improve forest microenvironment, and increase biodiversity of forest ecosystem. Traditionally, object of thinning operation is to mainly promote stand growth. Much related research about promoting stand growth and ground vegetation by thinning operation was executed. Nevertheless, seldom related research about tree plantations thinning operation, open forest canopy and disturb land surface could introduce throughfall impacting land surface, which increase soil water content, surface runoff, and soil erosion in Taiwan. Different thinning intensity of tree plantations influence forest microenvironment would be investigated in this study. Japanese Cedar (Cryptomeria japonica) stand located in Nantou Forest District Offices, Taiwan Forestry Bureau was selected. Twelve experimental plots, each plot is 1 hectare, are planed by three thinning intensity, 0%, 25%, and 50%, with four replication individually. Observational equipment was set in each plot that to investigate relative humidity, air temperature, soil temperature and soil water content. Also, small plot with length 10 m and width 5 m was set in different thinning intensity plot considering similar topographic condition in order to investigate soil water condition, surface runoff, and soil erosion when rainfall occurred. According to the research results, different thinning intensity operation of tree plantations affect forest microenvironment could be understandable, and we could suggest the method and criterion of thinning operation.人工林疏伐土壤水土壤沖蝕soil watersoil erosionthinningtree plantations.