2007-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/698997摘要：次生林對生物多樣性保育的貢獻一般認為比人工林大，但是這樣的觀念卻少有嚴謹的研究進行測試驗證。在相關研究中，人工林大多是集約經營的混農林地，或者是人工林栽植時間低於相比較的次生林演替時間，這時直接比較生物多樣性容易有所偏差。政府在追求水土保持及生物多樣性保育之目標下，已宣示台灣高海拔山區&#63847;再進&#64008;人工造&#63988;，轉而提倡森林自然演替，原有人工經濟&#63988;將轉為自然生態&#63988;。在如此研究背景下，本計畫擬進行二年，於包含許多人工林及次生林的台大實驗林溪頭營林區內，選擇彼此相鄰、發育時間相同、具有類似生育環境狀況的人工林及次生林，設立12組對偶樣站，另外也在當地天然闊葉林內選擇4個樣站做為老熟林之對照代表，於這28個樣站分別調查其內之鳥類群聚組成及植群結構。 預計二年之研究成果，將能有效回答下列重要問題：(1)次生林的鳥類豐富度、密度、及生態同功群數量是否高於人工林？(2)次生林的鳥類群聚結構及棲地結構是否比人工林更近似於老熟林？(3)人工林與次生林的樹種豐富度及棲地結構是否不同？(4)各樣站之樹種豐富度及枝葉垂直結構歧異度是否與其鳥類豐富度成正比？(5)鳥類群聚組成的年間變化是否差距甚大？本計畫的完成，將有助於釐清次生林的野生動物多樣性是否比人工林高。這不僅可對全球森林生態學及森林經營方面的研究提出顯著之貢獻，也可以就野生動物多樣性保育的角度，探討台灣減少人工造&#63988;、提倡森林自然演替的政策方向是否正確合適。若是結果顯示次生林內的生物多樣性比人工林高，研究結論將可以提供未來台灣人工經濟林轉為自然生態&#63988;的重要研究基礎。 <br> Abstract: Secondary forests have been considered as providing higher value in biodiversity conservation than plantations. However, this view was seldom scrutinized by rigorous field studies. In related studies, the plantations were usually tropical agroforestry under intensive human disturbance, or the development time of plantations was often shorter than secondary forests. Therefore, direct comparisons of such study sites could be totally misleading. For conserving biodiversity, water and soil, the Taiwan government will no longer cultivate new plantation in high-elevation area and current plantations will be gradually converted into natural secondary forests. Under this background, I propose a two-year research on comparing bird diversity of plantations and secondary forests in the Sitou Tract, Experimental Forest of National Taiwan University. Twelve sets of paired sampling stations will be established from neighboring plantations and secondary forests that have same development time and environmental condition. Four additional sampling stations in the broadleaf old-growth forests on the Phoenix Mountain will be also chosen. Bird community composition and vegetation structure in these 28 sampling stations will be measured over a two-year span. Results of this two-year study are expected to provide critical evidences for following key questions: (1) Are the species richness, total density, and guild number of birds in secondary forests higher than those in plantations? (2) Are the bird community composition and habitat structure in secondary forests more similar to old-growth forests? (3) Do the tree species richness and vegetation structure differ from those in plantations? (4) Do tree species richness and foliage height diversity positively correlate with bird species richness? (5) Is there any significant annual difference in bird community composition? Completion of this study will provide clear evidence to assess whether if biodiversity in secondary forests is higher than plantations, which will not only generate valuable insights to forest ecology and forest management but also critical evaluation of the policy recently adapted by Taiwan government. If secondary forests indeed have higher biodiversity than plantations, results of this study will be important guidelines to converting plantations into natural forest.