闊葉樹混合林之生長表現與碳儲存量變化

The Growth Performances and Carbon Stock Changes of Broadleaf Mixed Stands

本研究乃以太麻里研究中心闊葉樹混合林造林地為對象，探討三種原生造林樹種不同混植方式之生長表現，並藉由轉換係數估算碳儲存量變化，結果顯示：在九種混植方式中，以樟樹之胸高直徑為最佳；其他各項林木屬性之純林與混合林經統計分析，無顯著差異。由各樹種純林與混合林之徑級分佈圖可得知各林分大致呈中間偏左之鐘形曲線，可見其林分尚在發展階段；惟其中之光臘樹純林無較大徑級林木分布，混合林則有較大徑級林木分布，可推測就現階段而言，光臘樹混合林對其林分結構發展有正面之意義。在蓄積量方面，以核心樹種及外圍樹種皆為烏心石的混植處理組合為最佳，總蓄積量為183.99 m3 /ha，而以核心樹種為光蠟樹，外圍樹種為烏心石混植處理組合的總蓄積量為最低僅為113.24 m3 /ha。而碳儲存量，則以核心樹種及外圍樹種皆為光蠟樹的混植處理組合為最佳，總碳儲存量為85.74 ton/ha，而核心樹種及外圍樹種皆為樟樹的混植處理組合為最低僅為 47.09 ton/ha。本研究結果顯示，總蓄積量高的樣區而碳儲存量不一定高的原因，主要是由於不同樹種由蓄積量轉為碳儲存量的轉換係數不同所致。 This research focuses on growth performances studies and carbon stock changes between 3 different native species of Taimalii research center, Taiwan Forestry Research Institute. The result reveals that Camphor tree (Cinnamomum camphora) pure stand has the best diameter at breast height (DBH) performance among 9 types of stands; and the rest types of stands show no significant difference statistically. The diameter distributions of all stands share a similar pattern of left-center ball-shaped curve, which indicates the stands are still in growth phase; further analysis shows mixed Formosan Ash (Fraxinus formosana) stands have bigger DBH than pure stands. In a mixed stand, the center and peripheral species are both Formosan Michelia (Michelia compressa) earning the best highest volume of 183.99 m3/ha; the center and peripheral species are Formosan Ash and Formosan Michelia respectively showing the lowest volume of 113.24 m3/ha. In addition, the center and peripheral species are both Formosan Ash having the highest carbon stock of 85.74 ton/ha; the center and peripheral species are both Camphor tree getting the lowest carbon stock of 47.09 ton/ha. Due to different species are provided with diverse carbon conversion factors, the high-volume stands do not get high carbon stock positively.