惠蓀林場紅檜人工林與闊葉樹次生林生態系經營模式之導入

Embodiment of Ecosystem Management Model toTaiwan Red Cypress Plantations and SecondaryBroadleaf Forest in Huisun Forest Station

林業經營目標從早期的傳統木材生產，擴展至1960年代的多目標經營，而於1992年美國農部林務署更發展出生態系經營的理念，強調森林生態系的多樣性與完整性。本研究選定國立中興大學惠蓀林場中二個林班內之紅檜造林地為試區，探討如何將生態系經營之理念落實於試區內，且於248號造林地附近之闊葉樹次生林，設置二個調查樣區作為試驗研究的對照組。試區中之紅檜多為分叉叢生，且多入侵的闊葉樹幼木，故進行疏伐處理，希藉以提高其生產力與歧異度，疏伐度的決定係以胸高斷面積為其介量，訂有30、50、60%等三種疏伐度，疏伐後若有較大之孔隙產生，再適度混植牛樟、香楠、烏心石等苗木於孔隙下，且定期監測土壤、微氣候環境因子、植群、土壤表層動物以及昆蟲等，以評估其施業的效應與影響。並在考量生態性、經濟性以及社會性的層面，發展適切的環境、生物以及生態經濟等生態指標，以為永續經營之評估指標，並藉由適應性經營的反饋，建構森林生態系經營模式，期供未來於大尺度之地景單元經營的參考與依據。 The goal of forest managements has transformed since the 1960s from timber productionto multi-purpose utilization, and culminated in the adoption of ecosystem management by USDAForestry Service in 1992, which emphasizes the maintenance of diversity and integrity of forestecosystems. In order to realize the concepts of ecosystem management, we conducted experiments intwo compartments of the Taiwan red cypress plantations in Huisun Forest Station of the NationalChung Hsing University. Two secondary broadleaf forest plots adjacent to the experimental plots werechosen as controls. Most Taiwan red cypress trees within experimental plots grow in clumps andbifurcate into branches at very low height, and the plots are invaded by broadleaf seedlings. Weperformed 30%, 50%, and 60% thinning based on breast height basal area. Three broadleaf tree species(Cinnamomum kanahirai, Machilus zuihoensis and Michelia compressa) were planted within largegaps after thinning. The effects of thinning on forests were evaluated by monitoring the soil properties,microclimate conditions, understory plant diversity, and surface-dwelling animal diversity before andafter thinning. This practice of developing suitable environmental, biological, and ecological-economicalindices for sustainable forest management is based on the consideration at several levels (ecology,economics, and society). By means of feedback based on adaptive managment principles, we hopethis model of forest ecosystem management can be applied in landscape scale management in the future.

The goal of forest managements has transformed since the 1960s from timber productionto multi-purpose utilization, and culminated in the adoption of ecosystem management by USDAForestry Service in 1992, which emphasizes the maintenance of diversity and integrity of forestecosystems. In order to realize the concepts of ecosystem management, we conducted experiments intwo compartments of the Taiwan red cypress plantations in Huisun Forest Station of the NationalChung Hsing University. Two secondary broadleaf forest plots adjacent to the experimental plots werechosen as controls. Most Taiwan red cypress trees within experimental plots grow in clumps andbifurcate into branches at very low height, and the plots are invaded by broadleaf seedlings. Weperformed 30%, 50%, and 60% thinning based on breast height basal area. Three broadleaf tree species(Cinnamomum kanahirai, Machilus zuihoensis and Michelia compressa) were planted within largegaps after thinning. The effects of thinning on forests were evaluated by monitoring the soil properties,microclimate conditions, understory plant diversity, and surface-dwelling animal diversity before andafter thinning. This practice of developing suitable environmental, biological, and ecological-economicalindices for sustainable forest management is based on the consideration at several levels (ecology,economics, and society). By means of feedback based on adaptive managment principles, we hopethis model of forest ecosystem management can be applied in landscape scale management in the future.