大安溪事業區林木經營區針葉樹人工林疏伐計畫之評估

Evaluation of Thinning Project for Conifer Plantations in Timber Management Zone of Da-An Shi Working Circle

疏伐作業為當前之重要林業政策之一，因此評估疏伐計畫的可行性在森林經營上相當重要。本研究以疏伐為課題，以東勢林區管理處大安溪事業區林木經營區六種針葉樹人工林造林台帳為研究題材，林分為評估單元，採用經濟性、公益性為評估準則，分別以0.5:0.5、0.7:0.3、0.3:0.7三種權重比，透過計畫評估之簡單加權法，評估各林分疏伐作業的可行性。綜合評估結果顯示，不論權重比，未達輪伐期之紅檜、扁柏、台灣杉大多適合採不處理作業，雲杉適合中度疏伐，而達輪伐期之杉木、柳杉則需採強度疏伐以上之處理。 Thinning is nowadays one of the major policies for Taiwan Forest Bureau. Therefore,evaluation the feasibility of thinning project is very important in forest management. The purpose of thisstudy focused on evaluation of thinning project. Conifer plantations of six kinds of tree species in thetimber management zone of Da-An Shi working circle were used as study material and attribute data ofthese plantations were collected to calculate timber volumes in this research. Simple additive weightingmethod (SAW) was applied to integrate economic and public interest criteria and used different weightrates of 0.7:0.3, 0.5:0.5 and 0.3:0.7 to evaluate four different thinning projects. The final evaluation bySAW showed Chamaecyparis formosensis, Chamaecyparis obtusa var. formosana, and Taiwaniacryptomerioides were suitable for treatment without thinning, Picea morrisonicola were suitable for treatment with intermediate thinning and Cunninghamia lanceolata var lanceolata, Cryptomeria japonicavar japonica were suitable for heavy thinning and clear cutting, respectively.

Thinning is nowadays one of the major policies for Taiwan Forest Bureau. Therefore,evaluation the feasibility of thinning project is very important in forest management. The purpose of thisstudy focused on evaluation of thinning project. Conifer plantations of six kinds of tree species in thetimber management zone of Da-An Shi working circle were used as study material and attribute data ofthese plantations were collected to calculate timber volumes in this research. Simple additive weightingmethod (SAW) was applied to integrate economic and public interest criteria and used different weightrates of 0.7:0.3, 0.5:0.5 and 0.3:0.7 to evaluate four different thinning projects. The final evaluation bySAW showed Chamaecyparis formosensis, Chamaecyparis obtusa var. formosana, and Taiwaniacryptomerioides were suitable for treatment without thinning, Picea morrisonicola were suitable for treatment with intermediate thinning and Cunninghamia lanceolata var lanceolata, Cryptomeria japonicavar japonica were suitable for heavy thinning and clear cutting, respectively.