應用鑽孔抵抗法推估六龜地區台灣杉不同疏伐處理之碳貯存量

Estimating Carbon Storage of Taiwania Grown Under Different Thinning Treatments in Lu-Kuei Area Using the Drilling Resistance Technique

邱志明(Chih-Ming Chiu) ； 林振榮(Cheng-Jung Lin) ； 唐盛林(Sheng-Lin Tang) ； 王松永(Song-Yung Wang)

《中華林學季刊》 41卷4期 (2008/12) Pp. 503-519

https://doi.org/10.30064/QJCF.200812.0006

摘要

本研究應用非破壞性之鑽孔抵抗法的年輪特徵值之密度值及永久樣區生長資料以推算不同疏伐處理對幼齡時期台灣杉的生物量及碳貯存量影響。在相同樹齡中，單株樹木疏伐處理的碳貯存量較未疏伐處理為高，其原因為單株材積（胸徑及樹高）隨疏伐處理增強而增加。而林木生物量及碳貯存量隨著樹齡增加而增加。不同疏伐處理，12年後單位面積林木總生物量及碳貯存量，其大小依序為未疏伐、中度疏伐、強度疏伐，但若以單位面積淨生產量而言，大小順序則為中度疏伐、未疏伐及強度疏伐，且在疏伐後6年，中度疏伐區生產力（生物量及碳貯存量）即超越未疏伐區。疏伐後12年，23年生時，強度疏伐區之林木株數枯死率為3.8%，中度為4.1%，未疏伐區為11.1%，而各處理區留存木平均每年之生產力差異不顯著，顯示林木又再度鬱閉，產生競爭，需再進行第二次疏伐處理。又林木疏伐後搬出利用，則可轉為木質材料應用及以碳素儲存形式存在木材產品中；未疏伐之林分，林木因競爭而枯死，將碳素釋放至大氣中，若將此加以考量，則中度疏伐區單位面積之林木總生產力之生物量及碳貯存量超越未疏伐區，且強度疏伐區和未疏伐區之差距更小，此更顯示人工林適當經營之重要。

關鍵字

生物量 ； 碳貯存量 ； 疏伐 ； 台灣杉

並列摘要

The effects of different thinning treatments on the biomass and carbon storage of young Taiwania (Taiwania cryptomeriodies Hay) using non-destructive evaluation (NDE) for tree growth and ring density characteristics of drilling resistance technique were investigated. The estimated carbon storage values of individual tree in thinning treatment were higher than no thinning treatment at the same age due to volume (diameter at breast height and height growth) of individual tree increased by thinning intensities. The forest biomass and carbon storage were increased with the increase of the tree ages. The average gross biomass and carbon storage per unit area in the 12 years after thinning treatments showed the following trend: no thinning ＞ medium thinning ＞ heavy thinning, but the average net productivity per unit area showed the following trend: medium thinning ＞ no thinning ＞ heavy thinning. Moreover, the average values of the productively (biomass and carbon storage) obtained from the trees of 6 years after medium thinning were higher than from trees of no thinning. The average rate of trees mortality for heavy thinning, medium thinning, and no thinning were 3.8%, 4.1%, and 11.1%, respectively. In addition, the effects of thinning on the average annual productivity were not statistically significant. Thus, the canopy of Taiwania in 12 years after thinning have been grown in closing and competing. Hence, the trees of closed crowns need to be released by second thinning regimens. A substantial amount of the thinned tree (wood) could be utilized for wood-based material applications and carbon stock in wood product. In this study, an increase in tree competition was followed by an addition in rates of mortality as a result of decelerated carbon storage in forest due to accelerated biomass decomposition released to atmosphere layer. In the light of the above results and reasons, the average gross productivity of biomass and carbon storage per unit area obtained from trees of medium thinning were higher than no thinning, and the trees of heavy thinning were similar to the trees of no thinning. Therefore, the appropriate forest management (ex. Silvicultural practices and tending) of plantation is very important.

並列關鍵字

Biomass ； Carbon storage ； Thinning ； Taiwania