不同伐採強度對蓮華池桂竹林生長與生物量的影響

Effects of Thinning on the Growths and Biomass of Makino Bamboos in Lienhuachih

鍾欣芸(Hsin-Yun Chung) ； 劉瓊霦(Chiung-Pin Liu) ； 陳財輝(Tsai-Huei Chen)

《中華林學季刊》 43卷2期 (2010/06) Pp. 223-231

https://doi.org/10.30064/QJCF.201006.0004

摘要

本試驗之目的在於瞭解不同強度之伐採作業對桂竹(Phyllostachys makinoi)未來生長的影響。伐採強度分為4種等級，分為皆伐、1/2劣勢竹疏伐、1/3劣勢竹疏伐及對照組（無伐採處理），於2008年8月進行生長調查及不同伐採強度處理，2009年再次調查，記錄樣區內之新生竹和其他竹株之生長變化。在新生竹密度方面，以皆伐處理之2,600±520 culms ha^(-1)顯著高於1/3疏伐之1,467±321 culms ha^(-1)及對照組之700±361 culms ha^(-1)，但與1/2疏伐者未有顯著差異。新生竹之平均胸徑、竹高及枝下高則是以對照組之3.3±1.1cm、8.9±2.4m及3.6±1.2m顯著高於其他疏伐處理者，而其他三者之胸徑、竹高及枝下高之大小，隨著疏伐強度的增加而減少。伐採處理隔年，平均胸徑以1/3疏伐者增加0.3cm為最多，而皆伐者則減少0.4cm，顯示竹林皆伐會使後續生長之竹稈胸徑趨小，並以1/3疏伐對竹林的胸徑生長最佳。另外竹林生物量的部分，未進行處理前，地上部生物量乾重累積約介於18.95至30.76ton ha^(-1)，隔年各伐採強度下之新生竹竹稈累積量皆不同，依序為皆伐處理之2.4±1.3 ton ha^(-1)，1/2疏伐之1.6±0.8 ton ha^(-1)，1/3疏伐之1.3±0.4 ton ha^(-1)及對照組之1.1±0.4 ton ha^(-1)，雖然新生竹生物量累積會隨伐採強度減弱而降低，但伐採後之短期間內，竹林地上部生物量仍以對照組最高。

關鍵字

疏伐作業 ； 桂竹林 ； 生長 ； 生物量

並列摘要

The purpose of this research was to study how different cutting level practices to affect the growth of Phyllostachys makinoi bamboos in the future. The treatments had four cutting levels, which were clear cutting, 1/2 thinning of inferior culm, 1/3 thinning of inferior culm and control. The first growth investigation was in August, 2008. At the same time, we treated the bamboos for different cutting levels. The second growth investigation was in July, 2009, when we recorded the growth of new bamboos and the changes of other bamboos in the plots. In the mount of new bamboos, the clear cutting was 2,600±520 culms ha^(-1). It is significantly higher than 1,467±321 culms ha^(-1) of 1/3 thinning treatment and 700±361 culms ha^(-1) of control. However, there was no difference between clear cutting and 1/2 thinning treatment. The diameter of breast height, total height and crown height of new bamboos in clear cutting treatment were 3.3±1.1 cm, 8.9±2.4 m and 3.6±1.2 m, respectively. They were significantly higher than the other treatments and were decreased with the increase of cutting level. After one year's treatment, the average diameter of breast height increased 0.3 cm in 1/3 thinning treatment. It was the highest of all. On the other hand, the clear cutting level decreased 0.4 cm. It is implied that clear cutting practice in the bamboo stand would decrease the diameter of breast height in the future. And 1/3 thinning practice would be the best for the diameter growth. Besides, the bamboo stands biomass accumulated between 18.95 to 30.76 ton ha^(-1) before cutting level treatment. After one year's treatment, there were different in every kind of treatment. It was 2.4±1.3 ton ha^(-1) in clear cutting, 1.6±0.8 ton ha-1 in 1/2 thinning, 1.3±0.4 ton ha^(-1) in 1/3 thinning and 1.1±0.4 ton ha^(-1) in control. The biomass accumulation of new bamboo decreased when cutting strength decreased, but the control treatment was still the highest in the above ground biomass of bamboo stands in the short time after cutting.

並列關鍵字

Thinning practice ； Makino bamboo ； Growth ； Biomass