Cheng Chih-Hsin, Hung Chih-Yu, Chen Chiou-Peng, Pei Chuang-Wun
School of Forestry and Resource Conservation, National Taiwan University, Taipei, Taiwan.
NTU Experimental Forest, National Taiwan University, Nantou, Taiwan.
Bot Stud. 2013 Dec;54(1):60. doi: 10.1186/1999-3110-54-60. Epub 2013 Dec 3.
Japanese cedar (Chrytomeria japonica D. Don) is an important plantation species in Taiwan and represents 10% of total plantation area. It was first introduced in 1910 and widely planted in the northern and central mountainous areas of Taiwan. However, a change in forest management from exotic species to native species in 1980 had resulted in few new Japanese cedar plantations being established. Most Japanese cedar plantations are now between 30 and 50 years old and reaching their rotation period. It is of interest to know whether these plantations could be viable for future carbon sequestration through the accumulations of stand carbon stocks. Twelve even-aged Japanese cedar stands along a stand age gradient from 37 to 93 years were selected in Xitou of central Taiwan. The study aims were to investigate the basic stand characteristics and biomass carbon stock in current Japanese cedar stands, and determine the relationships among stand characteristics, tree biomass carbon, and stand age.
Our results indicate that existing Japanese cedar plantations are still developing and their live tree biomass carbon continues to accumulate. At stands with a stand age of 90 years, tree density, canopy height, mean diameter at breast height, basal area, and live tree biomass carbon stocks reach to nearly 430 tree ha, 27 m, 48 cm, 82 m ha and 300 Mg C ha, respectively.
Therefore, with no harvesting, current Japanese cedar plantations provide a carbon sink by storing carbon in tree biomass.
日本柳杉（Cryptomeria japonica D. Don）是台湾重要的人工林树种，占人工林总面积的10%。它于1910年首次引入，广泛种植于台湾北部和中部山区。然而，1980年森林经营从外来树种转向本土树种，导致新的日本柳杉人工林很少建立。现在大多数日本柳杉人工林树龄在30至50年之间，已到轮伐期。了解这些人工林通过林分碳储量的积累是否能在未来实现碳固存很有意义。在台湾中部溪头选择了12个树龄从37年到93年的同龄日本柳杉林分。研究目的是调查当前日本柳杉林分的基本林分特征和生物量碳储量，并确定林分特征、树木生物量碳和林分年龄之间的关系。
我们的结果表明，现有的日本柳杉人工林仍在生长，其活立木生物量碳仍在积累。在树龄为90年的林分中，树木密度、林冠高度、平均胸径、断面积和活立木生物量碳储量分别达到近430株/公顷、27米、48厘米、82平方米/公顷和300吨碳/公顷。
因此，在不进行采伐的情况下，当前的日本柳杉人工林通过将碳储存在树木生物量中提供了一个碳汇。
