燕山北部山地华北落叶松人工林生物碳贮量

Biological Carbon Storage in Larix principis-rupprechtii Plantations in North Region of Yanshan Mountain

为了了解燕山北部山地大面积分布的华北落叶松人工林的碳汇功能,对该地区不同年龄阶段的华北落叶松林的生物碳贮量进行了研究。结果表明:燕山北部山地华北落叶松人工林生物碳贮量随林分年龄的增加呈明显的增加趋势,9、13、33、43年生华北落叶松人工林生物碳贮量分别为21.97、34.14、55.62和141.70t/hm2;不同林龄华北落叶松人工林地上部分和地下部分碳元素的贮量所占比例变化不大,枝、叶中碳元素所占比例随林龄的增加而逐渐降低;各林龄华北落叶松人工林生物碳库中,凋落物占有较大比例,一般可达到20%以上。该地区华北落叶松人工林生物量转化和扩展因子FBCE和生物量扩展因子FBE有随林木胸径的增加而下降的趋势,初期下降速度较快,胸径大于8cm时,下降速度趋缓,最后趋于稳定;同时,FBCE、FBE及根茎比有随林龄的增加而逐渐下降的趋势,该地区华北落叶松林的FBCE和FBE值接近于中国各地区落叶松林的平均水平。燕山北部山地40年生以下的华北落叶松人工林生长迅速,生物有机碳积累速率快,该地区大面积分布的华北落叶松中、幼龄人工林是中国北方重要的碳汇之一。

A survey was conducted to study the biological carbon storage in Larix principis-rupprechtii plantations of different ages located in North region of Yanshan Mountain in order to discuss the functions of large area of L. principis-rupprechtii plantations as a carbon sink. Results showed that the biological carbon storage in L. principis-rupprechtii plantations increased with the increase of plantation age,and the carbon storage values of 9-,13-,33-,and 43-year-old plantations were 21.97,34. 14, 55. 62 and 141. 70 t/hm2,respectively. There was no distinct difference in the ratio of aboveground or underground carbon storage to the total between the plantations of different ages,and the ratio of carbon storage in leaf or in branch to the total decreased with the increase of plantation age. For most of the plantations,the proportion of carbon storage in the litter to the total carbon pool was above 20% . The Biomass Conversion and Expansion Factor （ BCEF） and Biomass Expansion Factor （ BEF） decreased with increasing diameter at breast height （ DBH） of plantations,and they changed abruptly at the beginning and then approached a constant when DBH exceeded 8 cm. BCEF,BEF,and root-shoot ratio gradually decreased with plantation age increasing. The BCEF and BEF of the L. principis-rupprechtii plantations in this region are close to the averages of Larix forests in other regions in China. It is concluded that the L. principis-rupprechtii plantations below 40 years accumulate carbon at a high speed due to its quick growth,and large areas of young and middle-aged L. principis-rupprechtii plantations are an important carbon sink in the north of China.