兴安落叶松(Larix gmelini)幼中龄林的生物量与碳汇功能

Biomass and carbon pool of Larix gmelini young and middle age forest in Xing′an Mountains Inner Mongolia

兴安落叶松是我国的主要用材林,由于传统上对木材的长期依赖,使得其资源受到破坏,年龄结构发生改变,成过熟的原始林日渐减少,绝大部分是次生的幼中龄林。因此,研究其幼中龄林的生物量及碳汇功能很重要。森林生物量与森林生态系统的固碳能力密切相关,生物量与碳储量的多少直接影响到森林生态系统的功能,因而生物量与碳储量问题成为不同尺度生态学研究的热点。以我国大兴安岭兴安落叶松林为研究对象,通过样地调查,并结合我国森林资源清查资料对内蒙古大兴安岭地区兴安落叶松林的幼中龄林的生物量转换因子(BEF)、生物量及碳储量、碳密度、碳汇功能等进行了估算。通过实测数据及模型分析,得出以下基本结论:研究对象的BEF在0.4557与0.6988之间变动,平均值为0.5332。干、皮、枝、叶各组分生物量的分配比为:68.74:14.86:10.54:5.86。分别树干、树皮、枝、叶等组分,对其生物量与蓄积量的关系进行了拟合,建立了多组分生物量蓄积量的相关模型,分别是:干:y=0.4683x-11.291;皮:y=0.0472x+3.5674;枝:y=0.0415x+1.6787;叶:y=0.0197x+1·3405,均有很好的线性关系。地上生物量随蓄积量的增加而增加,其线性关系为:B=0.5767V-4.7042。利用近期清查数据,按材积源生物量法推算总生物量为9.49×107t,按0.5097的含碳率计算,得出兴安落叶松林幼中龄林总的碳储量为4.84×107t,碳密度为19.616t/hm2。通过两期数据对比分析,5a间所研究林分的碳储量增加0.89×107t,碳密度增加0.404t/hm2,说明其发挥着一定的碳汇作用。尽管近年来大兴安岭兴安落叶松林表现出了明显的碳汇功能,但整体上碳固定能力还不强,碳密度低于我国平均森林碳密度。应通过科学经营,挖掘潜力,使大兴安岭地区的森林生态系统在全球碳循环中发挥更大的作用。

Larix gmelini forest is the predominant timber has significantly modified this forest type. Larix gmelini mature and over-mature virgin forest have declined. Most middle-age forest. Therefore, it is important to research the close relationship between forest biomass and fixed source in China. Chronic dependence on this species for lumber forest has been damaged. Age structures have changed; areas of of the remaining forest type is comprised of secondary young and biomass and carbon pool of young and middle-age forest. There is carbon of forest ecosystems. The amount of biomass and carbon storage directly affect functions of forest ecosystems, so biomass and carbon storage have been the focus of ecological researches in different scale. In researching the young and middle age forest Larix gmelini of Da Xing＇an mountains Inner Mongolia, we estimate BEF （Biomass Expansion Factor）, biomass, carbon storage, carbon density and carbon pool function of Larix gmelini＇s using the standard Sample-plot survey data combined with Chinese Continuous Forest Inventory data. Through measurement data and model analysis, basic conclusions are as follows： BEF moves between 0. 4557 and 0. 6955, the average is 0.5332. The partition ratio of trunks, bark, branches and leaves＇ biomass is 68.74 ： 14.86：10. 54 ：5.86. The relationship between biomass and stock volume of trunks, bark, branches, and leaves is fitted to estimate the correlative model of biomass and stock volume of multiple components： Trunks： y =0. 4683x - 11. 291 ; Bark： y =0. 0472x ＋ 3.5674 ; Branches ： y = 0. 0415x ＋ 1. 6787 ; Leaves ： y = 0. 0197x ＋ 1. 3405, which are fairly linear. The above-ground biomass also increases as volume increases and the linear equation they follow is ： B = 0.5767V - 4. 7042. According to the latest CFI data, total biomass is estimated as 9.49×10^7t by the volume-biomass method. According to 0. 5097 carbon content, total carbon storage of Larix gmelini＇s young and middle-age forest is 4. 84 ×10^7t, and carbon density is 19.616t/ hm^2. Comparing two period data, carbon storage of forest stand and carbon density for 5 years increase by 0.89×10^7t and 0. 404t/hm^2 respectively, demonstrating that young and middle age forest of Larix gmelini has certain carbon sink functions. Although recently Larix gmelini of Da Xing＇an mountains shows obvious carbon pool functions, overall capacity of fixing carbon is not strong and carbon density is less than Chinese average forest carbon density. By emphasising quality of intensive management and digging potential, forest ecosystem of Da Xing＇an mountains will have greater influences on global carbon cycle.