长白落叶松林龄序列上的生物量及碳储量分配规律

由于多年来的过量采伐和重采轻育,伊春东折棱河林场人工长白落叶松林分质量普遍下降,森林生态功能严重衰退。结合对该研究地同一立地类型的人工长白落叶松林(Larix ologensis)林木各组分生物量垂直分配规律的分析,研究了其生物量在年龄序列上的分布及分配规律,为提高其林分生物量及碳储量采取相应的抚育管理措施提供一定的理论基础。结果表明,处于中龄、近熟及成熟林中的林木树干、树皮及活枝生物量所占比例受年龄影响较小,而叶生物量随林龄增大呈现明显递减变化;不同年龄长白落叶松的垂直分布规律基本一致:其树皮及树干生物量随树高增大呈现递减规律,其活枝及叶生物量主要集中分布于树冠中部,而其死枝生物量未呈现明显分布规律;长白落叶松根系生物量随着林分年龄的增大,其粗根、中根及细根所占比例呈现递减规律,而其大根所占比例随年龄的增大基本呈增大趋势。通过统计分析得出,长白落叶松生物量与林分蓄积的最优模型为:W=0.4909M+9.6624(R²=0.8893),进而估算得出:研究区域幼龄长白落叶松林分生物量为1273.72 t/hm²,碳储量为656.98 t/hm²;中龄长白落叶松林分生物量为15480.13 t/hm²,碳储量为7984.65 t/hm²;近熟、成熟龄长白落叶松林分生物量为7684.41 t/hm²,碳储量为3963.62 t/hm²。随林分结构的改善以及中龄、近熟及成熟林分的不断增加,生物量及碳储量会相应增加。

Age structure effects on stand biomass and carbon storage distribution of Larix olgensis plantation

It is essential to study forest biomass, which is an important quantity character for forest ecosystems. Although intense studies have been carried out on the biomass of Larix olgensis plantations, little attention was paid on the dynamics of biomass and carbon storage with age structure variation. We researched the age structure effect on forest biomass and carbon storage by investigating its vertical distribution of Larix ologensis plantations. For many years excessive cutting and slighting fostering, the stand quality and the function of forest ecosystem have descended in Dong Zhelenghe forestry centre of Yi Chun, China. By analyzing the vertical distribution biomass of different components for Larix ologensis plantations in a homogenous site condition, the biomass distribution in age sequence was studies. The study was aimed to provide the quantitative reference for improving the productivity and carbon storage by adjusting the stand structure. The proportions of trunk, bark and living branch biomass were less correlated with age structure, but that of leaves decreased with stand growth significantly. We analyzed vertical distribution of biomass for different components in varying-age stands. The relationship between biomass and tree height showed a uniform pattern among age structures. The bark- and trunk-biomass descended with tree height, and that of living branches and leaves concentrated in middle of tree canopy, while the dead-branches biomass appeared less difference vertically. The biomass proportions of coarse, medium and fine roots decreased with stand age, but opposite for main-root biomass. The relationship between stand biomass and stock volume was fitted as W=0.4909M+9.6624(R²=0.8893). We know from the estimated results that the total biomass of Larix olgensis young plantations in the study area was 1273.72t/hm², and carbon storage 656.98 t/hm².The total biomass of middle-age forests was 15480.13 t/hm², or carbon storage 7984.65 t/hm² as. Total biomass of the pre-mature and mature plantations was 7684.41t/hm², or carbon storage was 3963.62t/hm² as. The forest biomass or carbon storage is expected to increase under shifting age structures and new management strategies.