白桦和紫椴树干非结构性碳水化合物的空间变异  

Spatial variation of non-structural carbohydrates in Betula platyphylla and Tilia amurensis stems

作　　者：张海燕[1] 王传宽[1] 王兴昌[1] 成方妍[1] 

机构地区：[1]东北林业大学生态研究中心,哈尔滨150040

出　　处：《应用生态学报》2013年第11期3050-3056,共7页Chinese Journal of Applied Ecology

基　　金："十二五"国家科技支撑计划项目(2011BAD37B01);长江学者和创新团队发展计划项目(IRT1054)资助

摘　　要：以中国东北温带森林两个散孔材树种白桦和紫椴为对象,研究落叶后树干木质部中非结构性碳水化合物(NSC)浓度的空间变异.结果表明:两种树种的可溶性糖与淀粉的总和(TNC)与可溶性糖浓度均随树干径向深度增加而缓慢下降,淀粉的径向变化不明显,即使在树干径向深处仍存有大量的NSC.两种树种树干的TNC、可溶性糖和淀粉浓度从根颈到胸高降低,之后逐渐升高,最大值出现的高度因树种和TNC组分而异.两种树种树干糖淀粉比值的纵向变化趋势为:白桦随树干升高而增大,紫椴则随之减小.树干NSC储量估算的误差主要来源于NSC浓度的纵向变化,其次是径向变化.喜光树种白桦的树干TNC浓度(1.0%干质量)显著低于耐阴树种紫椴(4.3%干质量),可能与其生活史对策差异有关.采用考虑了树干NSC纵向和径向变化的取样方法,可以有效地降低树木或林分水平上NSC储量估算的不确定性.Taking the two diffuse-porous tree species Betula platyphylla and Tilia amurensis in a temperate forest in Northeast China as test objects, this paper studied the spatial variation of the non-structural carbohydrates （NSC） concentrations in the stem xylem after leaf-fall. For the two tree species, the concentrations of total non-structural carbohydrate （TNC, soluble sugars plus starch） and soluble sugars in the stem xylem decreased gradually with the increasing depth from cambium to pith, whereas the starch concentration showed little radial variation. There was still a substantial amount of NSC in the inner wood close to pith. The concentrations of the NSC in the two species stems decreased gradually from the stump to the breast height, and then increased vertical- ly. The maximum concentrations of the TNC, soluble sugars, and starch occurred at different heights, depending on the species and the TNC components. The ratio of sugar to starch showed a contrasting vertical trend for the two species, i. e. , increasing from the stump to the top for B. platyphylla, but decreasing for T. amurensis. The estimation error of the stem NSC storage was mainly from the axial variation, and then, from the radial variation of NSC concentration. The TNC concentration （ 1.0% dry mass） in the stem of shade-intolerant species B. platyphylla was signifi- cantly lower than that （4.3 % dry mass） of shade-tolerant species T. amurensis, which could be re- lated to their different life-history strategies. Applying the sampling protocols considering the axial and radial variations of NSC could effectively reduce the potential uncertainty in estimating the NSC storage at tree or stand level.

关 键 词：非结构性碳水化合物 木质部 径向和纵向变化 白桦 紫椴 耐阴性 

分 类 号：S718.43[农业科学—林学]