5个温带树种冠层枝叶非结构性碳水化合物浓度的空间变异  

Within-crown variation in concentrations of non-structural carbohydrates of five temperate tree species

作　　者：张海燕[1] 王传宽[1] 王兴昌[1] 

机构地区：[1]东北林业大学生态研究中心,哈尔滨150040

出　　处：《生态学报》2015年第19期6496-6506,共11页Acta Ecologica Sinica

基　　金：国家"十二五"科技支撑项目(2011BAD37B01);教育部长江学者和创新团队发展计划(IRT1054)

摘　　要：非结构性碳水化合物(NSC)是树木存活和生长的重要能源物质。冠层NSC不但是全树NSC的来源,也是全树NSC的重要储存库。然而,冠层NSC空间变异的研究较少,因而影响了树木NSC分配的估算精度。以红松(Pinus koraiensis)、兴安落叶松(Larix gmelinii)、水曲柳(Fraxinus mandshurica)、蒙古栎(Quercus mongolica)和白桦(Betula platyphylla)5个温带树种为研究对象,测定了不同高度冠层叶和细枝(直径≤3 cm)NSC浓度,分析了粗枝(一级侧枝)枝皮、边材和心材NSC浓度轴向变化及其与枝径的关系。结果表明:(1)除了5月末兴安落叶松树冠中层叶淀粉浓度显著高于树冠下层,以及8月中旬树冠上层叶可溶性糖浓度显著高于树冠中层之外,其他树种冠层叶NSC浓度的垂直变化不显著。常绿树种红松叶龄对NSC浓度的影响在生长季中期显著,但在生长季末期和休眠季节的影响不显著。(2)除了5月末红松树冠上层细枝可溶性糖浓度显著高于树冠中层之外,其他树种不同高度冠层间细枝NSC浓度差异不显著。(3)在纵向上,阔叶树种蒙古栎、水曲柳和白桦粗枝的枝皮、边材和心材NSC浓度多随着距树枝基部距离的增加而升高;在径向上,NSC浓度(除了水曲柳边材淀粉和白桦枝皮淀粉之外)多随着枝径增加而降低,表明树枝中的NSC浓度随着远离碳源而降低。总体上,5个温带树种冠层叶、细枝NSC浓度的空间变异不显著,但枝径和叶龄对NSC浓度的影响因树种、组织和季节而异,这在未来研究中应予考虑。Non-structural carbohydrates（ NSC） are important carbon reserves,particularly in trees,because they represent a large pool of biomass. Diverse strategies for carbon use and allocation are closely connected to ecological and evolutionary theories of trade-offs and niche partitioning. Crown is not only the source of NSC in a tree,but also a key NSC storage pool.However,few studies investigated within-crown variation in NSC concentrations,although such variation may introduce uncertainties in estimating NSC allocation in trees. In this study,we measured NSC concentrations in foliage and branches of five temperate tree species in northeastern China. The species included one evergreen conifer（ Pinus koraiensis）,one deciduous conifer（ Larix gmelinii）,and three deciduous broadleaved species（ Quercus mongolica,Fraxinus mandshurica,and Betula platyphylla）. The objectives were to（ 1） examine vertical differences in NSC concentrations among foliage and small branches of different ages（ diameter ≤ 3 cm） within the crown,（ 2） examine axial variations in NSC in bark,sapwood and heartwood of coarse branches（ i. e. first order branches）,and（ 3） explore the relationship between NSCconcentration and diameter in coarse branches. Branch samples were randomly taken from the upper-,mid- and lower-crown layers 3—7 times across the season. The samples were divided into foliage（ current-year,one-year-old,and older than one year） and small branches. In late October,one coarse branch from each of the three broadleaved species was sampled and separated into 1—2 m-long sections consisting of bark,sapwood,and heartwood. All samples were analyzed for NSC concentration（ including soluble sugars and starch） with a modified phenol-sulfuric method. The results showed that：（ 1）There were no significant vertical variations in foliage NSC concentration for any species except L. gmelinii,for which the starch concentration in late May was significant higher in the mid-crown and soluble sugar conce

关 键 词：非结构性碳水化合物(NSC) 叶 枝 空间变异 温带森林 

分 类 号：S718.4[农业科学—林学]