文献类型： 外文期刊

作者： Cong, Yu ¹ ; Saurer, Matthias ³ ; Bai, Edith ¹ ; Siegwolf, Rolf ³ ; Gessler, Arthur ³ ; Liu, Kai ¹ ; Han, Hudong ¹ ; Dang, Yongcai ¹ ; Xu, Wenhua ⁵ ; He, Hong S. ⁷ ; Li, Mai-He ¹ ;

作者机构： 1.Northeast Normal Univ, Sch Geog Sci, Key Lab Geog Proc & Ecol Secur Changbai Mt, Minist Educ, 5268 Renmin St, Changchun 130024, Peoples R China

2.Chinese Acad Sci, Northeast Inst Geog & Agr Ecol, 4888 Shengbei St, Changchun 130102, Peoples R China

3.Swiss Fed Inst Forest Snow & Landscape Res WSL, Zuercherstr 111, CH-8903 Birmensdorf, Switzerland

4.Swiss Fed Inst Technol, Inst Terr Ecosyst, Univ Str 16, CH-8092 Zurich, Switzerland

5.Jilin Acad Agr Sci, Inst Agr Resource & Environm, 1363 Shengtai St, Changchun 130033, Peoples R China

6.Chinese Acad Sci, Inst Appl Ecol, CAS Key Lab Forest Ecol & Management, 72 Wenhua Rd, Shenyang 110016, Peoples R China

7.Univ Missouri, Sch Nat Resources, Columbia, MO 65211 USA

关键词： C-13 pulse labeling; alpine treeline; carbon allocation; non-structural carbohydrates (NSC); photoassimilates; sink activity

期刊名称：TREE PHYSIOLOGY （ 影响因子：4.561； 五年影响因子：5.121 ）

ISSN： 0829-318X

年卷期：

页码：

收录情况： SCI

摘要： Carbon (C) allocation plays a crucial role for survival and growth of alpine treeline trees, however it is still poorly understood. Using in situ (CO2)-C-13 labeling, we investigated the leaf photosynthesis and the allocation of C-13 labeled photoassimilates in various tissues (leaves, twigs and fine roots) in treeline trees and low-elevation trees. Non-structural carbohydrate concentrations were also determined. The alpine treeline trees (2000 m. a.s.l.), compared with low-elevation trees (1700 m a.s.l.), did not show any disadvantage in photosynthesis, but the former allocated proportionally less newly assimilated C belowground than the latter. Carbon residence time in leaves was longer in treeline trees (19 days) than that in low-elevation ones (10 days). We found an overall lower density of newly assimilated C in treeline trees. The alpine treeline trees may have a photosynthetic compensatory mechanism to counteract the negative effects of the harsh treeline environment (e.g., lower temperature and shorter growing season) on C gain. Lower temperature at treeline may limit the sink activity and C downward transport via phloem, and shorter treeline growing season may result in early cessation of root growth, decreases sink strength, which all together lead to lower density of new C in the sink tissues and finally limit the growth of the alpine treeline trees.