Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (7): 746-752.DOI: 10.17521/cjpe.2015.0071

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Variations of non-structural carbohydrate concentration of Picea meyeri at different elevations of Luya Mountain, China

WANG Biao1,2, JIANG Yuan1,2,3(), WANG Ming-Chang1,2, DONG Man-Yu1,2, ZHANG Yi-Ping1,2   

  1. 1Beijing Municipal Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Beijing Normal University, Beijing 100875, China
    2College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China
    3State Key Laboratory of Earth Surface Process and Resource Ecology, Beijing Normal University, Beijing 100875, China
  • Online:2015-07-01 Published:2015-07-22
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Abstract: Aims The alpine timberline is highly sensitive to environmental changes, although the mechanism controlling timberline formation is still inconclusive. Our objectives in this study were to test whether the alpine timberline formation is determined by carbon limitation or growth limitation, and explore physiological and ecological mechanisms of timberline tree species adapting to alpine environments. We examined the concentrations of the overall nonstructural carbohydrates (NSC) and tissues NSC of Picea meyeri at the end of growing season and in three elevations (low, medium and timberline) along an altitudinal gradient on the north slope of Luya Mountain, Shanxi, China. Methods We collected samples of leaf, stem and fine root tissues of P. meyeri on September 15, 2013. The total soluble sugar concentration of plant tissue was measured by an anthrone-sulfuric acid colorimetric method, and starch was extracted by a perchloric acid method. Important findings The overall NSC and tissues NSC increased significantly with elevation, suggesting that there was no carbon limitation at the alpine timberline. The NSC source and sink are all increased significantly with elevation, and there is no significant difference in the source-sink ratio among three elevations, indicating an adaptation of source-sink balances to altitudes and no restriction of carbon source activity in timberline trees. The ratio of sugar to starch in tissues showed an increasing trend with elevation, which suggests that the colder the environment was, the stronger the protective strategy adopted in plant tissues through resource investments, implying more growth limitation in trees near timberlines, The research results appear to support the “growth limit” hypothesis to some degree.

Key words: elevation, nonstructural carbohydrate, source-sink balance, ratio of soluble sugar to starch, Picea meyeri, timberline