Chin J Plan Ecolo ›› 2010, Vol. 34 ›› Issue (10): 1174-1184.DOI: 10.3773/j.issn.1005-264x.2010.10.006

• Research Articles • Previous Articles     Next Articles

Combined effects of elevated temperature, elevated [CO2] and nitrogen supply on non-structural carbohydrate accumulation and allocation in Quercus mongolica seedlings

MAO Zi-Jun*, JIA Gui-Mei, LIU Lin-Xin, and ZHAO Meng   

  1. Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China
  • Received:2009-11-09 Revised:2010-01-06 Online:2010-10-01 Published:2010-10-31
  • Contact: MAO Zi-Jun

Abstract: Aims Quercus mongolica is the main secondary forest species in northeastern China. Study of the responses of its organic carbon accumulation and storage capacity to climate changes may provide a scientific basis for predicting community regeneration and growth. Our aim was to determine responses of non-structural carbohydrate (NSC) of Q. mongolica seedlings to the combined effects of elevated CO2 concentration, temperature and soil nitrogen. Methods We used three artificial climate chambers whose environmental conditions were 1) CO2 concentration elevated to 700 μmol·mol–1 and temperature elevated 4 °C (HCHT), 2) temperature elevated 4 °C and CO2 concentration unaltered (HT) and 3) temperature and CO2 concentration unaltered. Three different soil nitrogen concentrations were used to determine effects on the dynamics of NSC in one-year old seedlings during the growing season: N2 (15 mmol·L–1), N1 (7.5 mmol·L–1, i.e., the normal nitrogen supply) and N0 (no nitrogen). Important findings The HTHC treatment changed the proportion of NSC partitioned to different organs of the seedlings and increased the accumulation of sugar and starch by the seedlings. N2 supply increased the accumulation of NSC, but there was no promotion effect on the accumulation of total NSC of the seedlings. The HT treatment significantly affected the accumulation and allocation of NSC of the seedlings, promoted the accumulation of NSC of the seedlings and increased the proportion of allocation of NSC to taproots under N2 supply. The dynamics of the soluble sugar content were different among the three treatments in different organs of the seedlings. The starch content increased in taproots, but gradually decreased in fine roots. Added nitrogen may promote the growth of Q. mongolica seedlings with future climate warming, thereby increasing their carbon storage, ability to withstand adverse environmental conditions and potential natural regeneration.