Chin J Plan Ecolo ›› 2010, Vol. 34 ›› Issue (9): 1025-1032.DOI: 10.3773/j.issn.1005-264x.2010.09.003

• Research Articles • Previous Articles     Next Articles

Nitrogen allocation and partitioning within a leguminous and two non- leguminous plant species growing at the southern fringe of China’s Taklamakan Desert

ZHU Jun-Tao1,2,3; LI Xiang-Yi1,2*; ZHANG Xi-Ming1,2; LIN Li-Sha1,2; and YANG Shang-Gong1,2,3   

  1. 1Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China;
    2Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele, Xinjiang 848300, China; and
    3Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-02-08 Revised:2010-04-06 Online:2010-09-01 Published:2010-10-08
  • Contact: LI Xiang-Yi

Abstract: Aims We previously found that non-leguminous species had a higher photosynthetic rate despite lower leaf N content. Nitrogen is a critical factor limiting plant growth in the desert. Our objectives were to determine if, as hypothesized, non-leguminous species have lower leaf N content, allocate a lower fraction of leaf N to photosynthesis and have higher maximum net photosynthetic rate (Pmax) and photosynthetic N-use efficiency (PNUE). Methods We compared the leguminous species Alhagi sparsifolia and non-leguminous species Karelinia caspica and Tamarix ramosissima in their typical habitat at the southern fringe of China’s Taklamakan Desert. Important findings As hypothesized, the non-leguminous species had significantly lower leaf N content and allocated a lower fraction of leaf N to photosynthesis. They also were more efficient in photosynthetic N partitioning. The non-leguminous species partitioned a higher fraction of the photosynthetic N to carboxylation and showed higher use efficiency of the photosynthetic N, while the leguminous species partitioned a higher fraction of the photosynthetic N to light-harvesting components. For the non-leguminous species, the higher fraction of leaf N allocated to carboxylation and bioenergetics led to higher Pmax and therefore to higher PNUE, water-use efficiency and apparent quantum yield. These physiological advantages of the non-leguminous species and their higher leaf area ratio may contribute to their higher resource capture ability.