Chin J Plan Ecolo ›› 2011, Vol. 35 ›› Issue (6): 596-604.DOI: 10.3724/SP.J.1258.2011.00596

Special Issue: 稳定同位素生态学

• Research Articles • Previous Articles     Next Articles

Relationships between foliar stable carbon isotope composition and environmental factors and leaf element contents of Pinus tabulaeformis in northwestern China

LI Shan-Jia1, ZHANG You-Fu2,3, CHEN Tuo3*   

  1. 1College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China;

    2College of Agricultural, Henan University of Scienceand Technology, Luoyang 471003, China;

    3State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering ResearchInstitute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2010-05-18 Revised:2010-12-11 Online:2011-06-01 Published:2011-06-30
  • Contact: CHEN Tuo

Abstract:

Aims Our objective was to analyze relationships between foliar stable carbon isotope composition (δ13C) and environmental factors and leaf element contents in Pinus tabulaeformis, which is widely distributed in northwestern China.
Methods Leaf samples were taken in ten natural populations of P. tabulaeformis from Gansu, Ningxia and Inner Mongolia. The δ13C was determined using an isotope mass spectrometer. Environmental factors were recorded by Magellan GPS320 and from nearby weather stations. Leaf element contents were measured with low vacuum scanning electron microscope and X-ray energy dispersive spectroscopy. Carbon content was estimated with the potassium dichromate method, and nitrogen content was measured with the micro-Kjeldahl method. Data were evaluated with Excel 2003 and SPSS 13.0 analysis of correlation and regression.
Important findings Foliar δ13C ranged from –28.68‰ to –25.02‰, with an average value of –26.82‰. Foliar δ13C did not closely correlate with altitude and longitude, but was significantly positively correlated to latitude and negatively correlated with annual mean precipitation and temperature. Therefore, δ13C in different natural populations of P. tabulaeformis is significantly influenced by environmental factors, and annual mean temperature and precipitation are essential factors in δ13C’s capability of fractionation and growth. Leaf N, P and K content were significantly negatively correlated with δ13C; however, Si, Ca and Fe content were significantly positively correlated with δ13C. Different δ13C in different natural populations reflects changes in plant nutrient element
content. Response mode of climatic factors and element content under different habitat conditions reflected and affected properties of δ13C change in natural populations of P. tabulaeformis.