Chinese Bulletin of Botany

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Seasonal Variation in Contents of C, N and P and Stoichiometry Characteristics in Fine Roots, Stems and Needles of Larix principis-rupprechtii

Yafang Zhao1,2, Fuli Xu1,3*, Weiling Wang3, Lingling Wang3, Guoxing Wang3, Pengyue Sun3, Xiaofang Bai1,2   

  1. 1Institute of Soil and Water Conservation, Ministry of Water Resources, Chinese Academy of Sciences, Yangling 712100, China

    2University of Chinese Academy of Sciences, Beijing 100049, China; 3Northwest A&F University, Yangling 712100, China
  • Received:2014-04-24 Revised:2014-06-29 Online:2014-09-01 Published:2014-07-02
  • Contact: Fuli Xu

Abstract: We collected 20-year-old Larix principis-rupprechtii from a plantation in Qinling to explore the contents of C, N and P and their ecological stoichiometry characteristics in fine roots, stems and needles in different seasons. The content of C increased first, then decreased and increased again throughout the growing season (May to October). The order of the mean content of C in organs was stems > needles > fine roots. The content of N in fine roots, stems and needles tended to fluctuate during the growing season. The content of P in both needles and fine roots decreased first, then increased and decreased again, then remained stable. The content of P in stems decreased first and then increased, then decreased gradually. The order of the mean content of both N and P in organs was needles > fine roots > stems. The content of N had the greatest variability in fine roots and needles throughout the growing season. The coefficient of variation (cv%) of P was greatest for stems. The variability of C in the 3 organs was the smallest. The changes in C:N and C:P ratios were opposite to that of corresponding N, P content in fine roots, stems and needles. The ratio of N:P peaked in stems and was minimal in fine roots. The order of the cv% for C:N throughout the growing season was fine roots < stems < needles and for both C:P and N:P was fine roots < needles < stems. Factorial analysis of variation for each parameter, with sampling season and organs as independent variables, showed that the content of C, N and P and C:N mass ratio mainly depended on the organ. C:P and N:P mass ratios were mainly determined by the interaction of organs and season. The mass ratio of C:N:P was similar in fine roots (369:7:1) and needles (309:10:1). The characteristics of C, N and P stoichiometry were relatively stable in fine roots. Quantitative characteristics in fine roots were affected less in different seasons in L. principis-rupprechtii in Qinling, which helps in analysis of the ecological system.

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