Journal of Resources and Ecology ›› 2019, Vol. 10 ›› Issue (3): 315-323.DOI: 10.5814/j.issn.1674-764X.2019.03.010

• Forest Ecosystem • Previous Articles     Next Articles

Self-thinning Rules at Chinese Fir (Cunninghamia lanceolata) Plantations—Based on a Permanent Density Trial in Southern China

DUAN Aiguo1,2(), FU Lihua3(), ZHANG Jianguo1,2,*()   

  1. 1. State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
    2. Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
    3. Saihanba Machinery Forestry Center, Weichang, Hebei 068466, China
  • Received:2018-03-09 Accepted:2018-11-20 Online:2019-05-30 Published:2019-05-30
  • Contact: ZHANG Jianguo
  • About author:

    The authors contributed equally to the work.

  • Supported by:
    The 12th and 13th Five-Year Plan of the National Scientific and Technological Support Projects (2015BAD09B01, 2016YFD0600302), Jiangxi Scientific and Technological innovation plan (201702) and National Natural Science Foundation of China (31570619, 31370629).


Data selection and methods for fitting coefficients were considered to test the self-thinning law. The Chinese fir (Cunninghamia lanceolata) in even-aged pure stands with 26 years of observation data were applied to fit Reineke’s (1933) empirically derived stand density rule (N $propto$ d¯ -1.605, N = numbers of stems, d¯ = mean diameter), Yoda’s (1963) self-thinning law based on Euclidian geometry ($propto$ N -3/2, v¯ = tree volume), and West, Brown and Enquist’s (1997, 1999) (WBE) fractal geometry ( $propto$ d¯ -8/3). OLS, RMA and SFF algorithms provided observed self-thinning exponents with the seven mortality rate intervals (2%-80%, 5%-80%, 10%-80%, 15%-80%, 20%-80%, 25%-80% and 30%-80%), which were tested against the exponents, and expected by the rules considered. Hope for a consistent allometry law that ignores species-specific morphologic allometric and scale differences faded. Exponents α of N $propto$ d¯α, were significantly different from -1.605 and -2, not expected by Euclidian fractal geometry; exponents β of $propto$ Nβ varied around Yoda’s self-thinning slope -3/2, but was significantly different from -4/3; exponent γ of $propto$ d¯γ tended to neither 8/3 nor 3.

Key words: Chinese fir, self-thinning, stand density, mortality rate