Study on the Self-pruning of Chinese Fir Plantation

SUN Hong-gang; ZHANG Jian-guo; DUAN Ai-guo

The data of 25 years’ positional observation were used to investigate the effects of self-pruning on Chinese fir (Cunninghamia lanceolata) plantations. The study examined five initial density levels (2m×3m, 2m×1.5m, 2m×1m, 1m×1.5m, and 1m×1m) with three replications at each level based on the randomized block design. The higher the initial planting density, the sooner the self-pruning happened and the higher the self-pruning intensity was. While living crown ratio (CL/TH) decreased to 0.4, the CL/TH ratio fluctuation tended to a constant. When the CL/TH ratio decreased to 0.3, the self-thinning happened, regardless the initial planting density and mortality. When self-pruning happened, the ratio of tree crown width to the living crown height (CW/CH) rapidly increased, then slowly increased during the early self-thinning and increased rapidly again during the late self-thinning. However, the CW/CH ratio was always below 1. Allocation pattern with assimilation matter changed when self-pruning happened, and stem form index (H/D) decreased when the living crown ratio increased.

1. Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang 311400, Zhejiang, China

2. Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, hinese Academy of Forestry, Beijing 100091, China

Received Date: 2013-07-25

Abstract: The data of 25 years’ positional observation were used to investigate the effects of self-pruning on Chinese fir (Cunninghamia lanceolata) plantations. The study examined five initial density levels (2m×3m, 2m×1.5m, 2m×1m, 1m×1.5m, and 1m×1m) with three replications at each level based on the randomized block design. The higher the initial planting density, the sooner the self-pruning happened and the higher the self-pruning intensity was. While living crown ratio (CL/TH) decreased to 0.4, the CL/TH ratio fluctuation tended to a constant. When the CL/TH ratio decreased to 0.3, the self-thinning happened, regardless the initial planting density and mortality. When self-pruning happened, the ratio of tree crown width to the living crown height (CW/CH) rapidly increased, then slowly increased during the early self-thinning and increased rapidly again during the late self-thinning. However, the CW/CH ratio was always below 1. Allocation pattern with assimilation matter changed when self-pruning happened, and stem form index (H/D) decreased when the living crown ratio increased.

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Reference (18)

[1]	Cornelius J P. The effectiveness of pruning in mitigating Hypsipyla grandella attack on young mahogany (Swietenia macrophylla King) trees [J]. Forest Ecology and Management, 2001, 148(1-3): 287-289.
[2]	Douglas G P, Bell F W. Effects of stand tending on the estimation of aboveground biomass of planted juvenile white spruce [J]. Canadian Journal of Forest Research, 2004, 34(3): 649-658.
[3]	Smith R G B, Dingle J, Kearney D, et al. Branch occlusion after pruning in four contrasting sub-tropical eucalypt species [J]. Journal of Tropical Forest Science, 2006, 18(2): 117-123.
[4]	Luckhofhf A. Pruning of Eucalyptus grandis [J]. Forestry in South Africa, 1967, 8: 75-85.
[5]	Majidn M, Paudyabl K. Pruning trial for Acacia mangium Wild. plantation in Peninsular Malaysia [J]. Forest Ecology and Management, 1992, 47(1-4): 285-393.
[6]	Reichp B, Waltersm B, Krauses C, et al. Growth, nutrition and gas exchange of Pinus resinosa following artificial defoliation [J]. Trees, 1993, 7(2): 67-77.
[7]	Uotila A, Mustonen S. The effect of different levels of green pruning on the diameter growth of Pinus sylvestris L.[J]. Scandinavian Journal of Forestry Research, 1994, 9(1-4): 226-232.
[8]	Makella A. A carbon balance model of growth and self-pruning in trees based on structural relationships [J]. Forest Science, 1997, 43(1): 7-23.
[9]	Mäkinen H. Growth, suppression, death, and self-pruning of branches of Scots pine in southern and central Finland [J]. Canadian Journal of Forest Research, 1999, 29(4): 585-594.
[10]	O'Harak K L. A biological justification for pruning in coastal Douglas fir stands [J]. Western Journal of Applied Forestry, 1991,6(3): 59-63.
[11]	黄冶,袁玉峰,孔红娃.修枝对红松人工林林木生长和木材力学性质的影响 [J]. 东北林业大学学报,2002,30(1): 76-77.
[12]	段爱国,赵世荣,章允清,等. 杉木中密度幼林光环境与生长修枝效应[J]. 福建林学院学报,2009,29(4):340-344.
[13]	程朝阳. 杉木人工林无节材培育技术研究 [J]. 林业科学研究,2005,18(5): 530-534.
[14]	张群. 人工修枝对提高杉木木材质量影响的研究[D]. 北京:中国林业科学研究院,2011.
[15]	肖祥希. 修枝对福建柏林分生长及无节材形成的影响 [J]. 林业科学研究,2005,18(1):22-26.
[16]	陈森锟,尹伟伦,刘晓东,等. 修枝对欧美107杨木材生长量的短期影响 [J]. 林业科学,2008,44(7):130-135.
[17]	Sun H, Zhang J, Duan A, et al. Estimation of the self-thinning boundary line within even-aged Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) stands: Onset of self-thinning [J]. Forest Ecology and Management, 2011,261(6): 1010-1015.
[18]	Bouvet J, Vigeron P, Saya A. Phenotypic plasticity of growth trajectory and ontogenic allometry in response to density for eucalyptus hybrid clones and families [J]. Annals of Botany, 2005,96(5): 811-821.

Study on the Self-pruning of Chinese Fir Plantation

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References

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