Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (9): 811-819.DOI: 10.3724/SP.J.1258.2013.00085

• Research Articles • Previous Articles     Next Articles

Biomass allocation of branches and leaves in Phyllostachys heterocycla‘Pubescens’ under different management modes: allometric scaling analysis

ZHU Qiang-Gen1, JIN Ai-Wu1,*(), WANG Yi-Kun1, QIU Yong-Hua2, LI Xue-Tao3, ZHANG Si-Hai1   

  1. 1Lishui College, Lishui, Zhejiang 323000, China
    2Suichang County Forestry Bureau, Suichang, Zhejiang 323300, China
    3Anji County Forestry Bureau, Anji, Zhejiang 313300, China
  • Received:2013-05-28 Accepted:2013-07-16 Online:2013-05-28 Published:2013-09-02
  • Contact: JIN Ai-Wu

Abstract:

Aims Allometric relationship between branch and leaf is limited by plant ontogeny and affected by environmental conditions, which is not well investigated in giant clone species such as Phyllostachys heterocycla‘Pubescens’. Our objectives were to study the effects of different management modes (obtruncation and fertilization) on branch and leaf biomass allocations ofP. heterocycla‘Pubescens’ and to discuss the effects within canopy.
Methods Obtruncation is a particular pruning operation cutting off the top (about 40%-70% canopy) of P. heterocycla‘Pubescens’. This management methods used in north Zhejiang of China to reduce trees falling from strong wind or heavy snow. A replicated 2 × 2 factorial experiment (obtruncation and fertilization) was established in Zhejiang Province in 2004. In 2010 and 2011, a total of 50 plants were cut down to investigate branch and leaf biomass, as well as leaf area of selected leaves within the canopy. Allometric scaling was applied to analyze the relation of branch and leaf biomass.
Important findings Averaged branch and leaf biomass for individual plant were decreased 40.23% and 41.01%, respectively, following obtruncation and increased 20.18% and 30.23%, respectively, following fertilization. Obtruncation severely changed the growth trajectory and resulted in a greater standardized major axis (SMA) slope, which indicated relatively more biomass was allocated to leaves. This was more significant under non-fertilization treatments. When compared to non-fertilization, fertilization significantly decreased SMA slope in unobtruncated trees, which was attributed to relatively larger leaf photosynthetic products partitioning to branches after fertilization. In addition, allocation patterns of branch and leaf biomass at different canopy parts were affected by light availability that was different in different fertilization treatments. Obtruncation changed SMA slope by nearly 50% and <10% for fertilization, which indicated that direct interference (obtruncation) easily changed the grown trajectory and indirect effects (fertilization) were more limited by plant ontogeny.

Key words: allometry, branch and leaf allocation, fertilization, obtruncation