Chin J Plant Ecol ›› 2006, Vol. 30 ›› Issue (5): 810-816.DOI: 10.17521/cjpe.2006.0103

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A STUDY ON VEGETATIVE COMPENSATORY GROWTH OF SHRUB, CARAGANA KORSHINSKII, UNDER DIFFERENT CLIPPING TREATMENTS IN DISTURBANCE ENVIRONMENT

FANG Xiang-Wen1, WANG Wan-Peng2, HE Xiao-Qin3, WANG Gang1,*()   

  1. 1 Key Laboratory of Arid and Grassland Agroecology at Lanzhou University, Ministry of Education, Lanzhou 730000, China
    2 Lanzhou Administration of Environment and Afforestation of South-North Mountains, Lanzhou, 730046, China
    3 Forestry College of Gansu Agricultural University, Lanzhou, 730070, China
  • Received:2005-06-06 Accepted:2005-10-30 Online:2006-06-06 Published:2006-09-30
  • Contact: WANG Gang

Abstract:

Background and Aims After browsing or clipping, Caragana korshinskii can compensate for loss of biomass, which is the foundation for repeated use of resources of this species. However, the pattern of vegetative compensatory growth under different clipping treatments is still poorly understood.

Methods In order to test the effects of removal of partial shoot length (RSL) and partial shoot number (RSN) on vegetative growth, we removed 30% (30%RSL), 60% (60%RSL) of main shoot length, and 25% (25%RSN), 50% (50%RSN), and 100% (100%RSN) of main shoot number.

Key Results Clipped shrubs overcompensated for tissue loss, and current year shoot number per shoot, current year shoot length, current year shoot biomass per shoot and current year shoot biomass per shrub were higher than those of the control. The control, 30%RSL and 60%RSL shrubs did not resprout after clipping, while 25%RSN, 60%RSN and 100%RSN treatments did resprout and the biomass per shrub increased when more shoot biomass were removed. Differences in resprout number per removal shoot, resprout length, individual resprout biomass were not significant between 25%RSN and 50%RSN treatment, but resprout number per removal shoot, resprout length, individual resprout biomass of both were less than those of 100%RSN treatment. Fruit production in clipping treatments was higher or equal to that of the control with the exception of 100%RSN, which grew no fruit. There was a negative relationship between annual shoot biomass and fruit production with the exception of the control, which had less fruit production and the annual shoots almost did not grow. During growth season, biomass of current year vegetative growth increased quickly from current year's shoot growth to fruit ripeness. In the following three months, from fruit ripeness to leaf abscission, however, it increased slowly.

Conclusions 100%RSN treatment may be a reasonable mode to prompt shrubs to recover quickly from damage. Plants' responses associated with compensation may include: increased branching or tillering after alteration of the apical dominance, increased availability of water and/or nutrients after the change in the ratio of shoot to root, and remobilization of resources reserved in roots to aboveground organs. Decreased allocation of resources to reproductive growth may be another important mechanism for 100%RSN shrubs to compensate for the loss of organs.

Key words: Caragana korshinskii, Current year shoot, Resprout, Vegetative compensatory growth, Clipping