Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (2): 177-.DOI: 10.17521/cjpe.2015.0182

• Research Articles • Previous Articles    

Effect of neighboring competition on photosynthetic characteristics and biomass allocation of Chinese fir seedlings under low phosphorus stress

Zhi-Yu CHEN1,2, Qi LI1,2,3, Xian-Hua ZOU1,2, Xiang-Qing MA1,2, Peng-Fei WU1,2,*()   

  1. 1College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China

    2The State Forestry Administration Fir Engineering Technology Research Center, Fuzhou 350002, China

    3Soil and Water Conservation Monitoring Centre of Zhumadian, Zhumadian, Henan 463000, China
  • Online:2016-02-10 Published:2016-03-08
  • Contact: Peng-Fei WU

Abstract: Aims

To explore the effects of neighbor competition on photosynthetic characteristics in needles and biomass accumulation and allocation of Chinese fir (Cunninghamia lanceolata) seedlings under low phosphorus (P) environment, and to investigate the complex adaptive responses of Chinese fir to available P limitation and intraspecific competition.


The experiment was performed in a greenhouse at Fujian Agriculture and Forestry University with a Chinese fir clone named 'YANG-020'. The specially designed glass pots of 30 cm length, 30 cm width and 40 cm height were made for the P stress and competition simulation. Two seedlings were planted in each pot, except the control with a single seedling in the center of pot. All the competition treatments were involved three P supply levels: no P supply (0 mg·kg-1 KH2PO4), low P supply (6 mg·kg-1 KH2PO4) and normal P supply (12 mg·kg-1 KH2PO4). The seedlings of each treatment were harvested to determine shoot biomass, root biomass and root: shoot ratio at the prime stage (9th September, 2013), interim stage (30th October, 2013) and last stage (19th December, 2013), separately, after determining the intercellular CO2 concentration, net photosynthetic rate, transpiration rate and stomatal conductance in needles over the the experimental period.Important findings There were significantly three-way interactive effects among competition treatment, P supply level and stress stage on the photosynthetic indexes of Chinese fir seedlings, including intercellular CO2 concentration, net photosynthetic rate, transpiration rate and stomatal conductance (p < 0.05), but no significantly interactive effect was exhibited among the three factors on the biomass allocation (p > 0.05). Compared to the normal P supply, all of the values (i.e., net photosynthetic rate, transpiration rate and stomatal conductance) decreased markedly in Chinese fir needles. The factors of low P supply and neighboring competition additively affected stomatal conductance of needles. Over the course of the stress experimental period, the value of transpiration rate in needles gradually decreased, but both root biomass and root:shoot ratio sharply increased. For the stomatal conductance and intercellular CO2 concentration, both of them gradually declined from the prime stress stage to the interim stage, while increased during the last stress stage.

Key words: assimilate transport, Cunninghamia lanceolata, competitive strategy, low phosphorus stress, root: shoot ratio