Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (11): 1231-1240.DOI: 10.17521/cjpe.2021.0135

• Research Articles • Previous Articles     Next Articles

Responses of biomass allocation patterns to nitrogen addition of Cunninghamia lanceolata seedlings

WANG Jiao1,3, GUAN Xin1,2, ZHANG Wei-Dong1,2, HUANG Ke1,2, ZHU Mu-Nan1,2, YANG Qing-Peng1,2,*()   

  1. 1Huitong Experimental Station of Forest Ecology, Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
    2Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical Forest, Huitong, Hunan 418307, China
    3College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
  • Received:2021-04-09 Accepted:2021-07-08 Online:2021-11-20 Published:2021-09-18
  • Contact: YANG Qing-Peng
  • Supported by:
    National Natural Science Foundation of China(41630755);National Natural Science Foundation of China(41977092);National Natural Science Foundation of China(41877092)


Aims Sharply increasing atmospheric nitrogen (N) deposition may have profound effects on carbon (C) fixation and allocation of plants. However, a comprehensive understanding of how nitrogen addition influences allocation dynamics of carbohydrates among different organs in plants is still lacking.
Methods In this study, a pot experiment of seedlings of Cunninghamia lanceolate was established to investigate the allocation pattern and regulation mechanism of non-structural carbohydrates (NSC) and structural carbohydrates (SC) in different organs of C. lanceolate seedlings after N addition. The concentrations and pool sizes of NSC and SC were measured.
Important findings The results showed that: (1) N addition significantly increased the net photosynthetic rate by 143.96%, but decreased the concentration and pool size of NSC in needles. There was no significant change in the components of NSC concentration and pool in current-year stems. Furthermore, N addition resulted in a significant decrease in the starch concentration of one-year-old stems, but a non-significant change in soluble sugar concentration. In addition, the components of NSC concentration and pool in seedlings roots also tended to decrease. (2) After N addition, the ratio of below- to above-ground biomass decreased by 22.09%, and the ratio of below- to above-ground SC pool also decreased by 31.07%, and the ratio of below- to above-ground NSC pool showed no significant difference between control and N addition treatment. (3) N addition significantly increased the phosphorus (P) pool size in the above-ground part and decreased the ratio of below- to above-ground P pool, while the ratio of below- to above-ground N pool showed no obvious difference between control and N addition treatment. (4) Under N addition, soil pH decreased significantly from 4.94 to 4.02, ammonium and nitrate nitrogen concentration increased by 7.17 times and 11.55 times, respectively, and soil available P concentration increased by 42.86%, while the activities of urease (62.75%) and acid phosphatase (56.52%) in the soil decreased significantly compared to control. Our results indicates that C. lanceolate seedlings increased nutrient uptake amount mainly by the construction of root structure, but not by the allocation of more NSC to the root under low nutrient conditions, while nutrient alleviation driven by nitrogen addition resulted in more carbohydrates allocation to above-ground organs, resulting in the accumulation of SC in above-ground parts.

Key words: nitrogen addition, biomass allocation, carbohydrates, non-structural carbohydrates, phosphorus, optimal partitioning theory