Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (7): 760-770.DOI: 10.17521/cjpe.2020.0420

Special Issue: 生态化学计量

• Research Articles • Previous Articles     Next Articles

Nitrogen uptake strategy of annual plants in Gurbantünggüt Desert

HOU Bao-Lin, ZHUANG Wei-Wei()   

  1. Key Laboratory of Special Environment Biodiversity Application and Regulation in Xinjiang, Ürümqi 830000, China; Key Laboratory of Special Environment Biodiversity Application and Regulation in Xinjiang, Ürümqi 830000, China; Key Laboratory of Plant Stress Biology in Arid Land, Xinjiang Normal University, Ürümqi 830000, China;
  • Received:2020-12-17 Accepted:2021-05-17 Online:2021-07-20 Published:2021-10-22
  • Contact: ZHUANG Wei-Wei
  • Supported by:
    National Natural Science Foundation of China(41763009)

Abstract:

Aims Plants of the same life-form may utilize different forms of nitrogen to avoid or reduce the competition for resources, thus achieving co-existence. Studying on whether niche separation exists in nitrogen uptake by plants of the same life-form in desert ecosystems is helpful to understand the survival strategy of desert plants and the effect of nitrogen on the survival of desert plants.

Methods Two annual plants, Ceratocarpus arenarius and Suaeda glauca, are widely distributed in Gurbantünggüt Desert. 15N isotope tracer method was used to study the nitrogen uptake strategies of two desert annuals in different months and from different soil layers.

Important findings The results showed that the nitrogen absorption rates of the two plants in shallow soil were higher in July than those in June. Comparing the absorption rates of different nitrogen forms, plants preferred inorganic nitrogen to organic nitrogen. Ceratocarpus arenarius preferred nitrate nitrogen, and the highest nitrogen absorption rate was 3.81 μg·h-1 per gram dry root, while S. glauca preferred ammonium nitrogen, and the highest nitrogen absorption rate was 4.74 μg·h-1 per gram dry root. The contribution rates of nitrate nitrogen out of total nitrogen uptake ranged from 35.7% to 43.9% for C. arenarius; while the contribution rate of ammonium nitrogen out of total nitrogen uptake ranged from 40.0% to 48.3% for S. glauca. The two annual plants can not only utilize inorganic nitrogen, but also directly absorb organic nitrogen in soil. The findings showed that the nitrogen uptake capacity of annual plants in Gurbantünggüt desert was different and diversified, and all of them could absorb the soluble organic nitrogen sources in the soil.

Key words: annual plant, isotopic labeling, nitrogen absorption, Gurbantünggüt desert