植物生态学报 ›› 2021, Vol. 45 ›› Issue (7): 760-770.DOI: 10.17521/cjpe.2020.0420

所属专题: 生态化学计量

• 研究论文 • 上一篇    下一篇

古尔班通古特沙漠一年生植物的氮吸收策略

侯宝林, 庄伟伟()   

  1. 新疆特殊环境物种多样性应用与调控重点实验室, 乌鲁木齐 830000; 新疆特殊环境物种多样性应用与调控重点实验室, 乌鲁木齐 830000; 新疆师范大学干旱区植物逆境生物学实验室, 乌鲁木齐 830000; 中亚区域有害生物联合控制国际研究中心, 乌鲁木齐 830000
  • 收稿日期:2020-12-17 接受日期:2021-05-17 出版日期:2021-07-20 发布日期:2021-10-22
  • 通讯作者: 庄伟伟
  • 作者简介:* zww8611@sina.com
  • 基金资助:
    国家自然科学基金(41763009)

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)

摘要:

同一生活型的植物可能通过吸收不同形态的氮来利用陆地生态系统中有限的氮, 避免和减少对资源的竞争, 从而完成共生。研究荒漠生态系统同一生活型植物对氮的利用是否存在生态位分离, 有助于深入了解荒漠植物的生存策略, 更好掌握氮利用对荒漠植物生存的影响。该研究利用15N同位素示踪法, 研究古尔班通古特沙漠中广泛分布的2种一年生植物——角果藜(Ceratocarpus arenarius)和碱蓬(Suaeda glauca)在不同月份和不同土壤深度对不同形态氮的吸收策略。结果显示, 在浅层土壤中, 2种植物7月的氮吸收速率均高于6月; 对比不同形态氮的吸收速率, 植物对无机氮的吸收均高于有机氮, 角果藜更偏好吸收硝态氮, 每克干根系最高氮吸收速率可达3.81 μg·h-1, 碱蓬更偏好吸收铵态氮, 每克干根系最高氮吸收速率可达4.74 μg·h-1; 从不同形态氮对总氮的贡献率看, 硝态氮是角果藜吸收氮的有利形态, 占比在35.7%-43.9%之间, 铵态氮是碱蓬吸收氮的有利形态, 占比最高可达48.3%, 最低也有40.0%。2种一年生植物不仅可以利用土壤中的无机氮, 也可以直接吸收利用土壤有机氮。研究结果表明: 在古尔班通古特沙漠生态系统中, 一年生植物对氮的吸收能力有着差异和多元化的特点, 且均可吸收土壤中的可溶性有机态氮源。

关键词: 一年生植物, 同位素标记, 氮吸收, 古尔班通古特沙漠

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