植物生态学报 ›› 2023, Vol. 47 ›› Issue (11): 1493-1506.DOI: 10.17521/cjpe.2022.0426

• 研究论文 • 上一篇    下一篇

模拟氮沉降对鄂西南湿地泥炭藓生理及形态特征的影响

余玉蓉1,2, 吴浩1,2, 高娅菲1,2, 赵媛博1,2, 李小玲2,3, 卜贵军1,2, 薛丹4, 刘正祥5, 武海雯5, 吴林1,2,*()   

  1. 1生物资源保护与利用湖北省重点实验室, 湖北恩施 445000
    2湖北民族大学林学园艺学院, 湖北恩施 445000
    3湖北省农业科学院中药材研究所, 湖北恩施 445000
    4中国科学院山地生态恢复与生物资源利用重点实验室, 生态恢复与生物多样性保育四川省重点实验室, 中国科学院成都生物研究所, 成都 610041
    5中国林业科学研究院生态保护与修复研究所, 北京 100091
  • 收稿日期:2022-10-28 接受日期:2023-02-15 出版日期:2023-11-20 发布日期:2023-12-22
  • 通讯作者: 吴林 (wulin20054557@163.com)
  • 基金资助:
    国家自然科学基金(41867042);中央级公益性科研院所基本科研业务费专项资金项目(CAFYBB2020ZC005)

Effects of simulated nitrogen deposition on physiological and morphological characteristics of Sphagnum in wetland, southwestern Hubei Province, China

YU Yu-Rong1,2, WU Hao1,2, GAO Ya-Fei1,2, ZHAO Yuan-Bo1,2, LI Xiao-Ling2,3, BU Gui-Jun1,2, XUE Dan4, LIU Zheng-Xiang5, WU Hai-Wen5, WU Lin1,2,*()   

  1. 1Biological Resources Protection and Utilization of the Key Laboratory of Hubei Province, Enshi, Hubei 445000, China
    2Forestry and Horticulture College, Hubei Minzu University, Enshi, Hubei 445000, China
    3Institute of Chinese Herbal Medicines, Hubei Academy of Agricultural Sciences, Enshi, Hubei 445000, China
    4Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
    5Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
  • Received:2022-10-28 Accepted:2023-02-15 Online:2023-11-20 Published:2023-12-22
  • Contact: WU Lin (wulin20054557@163.com)
  • Supported by:
    National Natural Science Foundation of China(41867042);Basic Research Funds for Public Welfare Research Institutes of the Central Government(CAFYBB2020ZC005)

摘要:

泥炭藓(Sphagnum)作为泥炭藓湿地中的优势种, 是泥炭藓湿地最主要的固碳(C)植物, 其生理与形态特征关系着泥炭藓湿地的碳汇潜力。氮(N)沉降对泥炭藓生理和形态特征具有显著影响, 但有关N沉降对湿地泥炭藓生理及形态特征的影响还存在很大的争议, 并且N沉降对亚热带湿地泥炭藓生理及形态特征影响的研究鲜有报道。该研究以鄂西南泥炭藓湿地为研究对象, 通过原位喷洒不同浓度的NH4Cl溶液, 探讨模拟N沉降对泥炭藓生理及形态特征的影响。模拟N浓度设置4个水平, 分别为0 (N0)、3 (N3)、6 (N6)、12 g·m-2·a-1 (N12), 其中N0为对照(CK)。研究结果表明: (1) N沉降对泥炭藓体内总C、总N含量有显著影响。其中, N3处理下的总C、总N含量最高, 相比于CK分别增加了3.78%和88.52%。(2) N沉降对泥炭藓叶绿素含量和荧光活性影响不显著, 但对泥炭藓抗氧化酶活性和渗透调节物质的含量有显著促进作用, 尤其是可溶性糖含量与过氧化物酶活性。(3)随N沉降量增加, 泥炭藓株高、分枝数、单株质量及叶细胞面积均表现为先增加后降低趋势, 且最大值出现在N3处理。(4)泥炭藓对N沉降很敏感, 2年的N沉降对泥炭藓的生理及形态特征的影响存在一定的N沉降负荷值, 约为3 g·m-2·a-1, 大于该值后, 泥炭藓各类形态指标受到抑制, 受到胁迫显著增加。该研究表明, 当前自然大气N沉降量对鄂西南湿地泥炭藓生长有一定的促进作用, 但持续或加倍的N沉降可能会对泥炭藓生长造成伤害。

关键词: 泥炭藓, 氮输入, 叶绿素, 抗氧化酶, 形态

Abstract:

Aims Sphagnum, as the dominant species in Sphagnum wetland, is the most important carbon (C) sequestration plant. The physiological and morphological characteristics of Sphagnum determine the carbon sink potential of Sphagnum wetland. Nitrogen (N) deposition has a significant effect on the physiological and morphological characteristics of Sphagnum,but the effects of N deposition on such characteristics of Sphagnum in the wetland environment remain controversial. Moreover, there are few reports on the physiological and morphological characteristics of Sphagnum in subtropical wetlands.

Methods We selected a Sphagnum wetland in southwestern Hubei Province as the study area. Different concentrations of NH4Cl solution were sprayed in situto investigate the effects of simulated N deposition on physiological and morphological characteristics of Sphagnum. Four N concentrations were applied, namely 0 (N0), 3 (N3), 6 (N6) and 12 g·m-2·a-1 (N12), with N0 representing the control (CK).

Important findings (1) Nitrogen deposition had significant effects on the contents of total C and total N in Sphagnum. Among the treatments, the contents of total C and total N in Sphagnumunder the N3 treatment were the highest, and compared with those of the CK, increased by 3.78% and 88.52%, respectively. (2) Nitrogen deposition had no obvious effect on chlorophyll content and fluorescence activities of Sphagnum. However, N deposition significantly promoted the antioxidant enzyme activities and the contents of osmotic substances in Sphagnum,especially the contents of soluble sugars and peroxidase activity. (3) With the increase in N deposition, the height, branch number, mass per plant, and leaf cell area of Sphagnum tended to initially increase and thereafter decrease. The maximum values were observed in response to N deposition of 3 g·m-2·a-1. (4) Sphagnum was sensitive to N deposition, and there was a certain load value of the effect of N deposition on physiological and morphological characteristics of Sphagnumafter 2 years treatment, which was approximately 3 g·m-2·a-1. When the amount of N deposition is greater than 3 g·m-2·a-1, the effects on morphological indicators of Sphagnum are detrimental and the stress to Sphagnumwill increase significantly. The results of this study indicated that the current natural atmospheric N deposition is beneficial to the growth of Sphagnum in the wetland in southwestern Hubei Province. However, continual or doubled N deposition might be harmful to the growth of Sphagnum.

Key words: Sphagnum, nitrogen input, chlorophyll, antioxidant enzymes, morphology