植物生态学报 ›› 2018, Vol. 42 ›› Issue (7): 774-784.DOI: 10.17521/cjpe.2018.0104

所属专题: 红树林及红树植物 入侵生态学

• 研究论文 • 上一篇    下一篇

互花米草入侵对漳江口红树林湿地土壤有机碳官能团特征的影响

孙慧敏1,姜姜1,*(),崔莉娜1,张水锋2,张金池1   

  1. 1 南方现代林业协同创新中心, 南京林业大学江苏省水土保持与生态修复重点实验室, 南京 210037
    2 南京森林警察学院, 南京 210023
  • 出版日期:2018-07-20 发布日期:2018-09-26
  • 通讯作者: 姜姜
  • 基金资助:
    国家自然科学基金(41701225);江苏省自然科学基金BK20170920和江苏省研究生培养创新工程项目(KYCX17_0854)

Effects of Spartina alterniflora invasion on soil organic carbon composition of mangrove wetland in Zhangjiang River Estuary

SUN Hui-Min1, JIANG Jiang1,*(), CUI Li-Na1, ZHANG Shui-Feng2, ZHANG Jin-Chi1   

  1. 1 Co-Innovation Center of Sustainable Forestry in Southern China, Key Laboratory of Soil and Water Conservation and Ecological Restoration in Jiangsu Province, Nanjing Forestry University, Nanjing 210037, China
    2 Nanjing Forest Police College, Nanjing 210023, China
  • Online:2018-07-20 Published:2018-09-26
  • Contact: Jiang JIANG
  • Supported by:
    Supported by the National Natural Science Foundation of China(41701225);the Natural Science Foundation of Jiangsu Province (BK20170920), and the Postgraduate Research & Practice Innovation Program of Jiangsu Province(KYCX17_0854)

摘要:

红树林对全球气候变化敏感, 近年来不少区域又受互花米草(Spartina alterniflora)入侵的影响, 土壤碳库组成发生显著变化, 然而鲜有从有机碳官能团特征角度出发的关于两群落的研究。为了解在红树林群落与互花米草群落下土壤碳库及其有机碳官能团的特征差异, 在福建省云霄县漳江口红树林自然保护区湿地内由内陆到海岸方向选取3条样带, 每条样带依次选取3个样地: 红树林群落(MC)、秋茄(Kandelia obovata)-互花米草过渡带(TC)和互花米草群落(SC), 每个样地选取3个呈品字形分布的采样点, 分5层采集0-100 cm土壤样品, 分析土壤中的总有机碳(TOC)、颗粒有机碳(POC)以及可溶性有机碳(DOC)特征, 并利用核磁共振波谱法测定表层0-15 cm与深层75-100 cm土壤总有机碳官能团特征, 以空间换时间法研究入侵前后土壤碳库变化特征。结果表明: (1)从MC群落到SC群落, 土壤有机碳库显著减小, 各样地总有机碳与颗粒有机碳含量表现为MC > TC > SC, 并随着土层深度增加而减少, DOC含量没有表现出明显的变化趋势。(2)各植被类型土壤有机碳以烷基碳与烷氧碳为主, 其次是芳香碳与羰基碳, N-烷氧碳与酚基碳含量最少, 其中表层0-15 cm土壤从红树林群落到互花米草群落, 烷基碳与烷氧碳含量呈现增加趋势但不显著, 芳香碳与酚基碳含量显著减少, 其余有机碳组分含量无显著差异。在深层75-100 cm随着植被类型的改变, 土壤有机碳组成结构均无显著差异。(3)在0-15 cm土层, 烷基碳/烷氧碳含量表现为: SC > MC > TC; 芳香度表现为SC最小, MC与TC无显著差异; 疏水碳/亲水碳无显著差异; 脂族碳/芳香碳表现为SC显著大于其他两种植被类型, MC与TC无显著差异。在75-100 cm土层, 各比值无显著差异。综上所述, 红树林群落碳储量显著高于互花米草群落, 受植被的影响, 互花米草群落表层土壤有机碳分解程度显著高于红树林群落, 而红树林群落的土壤有机碳分子结构要比互花米草群落更复杂, 以维持其土壤有机碳的稳定性。因此, 互花米草入侵红树林后可能会加快有机碳的分解, 最终稳定在相对简单的分子结构, 降低土壤碳储量。

关键词: 互花米草, 红树林, 有机碳官能团, 核磁共振

Abstract:

Aims The composition of soil organic carbon has been changed significantly in mangrove ecosystems due to the invasion of Spartina alterniflora in recent years. However, few studies were reported on functional groups of soil organic carbon in the two communities. The object of this study was to understand the differences in soil carbon pool and organic carbon functional group characteristics in mangrove community and S. alterniflora community of Zhangjiang Mangrove Nature Reserve in Fujian Province.

Methods We used the method of “space for time” to study the changes of soil carbon composition following the invasion of S. alterniflora. Three transects were selected from landward to seaward in the wetland of Zhangjiang Mangrove Nature Reserve in Fujian Province, with three sampling sites in each transect: mangrove community (MC), transitional community (TC), and S. alterniflora community (SC). We sampled three plots in each site for replicates. Soil samples from five soil layers at 0-100 cm were collected to analyze the characteristics of total organic carbon (TOC), particulate organic carbon (POC) and dissolve organic carbon (DOC). Nuclear magnetic resonance (NMR) spectroscopy was used to analyze the functional group characteristics for surface (0-15 cm) and deep layers (75-100 cm).

Important findings We found that: (1) soil organic carbon decreased from MC to SC, with TOC and POC following the pattern of MC > TC > SC. However, the DOC did not show a clear trend. (2) The functional groups of soil organic carbon in all vegetation types were mainly alkyl carbon and alkoxy carbon, followed by aromatic carbon and carbonyl carbon. In the surface soil 0-15 cm, the alkyl carbon and alkoxy carbon showed an increasing trend from MC to SC. The aromatic carbon and phenolic carbon decreased from MC to SC. In the deep layer of 75-100 cm soil, however, soil organic carbon composition showed no significant difference among the three communities. (3) In the surface 0-15 cm soil, alkyl carbon/alkoxy carbon showed the following pattern: SC > MC > TC; SC has the least aromaticity; hydrophobic carbon/hydrophilic carbon showed no significant difference; aliphatic carbon/aromatic carbon showed larger values in SC than in MC and TC. At the depth of 75-100 cm, there were no significant differences for all the ratios. In summary, the carbon storage of MC was higher than that of SC. The decomposition rate of soil organic carbon of SC in surface soil layer was higher than that of MC, indicating more complex organic carbon in MC. The deep layer carbon pool was more stable and less affected by vegetation type. The results indicated that S. alterniflora would reduce soil carbon storage after invading mangroves, as well as changing the composition of soil organic carbon functional groups. The molecular structure of soil organic carbon in SC was simpler than MC, and the degree of decomposition was greater in SC than MC.

Key words: Spartina alterniflora, mangrove, organic carbon functional group, nuclear magnetic resonance