植物生态学报 ›› 2025, Vol. 49 ›› Issue (4): 526-539.DOI: 10.17521/cjpe.2024.0253  cstr: 32100.14.cjpe.2024.0253

• 研究论文 • 上一篇    下一篇

淹水高度增加对短叶茳芏潮汐湿地净生态系统CO2交换量的影响

李琳1, 黄佳芳1,3,*(), 丁中浩1, 郭萍萍3, 蔡芫镔2, 李诗华4, 李云琴2, 罗敏2,*()   

  1. 1福建师范大学地理研究所, 福州 350117
    2福州大学环境与安全工程学院, 福州 350116
    3福建闽江河口湿地生态系统定位观测研究站(国家林业和草原局), 福州 350215
    4福州大学先进制造学院, 福建泉州 362251
  • 收稿日期:2024-07-31 接受日期:2025-01-03 出版日期:2025-04-20 发布日期:2025-04-18
  • 通讯作者: * (Huang JF, wahugeo@fjnu.edu.cn;Luo M, luomin@fzu.edu.cn)
  • 基金资助:
    福建省科技厅公益类项目(2022R1002007);国家自然科学基金(32071598);福建省自然科学基金(2020J01503);福建省林业科技项目(2021FKJ30)

Impact of increased inundation height on the net ecosystem CO2 exchange in a Cyperus malaccensis tidal marsh

LI Lin1, HUANG Jia-Fang1,3,*(), DING Zhong-Hao1, GUO Ping-Ping3, CAI Yuan-Bin2, LI Shi-Hua4, LI Yun-Qin2, LUO Min2,*()   

  1. 1Institute of Geography, Fujian Normal University, Fuzhou 350117, China
    2College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350116, China
    3Wetland Ecosystem Research Station of Minjiang Estuary, National Forestry and Grassland Administration, Fuzhou 350215, China
    4College of Advanced Manufacturing, Fuzhou University, Quanzhou, Fujian 362251, China
  • Received:2024-07-31 Accepted:2025-01-03 Online:2025-04-20 Published:2025-04-18
  • Contact: * (Huang JF, wahugeo@fjnu.edu.cn;Luo M, luomin@fzu.edu.cn)
  • Supported by:
    Public Welfare Project of Science and Technology Department of Fujian Province(2022R1002007);National Natural Science Foundation of China(32071598);Natural Science Foundation of Fujian Province(2020J01503);Science and Technology Projects of the Forest Bureau of Fujian Province(2021FKJ30)

摘要:

海平面上升引起的淹水高度增加将改变潮汐湿地的碳循环过程。然而, 目前的研究主要集中在淹水高度增加对土壤总碳库的影响上, 对于其如何影响碳收支的平衡尚未厘清。基于此, 该研究在闽江河口潮汐湿地搭建“沼泽管”实验平台, 并设置CK (对照)、CK + 20 cm、CK + 40 cm 3种淹水处理, 模拟当前、未来50年和100年的海平面上升情景。通过测定淹水高度增加对短叶茳芏(Cyperus malaccensis)沼泽湿地净生态系统CO2交换量(NEE)、总初级生产力(GPP)、生态系统呼吸(ER)、植物生物量、植物光合特性指标和土壤理化指标的影响, 从而明晰海平面上升对潮汐湿地碳收支平衡的影响。研究结果表明: 淹水高度增加导致短叶茳芏地上生物量减少, 地下生物量增加。与CK相比, CK + 20 cm和CK + 40 cm处理中, GPP分别降低27%和32%, ER分别增加20%和58%。GPP的减少与淹水高度增加后地上生物量的减少和植物光合特性指标(净光合速率、气孔导度、胞间CO2浓度)的下降有关; 而ER的增加与淹水高度增加后土壤氧化还原电位和可溶性有机碳含量的增加相关。在CK、CK + 20 cm、CK + 40 cm 3种淹水处理下, NEE分别为-539.8、-102.7和185.6 g C·m-2·a-1。上述结果表明, 海平面上升情景下短叶茳芏沼泽湿地碳收支平衡被破坏。淹水高度增加20 cm, NEE增加, 表明短叶茳芏沼泽湿地碳吸收能力减弱; 淹水高度增加40 cm, NEE由负值转变为正值, 表明短叶茳芏沼泽湿地生态系统由碳吸收转变为碳排放。该研究为预测和应对未来海平面上升对潮汐湿地碳循环的影响提供了科学依据。

关键词: 淹水高度增加, 净生态系统CO2交换量, 总初级生产力, 生态系统呼吸, 短叶茳芏, 潮汐湿地

Abstract:

Aims Rising sea levels and the associated increase in inundation heights will alter the carbon (C) cycle in tidal marshes. However, current research primarily focuses on the impact of increased inundation on total soil C stocks, while the effects on the balance of C budget processes remain unclear. Therefore, understanding how sea level rise affects the C sequestration capacity of tidal marshes is essential for predicting future impacts.

Methods To address this, our study established a “marsh organ” experimental platform in the tidal marshes of the Minjiang River Estuary. Three inundation treatments—CK (control), CK + 20 cm, and CK + 40 cm—simulated the current and the projected sea level rise scenarios for the next 50 and 100 years. We measured the effects of increased inundation on the net ecosystem carbon dioxide exchange (NEE), gross primary productivity (GPP), ecosystem respiration (ER), plant biomass, plant photosynthetic characteristics, and soil physicochemical properties of the Cyperus malaccensis tidal marshes.

Important findings The results showed that increased inundation height led to a decrease in aboveground biomass and an increase in belowground biomass. Compared to the CK, GPP decreased by 27% and 32%, while ER increased by 20% and 58% in the CK + 20 cm and CK + 40 cm treatments, respectively. The reduction in GPP was related to decreased aboveground biomass and declining plant photosynthetic characteristics, such as net photosynthetic rates, stomatal conductance, intercellular CO2 concentrations. The increase in ER was associated with higher soil oxidation-reduction potential and dissolved organic carbon content. Under the CK, CK + 20 cm, and CK + 40 cm treatments, NEE was -539.8, -102.7, and 185.6 g C·m-2·a-1, respectively. These findings indicate that a 20 cm increase in inundation height leads to an increase in NEE, demonstrating a weakened carbon sequestration capacity of the Cyperus malaccensis tidal marshes. Furthermore, a 40 cm increase in inundation height results in NEE shifting from negative to positive, indicating a transition of the ecosystem from a carbon sink to a carbon source. This research provides a scientific basis for predicting and mitigating the impacts of future sea level rise on the C cycle of tidal marsh.

Key words: enhanced inundation height, net ecosystem CO2 exchange, gross primary productivity, ecosystem respiration, Cyperus malaccensis, tidal marsh