Temporal variations of carbon and water fluxes in a subtropical mangrove forest: Insights from a decade-long eddy covariance measurement

• Published in: Agricultural and forest meteorology Vol. 343; p. 109764
• Main Authors: Gou, Ruikun, Buchmann, Nina, Chi, Jinshu, Luo, Yunpeng, Mo, Lidong, Shekhar, Ankit, Feigenwinter, Iris, Hörtnagl, Lukas, Lu, Weizhi, Cui, Xiaowei, Meng, Yuchen, Song, Shanshan, Lin, Guangxuan, Chen, Yuechao, Liang, Jie, Guo, Jiemin, Peng, Haijun, Lin, Guanghui
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2023
• Subjects: Blue carbon; CO2 budget; Coastal wetland; Evapotranspiration; Forest Science; Meteorologi och atmosfärforskning; Meteorology and Atmospheric Sciences; Net ecosystem production; Skogsvetenskap; Blue carbon; CO2 budget; Coastal wetland; Net ecosystem production; Evapotranspiration
• ISSN: 0168-1923; 1873-2240; 1873-2240
• DOI: 10.1016/j.agrformet.2023.109764

•CO2 and H2O fluxes were measured in a subtropical mangrove forest over the decade.•This mangrove forest acted as a strong CO2 sink during the study period.•Global solar radiation and VPD primarily drove the mangrove NEP in the dry season.•Meteorological and tidal factors jointly controlled the NEP in the wet season.•The importance of certain climate conditions on NEP and ET changed over ten years. Mangroves, highly efficient ecosystems in sequestering CO2, are strongly impacted by climate change. The lack of long-term observation in mangroves hinders the evaluation of seasonal and inter-annual variability in carbon and water fluxes and their responses to various environmental drivers. In this study, we measured net ecosystem CO2 exchange and evapotranspiration between the atmosphere and subtropical mangroves using the eddy covariance technique over a decade (2010–2019) in southern China. This mangrove forest acted as a strong CO2 sink, with annual net ecosystem production (NEP) ranging from 622.5 to 832.8 g C m−2 year−1. The annual evapotranspiration (ET) varied between 934.6 and 1004.9 mm year−1. During the study period, ET consistently remained higher in the wet season (May to October) compared to the dry season, while NEP did not exhibit consistent seasonal variation. Path analysis indicated that during the dry season, NEP was primarily influenced by global solar radiation and vapor pressure deficit. However, in the wet season, NEP was regulated by a combination of global solar radiation, vapor pressure deficit, air temperature, and tidal inundation time. Additionally, the promoting effect of global solar radiation on NEP decreased in the wet season, while the inhibitory influences of higher temperature and vapor pressure deficit on NEP intensified during the period. Unlike NEP, the dominant factors affecting ET (global solar radiation, air temperature, and vapor pressure deficit) and their intensities remained relatively consistent during both seasons. Furthermore, the relative importance of global solar radiation on NEP and ET increased over the decade, while the influence of tidal inundation time diminished. This study not only improves the understanding of the response of subtropical mangroves to climate change but also provides a valuable benchmark dataset to validate the interannual variability of mangrove carbon and water fluxes estimated from the models.