1
|
Liao X, Wang Y, Malghani S, Zhu X, Cai W, Qin Z, Wang F. Methane and nitrous oxide emissions and related microbial communities from mangrove stems on Qi'ao Island, Pearl River Estuary in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:170062. [PMID: 38220023 DOI: 10.1016/j.scitotenv.2024.170062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 01/16/2024]
Abstract
Mangrove forests, crucial carbon-rich ecosystems, are increasingly vulnerable to soil carbon loss and greenhouse gas (GHG) emissions due to human disturbance. However, the contribution of mangrove trees to GHG emissions remains poorly understood. This study monitored CO2, CH4, and N2O fluxes from the stems of two mangrove species, native Kandelia obovata (KO) and exotic Sonneratia apetala (SA), at three heights (0.7 m, 1.2 m, and 1.7 m) during the dry winter period on Qi'ao Island, Pearl River Estuary, China. Heartwood samples were analyzed to identify potential functional groups related to gas fluxes. Our study found that tree stems acted as both sinks and sources for N2O (ranging from -9.49 to 28.35 μg m-2 h-1 for KO and from -6.73 to 28.95 μg m-2 h-1 for SA) and CH4. SA exhibited significantly higher stem CH4 flux (from -26.67 to 97.33 μg m-2 h-1) compared to KO (from -44.13 to 88.0 μg m-2 h-1) (P < 0.05). When upscaled to the community level, both species were net emitters of CH4, contributing approximately 4.68 % (KO) and 0.51 % (SA) to total CH4 emissions. The decrease in stem CH4 flux with increasing height, indicates a soil source. Microbial analysis in the heartwood using the KEGG database indicated aceticlastic methanogenesis as the dominant CH4 pathway. The presence of methanogens, methanotrophs, denitrifiers, and nitrifiers suggests microbial involvement in CH4 and N2O production and consumption. Remarkably, the dominance of Cyanobacteria in the heartwood microbiome (with the relative abundance of 97.5 ± 0.6 % for KO and 99.1 ± 0.2 % for SA) implies roles in carbon and nitrogen fixation for mangroves coping with nitrogen limitation in coastal wetlands, and possibly in CH4 production. Although the present study has limitations in sampling duration and area, it highlights the significant role of tree stems in GHG emissions which is crucial for a holistic evaluation of the global carbon sequestration capability of mangrove ecosystems. Future research should broaden spatial and temporal scales to enhance the accuracy of upscaling tree stem gas fluxes to the mangrove ecosystem level.
Collapse
Affiliation(s)
- Xiaolin Liao
- College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Ying Wang
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China
| | - Saadatullah Malghani
- College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, Jiangsu, China; Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Copenhagen, Denmark
| | - Xudong Zhu
- Key Laboratory of the Coastal and Wetland Ecosystems (Ministry of Education), College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian, China; Fujian Key Laboratory of Severe Weather, Fuzhou 350008, Fujian, China
| | - Wenqi Cai
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China
| | - Zhangcai Qin
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China; Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Zhuhai 519082, China
| | - Fan Wang
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, Guangdong, China; Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Zhuhai 519082, China; School of Ecology, Sun Yat-sen University, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, Guangdong, China.
| |
Collapse
|
2
|
Variability in Stem Methane Emissions and Wood Methane Production of Tree Different Species in a Cold Temperate Mountain Forest. Ecosystems 2022. [DOI: 10.1007/s10021-022-00795-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|