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Ren Y, Liu S, Luo H, Jiang Z, Liang J, Wu Y, Huang X, Macreadie PI. Seagrass decline weakens sediment organic carbon stability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 937:173523. [PMID: 38797423 DOI: 10.1016/j.scitotenv.2024.173523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/10/2024] [Accepted: 05/24/2024] [Indexed: 05/29/2024]
Abstract
Seagrass meadows are globally recognized as critical natural carbon sinks, commonly known as 'blue carbon'. However, seagrass decline attributed to escalating human activities and climate change, significantly influences their carbon sequestration capacity. A key aspect in comprehending the impact of seagrass decline on carbon sequestration is understanding how degradation affects the stored blue carbon, primarily consisting of sediment organic carbon (SOC). While it is widely acknowledged that seagrass decline affects the input of organic carbon, little is known about its impact on SOC pool stability. To address this knowledge, we examined variations in total SOC and recalcitrant SOC (RSOC) at a depth of 15 cm in nine seagrass meadows located on the coast of Southern China. Our findings revealed that the ratio of RSOC to SOC (RSOC/SOC) ranged from 27 % to 91 % in the seagrass meadows, and the RSOC/SOC increased slightly with depth. Comparing different seagrass species, we observed that SOC and RSOC stocks were 1.94 and 3.19-fold higher under Halophila beccarii and Halophila ovalis meadows compared to Thalassia hemprichii and Enhalus acoroides meadows. Redundancy and correlation analyses indicated that SOC and RSOC content and stock, as well as the RSOC/SOC ratio, decreased with declining seagrass shoot density, biomass, and coverage. This implies that the loss of seagrass, caused by human activities and climate change, results in a reduction in carbon sequestration stability. Further, the RSOC decreased by 15 %, 29 %, and 40 % under unvegetated areas compared to adjacent Halophila spp., T. hemprichii and E. acoroides meadows, respectively. Given the anticipated acceleration of seagrass decline due to climate change and increasing coastal development, our study provides timely information for developing coastal carbon protection strategies. These strategies should focus on preserving seagrass and restoring damaged seagrass meadows, to maximize their carbon sequestration capacity.
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Affiliation(s)
- Yuzheng Ren
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Hongxue Luo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Jiening Liang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Peter I Macreadie
- School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia; Biosciences and Food Technology Discipline, School of Science, RMIT University, Melbourne, VIC 3000, Australia
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Liu J, Failler P, Ramrattan D. Blue carbon accounting to monitor coastal blue carbon ecosystems. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 352:120008. [PMID: 38194876 DOI: 10.1016/j.jenvman.2023.120008] [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: 02/01/2023] [Revised: 12/30/2023] [Accepted: 12/30/2023] [Indexed: 01/11/2024]
Abstract
In the global context, countries must reduce carbon dioxide emissions to "net zero" by 2050 to limit global warming to 1.5 °C above pre-industrial levels. China's Nationally Determined Contributions (NDCs) are to peak carbon dioxide emissions by 2030 and achieve the carbon neutrality target by 2060. To monitor the achievements of the NDCs, establishing an annual-based accounting mechanism is necessary to record the carbon stocks in China, especially for Blue Carbon. The paper aims to present China's first national-scale systematic Blue Carbon accounting for mangroves, salt marshes, and seagrasses, covering the accounting subjects of physical and monetary assets, as well as relevant indicators for investors. It focuses on the design of the accounting method and system, the selection of data categories applied to this system, and the application of China's Blue Carbon accounting based on this accounting system. Taking Blue Carbon accounting as a starting point, this paper analyses the restoration prospects of these ecosystems and their application potential for NDCs in China compared with the terrestrial ecosystems. The results indicate that mangroves are the most cost-effective type of ecosystem, even compared to terrestrial forests. Thus, the paper provides policymakers with a new perspective on the decision-making of carbon sequestration relevant decisions, aiming to promote the monitoring, restoration, and expansion of China's coastal blue carbon ecosystem through the establishment of a sound Blue Carbon accounting system, and to help achieve the carbon neutrality goal in China's NDCs through regular and systematic monitoring of its national Blue Carbon inventories.
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Affiliation(s)
- Jiawen Liu
- University of Portsmouth, United Kingdom.
| | - Pierre Failler
- Centre for Blue Governance, University of Portsmouth, United Kingdom
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Liu S, Liang J, Jiang Z, Li J, Wu Y, Fang Y, Ren Y, Zhang X, Huang X, Macreadie PI. Temporal and spatial variations of air-sea CO 2 fluxes and their key influence factors in seagrass meadows of Hainan Island, South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 910:168684. [PMID: 37981158 DOI: 10.1016/j.scitotenv.2023.168684] [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: 11/20/2022] [Revised: 11/13/2023] [Accepted: 11/16/2023] [Indexed: 11/21/2023]
Abstract
Seagrass ecosystems have received a great deal of attention for contributing to uptake of atmospheric CO2, and thereby helping to mitigate global climate change ('blue carbon'). Carbon budgets for seagrass ecosystems are developed by estimating air-sea CO2 fluxes. Data for air-sea CO2 flux for tropical seagrass ecosystems are lacking, which is problematic for constraining global seagrass carbon budgets. Here, we sought to address this important data gap for tropical seagrass ecosystems (dominated by Thalassia hemprichii and Enhalus acoroides) from the Hainan Island of South China Sea, while also testing what the main factors driving the variations of air-sea CO2 fluxes are. We found that air-sea CO2 fluxes exhibited a U-shape diurnal variability from 6 a.m. to 6 a.m. of the next day, with the highest and lowest air-sea CO2 fluxes values at early morning and afternoon, respectively. Biological processes were the driving force for mediating diurnal variations of seawater pCO2. The pCO2, sea in different seasons displayed a trend of increasing from spring, reaching maximum in summer and then a decreasing trend after summer, where water temperature, wind speed and seagrass growth mainly drove the variations. This resulted in net uptake of CO2 in all seasons except during summer in our study seagrass ecosystems, with greater negative values found in autumn (-3.63 ± 0.76 mmol m-2 d-1) than those in winter (-2.84 ± 0.60 mmol m-2 d-1). While the nutrient loading induced seagrass biomass changes (especially the seagrass T. hemprichii), which mediated the air-sea CO2 fluxes changes among different seagrass meadows. Net annual CO2 uptake potential under low nutrient loading (-0.77 ± 0.16 mol m-2 yr-1) was 23-54 % greater than high nutrient loading seagrass meadows, with the average annual air-sea CO2 flux of the three seagrass meadows as -0.64 ± 0.13 mol m-2 yr-1. These results suggest that tropical seagrass meadows of Hainan Island are a significant CO2 sink of atmospheric CO2, but this capacity can be diminished by nutrient loading. Scaling up, we estimate the annual atmospheric CO2 uptake by seagrass meadows of Hainan Island (total area 55.28 km2) was 1544 t of CO2 yr-1, equivalent to the annual emissions from the wholesale, retail, accommodation and catering industries of 164,000 tourists in Hainan Island. With carbon neutrality becoming an important part of global climate governance, this study provides timely information for capitalising on the ability of seagrasses to contribute to natural climate solutions.
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Affiliation(s)
- Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Jiening Liang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Jinlong Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yuzheng Ren
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xia Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Peter I Macreadie
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia
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Liu S, Ren Y, Jiang Z, Luo H, Zhang X, Wu Y, Liang J, Huang X, Macreadie PI. Changes in surface sediment carbon compositions in response to tropical seagrass meadow restoration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166565. [PMID: 37633380 DOI: 10.1016/j.scitotenv.2023.166565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
Seagrass meadows are declining at a global scale, threatening their capacity as blue carbon sinks. Restoration of seagrasses (via seagrass seeds or plant transplantation) may recover their carbon sequestration capacity. Previous studies have predominantly focused on sediment organic carbon (SOC), while variations in sediment carbon compositions remain poorly understood, limiting our comprehension of the influence of seagrass restoration on sediment carbon stability. Here, we researched the differences in surface (0-3 cm) sediment carbon compositions in response to tropical seagrass transplantation among species (Thalassia hemprichii and Enhalus acoroides); specifically, differences in labile, recalcitrant and refractory SOC, as well as sediment inorganic carbon (SIC) compositions variations under transplanted T. hemprichii and E. acoroides communities. It was found that seagrass transplantation enhanced suspended particle organic matter, and epiphyte and macroalgae input to surface sediment, which recovered the surface SOC concentration and stock rapidly to natural levels (increased ∼1.6-fold) within two years following transplantation. The elevated contribution of epiphyte and macroalgae significantly increased the surface labile sediment organic matter (SOM), but not the recalcitrant and refractory SOM composition after short-term transplantation. Meanwhile, surface SIC was significantly elevated, which might be mainly ascribed to allochthonous carbonate particle trapped under transplanted area with implications for carbon sequestration. The higher canopy and longer leaf seagrass species, E. acoroides, had elevated SOC, SIC and was more labile composition, compared to T. hemprichii transplant. Overall, this research suggests that tropical seagrass transplantation can increase the surface SOC, SIC concentration by increasing the labile organic matter and allochthonous carbonate particle input, respectively, with varying significantly among seagrass species.
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Affiliation(s)
- Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yuzheng Ren
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Hongxue Luo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xia Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Jiening Liang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572100, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Peter I Macreadie
- School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia
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Wang F, Liu J, Qin G, Zhang J, Zhou J, Wu J, Zhang L, Thapa P, Sanders CJ, Santos IR, Li X, Lin G, Weng Q, Tang J, Jiao N, Ren H. Coastal blue carbon in China as a nature-based solution toward carbon neutrality. Innovation (N Y) 2023; 4:100481. [PMID: 37636281 PMCID: PMC10451025 DOI: 10.1016/j.xinn.2023.100481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 07/09/2023] [Indexed: 08/29/2023] Open
Abstract
To achieve the Paris Agreement, China pledged to become "Carbon Neutral" by the 2060s. In addition to massive decarbonization, this would require significant changes in ecosystems toward negative CO2 emissions. The ability of coastal blue carbon ecosystems (BCEs), including mangrove, salt marsh, and seagrass meadows, to sequester large amounts of CO2 makes their conservation and restoration an important "nature-based solution (NbS)" for climate adaptation and mitigation. In this review, we examine how BCEs in China can contribute to climate mitigation. On the national scale, the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha, including over 75% as unvegetated tidal flats. The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year-1, of which most occurs in salt marshes and tidal flats. The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year-1 along the Chinese coastline. Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of $32,000 ha-1 year-1. The potential practices and technologies that can be implemented in China to improve BCE C sequestration, including their constraints and feasibility, are also outlined. Future directions are suggested to improve blue carbon estimates on aerial extent, carbon stocks, sequestration, and mitigation potential. Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.
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Affiliation(s)
- Faming Wang
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
| | - Jihua Liu
- Marine Research Institute, Shandong University, Qingdao 266237, China
| | - Guoming Qin
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingfan Zhang
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinge Zhou
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingtao Wu
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
| | - Lulu Zhang
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
| | - Poonam Thapa
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
| | - Christian J. Sanders
- National Marine Science Centre, Faculty of Science and Engineering, Southern Cross University, Coffs Harbour, NSW 2450, Australia
| | - Isaac R. Santos
- Department of Marine Sciences, University of Gothenburg, 41319 Gothenburg, Sweden
| | - Xiuzhen Li
- State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming, East China Normal University, Shanghai 201100, China
| | - Guanghui Lin
- Key Laboratory for Earth System Modeling, Ministry of Education, Department of Earth System Science, Tsinghua University, Beijing 100084, China
- Laboratory of Stable Isotope and Gulf Ecology, Institute of Ocean Engineering, Tsinghua’s Shenzhen International Graduate School, Shenzhen 518055, China
| | - Qihao Weng
- Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hongkong 999077, China
| | - Jianwu Tang
- State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming, East China Normal University, Shanghai 201100, China
| | - Nianzhi Jiao
- Innovative Research Center for Carbon Neutralization, Global ONCE Program, Xiamen 361005, China
| | - Hai Ren
- Xiaoliang Research Station of Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 510650, China
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He B, Zhao Y, Liu S, Ahmad S, Mao W. Mapping seagrass habitats of potential suitability using a hybrid machine learning model. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1116083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Seagrass meadows provide essential ecosystem services globally in the context of climate change. However, seagrass is being degraded at an accelerated rate globally due to ocean warming, ocean acidification, aquaculture, and human activities. The need for more information on seagrasses’ spatial distribution and health status is a serious impediment to their conservation and management. Therefore, we propose a new hybrid machine learning model (RF-SWOA) that integrates the sinusoidal chaos map whale optimization algorithm (SWOA) with a random forest (RF) model to accurately model the suitable habitat of potential seagrasses. This study combines in situ sampling data with multivariate remote sensing data to train and validate hybrid machine learning models. It shows that RF-SWOA can predict potential seagrass habitat suitability more accurately and efficiently than RF. It also shows that the two most important factors affecting the potential seagrass habitat suitability on Hainan Island in China are distance to land (38.2%) and depth to sea (25.9%). This paper not only demonstrates the effectiveness of a hybrid machine learning model but also provides a more accurate machine learning model approach for predicting the potential suitability distribution of seagrasses. This research can help identify seagrass suitability distribution areas and thus develop conservation strategies to restore healthy seagrass ecosystems.
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Zhu W, Zhu M, Liu X, Xia J, Wang H, Chen R, Li X. Adaptive changes of coral Galaxea fascicularis holobiont in response to nearshore stress. Front Microbiol 2022; 13:1052776. [PMID: 36425038 PMCID: PMC9678930 DOI: 10.3389/fmicb.2022.1052776] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 10/18/2022] [Indexed: 02/07/2024] Open
Abstract
Global change and local stressors are simultaneously affecting the nearshore corals, and microbiome flexibility may assist corals in thriving under such multiple stressors. Here, we investigated the effects of various environmental variables on Galaxea fascicularis holobiont from nearshore and offshore reefs. These nearshore reefs were more turbid, eutrophic, and warm than offshore reefs. However, coral physiological parameters did not differ significantly. Corals under stressful nearshore environments had low symbiont diversity and selected more tolerant Symbiodiniaceae. The bacterial diversity of offshore corals was significantly higher, and their community composition varied obviously. Diffusion limitations and environmental heterogeneity were essential in structuring microbial communities. Functional annotation analysis demonstrated significant differences between nearshore and offshore corals in bacterial functional groups. Environmental stress significantly reduced the complexity and connectivity of bacterial networks, and the abundances of keystone taxa altered considerably. These results indicated that corals could thrive nearshore through holobiont plasticity to cope with multiple environmental stresses.
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Affiliation(s)
- Wentao Zhu
- College of Ecology and Environment, Hainan University, Haikou, China
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Ming Zhu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
- College of Marine Science, Hainan University, Haikou, China
| | - Xiangbo Liu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
- College of Marine Science, Hainan University, Haikou, China
| | - Jingquan Xia
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Hao Wang
- College of Marine Science, Hainan University, Haikou, China
| | - Rouwen Chen
- College of Marine Science, Hainan University, Haikou, China
| | - Xiubao Li
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
- College of Marine Science, Hainan University, Haikou, China
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Lin J, Jiang Z, Li L, Fang Y, Wu Y, Liu S, Huang X. Effects of nutrients on the utilization pattern of photosynthetic inorganic carbon of the tropical <italic>Thalassia hemprichii</italic>. CHINESE SCIENCE BULLETIN-CHINESE 2022. [DOI: 10.1360/tb-2022-0796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Jiang Z, Li L, Fang Y, Lin J, Liu S, Wu Y, Huang X. Eutrophication reduced the release of dissolved organic carbon from tropical seagrass roots through exudation and decomposition. MARINE ENVIRONMENTAL RESEARCH 2022; 179:105703. [PMID: 35853314 DOI: 10.1016/j.marenvres.2022.105703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/23/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
Seagrass bed ecosystem is one of the most effective carbon capture and storage systems on earth. Seagrass roots are the key link of carbon flow between leaf-root-sediment, and the release of dissolved organic carbon (DOC) from seagrass roots through exudation and decomposition are vital sources to the sediment organic carbon (SOC) in the seagrass beds. Unfortunately, human-induced eutrophication may change the release process of DOC from seagrass roots, thereby affecting the sediment carbon storage capacity. However, little is known about the effect of nutrient enrichment on the release of DOC from seagrass roots, hindering the development of seagrass underground ecology. Therefore, we selected Thalassia hemprichii, the tropical dominant seagrass species, as the research object, and made a comparison of the release of DOC from roots through exudation and decomposition under different nitrate treatments. We found that under control, 10 μmol L-1, 20 μmol L-1 and 40 μmol L-1 nitrate treatments, soluble sugar of T. hemprichii roots were 71.37 ± 3.43 mg g-1, 67.03 ± 5.33 mg g-1, 49.14 ± 3.48 mg g-1, and 18.51 ± 2.09 mg g-1, respectively, while the corresponding root DOC exudation rates were 7.00 ± 0.97 mg g DW root-1 h-1, 5.11 ± 0.42 mg g DW root-1 h-1, 4.08 ± 0.23 mg g DW root-1 h-1, and 3.78 ± 0.74 mg g DW root-1 h-1, respectively. There was a significant positive correlation between root soluble sugar and DOC exudation rate. DOC concentration of sediment porewater and SOC content also decreased under nitrate enrichment (though not significantly), which were both significantly positively correlated with the rate of root exuded DOC. Meanwhile, nitrate enrichment also reduced the release rate of DOC from seagrass roots during initial decomposition, and the release flux of DOC from decomposition. Therefore, nutrient enrichment could decrease nonstructural carbohydrates of seagrass roots, reducing the rate of root exuded DOC, thereby lowered SOC, as well as the DOC release from seagrass root decomposition. In order to increase the release of DOC from seagrass roots and improve the carbon sequestration capacity of seagrass beds, effective measures should be taken to control the coastal nutrients input into seagrass beds.
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Affiliation(s)
- Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572000, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, Guangzhou, 510301, PR China
| | - Linglan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jizhen Lin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572000, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, Guangzhou, 510301, PR China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572000, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, Guangzhou, 510301, PR China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572100, China; Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya, 572000, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, Guangzhou, 510301, PR China.
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10
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Jiang Z, Liu S, Cui L, He J, Fang Y, Premarathne C, Li L, Wu Y, Huang X, Kumar M. Sand supplementation favors tropical seagrass Thalassia hemprichii in eutrophic bay: implications for seagrass restoration and management. BMC PLANT BIOLOGY 2022; 22:296. [PMID: 35710355 PMCID: PMC9205049 DOI: 10.1186/s12870-022-03647-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Sediment is crucial for the unique marine angiosperm seagrass growth and successful restoration. Sediment modification induced by eutrophication also exacerbates seagrass decline and reduces plantation and transplantation survival rates. However, we lack information regarding the influence of sediment on seagrass photosynthesis and the metabolics, especially regarding the key secondary metabolic flavone. Meanwhile, sulfation of flavonoids in seagrass may mitigate sulfide intrusion, but limited evidence is available. RESULTS We cultured the seagrass Thalassia hemprichii under controlled laboratory conditions in three sediment types by combining different ratios of in-situ eutrophic sediment and coarse beach sand. We examined the effects of beach sand mixed with natural eutrophic sediments on seagrass using photobiology, metabolomics and isotope labelling approaches. Seagrasses grown in eutrophic sediments mixed with beach sand exhibited significantly higher photosynthetic activity, with a larger relative maximum electron transport rate and minimum saturating irradiance. Simultaneously, considerably greater belowground amino acid and flavonoid concentrations were observed to counteract anoxic stress in eutrophic sediments without mixed beach sand. This led to more positive belowground stable sulfur isotope ratios in eutrophic sediments with a lower Eh. CONCLUSIONS These results indicated that coarse beach sand indirectly enhanced photosynthesis in T. hemprichii by reducing sulfide intrusion with lower amino acid and flavonoid concentrations. This could explain why T. hemprichii often grows better on coarse sand substrates. Therefore, it is imperative to consider adding beach sand to sediments to improve the environmental conditions for seagrass and restore seagrass in eutrophic ecosystems.
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Affiliation(s)
- Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- University of Chinese Academy of Sciences, Beijing, 100049, PR China
- Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China
- Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China
- Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China
| | - Lijun Cui
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jialu He
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Chanaka Premarathne
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Linglan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, PR China
- Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China
- Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China.
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, PR China.
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, PR China.
- University of Chinese Academy of Sciences, Beijing, 100049, PR China.
- Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China.
- Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya, 572000, China.
| | - Manoj Kumar
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia
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11
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Song Z, Sun Y, Liu P, Wang Y, Huang Y, Gao Y, Hu X. Invasion of
Spartina alterniflora
on
Zostera japonica
enhances the abundances of bacteria by absolute quantification sequencing analysis. Ecol Evol 2022; 12:e8939. [PMID: 35600690 PMCID: PMC9120208 DOI: 10.1002/ece3.8939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 04/15/2022] [Accepted: 05/04/2022] [Indexed: 11/26/2022] Open
Abstract
Plant invasion can alter soil organic matter composition and indirectly impact estuary ecology; therefore, it is paramount to understand how plant invasion influences the bacterial community. Here, we present an absolute quantification 16S rRNA gene sequencing to investigate the bacterial communities that were collected from Zostera japonica and Spartina alterniflora covered areas and Z. japonica degradation areas in the Yellow River Estuary. Our data revealed that the absolute quantity of bacteria in the surface layer was significantly (p < .05) higher than that in the bottom and degradation areas. Following the invasion of S. alterniflora, the abundances of Bacteroidia, Acidimicrobiaceae, and Dehalococcoidaceaewere enriched in the S. alterniflora sediment. In addition, variations in the composition of sediment bacterial communities at the phylum level were the most intimately related to total organic carbon (TOC), and the content of heavy metals could reduce the abundance of bacteria. This study provided some information to understand the effects of S. alterniflora invasion on Z. japonica from the perspective of microbiome level.
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Affiliation(s)
- Zenglei Song
- Key laboratory of Coastal Biology and Bioresource Utilization Yantai Institute of Costal Zone Research Chinese Academy of Sciences Yantai China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao China
- University of Chinese Academy of Sciences Beijing China
| | - Yanyu Sun
- Key laboratory of Coastal Biology and Bioresource Utilization Yantai Institute of Costal Zone Research Chinese Academy of Sciences Yantai China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao China
- University of Chinese Academy of Sciences Beijing China
| | - Pengyuan Liu
- Key laboratory of Coastal Biology and Bioresource Utilization Yantai Institute of Costal Zone Research Chinese Academy of Sciences Yantai China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao China
- University of Chinese Academy of Sciences Beijing China
| | - Yibo Wang
- Key laboratory of Coastal Biology and Bioresource Utilization Yantai Institute of Costal Zone Research Chinese Academy of Sciences Yantai China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao China
- University of Chinese Academy of Sciences Beijing China
| | - Yanyan Huang
- Key laboratory of Coastal Biology and Bioresource Utilization Yantai Institute of Costal Zone Research Chinese Academy of Sciences Yantai China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao China
- University of Chinese Academy of Sciences Beijing China
| | - Yan Gao
- Marine Science Research Institute of Shandong Province National Oceanographic Center of Qingdao Qingdao China
| | - Xiaoke Hu
- Key laboratory of Coastal Biology and Bioresource Utilization Yantai Institute of Costal Zone Research Chinese Academy of Sciences Yantai China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao China
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12
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Kim SH, Suonan Z, Qin LZ, Kim H, Park JI, Kim YK, Lee S, Kim SG, Kang CK, Lee KS. Variability in blue carbon storage related to biogeochemical factors in seagrass meadows off the coast of the Korean peninsula. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 813:152680. [PMID: 34971692 DOI: 10.1016/j.scitotenv.2021.152680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
Coastal vegetated habitats such as mangroves, salt marshes, and seagrasses, referred to as blue carbon ecosystems, play an important role in climate change mitigation by an effective CO2 capture from atmosphere and water columns and long-term organic carbon (Corg) storage in sediments. Although seagrass meadows are considered intense carbon sinks, information on regional variability in seagrass blue carbon stock and factors influencing its capacity still remain sparse. In the present study, seagrass blue carbon storage by measuring Corg stocks in sediments and living seagrass biomass, and carbon accumulation rates (CARs) in seagrass meadows were estimated along the Korean coast. Factors affecting variability in Corg stocks were also analyzed using partial least squares (PLS) regression and principal component analysis (PCA). Projected Corg stocks in sediment, extrapolated to a depth 1 m, exhibited substantial variability among sites, ranging from 49.91 to 125.71 Mg C ha-1. The majority of Corg (96-99%) was stored in sediments, whereas the contribution of living biomass was minor. PLS regression and PCA indicated that Corg stocks in seagrass meadows are strongly associated with sediment characteristics such as dry bulk density and water and mud content. Among seagrass traits, above- to below-ground biomass ratio was significantly related to the quantity of Corg stocks in seagrass meadows. Because of the high spatial variability in Corg stocks and CARs, local and regional differences in seagrass blue carbon storage should be considered to accurately assess the climate change mitigation potential of seagrass ecosystems.
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Affiliation(s)
- Seung Hyeon Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Zhaxi Suonan
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Le-Zheng Qin
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea; College of Marine Science, Hainan University, Haikou 570228, China
| | - Hyegwang Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Jung-Im Park
- Marine Eco-Technology Institute, Busan 48520, Republic of Korea
| | - Young Kyun Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea; School of Earth Sciences & Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Sukhui Lee
- Korea Marine Environment Management Corporation, Seoul 05718, Republic of Korea
| | - Seong-Gil Kim
- Korea Marine Environment Management Corporation, Seoul 05718, Republic of Korea
| | - Chang-Keun Kang
- School of Earth Sciences & Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Kun-Seop Lee
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea.
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13
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Zou YF, Chen KY, Lin HJ. Significance of belowground production to the long-term carbon sequestration of intertidal seagrass beds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 800:149579. [PMID: 34399336 DOI: 10.1016/j.scitotenv.2021.149579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 06/13/2023]
Abstract
The high biomass and sediment features of seagrass beds can make their belowground portions critical sources of blue carbon sinks. However, seagrass belowground production and decomposition have rarely been quantified in the field. To assess the significance of seagrass belowground production to carbon sequestration, belowground carbon budgets were constructed in intertidal seagrass beds of the late-successional species Thalassia hemprichii and the early-successional species Haloduleuninervis in southern Taiwan. For both species, the turnover rates of the belowground portions were much longer than that of the aboveground portion, so the belowground biomass was much higher than the aboveground biomass. The leaf productivity of both species was significantly higher than the belowground productivity, but most of the leaf production decomposed within a year. The lower turnover and slower decomposition rates of the belowground portions allowed the late-successional seagrass T. hemprichii to store more carbon in the sediments than the early-successional seagrass H. uninervis. Long-term changes for the past 20 years in the sediment depth showed that the sediments of seagrass beds were increasing in the habitats at low elevation but were decreasing or had no clear trends in the habitats at high elevation or on the windward side. The carbon storage rates according to the belowground production of T. hemprichii and H. uninervis were 0.3-4.7 and 1.5-2.3 g C m-2 yr-1, respectively, which can potentially contribute 53% of the long-term organic carbon storage in the low-elevation sediments.
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Affiliation(s)
- Yi-Fang Zou
- Department of Life Sciences and Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan
| | - Kuan-Yu Chen
- Department of Life Sciences and Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan
| | - Hsing-Juh Lin
- Department of Life Sciences and Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan.
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14
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Li L, Jiang Z, Wu Y, He J, Fang Y, Lin J, Liu S, Huang X. Interspecific differences in root exudation for three tropical seagrasses and sediment pore-water dissolved organic carbon beneath them. MARINE POLLUTION BULLETIN 2021; 173:113059. [PMID: 34715432 DOI: 10.1016/j.marpolbul.2021.113059] [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: 08/18/2021] [Revised: 10/09/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Seagrass beds act as blue carbon sinks globally; however, little attention has been given to carbon dynamics in the seagrass rhizosphere. Hence, in this study, the quantity and characteristics of dissolved organic carbon (DOC) from root exudation of the three dominant tropical seagrasses (Thalassia hemprichii, Enhalus acoroides, and Cymodocea rotundata) and sediment pore water beneath them were compared, to examine their interspecific differences, and to establish a connection between seagrass root exudation and sediment carbon. The rate of root-exuded DOC from T. hemprichii (2.15 ± 1.06 mg g DW root-1 h-1) was significantly higher (p < 0.05) than that from E. acoroides (0.72 ± 0.39 mg g DW root-1 h-1) and C. rotundata (0.46 ± 0.25 mg g DW root-1 h-1). Root exudation rates were more affected by root hair density and root hair length than by root carbon, nitrogen, and soluble sugar content. Simultaneously, DOC concentrations of the sediment pore water beneath T. hemprichii, E. acoroides and C. rotundata were 22.05 ± 11.61 mg l-1, 15.55 ± 2. 66 mg l-1, and 14.32 ± 1.82 mg l-1, respectively. The corresponding absorption coefficients at 254 nm (a254) were 30.53 ± 18.00, 17.31 ± 2.24, and 14.07 ± 2.03, respectively, while the relevant specific ultraviolet absorbances at 254 nm (SUVA254) were 1.38 ± 0.29, 1.19 ± 0.26 and 1.03 ± 0.28, respectively. Therefore, the roots of T. hemprichii exuded DOC at a higher rate, leading to a higher pore-water DOC pool in the sediment. This suggests that T. hemprichii played a greater role in the sediment carbon pool through root exudation. Thus, it can be considered as the priority species for transplantation to promote the carbon sink function of seagrass beds.
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Affiliation(s)
- Linglan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya 572100, China.
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya 572100, China
| | - Jialu He
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Marine Development Planning and Research Center of Guangdong Province, Guangzhou 510220, China
| | - Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jizhen Lin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya 572100, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sanya National Marine Ecosystem Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sanya 572000, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya 572100, China.
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15
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Lin X, Dong J, Yang Q, Zhou W, Wang Y, Zhang Y, Ahmad M, Sun Y, Wang Y, Ling J. Identification of three seagrass species in coral reef ecosystem by using multiple genes of DNA barcoding. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:919-928. [PMID: 33830383 DOI: 10.1007/s10646-021-02397-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/14/2021] [Indexed: 06/12/2023]
Abstract
Seagrasses constitute a significant part of coral reef ecosystems, representing high primary productivity and one of the most important coastal habitats in marine ecosystems. Though seagrasses possess irreplaceable ecological services to the marine environment, taxonomical ambiguity still exists due to similar morphological characters and phenotypic plasticity. As an emerging technology, DNA barcoding can effectively identify cryptic species using a short orthologous DNA region. In this study, we collected samples from five different locations (Daya Bay, Xincun Bay, Sanya Bay, Xisha Islands, and Nansha Islands), and three seagrass species Cymodocea rotundata, Thalassia hemprichii and Halophila ovalis was evaluated. Moreover, ITS, matK and rbcL genes were used as DNA barcodes. The results indicated that single ITS and concatenated ITS/matK/rbcL both conducted better species resolution than single matK and rbcL. Nevertheless, single ITS was more convenient. Furthermore, in all the four topology trees, three species resolved as 3 clusters as well H. ovalis and T. hemprichii grouped as sister clade. In the meantime, differentiation lay in intra-species based on the result of single ITS and three-locus analysis. Within H. ovalis and T. hemprichii separately, individuals from Xisha Islands first group together, then grouped with individuals from Nansha Islands and/or Xincun Bay and/or Sanya Bay and/or Daya Bay, which indicated that geographical distribution influenced population evolution. However, intra-species differentiation did not emerge in the tree of matK or rbcL.
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Affiliation(s)
- Xiancheng Lin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junde Dong
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China
- Guangdong Science and Technology Library (Guangdong Institute of Scientific and Technical Information and Development Strategy), Guangzhou, 510070, China
| | - Qingsong Yang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Weiguo Zhou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Yan Wang
- Guangdong Science and Technology Library (Guangdong Institute of Scientific and Technical Information and Development Strategy), Guangzhou, 510070, China
| | - Ying Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Manzoor Ahmad
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yingting Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Youshao Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Juan Ling
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences and Hainan Key Laboratory of Tropical Marine Biotechnology, Sanya, 572000, China.
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China.
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16
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Deng Y, Liu S, Feng J, Wu Y, Mao C. What drives putative bacterial pathogens removal within seagrass meadows? MARINE POLLUTION BULLETIN 2021; 166:112229. [PMID: 33711607 DOI: 10.1016/j.marpolbul.2021.112229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 02/21/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
To analyze the mechanism of bacterial pathogen removal in seagrass meadows, we compared bacterial pathogens abundance in trapped particles in different seagrass meadows under different intensities of human activities. We compared the particle deposition rates and abundances of bacterial pathogen in Thalassia hemprichii, Enhalus acoroides stands and adjacent unvegetated patches. The bacterial pathogens abundance was much higher in E. acoroides than in adjacent unvegetated patches, however, the trapped particles under T. hemprichii were lower than in nearby unvegetated areas with the exception of the pristine seagrass meadow. These results indicate that seagrass, at least E. acoroides, can remove bacterial pathogens by trapping particles. What is unknown, nevertheless, is how the trapped bacterial pathogens are removed by T. hemprichii. We put forward that antibacterial chemical compounds release from seagrass was stimulated by stress from human activities for inhibition of bacterial pathogen. This putative mechanism needs to be explored in future studies.
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Affiliation(s)
- Yiqin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, Sanya 572100, China.
| | - Juan Feng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Can Mao
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
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17
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Premarathne C, Jiang Z, He J, Fang Y, Chen Q, Cui L, Wu Y, Liu S, Chunyu Z, Vijerathna P, Huang X. Low Light Availability Reduces the Subsurface Sediment Carbon Content in Halophila beccarii From the South China Sea. FRONTIERS IN PLANT SCIENCE 2021; 12:664060. [PMID: 34163504 PMCID: PMC8215720 DOI: 10.3389/fpls.2021.664060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/16/2021] [Indexed: 05/15/2023]
Abstract
Eutrophication, dredging, agricultural and urban runoffs, and epiphyte overgrowth could reduce light availability for seagrass. This may affect "blue carbon" stocks in seagrass beds. However, little research is available on the effect of light intensities on carbon sequestration capacity in seagrass beds, especially small-bodied seagrasses. The dominant seagrass Halophila beccarii, a vulnerable species on the IUCN Red List, was cultured in different light intensities to examine the response of vegetation and sediment carbon in seagrass beds. The results showed that low light significantly reduced leaf length and above-ground biomass, while carbon content in both above-ground and below-ground tissues were not affected. Low light reduced both the above-ground biomass carbon and the total biomass carbon. Interestingly, while under saturating light conditions, the subsurface and surface carbon content was similar, under low light conditions, subsurface sediment carbon was significantly lower than the surface content. The reduction of subsurface sediment carbon might be caused by less release flux of dissolved organic carbon from roots in low light. Taken together, these results indicate that reduced light intensities, to which these meadows are exposed to, will reduce carbon sequestration capacity in seagrass beds. Measures should be taken to eliminate the input of nutrients on seagrass meadows and dredging activities to maintain the "blue carbon" storage service by enhancing light penetration into seagrass.
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Affiliation(s)
- Chanaka Premarathne
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- *Correspondence: Zhijian Jiang,
| | - Jialu He
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yang Fang
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qiming Chen
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lijun Cui
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
| | - Zhao Chunyu
- College of Resources, Environment and Planning, Dezhou University, Dezhou, China
| | | | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- Xiaoping Huang,
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18
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Thorhaug A, Gallagher JB, Kiswara W, Prathep A, Huang X, Yap TK, Dorward S, Berlyn G. Coastal and estuarine blue carbon stocks in the greater Southeast Asia region: Seagrasses and mangroves per nation and sum of total. MARINE POLLUTION BULLETIN 2020; 160:111168. [PMID: 33181914 DOI: 10.1016/j.marpolbul.2020.111168] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/16/2020] [Accepted: 04/11/2020] [Indexed: 06/11/2023]
Abstract
Climate Change solutions include CO2 extraction from atmosphere and water with burial by living habitats in sediment/soil. Nowhere on the planet are blue carbon plants which carry out massive carbon extraction and permanent burial more intensely concentrated than in SE Asia. For the first time we make a national and total inventory of data to date for "blue carbon" buried from mangroves and seagrass and delineate the constraints. For an area across Southeast Asia of approximately 12,000,000 km2, supporting mangrove forests (5,116,032 ha) and seagrass meadows (6,744,529 ha), we analyzed the region's current blue carbon stocks. This estimate was achieved by integrating the sum of estuarine in situ carbon stock measurements with the extent of mangroves and seagrass across each nation, then summed for the region. We found that mangroves ecosystems regionally supported the greater amount of organic carbon (3095.19Tg Corg in 1st meter) over that of seagrass (1683.97 Tg Corg in 1st meter), with corresponding stock densities ranging from 15 to 2205 Mg ha-1 and 31.3 to 2450 Mg ha-1 respectively, a likely underestimate for entire carbon including sediment depths. The largest carbon stocks are found within Indonesia, followed by the Philippines, Papua New Guinea, Myanmar, Malaysia, Thailand, Tropical China, Viet-Nam, and Cambodia. Compared to the blue carbon hotspot of tropical/subtropical Gulf of Mexico's total carbon stock (480.48 Tg Corg), Southeast Asia's greater mangrove-seagrass stock density appears a more intense Blue Carbon hotspot (4778.66 Tg Corg). All regional Southeast Asian nation states should assist in superior preservation and habitat restoration plus similar measures in the USA & Mexico for the Gulf of Mexico, as apparently these form two of the largest tropical carbon sinks within coastal waters. We hypothesize it is SE Asia's regionally unique oceanic-geologic conditions, placed squarely within the tropics, which are largely responsible for this blue carbon hotspot, that is, consistently high ambient light levels and year-long warm temperatures, together with consistently strong inflow of dissolved carbon dioxide and upwelling of nutrients across the shallow geological plates.
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Affiliation(s)
- A Thorhaug
- Yale University School of Forestry & Environmental Studies, New Haven, CT 00651, USA.
| | - John Barry Gallagher
- Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, 7000, Australia.
| | - W Kiswara
- Division of Earth Sciences, Indonesian Institute of Sciences, Jakarta, Indonesia
| | - Anchana Prathep
- Seaweed and Seagrass Research Unit, Prince of Songkla University, HatYai, Songkhla, 90112 Thailand
| | - Xiaoping Huang
- South China Sea Institute of Oceanology, Chinese Academy of Sciences,Guangzhou, China
| | - Tzuen-Kiat Yap
- Borneo Marine Research Institute, University Malaysia Sabah, Kota Kinabalu, Malaysia
| | | | - Graeme Berlyn
- Yale University School of Forestry & Environmental Studies, New Haven, CT 00651, USA
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19
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Liu S, Deng Y, Jiang Z, Wu Y, Huang X, Macreadie PI. Nutrient loading diminishes the dissolved organic carbon drawdown capacity of seagrass ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 740:140185. [PMID: 32563887 DOI: 10.1016/j.scitotenv.2020.140185] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/18/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Seawater dissolved organic carbon (DOC) in seagrass meadows is gaining attention for its role in carbon sequestration. Abundant refractory compounds in DOC are exported by seagrass meadows to the deep sea, thereby contributing to long-term carbon drawdown. DOC lability and bacterioplankton communities are key determining factors in this carbon sequestration process, and it has been hypothesized that these may be affected by nutrient loading - however, scientific evidence is so far weak. Here, we studied the response of DOC composition and bacterioplankton communities to nutrient loading in seagrass meadows of the South China Sea. We found that increasing nutrient loads enhanced nitrogen and phosphorus concentrations in DOC, which promoted algae blooms (i.e. epiphyte, phytoplankton and macroalgae) in seagrass meadows, and presumably increased the lability of DOC and its bioavailability to microbes. Also, the relative abundance of K-strategist bacterioplankton communities with the potential to degrade refractory compounds (Acidimicrobiia, Verrucomicrobiales and Micrococcales) increased in the seagrass meadows exposed to high nutrient loads. These results suggest that high nutrient loading can enhance labile DOC composition, and thus increase refractory DOC remineralization rate, thereby weakening the DOC contribution potential of seagrass meadows to long-term carbon sequestration.
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Affiliation(s)
- Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yiqin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Peter I Macreadie
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
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20
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Thomsen E, Herbeck LS, Jennerjahn TC. The end of resilience: Surpassed nitrogen thresholds in coastal waters led to severe seagrass loss after decades of exposure to aquaculture effluents. MARINE ENVIRONMENTAL RESEARCH 2020; 160:104986. [PMID: 32907724 DOI: 10.1016/j.marenvres.2020.104986] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 04/01/2020] [Accepted: 04/07/2020] [Indexed: 05/21/2023]
Abstract
Although eutrophication is considered a major driver for global seagrass loss with aquaculture effluents being a main factor, little is known about the effect on seagrass meadows in eastern Asia and their resilience to long-term nutrient impact. Seagrass meadows impacted by land-based aquaculture since the 1990s, were visited in 2008/2009 and revisited after another 9 years of effluent exposure. During that period seagrass aboveground biomass declined by 87%. Species diversity decreased with increasing effluent exposure. A δ15N of 9.0‰ of seagrass leaves and additional biogeochemical and biological indicators identify pond effluents as the driver of the observed eutrophication. When continuously exposed to dissolved inorganic nitrogen (DIN) concentrations exceeding a calculated threshold of 8 μM DIN seagrass meadows will disappear. Chronic nutrient pollution from aquaculture effluents can lead to a reduction of biodiversity and ultimately to a complete loss of seagrasses along the aquaculture-dominated coasts in E and SE Asia.
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Affiliation(s)
- Esther Thomsen
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany; Faculty of Biology and Chemistry, University of Bremen, Bremen, Germany.
| | - Lucia S Herbeck
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany
| | - Tim C Jennerjahn
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany; Faculty of Geosciences, University of Bremen, Bremen, Germany
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21
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Jiang Z, Cui L, Liu S, Zhao C, Wu Y, Chen Q, Yu S, Li J, He J, Fang Y, Premarathne Maha Ranvilage CI, Huang X. Historical changes in seagrass beds in a rapidly urbanizing area of Guangdong Province: Implications for conservation and management. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01035] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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22
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Su Z, Qiu G, Fan H, Li M, Fang C. Changes in carbon storage and macrobenthic communities in a mangrove-seagrass ecosystem after the invasion of smooth cordgrass in southern China. MARINE POLLUTION BULLETIN 2020; 152:110887. [PMID: 31957684 DOI: 10.1016/j.marpolbul.2020.110887] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 12/23/2019] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
The exotic smooth cordgrass (Spartina alterniflora) has invaded intertidal wetlands near the Ronggenshan tidal flats of Beihai, Guangxi, China, where historically seagrasses and mangroves coexisted. We investigated sediment organic carbon (SOC) storage and macrobenthic community structure in the existing mangroves (MG), S. alterniflora (SA), seagrass bed (SG), and unvegetated flat (UnV) habitats following the S. alterniflora invasion. SOC storage increased after S. alternifolia invasion in the SG and UnV habitats. Spartina alterniflora invasion changed the dominant species of the macrobenthos in the original habitats and reduced the diversity of macrobenthos in SG and UnV habitats. Clearly, S. alternifolia invasion can change the ecological functioning of south China's coastal ecosystems by altering carbon sequestration and affecting biodiversity.
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Affiliation(s)
- Zhinan Su
- Forestry College, Guangxi University, Nanning 530004, Guangxi, China; Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, Guangxi, China
| | - Guanglong Qiu
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, Guangxi, China.
| | - Hangqing Fan
- Forestry College, Guangxi University, Nanning 530004, Guangxi, China; Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, Guangxi, China
| | - Meng Li
- Guangxi Academy of Oceanography, Nanning 530004, Guangxi, China
| | - Chao Fang
- Guangxi Key Lab of Mangrove Conservation and Utilization, Guangxi Mangrove Research Center, Guangxi Academy of Sciences, Beihai 536000, Guangxi, China
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23
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Fang Y, Jiang Z, Zhao C, Li L, Ranvilage CIPM, Liu S, Wu Y, Huang X. Efficient Heat Dissipation and Cyclic Electron Flow Confer Daily Air Exposure Tolerance in the Intertidal Seagrass Halophila beccarii Asch. FRONTIERS IN PLANT SCIENCE 2020; 11:571627. [PMID: 33329629 PMCID: PMC7733926 DOI: 10.3389/fpls.2020.571627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/15/2020] [Indexed: 05/03/2023]
Abstract
Seagrasses inhabiting the intertidal zone experience periodically repeated cycles of air exposure and rehydration. However, little is known about the photoprotective mechanisms in photosystem (PS)II and PSI, as well as changes in carbon utilization upon air exposure. The photoprotective processes upon air exposure in Halophila beccarii Asch., an endangered seagrass species, were examined using the Dual-PAM-100 and non-invasive micro-test technology. The results showed that air exposure enhanced non-photochemical quenching (NPQ) in both PSII and PSI, with a maximum increase in NPQ and Y(ND) (which represents the fraction of overall P700 that is oxidized in a given state) of 23 and 57%, respectively, resulting in intensive thermal energy dissipation of excess optical energy. Moreover, cyclic electron transport driven by PSI (CEF) was upregulated, reflected by a 50 and 22% increase in CEF and maximum electron transport rate in PSI to compensate for the abolished linear electron transport with significant decreases in pmfLEF (the proton motive force [pmf]) attributable solely to proton translocation by linear electron flow [LEF]). Additionally, H+ fluxes in mesophyll cells decreased steadily with increased air exposure time, exhibiting a maximum decrease of six-fold, indicating air exposure modified carbon utilization by decreasing the proton pump influxes. These findings indicate that efficient heat dissipation and CEF confer daily air exposure tolerance to the intertidal seagrass H. beccarii and provide new insights into the photoprotective mechanisms of intertidal seagrasses. This study also helps explain the extensive distribution of H. beccarii in intertidal zones.
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Affiliation(s)
- Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- *Correspondence: Zhijian Jiang,
| | - Chunyu Zhao
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- College of Resources Environment and Planning, Dezhou University, Dezhou, China
| | - Linglan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chanaka Isuranga Premarathne Maha Ranvilage
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- Xiaoping Huang,
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Exotic Halophila stipulacea is an introduced carbon sink for the Eastern Mediterranean Sea. Sci Rep 2019; 9:9643. [PMID: 31270338 PMCID: PMC6610076 DOI: 10.1038/s41598-019-45046-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 05/24/2019] [Indexed: 11/17/2022] Open
Abstract
Carbon and nitrogen storage in exotic Halophila stipulacea were compared to that in native Posidonia oceanica and Cymodocea nodosa meadows and adjacent unvegetated sediments of the Eastern Mediterranean Sea and to that in native H. stipulacea of the Red Sea at sites with different biogeochemical conditions and level of human pressure. Exotic H. stipulacea possessed considerable storing capacity, with 2-fold higher Corg stock (0.71 ± 0.05 kg m−2 in the top 20 cm of sediment) and burial (14.78 gCorg m−2 y−1) than unvegetated areas and C. nodosa meadows and, surprisingly, comparable to P. oceanica. N (0.07 ± 0.01 kg m−2) and Cinorg (14.06 ± 8.02 kg m−2) stocks were similar between H. stipulacea and C. nodosa or unvegetated sediments, but different to P. oceanica. Corg and N stocks were higher in exotic than native H. stipulacea populations. Based on isotopic mixing model, organic material trapped in H. stipulacea sediments was mostly allochthonous (seagrass detritus 17% vs seston 67%). Corg stock was similar between monospecific and invaded C. nodosa meadows by H. stipulacea. Higher stocks were measured in the higher human pressure site. H. stipulacea introduction may contribute in the increase of carbon sequestration in the Eastern Mediterranean.
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25
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Jiang Z, Zhao C, Yu S, Liu S, Cui L, Wu Y, Fang Y, Huang X. Contrasting root length, nutrient content and carbon sequestration of seagrass growing in offshore carbonate and onshore terrigenous sediments in the South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:151-159. [PMID: 30690350 DOI: 10.1016/j.scitotenv.2019.01.175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/09/2019] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
Due to distinct human disturbances and sediment type, seagrasses growing in offshore carbonate and onshore terrigenous sediments may show contrasting characteristics. A comparison of seagrass morphology, nutrient content and sediment carbon pools was taken for seagrass beds inhabiting offshore carbonate sediments in Xuande Atoll and onshore terrigenous sediments in Hainan Island, South China Sea. Lower nitrogen (N) content was observed in the aboveground (1.1%-2.8%) and belowground (0.4%-1.5%) tissue of seagrasses in Xuande Atoll than in the same species (aboveground: 2.7%-3.6%; belowground: 1.2%-2.8%) in Hainan Island. Greater depletion of leaf δ15N of Thalassia hemprichii (T. hemprichii) and Halodule pinifolia (H. pinifolia) in Xuande Atoll indicated nitrogen fixation might be the major source of nitrogen in oligotrophic reef environments. The root lengths of the seagrass species in Xuande Atoll were longer than the same species in Hainan Island. Sediment inorganic carbon (SIC) was considerably higher than sediment organic carbon (SOC) in the carbonate sediment, while the opposite trend was found in the terrigenous sediments. The SOC stock in the carbonate and terrigenous sediments was 2.41 ± 0.78 Mg C ha-1 and 2.20 ± 0.34 Mg C ha-1 in the top 5 cm, respectively, while the corresponding SIC was 84.38 ± 21.65 Mg C ha-1 and 1.27 ± 0.51 Mg C ha-1, respectively. The average CO2 net sequestered in the carbonate sediment in Xuande Atoll and the terrigenous sediment in Hainan Island were -48.22 ± -12.21 Mg C ha-1 and 1.44 ± 0.03 Mg C ha-1, respectively. This suggested seagrass sediment was a source of CO2 during sediment production in the carbonate sediment but a sink of CO2 in the terrigenous sediment. Thus, the N concentration in seagrass leaf, root length, sediment carbon composition and pools were contrasted between offshore carbonate sediments and onshore terrigenous sediments.
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Affiliation(s)
- Zhijian Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China
| | - Chunyu Zhao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Shuo Yu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China; Fouth Institute of Oceanography, State Oceanic Administration, Beihai 53600, China
| | - Songlin Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China
| | - Lijun Cui
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yunchao Wu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China
| | - Yang Fang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiaoping Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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