中国海岸线总长度超过3.26万km,同时拥有红树林、盐沼、海草床3类蓝碳生态系统,且海水养殖产量常年位居世界首位,蓝碳发展条件得天独厚。本文在系统梳理国内外蓝碳研究成果的基础上,基于广义蓝碳定义,尝试从自然生态系统和海水养殖系统两方面构建中国沿海省份蓝碳核算体系,基于相关统计数据、遥感数据、核算参数数据,对中国沿海省份蓝碳进行核算,分析其时空演化格局,并利用Super-SBM模型进一步对中国海水养殖碳汇渔业效率进行评估。研究表明：①中国蓝碳生态系统面积呈波动增长,1997—2019年红树林固碳量为0.033~0.078 Tg C/a,盐沼固碳量为0.234~0.646 Tg C/a,海草床固碳量为0.012~0.018 Tg C/a;②沿海九省2003—2020年的海水养殖年固碳总量为0.87~1.36 Tg C/a,省际空间差异显著,并在各时段表现出不同的增长特征;③沿海九省年蓝碳总量及结构的空间分布格局差异明显,就蓝碳能力而言,山东和福建蓝碳能力最高;就蓝碳结构而言,江苏的蓝碳构成比例较为均衡;④土地利用变化、蓝碳生态系统与海水养殖的不协调发展、气候变化等是影响蓝碳能力的重要因素,沿海九省2003—2020年的碳汇渔业效率值反映出海水养殖经济指标投入与生态环境产出存在一定失调,这也会遏制蓝碳的挖掘和利用。最后本文就蓝碳助力国家碳中和战略提出相应的优化建议。

China has a coastline of more than 32600 km and possesses three types of blue carbon ecosystems: mangroves, salt marshes, and seagrass beds, and mariculture production ranks first in the world all year round, so there are excellent conditions for blue carbon development. Based on a systematic review of blue carbon research results in China and abroad, this study constructed a blue carbon accounting framework for China’s coastal provinces, which includes the natural ecosystem and mariculture system from the perspective of a broad blue carbon definition. Meanwhile, based on relevant statistical data, remote sensing data, and accounting parameter data, the blue carbon of China’s coastal provinces was accounted for and their spatial and temporal change patterns were analyzed. This study also used the Super-SBM (slacks-based measure) model to evaluate the efficiency of China’s mariculture carbon sink fisheries. The results show that: (1) Blue carbon ecosystem areas showed fluctuating growth, and the annual average amount of carbon buried in mangroves in China from 1997 to 2019 ranged from 0.033-0.078 Tg C/yr, 0.234-0.646 Tg C/yr in salt marshes, and 0.012-0.018 Tg C/yr in seagrass beds; (2) The annual average amount of carbon buried in nine coastal provinces from 2003 to 2020 was 0.87-1.36 Tg C/yr, with significant inter-provincial spatial disparities and showing different growth characteristics in each time period; (3) The spatial distribution pattern of total blue carbon and structure of coastal provinces differed significantly, among which Liaoning and Shandong were the provinces with the highest blue carbon capacity, and the composition ratio of blue carbon was more balanced in Jiangsu Provinces; (4) Land use change, uncoordinated development between blue carbon habitat and mariculture, and climate change are important reasons affecting the blue carbon capacity of natural resources, and the efficiency values of carbon sink fisheries in nine coastal provinces for 2003-2020 reflected a imbalance between the economic indicators of mariculture inputs and ecological outputs, which could also curb the excavation and utilization of blue carbon capacity. Finally, corresponding optimization recommendations for blue carbon were proposed to contribute to the national carbon neutrality strategy.

. The carbon burial in vegetated sediments, ignored in past assessments of carbon burial in the ocean, was evaluated using a bottom-up approach derived from upscaling a compilation of published individual estimates of carbon burial in vegetated habitats (seagrass meadows, salt marshes and mangrove forests) to the global level and a top-down approach derived from considerations of global sediment balance and a compilation of the organic carbon content of vegeatated sediments. Up-scaling of individual burial estimates values yielded a total carbon burial in vegetated habitats of 111 Tmol C y-1. The total burial in unvegetated sediments was estimated to be 126 Tg C y-1, resulting in a bottom-up estimate of total burial in the ocean of about 244 Tg C y-1, two-fold higher than estimates of oceanic carbon burial that presently enter global carbon budgets. The organic carbon concentrations in vegetated marine sediments exceeds by 2 to 10-fold those in shelf/deltaic sediments. Top-down recalculation of ocean sediment budgets to account for these, previously neglected, organic-rich sediments, yields a top-down carbon burial estimate of 216 Tg C y-1, with vegetated coastal habitats contributing about 50%. Even though vegetated carbon burial contributes about half of the total carbon burial in the ocean, burial represents a small fraction of the net production of these ecosystems, estimated at about 3388 Tg C y-1, suggesting that bulk of the benthic net ecosystem production must support excess respiration in other compartments, such as unvegetated sediments and the coastal pelagic compartment. The total excess organic carbon available to be exported to the ocean is estimated at between 1126 to 3534 Tg C y-1, the bulk of which must be respired in the open ocean. Widespread loss of vegetated coastal habitats must have reduced carbon burial in the ocean by about 30 Tg C y-1, identifying the destruction of these ecosystems as an important loss of CO2 sink capacity in the biosphere.\n

生态保护红线是在自然保护区、重点生态功能区、风景名胜区、森林公园等诸多区域生态管理制度不断实践基础上,面对中国国土开发和生态保护的复杂关系,继承和创新提出的一种新型区域生态管控制度,已经成为推动国家生态文明建设的重大战略。如何科学评估生态保护红线保护成效,服务于生态保护红线综合管理和保障区域生态安全,成为普遍关注的热点问题之一。针对已有的区域生态保护成效评估案例的不足,基于划定生态保护红线是为保障国家和区域生态安全的基本认知,围绕着生态保护红线“生态功能不降低、面积不减少、性质不改变”的管控目标,以生态保护红线对区域生态系统保护作用为主要出发点,提出生态保护成效评估框架和指标方法。生态保护成效评估以生态系统类型构成和生态系统服务功能为内容主线,通过多维度时空尺度拓展,耦合分析生态保护红线内外、实施前后的生态状况变化,综合评估生态保护红线对保障区域生态安全的贡献和改善区域生态状况的作用。进而,可以关联分析可能引起生态保护红线生态状况变化的管控政策、制度和其他间接驱动因素,评估政策实施成效评估。实证上选择海南省生态保护红线和广东省严格控制区为案例进行了讨论。

海草床是地球生物圈中最富有生产力、服务功能价值最高的生态系统之一。目前, 全球各国海草分布信息正在逐渐明晰, 而中国在全国性海草分布的汇总信息中尚属空白, 种类多样性资料也急需更新, 中国海草“家底”信息的极度匮乏大大地阻碍了国家层面上海草保护与恢复工作的开展。为此, 我们对中国海草种类、面积及退化情况进行了汇总分析。结果表明: 中国现有海草22种, 隶属于10属4科, 约占全球海草种类数的30%。原在中国海草名录中的澳洲波喜荡(Posidonia australis)为鉴定错误, 中国到目前为止并未发现该种。中国海草分布区可划分为两个大区: 南海海草分布区和黄渤海海草分布区。前者包括海南、广西、广东、香港、台湾和福建沿海, 共有海草9属15种, 以喜盐草(Halophila ovalis)分布最广; 后者包括山东、河北、天津和辽宁沿海, 分布有3属9种, 以大叶藻(Zostera marina)分布最广。中国现有海草场的总面积约为8,765.1 ha, 其中海南、广东和广西分别占64%、11%和10%, 南海区海草场在数量和面积上明显大于黄渤海区。南海区海草场主要分布于海南东部、广东湛江市、广西北海市和台湾东沙岛沿海; 黄渤海区海草场主要分布于山东荣成市和辽宁长海县沿海。广东、广西两省的海草场主要以喜盐草为优势种, 海南和台湾多以泰来藻(Thalassia hemprichii)为优势种, 山东和辽宁多以大叶藻为优势种。中国海草场退化严重, 人为干扰是导致其退化的主要原因, 突出表现为在海草床海域破坏性的挖捕和养殖活动, 以及在海草生境和周边的围填海活动。中国海草资源的调查及保护研究整体落后, 但南海区领先于黄渤海区。为促进我国海草保护的全面推进, 应全面启动我国海草种类资源和海草场分布的普查行动, 加强海草场动态监测、建立中国国家海草监测网, 加快海草自然保护区的建立步伐, 强化海草床恢复和海草种质资源保护研究工作, 并规范海草植物的中文命名。

Seagrass beds are one of the most productive ecosystems on Earth and an important source of ecosystem services. Accurate mapping of spatial patterns of seagrass species diversity are lacking at the national scale in China, while taxonomic information on Chinese seagrass species requires an urgent update. This lack of information hinders national conservation and restoration programs for seagrass biodiversity. In this article we review studies of diversity, distributions and degradation of seagrass in China. A total of 22 seagrass species distributed along China’s coastal regions belong to ten genera and four families, and account for about 30% of known seagrass species worldwide. A check of herbarium material stored in Sun Yat-sen University showed that the seagrass species previously identified as Posidonia australis in Hainan is in fact Enhalus acoroides. From our analyses, two Chinese seagrass biotas are proposed. These include the South China Sea Bioregion (SCSBR) and China’s Yellow Sea and Bohai Sea Bioregion (CYSBSBR). The SCSBR includes Hainan, Guangxi, Guangdong, Hongkong, Taiwan and Fujian provinces, and contains 15 seagrass species representing nine genera with Halophila ovalis being most widely distributed. The CYSBSBR includes Shandong, Hebei, Tianjin and Liaonin provinces and contains nine seagrass species belonging to three genera with Zostera marina being most widely distributed. The total distribution area for China’s seagrass meadows is estimated to be 8,765.1 ha, with Hainan, Guangdong and Guangxi provinces accounting for 64%, 11% and 10% of the area, respectively. Both the number and area of seagrass meadows are much higher in the SCSBR than in the CYSBSBR. In the SCSBR, seagrass meadows are mainly located in the eastern Hainan coast, Zhanjiang in Guangdong, Beihai in Guangxi and Dongsha Island in Taiwan, whereas in the CYSBSBR they predominate in Rongcheng in Shandong and Changhai in Liaoning. Halophila ovalis, Thalassia hemprichii and Z. marina are the dominated species in seagrass meadows in Guangdong and Guangxi, Hainan and Taiwan, Shandong and Liaoning respectively. Seagrass degradation in China is mainly attributed to human disturbances caused by fishing, aquaculture and sea reclamation. For conservation purposes we advise the following: (1) initiate an extensive national survey of spatial patterns of seagrass species diversity; (2) conduct long-term monitoring of typical seagrass meadows and establish a national seagrass monitoring network; (3) accelerate legislation for seagrass conservation and include some ecologically-significant seagrass meadows as reserves; (4) invest more finance in research on the restoration of seagrass beds and conservation of seagrass germplasm resources; (5) standardize the Chinese names of seagrassesin China.