摘要
海草床是近岸海域生产力极高的生态系统,具有重要的储碳功能,其碳主要存储于沉积物中.海草床沉积物有机碳(sediment organic carbon,SOC)储量受其来源、组成和转化的共同影响,同时,近岸海域的富营养化会影响到SOC的储存.通过综述海草床SOC的来源、组成、转化、存储及其对富营养化响应等方面内容,总结其储碳研究进展.研究表明,海草床SOC来源多样,主要来源为海草和悬浮颗粒物;SOC形态组成主要包括活性有机碳和惰性有机碳,海草床沉积物中微生物活性较高,对SOC具有较高的利用效率;海草床沉积物碳储量呈现显著的地理差异和海草种类差异;富营养化会导致海草床藻类来源的SOC增加,从而提高SOC中活性组分,促进微生物的活性,加快SOC的利用与转化;从而影响海草床SOC存储.最后提出未来海草床沉积物储碳的重点研究方向:(1)开展海草床储碳量的全球普查;(2)加强环境变化对海草床沉积物储碳机制的影响研究;(3)发展海草床碳汇扩增技术;(4)开发惰性有机碳的研究方法.我国也应加强海草床储碳相关研究,并为我国未来的气候谈判和CO_2交易提供科学依据.
Seagrass meadows are recognized as important and productive coastal ecosystems. They are globally-significant hotspots for sediment organic carbon （SOC） sequestration, storing about 4.2-8.4 Pg, and could up to 19.9 Pg SOC--an amount equivalent to 10-times that stored in the earth＇s terrestrial soils. Sediment organic carbon （SOC） storage stocks in seagrasss meadows are affected by SOC sources, composition and transformations. Unfortunately, seagrass meadows are declining globally at a rate of 5% per year mainly due to eutrophication, which could influence the supply （source）, composition, and transformation of seagrass SOC. We systematically reviewed the literature of seagrass SOC sources, composition, transformation, and storage, as well as summarized their response to eutrophication. Seagrasses develop organic-rich sediment composed of both autochthonous and allochthonous organic carbon. Seagrass, epiphyte, macroalgae, and suspended particulate organic matter （SPOM） trapped from the water column can be common sources of sediment organic carbon in seagrass meadows. The main sources of SOC, however, are retained within seagrass and SPOM. According to a worldwide database of 61ac, the average contribution of seagrass to SOC is approximately 50%. The global average SOC content is 1.5%, with higher SOC concentrations have always been observed in the sediment of seagrass meadows compared to bare sediments. Additionally, there are significantly different of SOC contents between temperate regions and tropics. The SOC in seagrass meadows are composed of both labile organic carbon and recalcitrant organic carbon. Dissolved organic carbon and microbial biomass carbon are vital fractions of labile organic carbon, which are often served as an important indicator of change and future trends in SOC. Recalcitrant organic carbon is largely composed of belowground seagrass detritus. Sediment microorganisms determine the balance between SOC storage and remineralization processes within seagrass meadows, and high
作者
刘松林
江志坚
吴云超
张景平
赵春宇
黄小平
LIU SongLin JIANG ZhiJian WU YunChao ZHANG JingPing ZHAO ChunYu HUANG XiaoPing(Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guang- zhou 510301, China College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2017年第28期3309-3318,共10页
Chinese Science Bulletin
基金
国家重点基础研究发展计划(2015CB452905
2015CB452902)
国家自然科学基金(41306108
41406128)
国家基础性工作专项(2015FY110600)资助
关键词
海草床
沉积物有机碳
储碳
富营养化
响应
seagrass meadows, sediment organic carbon, carbon storage, eutrophication, response
