西北太平洋山间盆地沉积物有机碳质量累积速率及影响因素

Organic carbon mass accumulation rate and its influencing factors in intermountain basin sediments of northwest Pacific Ocean

海洋碳汇作用是大洋生态系统的重要生态系统服务功能,不仅影响着海洋生态系统的能量流动,也是元素循环的重要驱动力。本文以中国大洋48航次采集自西北太平洋典型海山区海盆的沉积物样品和资料为基础,对西北太平洋山间盆地沉积物有机碳质量累积速率(F_(orgc))特征及影响因素展开初步研究。结果表明,西北太平洋山间盆地有机碳质量累积速率变化范围为1.41~1.73 g/(m^(2)·ka),均值为1.60 g/(m^(2)·ka),以中部偏西海区的有机碳质量累积速率最高;全区平均净初级生产力转移效率约为0.0031%。西北太平洋山间盆地有机碳质量累积速率和净初级生产力转移效率均低于东太平洋海区和赤道太平洋海区。本区有机碳质量累积速率受水层和沉积层的生物地球化学循环驱动因素,如海洋净初级生产力、沉积物质量累积速率、有机碳含量、氧化还原电位等的综合影响,同时也受距海山距离、水深等地形因子的影响。

Carbon sinking is one of the important ecological services of ocean ecosystems,which acts as a driving force for energy flow and material cycle.Based on the 48th China scientific cruise in the northwest Pacific Ocean,the investigation on the sedimentary environment of intermountain basin was carried out regarding to the characteristics and influencing factors of total organic carbon mass accumulation rate(F_(orgc)).The results show that the Forgc in the northwestern Pacific Ocean basin ranges from 1.41 g/(m^(2)·ka)to 1.73 g/(m^(2)·ka),with an average of 1.60 g/(m^(2)·ka).As a whole,about 0.0031%of the region’s net primary productivity is buried in sediments annually.Both Forgc and net primary productivity transfer efficiency are lower in the northwestern Pacific intermountain basin in comparison with those in the eastern Pacific Ocean and equatorial Pacific Ocean.Many environmental factors influenced the Forgc in this area,induding biogeochemical factors in the water column and sediments,such as net primary productivity,sediment mass accumulation rate,organic carbon content,redox potential,and those topographic factors,such as the distance from the nearest seamount and water depth.