Seasonal compensation of microbial production and respiration in a temperate sea
Seasonal compensation of microbial production and respiration in a temperate sea
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温带海洋微生物生产和呼吸的季节性补偿
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
R. Anadón
中科院分区：
文献类型：
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作者：
P. Serret;E. Fernández;Jorge A. Sostres;R. Anadón
对比斯开湾南岸过渡带3个站点真光层16mo的总氧生产量(GP)、暗呼吸(DR)和净群落生产量(NCP)进行了研究，并与水文、营养条件、浮游植物生物量和C吸收有关。微生物O2通量表现出与水柱层结和混合的季节循环相关的季节模式，春季NCP为正值，夏季为负值，冬季接近于零。这种模式在沿海地区发生了变化，在沿海地区，生产期与沿海上升流有关，而在冬季，持续的净异养现象被测量到，可能与陆源有机质排放的增加有关。NCP与真光层O2和NO3浓度异常的比较、所研究的时空尺度和近海定态条件的普遍存在支持了该地区夏季异养的维持是基于对春季产生的剩余有机质的消耗。在温带海洋中，由于控制浮游植物生长和微生物异养活动的过程，基于溶解有机物的积累和延迟消耗，微生物自养和异养代谢的解偶联可以解释这种模式。NCP的季节变化与春季净生产量之间的密切关系，以及中纬度O2和大气O2异常季节周期的预测，使我们得出结论：生产和呼吸过程的季节性补偿是远洋生态系统动力学的一个特征，至少在沿海温带海域是这样。这一结论对于解释新的生产量和通过直接测量浮游生物净生产量来估计海洋的营养状态具有很大的相关性。
Gross oxygen production (GP), dark respiration (DR) and net community production (NCP) were studied for 16 mo in the euphotic layer of 3 stations through the coastal transitional zone of the southern Bay of Biscay, and related to hydrographic and nutrient conditions, phytoplankton biomass and C incorporation. Microbial O 2 fluxes exhibited seasonal patterns linked to the seasonal cycle of water column stratification and mixing, with positive NCP during the spring, negative throughout the summer and close to zero in winter. This pattern was altered at coastal regions, where productive periods were linked to coastal upwelling, whereas in winter persistent net heterotrophy was measured, presumably in relation to increases in organic matter discharge of continental origin. The comparison of NCP with O 2 anomaly and NO 3 concentration in the euphotic zone, the spatial and temporal scales studied and the prevalence of steady-state conditions offshore support the conclusion that the maintenance of summer heterotrophy in the region was based upon the consumption of the surplus of organic matter produced in spring. The uncoupling in the microbial auto- and heterotrophic metabolisms, based on the accumulation and delayed consumption of dissolved organic matter as a consequence of the processes controlling phytoplankton growth and microbial heterotrophic activity in temperate seas, would explain such a pattern. The close relationship observed between the seasonal variability in NCP and the magnitude of spring net production and predictions derived from the seasonal cycles of O 2 anomaly in middle latitudes and atmospheric O 2 led us to conclude that the seasonal compensation of production and respiration processes is a characteristic of the dynamics of the pelagic ecosystem, at least in coastal temperate seas. The implications of this conclusion are of great relevance for the interpretation of new production and the estimation of the trophic status of the ocean from direct measurements of plankton net production.