南海北部夏季浮游细菌生长效率初步研究

Preliminary study on marine bacterial growth efficiency in the northern South China Sea in summer

2010年9月对南海北部海域细菌生长效率、细菌呼吸率、细菌生产力及相关生态、环境因子进行了调查研究。结果表明,细菌生产力(C)和细菌呼吸率(C)表层平均值分别为0.08±0.02mg·m 3·h 1和0.92±0.18mg·m 3·h 1,细菌生长效率在6.20%—9.84%范围波动。细菌生产力、细菌生长效率的空间分布呈现由近岸向外海逐渐递减趋势,而细菌呼吸率的分布特征相对不显著。细菌呼吸率和细菌需碳量明显高于初级生产力,表明南海北部海域整体呈异养性特征,初级生产过程不足以满足细菌生长代谢对碳的需求。尽管细菌生产力与细菌呼吸率相关性显著,但与两者相关的环境因子不完全一致,说明它们可能存在不同的调控机制。综合分析细菌生产力、细菌呼吸率和相关生态环境因子,结果表明,南海北部异养细菌二次生产和呼吸代谢2种不同的生态功能在微食物环以及整个生态系统的物质循环和能量流动中均发挥重要作用。

An in situ study on bacterial growth efficiency, bacterial respiration, bacterial production, and related ecological and environmental factors were carried out in the northern South China Sea in September 2010. The average values of bacterial production （C） and bacterial respiration （C） were 0.08±0.02mg·m 3·h 1 and 0.92±0.18mg·m 3·h 1, respectively, while the bacterial growth efficiency varied between 6.20% and 9.84%. Both bacterial respiration and bacterial carbon demand were obviously higher than the primary production, indicating that the surface waters of the northern South China Sea were characterized as a heterotrophic system, and the carbon produced by primary productivity could not meet the demand of bacterial metabolism. Although the bacterial production was significantly correlated with the bacterial respiration in the northern South China Sea, the notable correlated environmental factors of these two parameters did not match, which suggests that these two ecological processes may have different regulation mechanisms in the study area. The integrated analysis on bacterial metabolism and related ecological and environmental factors indicated that both bacterial respiration and bacterial production played important roles in the circulation of materials and energy flux in microbial loop and the whole ecosystem of the northern South China Sea .