Plankton respiration in the northern South China Sea during summer and winter  

作　　者：ZENG Xiangxi HAO Qiang ZHOU Guangdong LE Fengfeng LIU Chenggang ZHOU Wenli 

机构地区：[1]Key Laboratory of Marine Ecosystem and Biogeochemistry,Second Institute of Oceanography,State Oceanic Administration,Hangzhou 310012,China [2]Center for Marine Ranching Engineering Science Research of Tianjin,Tianjin Bohai Sea Fisheries Research Institute,Tianjin 300457,China [3]State Key Laboratory of Satellite Ocean Environment Dynamics,Hangzhou 310012,China [4]Tianjin Key Laboratory of Aqua-ecology and Aquaculture,College of Fisheries,Tianjin Agricultural University,Tianjin 300384,China

出　　处：《Acta Oceanologica Sinica》2018年第8期74-83,共10页海洋学报（英文版）

基　　金：The National Natural Science Foundation of China(NSFC)under contract Nos 90711006,41306162 and 41006101;the National Key Research and Development Program of China under contract No.2016YFC1401601;the National Programme on Global Change and Air-Sea Interaction under contract No.GASI-0301-03-03

摘　　要：Plankton respiration is an important part of the carbon cycle and significantly affects the balance of autotrophic assimilation and heterotrophic production in oceanic ecosystems. In the present study, respiration rates of the euphotic zone plankton community（CR_（eu））, size fractionated chlorophyll a concentration（Chl a）, bacterial abundance（BAC）, and dissolved oxygen concentration（DO） were investigated during winter and summer in the northern South China Sea（n SCS）. The results show that there were obvious spatial and temporal variations in CR_（eu） in the n SCS（ranging from 0.03 to 1.10 μmol/（L·h））, CR_（eu） in winter（（0.53±0.27） μmol/（L·h）） was two times higher than that in summer（（0.26±0.20） μmol/（L·h））, and decreased gradually from the coastal zone to the open sea. The distribution of CR_（eu） was affected by coupled physical-chemical-biological processes, driven by monsoon events. The results also show that CR_（eu） was positively correlated with Chl a, BAC, and DO, and that BAC contributed the highest CR_（eu） variability. Furthermore, the results of the stepwise multiple linear regression suggest that bacteria and phytoplankton were the dominant factors in determining CR_（eu）（R^2 = 0.82, p〈0.05） in the n SCS. Based on this relationship, we estimated the integrated water column respiration rate（CRint） within 100 m of the investigated area, and found that the relationship between the biomass of the plankton community and respiration may be nonlinear in the water column.Plankton respiration is an important part of the carbon cycle and significantly affects the balance of autotrophic assimilation and heterotrophic production in oceanic ecosystems. In the present study, respiration rates of the euphotic zone plankton community（CR_（eu））, size fractionated chlorophyll a concentration（Chl a）, bacterial abundance（BAC）, and dissolved oxygen concentration（DO） were investigated during winter and summer in the northern South China Sea（n SCS）. The results show that there were obvious spatial and temporal variations in CR_（eu） in the n SCS（ranging from 0.03 to 1.10 μmol/（L·h））, CR_（eu） in winter（（0.53±0.27） μmol/（L·h）） was two times higher than that in summer（（0.26±0.20） μmol/（L·h））, and decreased gradually from the coastal zone to the open sea. The distribution of CR_（eu） was affected by coupled physical-chemical-biological processes, driven by monsoon events. The results also show that CR_（eu） was positively correlated with Chl a, BAC, and DO, and that BAC contributed the highest CR_（eu） variability. Furthermore, the results of the stepwise multiple linear regression suggest that bacteria and phytoplankton were the dominant factors in determining CR_（eu）（R^2 = 0.82, p〈0.05） in the n SCS. Based on this relationship, we estimated the integrated water column respiration rate（CRint） within 100 m of the investigated area, and found that the relationship between the biomass of the plankton community and respiration may be nonlinear in the water column.

关 键 词：northern South China Sea plankton community RESPIRATION PHYTOPLANKTON bacteria 

分 类 号：Q178[生物学—水生生物学]