Yuan Xi-gong, Huang Wen-min, Bi Yong-hHong, Hu Zheng-yu, Zhao Wei, Zhu Kong-xian
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Huan Jing Ke Xue. 2013 May;34(5):1754-60.
Water temperature (WT), pH, HCO3-, dissolved oxygen and the concentration of Chl-a in Xiangxi Bay were measured in spring. The partial pressure of carbon dioxide was calculated by the chemical balance and Henry's Law while CO2 flux by the thin-layer diffusion model. Results showed that pCO2 of surface water in Xiangxi Bay varied from 8.34 microatm to 168.70 microatm with a mean of 49.01 microatm. pCO2 increased along the stream with Chl-a decreased from upstream to the estuary. The mean of pCO2 was 117.92 microatm on the diurnal scale, ranging from 74.43 microatm to 168.70 microatm, and the mean concentration of Chl-a was 3.04 mg x m(-3) with the range from 2.22 mg x m(-3) to 4.55 mg x m(-3). There were statistically significant negative correlations between values for pCO2 and Chl-a (r = -0.844, P < 0.01). Phytoplankton photosynthesis in Xiangxi Bay played a crucial role in the spatial and temporal distribution of pCO2. The undersaturation observed suggests that surface waters in Xiangxi Bay represented a sink for atmospheric CO2 in spring, and the exchange rate of CO2 was estimated to be -35.17 mmol x (m2 x d)(-1).
在春季对香溪河湾的水温（WT）、pH值、碳酸氢根离子（HCO₃⁻）、溶解氧以及叶绿素a浓度进行了测量。二氧化碳分压通过化学平衡和亨利定律计算得出，而二氧化碳通量则通过薄层扩散模型计算得出。结果表明，香溪河湾地表水的pCO₂在8.34微大气压至168.70微大气压之间变化，平均值为49.01微大气压。pCO₂沿水流方向增加，而叶绿素a从上游到河口逐渐降低。在日尺度上，pCO₂的平均值为117.92微大气压，范围在74.43微大气压至168.70微大气压之间，叶绿素a的平均浓度为3.04毫克·米⁻³，范围在2.22毫克·米⁻³至4.55毫克·米⁻³之间。pCO₂值与叶绿素a之间存在显著的负相关（r = -0.844，P < 0.01）。香溪河湾浮游植物的光合作用在pCO₂的时空分布中起着关键作用。观察到的不饱和状态表明，春季香溪河湾地表水是大气CO₂的汇，CO₂的交换率估计为-35.17毫摩尔·（平方米·天）⁻¹。
