贵州喀斯特水库红枫湖、百花湖P(CO2)季节变化研究

针对贵州喀斯特地区富营养水库（红枫湖、百花湖）表层水中的CO₂分压P(CO₂)进行为期1 a的监测,分析了影响两湖P(CO₂)季节变化的因素并阐明了两湖P(CO₂)季节变化的机理.不同于北部温带地区水库,两湖出现明显的季节变化特征：夏季表层水中CO₂欠饱和,其他季节CO₂过饱和.通过对物理、化学及生物因素与P(CO₂)之间的相关性分析. 结果表明,两湖P(CO₂)与Chla之间存在的显著负相关,是由于浮游植物光合作用与细菌呼吸作用共同影响的结果,也是两湖P(CO₂)出现季节变化的主要原因.水温与P(CO₂)之间的显著负相关,主要是由于水温影响浮游植物生长引起的.降雨量与P(CO₂)之间的显著负相关,主要是由于降雨量影响水库中营养盐的输入和浮游植物生长引起的.NO^-₃、NO^-₂与P(CO₂)之间的显著正相关,是藻类吸收与有机质降解、硝化反应等共同作用的结果.SiO^{2-₃与P(CO₂)之间的显著负相关,是SiO2-₃受降雨输入及藻类吸收共同影响的结果.而两湖DOC与P(CO₂)相关性的差异可能与两湖DOC来源不同有关.}

Seasonal Variability of P(CO2) in the Two Karst Reservoirs, Hongfeng and Baihua Lakes in Guizhou Province, China

The partial pressure of carbon dioxide P(CO₂) in the surface water of the two karst eutrophic reservoirs,Hongfeng and Baihua Lakes near Guiyang city, Ghuizhou Province, China has been studied for one year. The factors regulating the seasonal variability of P(CO₂) in the two reservoirs have been analyzed. Unlike the reservoirs in boreal temperate regions, the P(CO₂) in the two reservoirs has significant seasonal changes: CO₂ was unsaturated during summer, but supersaturated at other seasons. According to the correlation analysis, there is a negative relationship between P(CO₂) and Chla in the two reservoirs, due to the production of the phytoplankton and the respiration of the organic matter by the bacteria, which are also the main factors regulating the P(CO₂). The negative relationship between temperature and P(CO₂) is considered to be due to the effect of temperature on the growth of the phytoplankton. Precipitation leads to the input of the nutriments into the reservoirs, and hence precipitation is negatively related to P(CO₂). The relationships between NO^-₃,NO^-₂and P(CO₂) are ascribed to the absorption of phytoplankton, and the degradation of the organic matter nitrification. The relationship between SiO^{2-₃and P(CO₂) is due to the absorption of phytoplankton and the precipitation. The differences of the relationship between P(CO₂) and DOC in the studied two lakes possibly lie in the variations of their sources.}