[Analysis of Greenhouse Gas Emission Characteristics and Their Influencing Factors in the Algae Zone of Lake Taihu].

In order to identify CH and CO emission flux characteristics and their impact factors in the algal lake zone of Lake Taihu, CH and CO fluxes were observed by the improved closed chamber method in Meiliang Bay in Lake Taihu. The relationships between CH and CO flux and meteorological factors were analyzed. The results showed that CH and CO fluxes had obvious diurnal variations. The CH flux in the daytime was higher than that in the nighttime in spring; however, the CH flux in the nighttime was higher than that in the daytime in summer. The CO uptake flux in the daytime was higher than that in the nighttime in spring and summer. The algae zone of Lake Taihu was a CH source for the atmosphere. The average CH flux was 4.047 nmol ·(m ·s) and 40.779 nmol ·(m ·s) in spring and summer, respectively. The zone was the CO sink for the atmosphere in spring and summer. The average CO flux was -0.160 μmol ·(m ·s) and -0.033 μmol ·(m ·s) in spring and summer, respectively. On an hourly scale, the CH emission flux was positively correlated with air temperature and water temperature (=0.20, <0.01 and =0.34, <0.01, respectively). When wind speed was lower than 6 m ·s, the CH flux was positively correlated with wind speed (=0.71, <0.01). The CO uptake flux had a significant positive correlation with air temperature and wind speed (=0.14, <0.01 and =0.33, <0.05, respectively). However, the CO uptake flux was negatively correlated with air pressure and solar radiation (=-0.41, <0.01 and =-0.35, <0.01, respectively). The CO efflux had a significant positive correlation with wind speed (=0.40, <0.05). The CO efflux was negatively correlated with solar radiation (=-0.35, <0.01). On a daily scale, the CH emission flux had a significant positive correlation with air temperature and water temperature (=0.83, <0.01 and =0.78, <0.01, respectively).