Figure Legends
Fig. 1. Setting and location. (a) Location of the Gonghe Basin (Google EarthTM). The red rectangle and red circle indicate the study site. Circulation systems influencing the study area are also shown. Dashed and solid lines indicate the modern extent of the East Asian summer monsoon (EASM) and Indian Ocean summer monsoon (ISM), respectively (Winkler & Wang, 1993). (b) Genggahai Lake, its surrounding physical environments, and the spatial distribution of modern aquatic vegetation (Qiang et al., 2013).
Fig. 2. Seasonal variations in the physical and chemical parameters of the lake water in different plant growth areas of Genggahai Lake from May to September (2012–2015). (a) Water temperature; (b) pH value; and (c) dissolved oxygen concentrations.
Fig. 3. Variations in the carbon isotopes of DIC precipitated from the (a)surface water in Genggahai Lake and (b) waterbodies within its catchment from May to September (2012–2015).
Fig. 4. Annual variations in the carbon isotopes of DIC precipitated from the surface water in Genggahai Lake and waterbodies within its catchment from 2012 to 2015.
Fig. 5. Correlation between the carbon isotopes of inflowing water DIC and lake water DIC in (a)Chara spp., (b) Potamogeton pectinatus , and (c)Myriophyllum spicatum growth areas.
Fig. 6. Correlation between the carbon isotopes of the lake water DIC and oxygen isotopes of the lake water in the (a) Charaspp., (b) Potamogeton pectinatus , (c) Myriophyllum spicatum growth areas.