PAN Guoyan1,2, CAO Xiayu1,2, ZHANG Xiang1.2*, BIN Jianping1,2,3
（1 State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, Hubei, China;2 Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, Jiangxi, China;3 Bureau of Hydrology, Changjiang Water Resources Commission, Wuhan 430010, Hubei, China)
Abstract:
Carex, the typical plant of Poyang Lake wetland, was selected to study the water use strategy in December of 2015 and 2016 by field sampling and analyzing on stable hydrogen and oxygen isotopic composition of plant water and soil water. The results showed that there was a significant linear correlation between the hydrogen and oxygen stable isotope ratios of soil water, which experienced more severe evaporation in the dry season of 2016 than in 2015. The soil water can be divided into three layers including surface soil water, deep soil water and groundwater according to the distribution of δ18O and soil moisture with depth. The absorption ratios of Carex to the three layers were among 28.2% to 41.4% in the dry season, indicating a generally roughly equal absorption to surface soil water, deep soil water and ground water. The ratios were distinct in two sections and were different in sampling points. The differences were more obvious in dry season of 2016 with lower water levels than in 2015.
KeyWords:
Poyang Lake; dry season; Carex; water source
