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Characteristics of δ 13 C DIC in lakes on the Tibetan Plateau and its implications for the carbon cycle
Author(s) -
Lei Yanbin,
Yao Tandong,
Sheng Yongwei,
Zhang Enlou,
Wang Weicai,
Li Junli
Publication year - 2011
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.8152
Subject(s) - dissolved organic carbon , plateau (mathematics) , carbon cycle , hydrology (agriculture) , carbonate , isotopes of carbon , geology , environmental science , environmental chemistry , total organic carbon , chemistry , oceanography , ecology , ecosystem , mathematical analysis , mathematics , geotechnical engineering , organic chemistry , biology
Dissolved inorganic carbon isotope (δ 13 C DIC ) is an important tool to reveal the carbon cycle in lake systems. However, there are only few studies focusing on the spatial variation of δ 13 C DIC of closed lakes. Here we analyze the characteristics of δ 13 C DIC of 24 sampled lakes (mainly closed lakes) across the Qiangtang Plateau (QTP) and identify the driving factors for its spatial variation. The δ 13 C DIC value of these observed lakes varies in the range of − 15·0 to 3·2‰, with an average value of − 1·2‰. The δ 13 C DIC value of closed lakes is close to the atmospheric isotopic equilibrium value, much higher than that in rivers and freshwater lakes reported before. The high δ 13 C DIC value of closed lakes is mainly attributed to the significant contribution of carbonate weathering in the catchment and the evasion of dissolved CO 2 induced by the strong evaporation of lake water. The δ 13 C DIC value of closed lakes has a logarithmic correlation with water chemistry (TDS, DIC and pCO 2 ), also suggesting that the evapo‐concentration of lake water can influence the δ 13 C DIC value. The δ 13 C DIC value shows two opposite logarithmic correlations with lake size depending on the δ 13 C DIC range. This study suggests that the δ 13 C in carbonates in lacustrine sediments can be taken as an indicator of lake volume variation in closed lakes on QTP. Copyright © 2011 John Wiley & Sons, Ltd.