Yina Lyu, Weijun Luo, Reni Ustiatik, Alena Gessert, Guangjie Luo, Guangneng Zeng, Yanwei Wang, Jia Chen, Anyun Cheng, Shijie Wang
It is essential to distinguish the effects of climate signals and cave microenvironments on speleothem δ18O, δ13C, and element/Ca records, because cave microenvironments can interfere with the reconstruction of climate signals preserved by speleothems. However, it remains difficult to separate the impacts of direct climate signals and cave microenvironments-including cave air temperature and CO2 concentration-on these proxies, even after numerous cave monitoring and laboratory simulation experiments. In this study, we compared outdoor Artificial Cave monitoring with natural cave monitoring, providing an innovative and efficient method to discriminate the effects of climate signals and cave microenvironments on the proxies. We presented seven years of time-series data from Shawan Cave (natural cave) and more than two years of time-series data from the outdoor Artificial Cave located in Guizhou Province, Southwest China, for δ18O, δ13C, and elemental compositions of cave drip water along with microenvironmental conditions. In Shawan Cave, the seasonal changes in drip water δ18O and δ13CDIC, which showed a significant inverse correlation with cave air p CO2, were attributed to the wide range of cave air p CO2 (972–21,627 ppm), The irregular seasonal changes in drip water Mg/Ca were affected by the opposing seasonal variations in rainfall amount and cave air p CO2. In contrast, in the Artificial Cave, the wider range of cave air temperature (11.78–25.25 °C) appeared to influence the seasonality of cave water δ18O and Mg/Ca values. Meanwhile, the δ18O and Mg/Ca values of water isolated from the cave were mainly affected by rainfall δ18O and rainfall amount, respectively. The δ13CDIC values in cave water and in water isolated from the cave were primarily influenced by rainfall amount, because the narrow range of cave air p CO2 was insufficient to drive a notable change in cave water δ13CDIC. Our study highlights that cave microenvironments, rather than direct climate signals, are key drivers of seasonal amplitudes in speleothems proxies in caves with wide ranges of cave air temperature and p CO2. When the ranges of cave air temperature and p CO2 are narrow, speleothem proxies primarily record precipitation and air temperature. © 2026 Elsevier Ltd.
Guizhou Provincial Key Laboratory of Geographic State Monitoring of Watershed, School of Geography and Resources, Guizhou Education University, Guiyang, 550018, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; Puding Karst Ecosystem Research Station, Chinese Academy of Sciences, Puding, 562100, China; Soil Science Department, Faculty of Agriculture, Universitas Brawijaya, Jl. Veteran, East Java, Malang, 65145, Indonesia; International Research Centre for the Management of Degraded and Mining Lands, Universitas Brawijaya, Jl. Veteran, East Java, Malang, 65145, Indonesia; Institute of Geography, Faculty of Science, Pavol Jozef Šafárik University, Jesenná, Košice, 504001, Slovakia; School of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, 550025, China; School of Geography and Planning, Ningxia University, Yinchuan, 750021, China
