Climatic and local effects on stalagmite δ13C values at Lianhua Cave, China

Abstract

Carbon isotopes in speleothems may serve as indicators of vegetative change, climatic conditions, and karst processes. In many recent studies of Chinese stalagmites, however, carbon isotopes have often been neglected or underutilized in interpreting paleoenvironments. Here, we present a continuous decadal-scale δ 13C record (819 measurements) of the mid- to late-Holocene from a precisely-dated (10 230Th dates) aragonite stalagmite from Lianhua Cave, Hunan Province, China. Compared to coeval stalagmites from other Chinese caves, the average δ 13C value (− 3.6‰) of stalagmite A1 is higher by ~ 2–7‰. Variations in the δ 13C values (0.1‰ to − 6.0‰) reflect changes in both vegetative productivity and inorganic processes, which respond to climatic processes. The δ 13C record of stalagmite A1 can be subdivided into three intervals: 1) warm–humid stage (6.6 to 3.8 ka); 2) transitional stage (3.8 to 1.6 ka); and 3) cool–arid stage (1.6 ka to present). Comparisons with other stalagmite and paleoclimatic records demonstrate that these intervals are generally consistent with changes in regional vegetation and climatic conditions.