Decrypting stable oxygen isotope variability in modern plants of the Dajiuhu peatland from Hubei Province, China: Implications for palaecology and palaeoenvironments

Stable oxygen isotopes (delta O-18) from alpha-cellulose of peatland plants represent a widely used tool for studying ecological processes and palaeoenvironmental evolution. However, comparison of different regions shows that the climate drivers of delta O-18 from peat cellulose vary by location. In addition, controversy remains about the parts of plants that are most suitable for analysis. In this study, delta O-18 from different parts of modern plants in the peatland of Dajiuhu (Hubei Province, China) were determined to better understand the environmental factors that influence delta O-18 in this area and at a seasonal scale. Results show that delta O-18 values do not significantly differ in different parts of the plants (whole sample, stem and leaf). Correlation analyses indicate that the major factor contributing to delta O-18 variability is the delta O-18 value of peatland water under the influence of monsoons. In addition, significant negative correlations exist between delta O-18 of plants and mean monthly temperature. Therefore, results demonstrate that delta O-18 of plants may preserve the O-18 isotopic signatures of the peatland water and mean monthly temperature signals, irrespective of the plant organ analysed. Our findings provide a reference and basis for a modern process that uses alpha-cellulose delta O-18 in plants to study palaeoenvironmental changes.