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

Abstract

Stable oxygen isotopes (δ18O) from α-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 δ18O from peat cellulose vary by location. In addition, controversy remains about the parts of plants that are most suitable for analysis. In this study, δ18O from different parts of modern plants in the peatland of Dajiuhu (Hubei Province, China) were determined to better understand the environmental factors that influence δ18O in this area and at a seasonal scale. Results show that δ18O 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 δ18O variability is the δ18O value of peatland water under the influence of monsoons. In addition, significant negative correlations exist between δ18O of plants and mean monthly temperature. Therefore, results demonstrate that δ18O of plants may preserve the 18O 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 α-cellulose δ18O in plants to study palaeoenvironmental changes.