Hydroclimate Signals in Peatland Tree-Ring Isotopes

This research article presents a study on the hydroclimate signals recorded in tree rings of Scots pine trees from a Swedish peatland. The study develops chronologies of tree-ring widths (TRW), stable carbon (δ13C), and stable oxygen (δ18O) isotopes to assess their responses to hydroclimate conditions. The findings indicate significant differences in mean TRW and δ13C values between peatland and reference sites. While TRW does not show distinct patterns across sites, both δ13C and δ18O chronologies exhibit uniform year-to-year variations. The research highlights the limited potential of TRW to record high-frequency hydroclimate information, while δ13C and δ18O provide robust signals correlated with key hydroclimate variables such as water table, precipitation, and vapor pressure deficit during summer. The study concludes that stable isotopes can serve as effective proxies for reconstructing past hydroclimate changes, addressing existing gaps in dendroclimatological research on peatlands.