Viability of High-elevation Peat Cores for Use as Stable Isotope (C and O) Paleoclimate Proxies

High-Andean peatlands, bofedales, contain peat forming vascular plants (Distichia muscoides) that may be used as a paleoclimate proxy. Stable isotope analysis of carbon and oxygen present a unique opportunity for a multi-proxy approach towards paleoenvironmental reconstruction applied to these peat cores. Carbon and oxygen stable isotope fractionation in vascular plants is driven by the processes of photosynthesis and respiration respectively which are codependent on moisture availability. This study seeks to test the viability of these isotopes as paleoclimate proxies by testing the following hypotheses: 1) carbon and oxygen isotope fractionation have a negative correlation with moisture conditions, and 2) δ13C and δ18O are positively correlated through time within the core. Preliminary results of this study indicate that δ13Cbulk and δ18Oleaf are not correlated, likely because δ13Cbulk has multiple dependencies (i.e., pCO2atm, temperature, and moisture variability). However, δ18Oleaf may be a good indicator of relative moisture conditions. Pending results from carbon stable isotope analysis of leaf cellulose will allow to further test the hypotheses.