Central European Hydroclimate Since the Younger Dryas Inferred From Vegetation‐Corrected Sedimentary Plant Wax δ 2 H Values

Abstract Plant wax hydrogen isotopes (δ 2 H) preserved in lake sediments provide valuable insights into past climatic changes. However, lake catchments often experience local shifts in vegetation type that can yield distinct isotopic signatures in the sediments, potentially obscuring hydroclimatic signals. Here, we compile regional plant wax data and test different approaches to correct for the impact of changes in vegetation type over time to isolate precipitation δ 2 H values (δ 2 H prc ) since the Younger Dryas (12.9–11.7 ka) from a sediment record from Rotsee (central Switzerland). Our method intercomparison shows that n ‐alkane relative abundances produced the most accurate δ 2 H prc estimates, agreeing with an independent speleothem fluid‐inclusion δ 2 H record from Milandre Cave. This indicates that sedimentary plant wax δ 2 H values represent a vegetation‐weighted community signal. Precipitation was 2 H‐depleted during the Younger Dryas (∼−75‰), and then δ 2 H prc values increased sharply into the Holocene. During the early Holocene (∼10 ka), δ 2 H prc values of ∼−55‰ were reached, consistent with maximum summer insolation, followed by a gradual long‐term decline toward the present, reflecting Neoglacial cooling and consistent with modern δ 2 H prc values (∼−67‰). Importantly, while plant wax δ 2 H values declined sharply due to deforestation beginning in the Roman period, this impact is effectively corrected for by using the relative abundance of n ‐alkanes. These findings underscore the need for site‐specific vegetation corrections to produce robust hydroclimate reconstructions from plant‐wax isotopes, especially in lakes with small catchments, thereby enhancing comparability of sedimentary records with climate models and deepening our understanding of past climate–vegetation–human interactions.