Throughout his career, Ulrich von Grafenstein left a lasting mark on palaeoclimatology by developing and validating the use of oxygen isotope ratios (δ¹⁸O) measured on benthic ostracode valves retrieved from Alpine lake sediments.
His approach, grounded in the rigorous accumulation of isotopic measurements, rested on a titanic body of work: the identification, picking and analysis of several hundred thousand ostracode valves from multiple species, sampled with exemplary care and precision. By demonstrating that deep, stratified Alpine lakes — such as the Ammersee, the Starnberger See, Lac d’Annecy and the Mondsee — can faithfully preserve the isotopic signature of precipitation in their biogenic carbonates, he provided the scientific community with a unique, calibrated and quantitative continental proxy for reconstructing climate variability across Europe over the past 15,000 years.
A pioneer in his field, Uli also launched one of the first lake monitoring programmes, aimed at improving our understanding of past environmental change. His landmark publications, notably in Science (1999), Geochimica et Cosmochimica Acta (1996) and Palaeogeography, Palaeoclimatology, Palaeoecology (1999), remain essential references in the field.
Yet Uli’s contribution extends well beyond these fundamental discoveries. A passionate fieldworker and expert in coring techniques, he initiated and participated in numerous campaigns across the Alps and beyond, recovering sedimentary sequences that have underpinned a wide range of projects. His commitment helped launch many scientific careers centred on the exploitation of lacustrine sedimentary archives, exploring topics as diverse as palaeotsunamis, flood frequency, and the impact of human activities on soils and erosion. He also played a key role in the development of lake coring equipment, collaborating for two decades with the company UWITEC, founded by his friend Richard Niederreiter.
Uli thus embodied a rare combination: a passion for rigorous work, the pleasure of fieldwork shared among friends, and a clear vision — to provide high-resolution continental palaeoclimate records from key sites across the European Alps.
A lasting legacy for continental palaeoclimatology
Beyond his publications, Uli leaves the community a body of reference datasets, isotopic records and analytical protocols that continue to feed data–model comparisons and climate reconstructions at the European scale. His departure marks the end of a founding era for Alpine lake palaeoclimatology, while opening the way for the work that follows in his footsteps.
William Rapuc