Abrupt diatom responses to recent climate and land use changes in the Cantabrian Mountains (NW Spain)

Abstract The multi-proxy study of sediment cores from Lake Isoba (43° 02? N, 5° 18? W; 1400 m a.s.l.) allows a detailed assessment the past hydrological and environmental dynamics in north-western Iberia resulting interplay between climate variability anthropogenic impact. combination diatom stratigraphy, sedimentology high-resolution elemental geochemistry along with robust chronological framework (established by 210 Pb, 137 Cs 14 C dating) provides reconstruction for ~ 500 years. Abrupt changes fossil assemblages indicate high sensitivity this small lake to change allow identifying four major stages related main fluctuations Little Ice Age (LIA) recent warming. High levels, enhanced runoff higher productivity characterised middle phase LIA (~ 1550 1630 CE), indicating an overall wet climate. Conversely, shallow decreased relatively low prevailed during last onset Industrial Era 1925 likely due colder drier conditions. levels carbonate input occurred after CE until 1980s CE, when our data show abrupt drop probably caused regional negative rainfall anomaly warming decades. Finally, since 1997 remarkable increase nutrient load turbidity is detected, associated replacement transhumant sheep flocks staying cattle. reconstructed at mostly agree other palaeoclimatic records northern Spain. However, patterns are opposed those observed on slopes Cantabrian Mountains. strong impact land-use lake, causing more ecological disruptions than previous changes, noteworthy demonstrates mountain lakes human activities global context.